Dissertations / Theses on the topic 'Controlled atmosphere storage'

Advanced research in Controlled/Modified Atmosphere storage systems has shown that open channels of different lengths and cross sectional areas, connected to an air tight storage chamber, are able to maintain variable stable gas concentrations which could be near optimal concentrations for CA/MA storage of various commodities.
This study was geared towards assessing the suitability of the diffusion channels in maintaining a desired gas concentration for CA storage of spinach. Initially, the respiratory behaviour of spinach was studied in gas sealed chambers (replicated four times) stored at four different temperatures, 2$ sp circ$C, 8$ sp circ$C, 15$ sp circ$C and 23$ sp circ$C. The respiration rate of spinach was 20 mgCO$ sb2$/kg.h, 66 mgCO$ sb2$/kg.h, 163 mgCO$ sb2$/kg.h and 271 mgCO$ sb2$/kg.h for 2$ sp circ$C, 8$ sp circ$C, 15$ sp circ$C and 23$ sp circ$C, respectively. A model was developed based on principles of enzymatic kinetics which could reliably predict the respiration rate of spinach at any given storage temperature.
Two other sets of experiments were carried in a cold room set at 2$ sp circ$C. (Abstract shortened by UMI.)

The primary objective of the research was to study the physiological and biochemical changes in Hass avocado fruit stored in different combination of oxygen and carbon dioxide concentrations at both 0 degrees and 5 degrees Centigrade (C), and to determine whether storage in controlled atmosphere (CA) can decrease the incidence of chilling injury (CI). A secondary objective was to identify possible correlations between CA, the incidence of CI, the activity of some ripening related enzymes and changes in proteins during ripening at 20 degrees C following storage at low temperatures. Fruit suffered no CI and ripened normally following CA storage for 3 weeks at both 0 degrees and 5 degrees C, then transferred to air for 6 days at 20 degrees C. CI symptoms did develop after CA storage for 6 and 9 weeks at 0 degrees C. Changes in proteins during ripening were analysed by 2D-PAGE. Some polypeptides were detected in unripe fruit but decreased with ripening. Polypeptides of 16.5, 25, 36 and 56 kD (kilo Dalton) were present early in ripening and their levels further increased during ripening. The appearance of three ripening related polypeptides with estimated molecular weights 80 kD (pI 3.6), 36 kD (pI 5.8) and 16.5 kD (pI 5.7) was observed in fruit at the climacteric stage. Three polypeptides with estimated molecular weights of 41 kD (pI7.8), 36 kD (pI 5.8) and 33 kD (pI 5.1) were found in air stored fruit but were not detected in fruit stored in CA. This research showed that CA did not ameliorate CI at 0 degrees C, instead storage at 0 degrees C caused a premature increase in ethylene production when the fruit were returned to air at 20 degrees C. In contrast, CA storage at 5 degrees C retarded ethylene production and ripening in fruit after it was returned to air at 20 degrees C.
Doctor of Philosophy (PhD)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Take into account the crescent consumers demand by quality foods and the need of constant supply of vegetables products, the aim of this study was to evaluate the conservation of Crioula and Bola Precoce onions stored in different controlled atmosphere (CA), relative humidity (RH), temperature and ethylene conditions. Were evaluated four experiments with cv. Crioula and one with cv Bola Precoce. In the Crioula experiment 1, was tested the effect of different O2 and CO2 levels in storage atmosphere, two RH and two temperatures levels. Crioula experiment 2 tested three RH levels (75, 80 and 85%), experiment 3 tested three temperature levels (0.5, -0.5 and -1.0 °C) and experiment 4 tested the effect of presence or absence of ethylene 10 μl l-1, all in cold storage (CS). Bola Precoce experiment conditions are identical to Crioula experiment 1. The analyses were realized after six months of storage. CA decreased the breaking of dormancy and the bulb sprout onset in relation to CS. Low O2 and high CO2 increased the response from CA on sprout development process. Respiratory rate of bulbs gradually decreased during shelf-life, being less in CA stored bulbs. The mainly form of mass loss was due to respiration in Crioula and due to water loss in Bola Precoce . CA, mainly with 0.5+2.0 (kPa O2+kPa CO2), reduced aliinase activity and the generation of precursor compounds of onion flavor, beyond decrease the soluble solids consume and polyphenols level. Therefore, CA decrease the bulb metabolism during storage, reflecting in retard in breaking of dormancy and sprout onset, beyond maintain better post-harvest bulb quality. Better results were obtained in AC 0.5+2.0 (kPa O2+kPa CO2).
Tendo em vista a crescente demanda do mercado consumidor por alimentos com qualidade e a necessidade de suprimento constante de produtos de origem vegetal, o objetivo deste trabalho foi avaliar a conservação de cebolas Crioula e Bola Precoce armazenadas em diferentes condições de atmosfera controlada (AC), umidade relativa (UR), temperatura e etileno. Foram realizados quatro experimentos com a cv. Crioula e um com a cv. Bola Precoce. No experimento 1, com Crioula , testou-se o efeito de diferentes níveis de O2 e CO2 na atmosfera de armazenagem, dois níveis de UR e duas temperaturas. O experimento 2 testou três níveis de UR (75, 80 e 85%), o experimento 3 testou três níveis de temperatura (0,5, -0,5 e -1,0 °C) e o experimento 4 testou a presença constante de 10 μl l-1 de etileno durante o armazenamento, todos mantidos em armazenamento refrigerado (AR). Os tratamentos testados em Bola Precoce foram iguais aos do experimento 1 de Crioula . As análises foram realizadas após seis meses de armazenamento. A AC reduziu a superação da dormência e início do processo de brotamento dos bulbos em relação ao AR. Condições com baixo nível de O2 e alto de CO2 aumentaram a resposta da AC no controle do processo de desenvolvimento dos brotos. A taxa respiratória dos bulbos reduziu gradativamente durante a vida de prateleira, sendo menor nos bulbos armazenados em AC. A principal forma de perda de massa foi através da respiração na Crioula e pela perda de água na Bola Precoce . A AC, principalmente com 0,5+2,0 (kpa O2+kpa CO2), reduziu a atividade da enzima aliinase e a geração de compostos precursores do flavor de cebolas, além de reduzir o consumo de sólidos solúveis e o teor de polifenois. Portanto, a AC reduz o metabolismo dos bulbos durante o armazenamento, refletindo em retardo na superação da dormência e início do processo de brotamento, além de manter melhor qualidade pós-colheita dos bulbos. Melhores resultados são obtidos em AC 0,5+2,0 (kPa O2+kPa CO2). .

Doutoramento em Engenharia Agronómica - Instituto Superior de Agronomia
Long-term storage of pears is a challenge in the absence of treatment with diphenylamine, due to the development of physiological disorders. Aspects of the ripening physiology and biochemistry of pears, particularly those treated with the ethylene action inhibitor 1-methylcyclopropene, also remain unknown. The aims of this thesis were to map the gradients of adenylate nucleotides and energy charge in the fruit and their changes during fruit ripening and storage period, to compare instrumental and sensory assessments of ripening, to relate the fruit mineral composition to the development of internal storage disorders and determine the optimal storage conditions for long-term storage of ‘Rocha’ pear under controlled atmosphere. Significant radial gradient in energy charge from the skin tissues to the fruit center may be related to internal storage disorders. Significant radial gradients in Ca and B decreasing from the skin tissues toward the fruit center were also consistent with the location of internal storage disorders. However, ‘Rocha’ pear were able to adjust the energy charge during ripening and long-term storage even under low respiration rates induced by 1- methylcyclopropene treatment or low oxygen partial pressure. ‘Rocha’ pear was able to ripen immediately after harvest without chilling or exogenous ethylene application. ‘Rocha’ pear tolerated extremely low 0.5 kPa O2 during 257 d storage without developing storage disorders and kept acceptable firmness and skin color after 7 d shelf life. The 46 d delay in the pull down of O2 partial pressure was detrimental to quality maintenance of ‘Rocha’ pear during long-term controlled atmosphere storage
N/A

iv In recent years, outbreaks of infections associated with raw and minimally processed fruits and vegetables have been reported. Possible sources for contamination are irrigation water, manure, wash water, handling by workers and contact with contaminated surfaces. Pathogens can occur on raw and minimally processed produce at populations ranging from 103 to 109 CFU/g and able to survive and sometimes grow under various storage conditions. The objective of this study was to analyse the growth/survival of Salmonella Enteritidis at spot-inoculated or stem-injected cherry tomatoes during passive modified atmosphere packaging (MAP), controlled atmosphere (CA) and air storage at 7 and 22°
C. Low density polyethylene (LDPE) with a package size of 10x10 cm2 for 25±
2 g tomatoes was used for MAP storage in which the gas composition equilibrated to 6% O2/ 4% CO2 and a carbon dioxide incubator was used for CA storage in which the CO2 level was monitored and maintained as 5% through the term of storage at 7 and 22°
C. During the research, the effect of ozone treatment (5-30 mg/L ozone gas for 0-20 min) was also considered for surface sanitation. The results demonstrate that S.Enteritidis can survive and/or grow during the storage of tomatoes depending on the location site of the pathogen on fruit, suspension cell density and storage temperature. During MAP, CA and air storage, S.Enteritidis with initial population of 7.0 log10 CFU/tomato survived on tomato surfaces with an approximate decrease of 4.0-5.0 log10 CFU/tomato in population within the storage period
however, in the case of initial population of 3.0 log10 CFU/tomato, cells died completely on day 4 during MAP storage and on day 6 during CA and air storage. The death rate of S.Enteritidis on the surfaces of tomatoes that were stored in MAP was faster than that of stored in air. Storage temperature was effective on the survival of S.Enteritidis for the samples stored at ambient atmosphere
cells died completely on day 6 at 7°
C and on day 8 at 22°
C. Stem scars provided protective environments for Salmonella
an approximate increase of 1.0 log10 CFU/tomato in stem-scar population was observed during MAP, CA and air storage at 22°
C within the period of 20 days. Cells survived with no significant change in number at 7°
C. The development of the microbial association in tomatoes was dominated by lactic acid bacteria (LAB). The pH values of the tomatoes changed approximately from 4.0 to 3.0 during the storage period. LAB grew well under all atmospheric conditions with or without the presence of S.Enteritidis. Gaseous ozone treatment has bactericidal effect on S.Enteritidis, inoculated on the surface of the tomatoes. 5 mg/L ozone gas treatment was not effective. 30 mg/L ozone gas treatment affected surface color.

Listeria monocytogenes represents a high risk for consumers, because it causes severe illness. This work studied in-vitro growth and survival of L. monocytogenes in media acidified with malic acid, lactic acid or blueberry extract. The growth of L. monocytogenes and shelf life extension of fresh blueberries were evaluated after storage at 4 deg C or 12 deg C under different controlled atmosphere conditions, including air (control); 5% O2 and 15% CO2, 80% N2 (CAS); or ozone gas (O3) 4ppm at 4 deg C or 2.5ppm at 12 deg C, at high relative humidity (90-95%) for a total of 10 days. L. monocytogenes growth in tryptic soy broth with yeast extract (TSB+YE) mixed with different acid solutions (malic acid, lactic acid and blueberry extract) and incubated at 25 deg C for 24h, was calculated measuring optical density. Complete inhibition occurred in the presence of treatments including malic acid pH 2.0 and pH 3.0; lactic acid pH 2.0, pH 3.0 and pH 4.0; and with blueberry extract pH 2.0 in the mixture. After 6h, there were significant differences among growing treatments. At 18h, there were no significant differences in turbidity among media mixed with blueberry extract at pH 3.0, 4.0 and 5.0, and their optical density values were higher than treatments including media mixed with malic acid 5.0 or lactic acid 5.0. Blueberry extract was not an effective acidifying media and acid adapted L. monocytogenes grew in acidified media. Fresh blueberries inoculated with L. monocytogenes were stored at 4 deg C or 12 deg C under different controlled atmosphere conditions (Air, CAS or O3 4ppm at 4 deg C or 2.5ppm at 12 deg C) and sampled on day 0, 1, 4, 7 and 10 for bacterial growth, weight loss, firmness and yeast and molds counts. CAS did not delay or inhibit Listeria monocytogenes, yeast, or molds by day 10. Storage at 4 deg C showed lower weight loss values compared to 12 deg C. Ozone controlled weight loss and firmness loss. Moreover, gaseous ozone achieved 3 and 2 log reductions when compared with air at 4 deg C and 12 deg C, respectively.
Ph. D.

Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia
Efficacy of the ethylene action inhibitor 1-methylcyclopropene (1-MCP) was evaluated in pear (Pyrus communis L.) ‘Rocha’ in comparison with the standard postharvest treatments currently used by the Portuguese pear industry. Fruit were harvested at commercial maturity from four representative orchards in the Oeste Region, Portugal, subjected to the postharvest treatments and stored at 0 ºC, 90-95% relative humidity, under normal atmosphere, for up to 6 months; under controlled atmosphere, for up 9 months, and 9 months under delayed controlled atmosphere with the first 2 months in normal air. 1-MCP, at the recommended dosis of 312 nL L-1, reduced fruit softening and skin yellowing, and increased the soluble solids content (SSC) of ‘Rocha’ pear during shelf-life (14 days) at room temperature following cold storage in comparison with control fruit. SmartFresh at the recommended dosis of 312 nL L-1 of 1-MCP was also more effective than the standard postharvest treatments in reducing the incidence of superficial scald and internal browning disorders in ‘Rocha’ pear. It is concluded that 1-MCP at 312 nL L-1 is effective in reducing physiological disorders in ‘Rocha’ pear under refrigerated storage and controlled atmosphere and in delaying ripening-related softening and color changes during shelf-life.

Tomatoes are widely produced and consumed due to their nutritional content and versatility. However, the tomato is a soft fruit liable to damage and flavour deterioration. Hence, the main challenge for the tomato producing industry is to prevent the high loss incurred during harvest, handling and transportation of the crops. The objective of this study was to investigate the overall nutritional implication of controlled storage of tomatoes using ozone on the ripening process and the basic nutritional components of tomatoes. This investigation was also designed to focus on the effect of different ozone doses on the basic components and properties (carotenoids, ascorbic acid, total antioxidant activity and soluble sugars content) of the quality and dynamic maturity of tomatoes. Green tomatoes (Rio Grande) were treated in glass chambers with ozone enriched air [(air + 2, 7 and 21 mg O3/g tomato) and control (air only)] under humidity and temperature of 90-95% and 14-17 oC respectively. Tomatoes were sampled after 14 days of ozone treatment in the storage chamber and analyzed for different quality parameters (appearance, weight loss, Total Soluble Solids (TSS), titratable acidity, total ascorbic acid and carotene) of the ripening. The variety Elegance tomatoes were selected and the fruits were graded by colour and subjected to treatment with ozone (in doses 0 (clean air), 0.25, 0.50, and1.00 mg O3/g tomatoes) during storage for 6 days under the same humidity and temperature conditions. The fruits were analysed for carotenoids, ascorbic acid content, total antioxidant activity and soluble sugars. Analysis of the fruits clearly showed that ozone significantly delayed the development of colour on the surface, particularly in the low doses, and caused black spots on the surface of the tomatoes, particularly in higher ozone doses. Ozone did not affect the ascorbic acid and titratable acidity content. However ozone did reduce the Total Soluble Solids (TSS) by about 10% at the lowest ozone dose. A high inhibition of accumulation of carotenoids, particularly at low dose, of the tomatoes (Rio Grande) was also observed. Tomatoes (Elegance) under ozone treatments contained higher ß-carotene than those under the control treatment and lycopene content increased during storage in the red stage of tomato fruits. Ascorbic acid (AsA), dehydroascorbic acid (DHA) and the total of AsA and DHA concentrations, and ratios of redox (ASA/ (ASA + DHA) and DHA/AsA in pericarp and pulp of tomatoes tissue, did not show clear differences between the different treatments. The concentrations of the glucose and fructose increased in the tomatoes which were subjected to ozone treatments. Results from this study show that controlled atmosphere storage of tomatoes using ozone is a viable technique which warrants further study.

A procura de frutas com boas características para exportação in natura tem aumentado, sendo em grande parte dependente da melhoria da qualidade da fruta. Neste sentido, a adequação das operações ligadas à produção e pós-colheita é fundamental para tornar a fruta cítrica brasileira mais competitiva no mercado externo. Em decorrência de grande parte da área citrícola brasileira localizar-se em regiões de clima tropical, os frutos cítricos alcançam à plena maturação interna, enquanto que a casca permanece parcialmente verde, tornando-os inaceitáveis para a comercialização in natura em mercados exigentes. Assim, há necessidade do estudo de métodos e condições mais apropriadas para o desverdecimento dos frutos em pós-colheita para as nossas variedades e condições climáticas. Este estudo teve como objetivo avaliar o uso da técnica de desverdecimento pós-colheita de tangor Murcott e de laranja Valência, por meio da aplicação de etileno, na forma líquida e gasosa (em câmara). Utilizaram-se concentrações de 0 a 8000 mg L-1 de ethephon aplicadas por imersão (3 minutos) e 0,0; 0,25; 0,5; 0,75 e 1,0 L m-3 de etileno aplicadas em câmaras por 24 a 120 horas de exposição e 15 a 30ºC e 90% UR. Foram definidas as melhores condições de desverdecimento e, posteriormente, parte dos frutos ficou por 3 dias a 25ºC e 80% UR, simulando a comercialização, e outra parte dos frutos foi submetida à refrigeração (5ºC e 90% UR) por período de 30 dias (+3 dias a 25ºC e 80% UR, simulando a comercialização). Foi avaliado também o efeito do desverdecimento em câmara após o armazenamento refrigerado dos frutos. Os frutos foram avaliados logo após os tratamentos, após a primeira simulação de comercialização, após a refrigeração e após a segunda simulação de comercialização. A condição de 0,5 L m-3 de etileno por 96 horas de exposição a 25ºC foi a mais eficiente para incrementar a coloração dos frutos. As taxas respiratórias e produção de etileno aumentaram em função da concentração usada de etileno. O incremento na atividade da clorofilase foi acompanhado pela queda no teor de clorofila, enquanto que o teor de carotenóides se manteve constante. Quanto às características internas não foram observadas alterações significativas em função dos tratamentos. Verificou-se que o armazenamento refrigerado após o desverdecimento não interfere no desenvolvimento da coloração da casca dos frutos, não afetando a qualidade dos mesmos. Além disso, o processo de desverdecimento após a refrigeração é eficaz para a mudança da coloração dos frutos das duas variedades estudadas.
The demand for fresh fruits with good characteristics to exportation has increased, being mostly dependent on the improvement of fruit quality. In this sense, the adequacy of the operations related to production and post-harvest is crucial to make the Brazilian citrus fruit more competitive in foreign markets. Due to the large part of Brazilian citrus growing area is located in the tropical, citrus fruit reaches full internal maturity, while the peel remains partially green, making them unacceptable for the demanding fresh fruit markets. Thus, there is a necessity to study methods and more suitable conditions for the degreening of post-harvest fruit in our climatic conditions and varieties. This study was based on the technique of post-harvest degreening of \'Murcott\' and \'Valencia\', involving the application of ethylene in liquid and gaseous form (chamber). The concentrations used were 0 to 8000 mg L-1 of ethephon by immersion (3 minutes) and 0.0, 0.25, 0.5, 0.75 and 1.0 L m-3 of ethylene applied inside the chamber for 24 to 120 hours of exposure and 15 to 30ºC and 90% RH. The best conditions for degreening were defined and later, part of the fruits was for 3 days at 25ºC and 80% RH, simulating the commercialization, and the other part was stored under refrigeration (5ºC) with 90% RH for 30 days, and after that, 3 days at 25ºC and 80% RH, simulating the commercialization. The effect of cold storage of the fruit before the degreening inside the chamber was also evaluated. The fruits were evaluated right after the applications, the first simulation of commercialization, the cooling and the second simulation. The condition of 0.5 L m-3 for 96 hours at 25ºC was the most efficient way to improve fruit color. Respiratory rate and ethylene production increased with the dosage of ethylene used. The increased activity of chlorophyllase was followed by decrease in chlorophyll content, while the carotenoid content remained constant. As for the internal features, significant changes in the treatments were not observed. It was found that refrigerated storage after degreening do not interfere on the development of the fruits peal color, neither affecting their quality. Beyond that the process of degreening after cooling is effective for changing the color of both studied varieties.

As doenças pós-colheita em goiabas podem representar danos entre 20 e 40%, em função de condições ambientais e manejo integrado de doenças tanto antes quanto após a colheita. A adequação dos produtores às normas do Programa Integrado de Frutas (PIF) garante a obtenção de frutos com qualidade, produzidos de forma sustentável. Porém, exige o uso racional de agroquímicos durante as fases de produção da fruta. Neste contexto, utilizando a variedade Kumagai de polpa branca, os objetivos deste trabalho foram: (i) determinar as condições ambientais favoráveis à colonização natural de Guignardia psidii em goiabas; (ii) quantificar a incidência das doenças pós-colheita em goiabas nos dois principais mercados atacadistas do Estado de São Paulo; (iii) detectar e quantificar as doenças quiescentes desde a flor até em frutos no ponto de colheita; (iv) verificar o efeito da atmosfera controlada utilizando altas concentrações de O2 no controle das principais doenças pós-colheita da goiaba. Experimentos em condições controladas foram conduzidos para determinar o efeito de condições ambientais na colonização de G. psidii em goiabas. Na CEASA e na CEAGESP foram realizados levantamentos para quantificar as doenças pós-colheita em goiabas. Em duas áreas de produção de goiabas quantificaram-se as doenças quiescentes da goiaba em duas áreas de produção pelo método de detecção precoce de infecções quiescentes. Armadilhas caça-esporos foram colocadas em plantas para quantificar esporos carregados pela chuva. Talhões com e sem restos de cultura ao redor das plantas foram avaliados. Experimentos in vitro e in vivo foram realizados com diferentes tratamentos de atmosfera controlada para o controle de antracnose e pinta preta da goiaba. A temperatura ótima para a colonização de G. psidii foi de 30 ºC, atingindo incidência de 100% com 24 horas de molhamento, 10 dias após incubação. As principais doenças observadas nos mercados atacadistas e nas duas áreas de produção de goiabas foram antracnose, pinta preta e podridão de Fusicocum, com incidências máximas de 56,6%, 46,1% e 41,9%, respectivamente nos mercados atacadistas e máximas de 86,4%, 62,0% e 44,0%, respectivamente, nas áreas de produção de goiabas, 10 dias após incubação a 25 ºC. A antracnose foi a única doença observada desde a flor até em frutos maduros. Houve correlação direta entre a temperatura máxima combinada ou não com a precipitação acumulada e a incidência de antracnose nos frutos. Todos os isolados de Colletotrichum obtidos de frutos doentes foram identificados como C. gloeosporioides. Não houve diferença significativa nas incidências das principais doenças quiescentes da goiaba para as áreas com e sem restos culturais. A ocorrência de chuva no florescimento e nos estádios iniciais de desenvolvimento do fruto associada a temperaturas elevadas resultaram em incidências elevadas das principais doenças quiescentes da goiaba \'Kumagai\' em pós-colheita. O tratamento 30% CO2 + 70% O2 proporcionou maiores reduções no crescimento micelial dos fungos avaliados e na incidência de frutos doentes, após 4 dias sob atmosfera controlada. Frutos armazenados em atmosferas contendo 60% N2O + 20% O2 + 20% N2 e 30% CO2 + 70% O2 apresentaram menores severidade da antracnose e pinta preta, respectivamente em goiabas.
Post-harvest diseases in guavas may represent damages from 20 to 40%. Environmental conditions and disease management, before or after harvesting, are among their major causes. Standards proposed by the Integrated Production Fruit (IPF) ensure fruit quality and sustainable production with rational use of agrochemicals. Using the white-fleshed variety Kumagai, the objectives were: (i) to determine the environmental conditions favorable to the natural colonization of Guignardia psidii in guava (ii) to quantify the incidence of major post-harvest diseases of guava at the main wholesale markets of São Paulo state, (iii) to detect and quantify the quiescent diseases from flower to fruit in the harvest point (iv) to evaluate the effect of controlled atmosphere using high concentrations of O2 to control the main post-harvest diseases of guava. Experiments were conducted under controlled conditions to determine the effect of environmental conditions on the colonization of G. psidii on guavas. Surveys were carried out to quantify the postharvest diseases in guavas in CEASA and CEAGESP. The quiescent diseases of guava were quantified in two production areas by the method of early detection of quiescent infection. Inverted-bottle samplers were placed on plants to quantify spores carried by rain. Plots with and without crop residues around the plants were evaluated. Experiments in vitro and in vivo experiments were performed with different controlled atmosphere treatments for control of anthracnose and black spot of guava. The optimum temperature for G. psidii colonization was 30 °C, reaching 100% incidence with 24 hours of wetness, 10 days after incubation. The main diseases observed in the wholesale markets and in the two production areas were guava anthracnose, black spot and Fusicocum rot. The highest incidences were 56.6%, 46.1% and 41.9%, for anthracnose, black spot and Fusicocum rot, respectively, stored at 25 °C. In the field, fruits presented maximum incidences of 86.4% for anthracnose, 62.0% for black spot and 44.0% for Fusicocum rot. Anthracnose was the only post-harvest quiescent disease that was observed from the flower to the mature fruit. There was direct correlation between the maximum temperature and the incidence of anthracnose regardless of rainfall. Colletotrichum sp. strains obtained from diseased fruit were identified as C. gloeosporioides. There was no significant difference in the incidence of major diseases of guava quiescent in areas with and without crop residues around the plants. The occurrence of rain during flowering and early stages of fruit development associated with high temperatures resulted in high diseases incidences of major diseases quiescent guava \'Kumagai\' in post-harvest. The treatment 30% CO2 + 70% provided greater reductions in mycelial growth of fungi and incidence of diseased fruits, after 4 days under controlled atmosphere. Fruit stored with 60% N2O + 20% O2 + 20% N2 and 30% CO2 + 70% O2 showed lower severity of anthracnose and black spot, respectively.

Doctor of Philosophy (PhD)
The goal of this research was to investigate changes in the physiological properties including firmness, stiffness, weight, background colour, ethylene production and respiration of ‘Cripps Pink’ apple stored under different temperature and atmosphere conditions,. This research also seeks to establish mathematical models for the prediction of changes in firmness and stiffness of the apple during normal atmosphere (NA) storage. Experiments were conducted to determine the quality changes in ‘Cripps Pink’ apple under three sets of storage conditions. The first set of storage conditions consisted of NA storage at 0oC, 2.5oC, 5oC, 10oC, 20oC and 30oC. In the second set of conditions the apples were placed in NA cold storage at 0oC for 61 days, followed by NA storage at the aforementioned six temperatures. The third set of conditions consisted of controlled atmosphere (CA) (2 kPa O2 : 1 kPa CO2) at 0oC storage for 102 days followed by NA storage at the six temperatures mentioned previously. The firmness, stiffness, weight loss, skin colour, ethylene and carbon dioxide production of the apples were monitored at specific time intervals during storage. Firmness was measured using a HortPlus Quick Measure Penetrometer (HortPlus Ltd, Hawke Bat, New Zealand); stiffness was measured using a commercial acoustic firmness sensor-AFS (AWETA, Nootdorp, The Netherlands). Experimental data analysis was performed using the GraphPad Prism 4.03, 2005 software package. The Least-Squares method and iterative non-linear regression were used to model and simulate changes in firmness and stiffness in GraphPad Prism 4.03, 2005 and DataFit 8.1, 2005 softwares. The experimental results indicated that the firmness and stiffness of ‘Cripps Pink’ apple stored in NA decreased with increases in temperature and time. Under NA, the softening pattern was tri-phasic for apples stored at 0oC, 2.5oC and 5oC for firmness, and at 0oC and 2.5oC for stiffness. However, there were only two softening phases for apples stored at higher temperatures. NA at 0oC, 2.5oC and 5oC improved skin background colour and extended the storage ability of apples compared to higher temperatures. CA during the first stage of storage better maintained the firmness and stiffness of the apples. However, it reduced subsequent ethylene and carbon dioxide (CO2) production after removal from storage. Steep increases in ethylene and CO2 production coincided with rapid softening in the fruit flesh and yellowing of the skin background colour, under NA conditions. The exponential decay model was the best model for predicting changes in the firmness, stiffness and keeping quality of the apples. The exponential decay model satisfied the biochemical theory of softening in the apple, and had the highest fitness to the experimental data collected over the wide range of temperatures. The softening rate increased exponentially with storage temperature complying with the Arrhenius equation. Therefore a combination of the exponential decay model with the Arrhenius equation was found to best characterise the softening process and to predict changes in the firmness and stiffness of apples stored at different temperatures in NA conditions.

Des experiences realisees sur grains stockes en cellules etanches a differentes activites d'eau ont permis de montrer qu'il est inutile de creer une atmosphere anoxique artificielle pour stabiliser les populations microbiennes naturelles. Une relation quantitative directe existe entre croissance, sporulation et quantite d'oxygene disponible dans l'ecosysteme. Aux tres faibles pressions partielles d'oxygene, la perte de viabilite des propagules fongiques est fonction de l'activite d'eau des grains. Les qualites technologiques des grains restent stables pour les activites d'eau inferieures a 0. 95. Seules les levures de stockage sont capables de se developper dans ces conditions gazeuses, des lors que l'activite d'eau est superieure ou egale a 0. 86. Le developpement particulier d'hyphopichia burtonii (boidin) en presence de traces d'oxygene et l'arret de sa croissance en anaerobiose stricte montrent que c'est une espece "microaerotolerante". En presence de traces d'oxygene, le dioxyde de carbone a un effet stabilisant sur les populations fongiques (aspergillus, penicillium). Cependant, le dioxyde de carbone employe seul ne saurait assurer la stabilite microbiologique des grains conserves en structures insuffisamment etanches

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We studied the transcriptional and translational expression of a group of genes associated with cell wall metabolism (Cob, GLS, GalT, CCR, PL, PG, PME, β-Gal, β- Man, α-Ara, Exp1, Exp2, Exp3 and Exp4), endomembrane transport (SFT2, Vap27-2, ADL1A, ROC7, Rab5, Vamp, Kin, Cla, Syn, ERD2 and Rab11), expression of HSPs (HSP40-1er, HSP70er, HSP40-2er, HSPCNX1, HSPCRT2 , HSP70ch, HSP17.8ch, HSP60mi, HSP26.5mi and HSP60-3Bmi) and ethylene synthesis (ACCO) in peaches treated and not treated with gibberellic acid (GA3), monitoring the evolution of ripening and the changes occurred after cold storage (CS) and controlled atmosphere (CA). As variables for characterization of ripening fruit evaluated the production of ethylene, firmness, total acidity (TA), soluble solids (SS), SS / TA ratio and background color of the skin. Initially molecular changes were evaluated in fruit at different maturation stages. Later, the effect of different storage conditions on woolliness development was studied, and finally, the effect of GA3 in delaying maturation and preventing woolliness was evaluated. It was verified that peach ripening is dependent on genes encoding proteins involved in synthesis and degradation of cell wall and proteins involved in the endomembrane transport. Analyzing different forms of storage was observed that the use of controlled atmosphere conditions reduced woolliness, against all expectations, it was found that woolliness is not caused by the reduction in the expression of genes associated with the endomembrane transport. No delay ripening was observed when evaluating the effect of GA3 application prior to pit hardening but help to increase the size and weight of fruit, and decreases the incidence of woolliness in peaches. Increase in fruit size could be explained by the induction of genes encoding expansins and woolliness prevention could be attributed to the induction of genes encoding proteins associated to stress abiotic response, especially HSPs.
Estudou-se a expressão transcricional e traducional de um grupo de genes associados ao metabolismo de parede celular (Cob, GLS, GalT, CCR, PL, PG, PME, β-Gal, β-Man, α-Ara, Exp1, Exp2, Exp3 e Exp4), transporte endomembranas (SFT2, Vap27-2, ADL1A, ROC7, Rab5, Vamp, Kin, Cla, Syn, ERD2 e Rab11), expressão de HSPs (HSP40-1er, HSP70er, HSP40-2er, HSPCNX1, HSPCRT2, HSP70ch, HSP17.8ch, HSP60mi, HSP26.5mi e HSP60-3Bmi) e síntese de etileno (ACCO) em pêssegos tratados e não tratados com ácido giberélico (AG3), monitorando-se a evolução da maturação e as variações ocorridas após o armazenamento em ar refrigerado (AR) e atmosfera controlada (AC). Como variáveis de caracterização do estádio de maturação dos frutos avaliou-se a produção de etileno, firmeza de polpa, acidez total (AT), sólidos solúveis (SS), relação SS/AT e coloração de fundo da epiderme. Inicialmente avaliaram-se alterações moleculares existentes em frutos em diferentes estádios de maturação. Posteriormente, estudou-se o efeito de diferentes formas de armazenamento sobre o desenvolvimento da lanosidade e, por fim, foi avaliado o efeito da aplicação de AG3 na pré-colheita sobre o retardamento da maturação e na prevenção da lanosidade. Verificou-se que o amadurecimento de pêssegos é dependente da transcrição de genes codificadores para proteínas envolvidas na síntese e na degradação da parede celular e para proteínas envolvidas no transporte endomembranário. Ao analisarem-se diferentes formas de armazenamento observou-se que a utilização de atmosfera controlada reduziu a incidência de lanosidade, e ao contrário do esperado, verificou-se que a lanosidade não é ocasionada pela redução da expressão de genes relacionados com o transporte via endomembranas. A aplicação de AG3 antes do endurecimento do caroço não retarda o amadurecimento, mas contribui para aumentar o tamanho e a massa dos frutos, e diminui a incidência de lanosidade. O aumento do tamanho pode ser explicado pela indução de genes codificadores de expansinas e a prevenção da lanosidade pode ser atribuída à indução de genes de proteção a estresses abiótiocos, com destaque para as HSPs.

Atmosferas com altas concentrações de O2, bem como atmosferas enriquecidas com N2O têm sido sugeridas como alternativas para as atmosferas com baixo O2 e alto CO2. O armazenamento de frutos em atmosferas com alto CO2 por um longo período pode ocasionar desordens fisiológicas. Além disso, existe pouca informação na literatura sobre os efeitos de altas concentrações de O2 no metabolismo oxidativo em frutos. O N2O é um gás de ocorrência natural, não tóxico descrito como um potente antagonista à produção e à ação do etileno. Este trabalho teve como objetivo estudar a influência da atmosfera controlada com altas concentrações de O2 associadas ou não a CO2 e N2O sobre a fisiologia, o metabolismo oxidativo e o comportamento pós-colheita de bananas e goiabas. Bananas Nanicão e goiabas Kumagai foram submetidas aos tratamentos com atmosfera controlada em sistema de fluxo contínuo. Os frutos foram dispostos em câmaras sob o fluxo de 200 mL min-1. Todos os tratamentos foram mantidos em câmara com temperatura controlada de 22°C. A umidade em torno dos frutos foi mantida em 95%UR. Os frutos foram avaliados quanto à qualidade, produção de CO2, etileno e atividade enzimática. O alto O2 acelerou o início da senescência em ambos os frutos. Porém, foram observadas diferenças entre a banana e a goiaba, sendo que na banana o pico climatérico e o processo de amadurecimento foram antecipados. Na goiaba, o efeito marcante foi a perda da cor verde da casca. Provavelmente, as respostas observadas estão diretamente relacionadas à influência do oxigênio no metabolismo do etileno e as capacidades antioxidantes da banana e goiaba. Quando o alto O2 foi associado ao CO2 e ao N2O também foi verificada antecipação do início da senescência, porém foram verificadas diferenças entre os tratamentos com CO2 e aqueles com N2O. O alto O2 associado ao CO2 evitou a ocorrência de processos fermentativos mesmo nas concentrações mais elevadas de CO2. Com relação ao N2O, a associação deste gás ao alto O2 não reteve o amadurecimento. Por outro lado, sua associação ao baixo O2 permitiu aumento na vida pós-colheita de ambos os frutos, sem a ocorrência de processos fermentativos. Em relação ao metabolismo oxidativo a banana com alto O2 desencadeou acúmulo de oxigênio reativo com conseqüente alteração na atividade das enzimas oxidativas, diferindo da goiaba na qual os teores de oxigênio reativo se mantiveram baixos durante todo armazenamento. Isso ocorre, provavelmente devido às diferenças na capacidade antioxidante entre estas frutas a qual é consideravelmente maior na goiaba.
Atmospheres with high O2 levels and N2O enriched atmospheres have been suggested as an alternative to the atmospheres of low O2 and high CO2. Fruit storage under atmospheres with high CO2 for a long period may develop physiological disorders. In addition, there is not enough information about the effects of high O2 concentrations on fruits oxidative metabolism. N2O is a gas present on nature, non-toxic described as a powerful antagonist to production and action of ethylene. This work aimed to study the influence of controlled atmosphere with high O2 concentrations, associated or not to CO2 and N2O on the physiology, oxidative metabolism and post-harvest behavior of bananas and guavas. Bananas Nanicão and guava Kumagai were treated under continuous flow system. The fruits were placed into chambers under flow of 200 mL min-1. All treatments were maintained in a chamber with controlled temperature of 22°C. The humidity around the fruits was kept at 95% UR. It was quality evaluated CO2 and ethylene production and enzyme activity. The high O2 accelerated the onset of senescence in both fruits. However, differences were observed between the banana and guava, banana anticipated the occurrence of the climacteric peak by changing all the variables related to maturity. The main effect observed over guavas was the loss of peel green color. Probably, the observed responses are related to oxygen effect on ethylene and antioxidant capacity of banana and guava. When the O2 was associated with high CO2 and N2O was also observed an anticipation of the beginning of senescence, but differences were observed between CO2 and N2O treatments. The high O2 associated with CO2 prevented the occurrence of fermentative processes even at the highest concentrations of CO2. The N2O associations with high O2 do not increase postharvest life too. On the other hand, the N2O associations with low O2 allow delay ripening process. In relation to oxidative metabolism at high O2 banana triggered accumulation of reactive oxygen and consequent change in the activity of enzymes involved, differing from guava in which the levels remained low throughout storage. This is probably due to differences in the antioxidant activity of these fruits and which is considerably higher in guava. Keywords: High oxygen; Nitrous oxide;

Os objetivos deste trabalho foram avaliar os efeitos isolados de distintas concentrações de dióxido de carbono (CO2), de oxigênio (O2) e de óxido nitroso (N2O); e também as combinações dos melhores resultados para a conservação de morangos \'Oso Grande\'. Os frutos foram selecionados, resfriados e armazenados a 10 °C em câmaras herméticas, com fluxo contínuo de 150 mL min-1. Os frutos foram avaliados a cada dois dias até se tornarem impróprios para o consumo. Quanto maior as concentrações de CO2 (0,03 %; 10 %; 20 %, 40 % e 80 %) associadas a 20 % de O2 em atmosfera de armazenamento menor foi a incidência de doenças. Os morangos armazenados com 80 % de CO2 foram considerados inadequados para o consumo, por apresentarem teores elevados de acetaldeído (4,9 mg 100g-1) e de etanol (105,3 mg 100g-1). Já as concentrações de 20 % e de 40 % CO2 conservaram os frutos por até oito dias, com manutenção da cor e das características comerciais. As concentrações de O2 (1 %; 3 %; 20 %; 60 %; e 90 %) demonstraram que a atividade respiratória dos morangos foi menor nas atmosferas com 1 % e 3 % de O2. O tratamento com 90 % O2 proporcionou menor incidência de podridões (2,8 %). Os morangos armazenados com 60 e 90 % de O2 mantiveram suas características comerciais por 10 dias. No ensaio com diferentes concentrações de N2O (0 %; 10 %; 30 %; 60 %; e 80 %) associadas a 20 % de O2, observou-se que os frutos com esse gás obtiveram as melhores avaliações de aparência, e reduziu em 36,3 % a respiração dos mesmos após 24 horas de armazenamento, e manteve-se estável até o fim do período. As concentrações de 60 % e de 80 % N2O se mostraram adequadas para a conservação dos morangos, por apresentarem menor ocorrência de doenças e de taxa respiratória, e, portanto, mantendo as características comerciais. Neste experimento foram avaliadas novamente as atmosferas com 0,03 % CO2 + 20 % O2; 80 % N2O + 20 % O2 e 90 % O2; além de avaliar as combinações de 60 % O2 + 40 % CO2 e de 20 % O2 + 20 % CO2 + 60 % N2O. As menores incidências de podridões e as melhores notas de aparência foram nos frutos armazenados com 80 % N2O + 20 % O2 e 20 % O2 + 20 % CO2 + 60 % N2O. Os morangos sob 60 % O2 + 40 % CO2 foram considerados inadequados para o consumo, por apresentarem teores elevados de acetaldeído (54,8 mg 100g-1) e de etanol (42,4 mg 100g-1). Os morangos \'Oso Grande\' a 10 ºC, sob atmosfera controlada com 80 % N2O + 20 % O2; 90 % O2 ou 20 % O2 + 20 % CO2 + 60 % N2O, conservam sua coloração, reduziram a ocorrência de doenças e mantiveram a qualidade comercial por 14 dias.
The aim of this work were to evaluate the isolates effects of different concentrations of carbon dioxide (CO2), oxygen (O2) and nitrous oxide (N2O); and also the combinations of the best results for the conservation of strawberries \'Oso Grande\'. The fruit have been selected, cooled and stored to 10 °C in air tight chambers with continuous flow of 150 ml min-1. The fruits were evaluated every two days to become unfit for consumption. The higher concentrations of CO2 (0,03 %; 10 %; 20 %, 40 % and 80 %) associated with 20 % O2 in the atmosphere of storage, it smaller was the incidence of diseases. The strawberries stored with 80 % of CO2 were considered unsuitable for the consumption on the present high levels of acetaldehyde (4,9 mg 100 g-1) and the ethanol (105,3 mg 100 g-1). Already concentrations of 20 % and 40% of CO2 were conserved the fruit for up to 8 days, with maintenance of the color and the commercial characteristics. The concentrations of O2 (1 %; 3 %; 20 %; 60 %; and 90 %) showed that strawberry respiratory activity was lower in atmospheres with 1 % and 3 % of O2. The treatment with 90 % O2 provided the lower incidence of rotting (2,8 %). The strawberries stored with 60 and 90 % O2 maintained their commercial characteristics for 10 days. In the test with different concentrations of N2O (0 %; 10 %; 30 %; 60 %; and 80 %) associated with 20 % O2, observed that the fruit with this gas obtained the best results of appearance, and the respiratory rate of the fruit reduced in 36,3 % after 24 hours of storage, and maintained stable until the end of the period. The concentrations of 60 % and 80 % of N2O showed appropriate for the conservation of strawberries for presented a lesser occurrence of diseases and of respiratory rate, and therefore maintaining the commercial characteristics. In this experiment were evaluated again the atmospheres with 0,03 % CO2 + 20 % O2; 80 % N2O + 20 % O2 and 90 % O2; in addition to evaluating the combinations of 60 % O2 + 40 % CO2 and 20 % O2 + 20 % CO2 + 60 % N2O. The smallest incidences rotting and best notes of appearance were in the fruit stored with 80 % N2O + 20 % O2 and 20 % O2 + 20 % CO2 + 60 % N2O. The strawberries under atmosphere with 60 % O2 + 40 % CO2 were considered unsuitable for consumption to the showed high levels of acetaldehyde (54,8 mg 100 g-1) and of ethanol (42,4 mg 100 g-1). The strawberries \'Oso Grande\' at 10 ºC, under controlled atmosphere with 80 % N2O + 20 % O2; 90% O2 or 20 % O2 + 20 % CO2 + 60 % N2O maintained their color, reduced the occurrence of diseases and maintained the commercial quality for 14 days.

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The objective of this work was to evaluate the effect of mechanical damage on the ripening and quality of cultivars Royal Gala apple, in two commercial systems of storage, treated or not with 1-MCP, and Fuji Suprema apple stored at ambient conditions. Three independent experiments were carried. In the first, with Royal Gala apples, were evaluated the following treatments: mechanical damage (with and without impact damage through the free fall of the fruit height of 20 cm) combined with the application of 1-MCP (0, 625 nL L-1). The fruits were stored for four months in cold storage (CS, 0 ° C ± 1 º C and 92 ± 2% RH) and eight months in controlled atmosphere (CA, 1.2 kPa to 2.0 kPa O2 + CO2, 0 º C ± 1 º C and 96 ± 2% RH). In the second experiment, also with Royal Gala apples, damage was applied at two intensities (free fall at a height of 10 and 20 cm) and the fruits were treated or not with 1- methylcyclopropene (625nL L-1), before and after the damage. The treatments evaluated were: control (without damage and without 1-MCP), 1-MCP, impact damage, 1-MCP + impact damage, impact damage + 1-MCP, combined with two periods of storage (two and four months) at 0 ± 1 ° C and (RH) of 92 ± 2%. The experimental design was randomized blocks, with three replications of five fruits. The third experiment was conducted with Fuji Suprema apples, which were applied three types of mechanical damage. The treatments were: control (no mechanical damage), mechanical damage by impact (free fall of 20 cm), mechanical damage by compression (10 kilogram) and mechanical damage by cut (3 mm width x 3.5 mm depth and 3.5 cm of lenght). The experimental design was completely randomized, using four replicates of five fruits. Fruits were evaluated for flesh firmness, titratable acidity, soluble solids content, L color index of the skin and flesh in Royal Gala apples, and besides these, hue angle of the skin and decay incidence in Fuji Suprema apples. Except damage by compression, mechanical damage, in them intensity evaluated, cause flesh browning in the damage place , but do not affect the ripening and other attributs of quality. The 1-MCP contribute to maintenance of flesh firmness and titratable acidity of Royal Gala apples, however it does not reduce the effects of mechanical damage on the flesh browning, independent time of damage application. As larger intensity of mechanical damage, higher the effects on the integrity of flesh tissue. The damage by cut is the more harmful damage due to the higher decay incidence
O objetivo deste trabalho foi avaliar o efeito do dano mecânico sobre o amadurecimento e qualidade de maçãs das cultivares Royal Gala, em dois sistemas comerciais de armazenamento, tratados ou não com 1-MCP, e Fuji Suprema armazenada em temperatura ambiente. Foram realizados três experimentos independentes. No primeiro, com a cultivar Royal Gala, avaliaram-se os seguintes tratamentos: dano mecânico (sem e com dano por impacto através da queda livre dos frutos a altura de 20 cm) combinado com a aplicação de 1- MCP (0 e 625nL L-1). Os frutos foram armazenados durante quatro meses em armazenamento refrigerado (AR; 0ºC±1ºC e 92±2% de UR) e durante oito meses em atmosfera controlada (AC; 1,2kPa de O2 + 2,0kPa de CO2; 0ºC±0,1ºC e 96±2% de UR). No segundo experimento, também com a cultivar Royal Gala, aplicou-se os danos em duas intensidades (queda livre a uma altura de 10 cm e 20 cm), sendo os frutos tratados ou não com 1-metilciclopropeno (625nL L-1), antes e após o dano. Os tratamentos avaliados foram: controle (sem dano e sem 1-MCP), 1-MCP, dano mecânico por impacto, 1-MCP + dano mecânico, dano mecânico + 1- MCP, combinados com dois períodos de armazenamento refrigerado (dois e quatro meses) a temperatura de 0±1ºC, com (UR) de 92±2%. Nesses dois experimentos o delineamento experimental utilizado foi o de blocos ao acaso, contendo três repetições de cinco frutos. O terceiro experimento foi conduzido com a cultivar Fuji Suprema, na qual se aplicou diferentes tipos de dano mecânico. Os tratamentos avaliados foram: controle (sem dano mecânico), dano mecânico por impacto (queda livre de 20 cm), dano mecânico por compressão (10 quilogramas) e dano mecânico por corte (3 mm de largura x 3,5 mm de profundidade e 3,5 cm de comprimento). O delineamento experimental utilizado foi o inteiramente casualizado, sendo utilizadas quatro repetições. Os frutos foram avaliados quanto à firmeza de polpa, acidez titulável, sólidos solúveis, índice de cor L da epiderme e da polpa para Royal Gala , e além destes, ângulo hue da casca e incidência de podridões na cultivar Fuji Suprema. Exetuando-se o dano por compressão, o dano mecânico, nas intensidades avaliadas, provoca escurecimento da polpa no local da lesão, porém não possui efeito sobre a indução do amadurecimento e sobre os demais atributos de qualidade. O 1-MCP contribui para manutenção da firmeza de polpa e da acidez titulável de maçãs Royal Gala , porém não reduz os efeitos do dano mecânico sobre o escurecimento da polpa, independente do momento de aplicação. Quanto maior a intensidade do dano mecânico, maior são os efeitos sobre a integridade dos tecidos da polpa. O dano por corte é o tipo de dano mais prejudicial devido à grande incidência de podridões

L'àrea de Lleida és una de les principals regions productores de pera del sud d'Europa, essent la ‘Conference’ la principal varietat de pera produïda. En els darrers 5 anys s'ha detectat una tendència decreixent en el consum de pera a Europa. Entre les raons de la disminució del consum reportat es troben els factors de qualitat, com la falta de gust i l’excessiva fermesa de la fruita, i la creixent exigència dels consumidors per productes lliures de químics. Aquests fets han promogut l’interès per comprendre els factors que afecten la evolució dels paràmetres de qualitat de la fruita durant el creixement en l’arbre, el període d’emmagatzematge en fred i la vida útil fins arribar al consumidor final. Durant el creixement en l’arbre, les condicions climàtiques i agronòmiques influeixen en la qualitat final de la fruita. Durant aquesta etapa, la fruita experimenta importants canvis morfològics i fisiològics fins a arribar a l'etapa de maduresa òptima en la collita, ja sigui en base una qualitat organolèptica o al potencial d’emmagatzematge. Desafortunadament, les tècniques més utilitzades per avaluar la qualitat en camp sovint es basen en mètodes destructius. A la primera part d'aquesta tesi (Part A), es descriuen aquests mètodes i s’investiguen les correlacions entre els mesuraments destructives i tecnologies modernes no destructives en pomes i peres, com l'espectrometria visible i els sensors acústics. Canvis en els paràmetres de qualitat es varen relacionar amb els canvis en la capacitat de producció d'etilè de les peres i amb la respiració. La forma i mida de la fruita es va digitalitzar mitjançant la tecnologia d’escaneig 3D. El diàmetre final del fruit es va predir un mes abans de la data òptima de collita. Els principals factors que causen la desvaloració comercial durant el període d'emmagatzematge en fred són la pèrdua de fermesa, el desenvolupament de sabors desagradables, l'aparició de trastorns fisiològics i la pèrdua de pes a causa de la deshidratació. Amb el creixent interès de disposar de fruita d'alta qualitat i lliures de químics durant tot l'any, la indústria alimentaria ha desenvolupat tècniques d'emmagatzematge capaces d’estendre la vida comercial de la fruita sense l'ús d’additius químics. Una de les tècniques recentment implementades és l’atmosfera controlada dinàmica (DCA). La qual consisteix a emmagatzemar la fruita en atmosferes baixes d'oxigen per alentir el metabolisme de la fruita i ajustar dinàmicament les concentracions de gasos en funció de l'estat fisiològic de la fruita. L'ús d'aquest tipus d'atmosfera requereix un control precís de la resposta fisiològica de la fruita, ja que el marge entre el punt de compensació anaeròbic i l’inici de la fermentació de la fruita és molt petit. Actualment es comercialitzen diferents tècniques de monitoratge de l'estat fisiològic de la fruita basades en l'anàlisi de l'evolució de la fluorescència de la clorofil·la, el mesurament continu del quocient respiratori, el contingut d'etanol, tant en la polpa de la fruita com en l'atmosfera de la cambra freda. Malgrat això, l'ús d'aquestes tècniques ha estat envoltat d'una certa controvèrsia, doncs els resultats no són sempre reproduïbles. En la Part B de la tesi es van dur a terme tres estudis durant el període d'emmagatzematge en fred de la fruita. En el primer estudi es va realitzar una comparació de tres tècniques comercials de monitoratge de DCA. En el segon estudi es va analitzar l'efecte sobre la qualitat final de la pera conservada sota diferents nivells baixos d'oxigen en fred i com tals condicions van afectar les emissions de compostos volàtils orgànics (VOC). Es va descobrir que la pera ‘Conference’ emmagatzemada durant 8 mesos sota tals condicions de DCA va mantenir la fermesa de la fruita pràcticament constant als valors observats en la collita. Les anàlisis periòdiques dels VOCs induïts durant l'emmagatzematge en fred van assenyalar que alguns d'ells podrien utilitzar-se com a indicadors de l'estat de la fruita i així poder regular les concentracions de gasos. El tercer estudi es va dedicar a la pèrdua de pes de la fruita durant l'emmagatzematge en fred. Es va desenvolupar un sistema per monitoritzar contínuament la pèrdua de pes i l'assentament de la fruita dins la cambra. Es va trobar una correlació entre la pèrdua de pes de la fruita i l'assentament de la massa de la fruita, obrint un nou camí al monitoratge continu de la pèrdua de pes. La Part C de la tesi inclou dos estudis sobre l'evolució de la qualitat de la fruita durant la vida útil, després del període d'emmagatzematge en fred. Durant aquest període, els canvis fisiològics es produeixen ràpidament, amb un estovament de la fruita i una pèrdua de les propietats de qualitat organolèptica. El primer estudi va tractar d'aclarir la relació entre els paràmetres mesurables de qualitat de la fruita i la satisfacció del consumidor proporcionada per l'anàlisi sensorial. Es va descobrir que els èsters i la fermesa de la fruita juguen un paper clau en la definició de l'acceptació del consumidor. La millor acceptació per part dels consumidors es va trobar al tercer dia de vida útil en peres emmagatzemades durant 8 mesos sota condicions de DCA. El segon estudi va analitzar la no uniformitat espacial dels processos de maduració en la polpa del fruit. La distribució espacial dels components bioquímics, l'activitat fisiològica i els VOC es va mesurar en diferents ubicacions de carn. Es va descobrir que el contingut de fructosa va disminuir cap a l’interior del fruit, des de la pell fins al cor, mentre que la glucosa i la sucrosa van augmentar. L’àcid màlic, junt amb la capacitat antioxidant i els compostos fenòlics totals (TPC), van mostrar un mínim en el punt mig entre la pell i el cor. També es va trobar que els VOC emesos de forma natural per les peres podrien aplicar-se com fungicides capaços d'inhibir els agents patògens de P. expansum i R. stolonifer. Els resultats d'aquesta tesi proporcionen informació detallada que pot ajudar a augmentar la qualitat de la fruita quan arriba al consumidor final.
El área de Lleida es una de las principales regiones productoras de pera del sur de Europa, siendo ‘Conference’ la principal variedad de pera producida. En los últimos 5 años se ha detectado una tendencia decreciente en el consumo de pera. Entre las razones de la disminución del consumo reportado se encuentran los factores de calidad, como la falta de sabor y la excesiva firmeza de la fruta, y la creciente exigencia de los consumidores de productos libres de químicos. Estos hechos promovieron el interés en comprender los factores que afectan la evolución de la calidad de la fruta sin el uso de productos químicos durante el crecimiento en árbol, el período de almacenamiento y la vida útil hasta el consumidor final. Durante el crecimiento en árbol, las condiciones climáticas y agronómicas influyen en la calidad final de la fruta. Durante esta etapa, la fruta experimenta importantes cambios morfológicos y fisiológicos hasta alcanzar la madurez óptima de cosecha, ya sea en base a una calidad organoléptica o potencial de almacenamiento. Desafortunadamente, las técnicas más comunes utilizadas para evaluar la calidad del fruto en campo a menudo se basan en métodos destructivos. En la primera parte de esta tesis (Parte A), se describen dichos métodos y se investigan las correlaciones entre las mediciones destructivas y las tecnologías modernas no destructivas en manzanas y peras, como la espectrometría visible y los sensores acústicos. Cambios en los parámetros de calidad se relacionaron con cambios en la capacidad de producción de etileno y con la respiración de la fruta. La forma y tamaño de la fruta fueron digitalizados mediante la tecnología emergente de escaneo 3D. El diámetro final se predijo con un mes de antelación a la fecha óptima de cosecha. Los principales factores que causan la pérdida de valor comercial durante el período de almacenamiento son la pérdida de firmeza, el desarrollo de sabores desagradables, la aparición de trastornos fisiológicos y la pérdida de peso debido a la deshidratación. Con el creciente interés de disponer de fruta de alta calidad y libres de aditivos sintéticos durante todo el año, la industria alimentaria ha desarrollado técnicas de almacenamiento capaces de extender la vida comercial de la fruta sin el uso de aditivos químicos. Una de las técnicas recientemente implementadas es la atmósfera controlada dinámica (DCA). Esta consiste en almacenar la fruta en atmósferas con bajas concentraciones de oxígeno para ralentizar el metabolismo de la fruta y luego ajustar dinámicamente las concentraciones de gases dependiendo del estado fisiológico de la fruta. El uso de este tipo de atmósferas requiere un control preciso de la respuesta fisiológica de la fruta, ya que el margen entre el punto de compensación anaeróbico y el comienzo de la fermentación de la fruta es muy pequeño. Actualmente, se dispone en el mercado de diferentes técnicas de monitoreo del estado fisiológico de la fruta, como el análisis de la evolución de la fluorescencia de la clorofila, la medición continua del cociente respiratorio, o el contenido de etanol tanto en la pulpa de la fruta como en la atmósfera de la cámara. Sin embargo, el uso de estas técnicas está rodeado de una cierta controversia, ya que los resultados no son siempre reproducibles. En la Parte B de esta tesis se realizaron tres estudios diferentes durante el período de almacenamiento en frío de la fruta. En el primero se efectuó una comparación entre tres técnicas de monitoreo de DCA. En el segundo se analizó el efecto de niveles bajos de oxígeno durante la conservación en la calidad final de la pera y cómo tales condiciones afectaron las emisiones de compuestos orgánicos volátiles (VOCs). Se descubrió que la pera ‘Conference’ almacenada durante 8 meses bajo dichas condiciones de DCA mantuvo su firmeza casi a los valores observados en el momento de la cosecha. Análisis periódicos de los compuestos VOCs inducidos durante el almacenamiento en frío señalaron que algunos de ellos podrían usarse como indicadores del estado fisiológico de la fruta y ser utilizados para controlar la composición de los gases de la atmosfera. El tercer estudio se dedicó a analizar la pérdida de peso de la fruta durante el almacenamiento en frío. Se desarrolló un sistema para monitorizar continuamente la pérdida de peso y el asentamiento de la fruta dentro de la cámara. Se encontró una correlación entre la pérdida de peso y el asentamiento de la masa de la fruta, abriendo camino a una monitorización continua y simple de la pérdida de peso. La Parte C de esta tesis incluye dos estudios sobre la evolución de la calidad de la fruta durante la vida útil. Durante este período, los cambios fisiológicos se producen rápidamente, con un ablandamiento de la fruta y una pérdida de las propiedades de calidad organoléptica. El primer estudio analizó relaciones entre los parámetros medibles de calidad de la fruta y la satisfacción del consumidor proporcionada por el análisis sensorial. Se observó que los ésteres y la firmeza de la fruta juegan un papel clave en la definición de la aceptación del consumidor. La mejor aceptación por parte de los consumidores se encontró al tercer día de vida útil en peras almacenadas durante 8 meses bajo condiciones de DCA. El segundo estudio se encargó de estudiar la heterogeneidad espacial en la pulpa del fruto en los procesos de maduración. La distribución espacial de los componentes bioquímicos, la actividad fisiológica y los VOCs se midió en diferentes ubicaciones de la pulpa. Se encontró que el contenido en fructosa disminuyó hacia el interior del fruto, des de la piel hasta el corazón, mientras que la glucosa y la sacarosa aumentaron. El ácido málico, junto con la capacidad antioxidante y los compuestos fenólicos totales (TPC), tuvieron un mínimo en el punto medio entre la piel y el corazón. También se encontró que, algunos de los VOCs naturales emitidos por las peras podrían aplicarse como fungicidas, siendo capaces de inhibir el crecimiento de P. expansum y R. stolonifer. Los resultados de esta tesis proporcionan información detallada que pueden ayudar a aumentar la calidad de la fruta cuando llega al consumidor.
The area around Lleida is one of the main pear producing regions in southern Europe, being ‘Conference’ pear the main produced variety. Over the past 5 years, a decreasing trend in pear consumption in Europe has been reported. Among the reasons for the reported consumption decrease are quality factors, like the lack of flavor and excessive fruit firmness, and the growing consumer’s exigence of chemical free products. These facts promoted the interest in understanding the factors affecting the evolution of fruit quality parameters during on-tree growth, the cold storage period, and the shelf-life until the end consumers. During on-tree growth, both climatic and agronomic conditions influence fruit quality. During this stage, fruit undergoes important morphological and physiological changes until achieving the optimal maturity stage at harvest, either based on palatable quality or storage potential. Unfortunately, the most common techniques used to evaluate quality on the orchard are often based on destructive methods. In the first part of this thesis (Part A), such methods were described and correlations between destructive measurements and non-destructive modern technologies such as visible spectrometry and acoustic sensors were investigated both in apples and pears. Changes in quality parameters were related to changes in the fruit ethylene production capacity or fruit respiration. Using the emerging 3D scanning technology the shape and size of the fruit was digitized. The final fruit diameter was predicted one month in advance to the optimal harvest date. Main factors responsible for the loss of commercial value during the cold storage period are loss of fruit firmness, development of off-flavors, appearance of physiological disorders, and weight-loss due to dehydration. With the growing consumer’s demand for high quality and chemical-free fruit during all year round, the fruit industry has developed storage techniques capable of extending the commercial life of fruit without the use of chemicals. One of the recently implemented technique, known as dynamic controlled atmosphere (DCA), consists in cold storing the fruit under low oxygen atmospheres in order to slow down the fruit metabolism and then dynamically adjust the gases concentration depending on the fruit physiological state. The use of this type of atmospheres requires a precise control of the physiological response of the fruit, since the margin between the anaerobic compensation point and the beginning of fruit fermentation is very narrow. Different monitoring techniques of the physiological state of the fruit, such as analysis of the chlorophyll fluorescence evolution, continuous measurement of the respiratory quotient, and determination of ethanol content, both in fruit pulp and in the cold room’s atmosphere, are currently available on the market. However, the use of these techniques has been surrounded by a certain controversy since results are not always reproducible. In Part B of this thesis, three different studies were carried out during the fruit cold storage period. In the first study, a comparison of three commercially available DCA monitoring techniques was done. The second study assessed the effect of different low oxygen levels during cold-storage on the final pear quality and how these conditions affected the emission of volatile organic compounds (VOCs). It was found that ‘Conference’ pears stored for up to 8 months under such DCA conditions maintained the fruit firmness nearly to the values observed at harvest. Periodic analyses of the induced VOCs during the cold storage period pointed out that some of them could be used as indicators of the fruit’s physiological state in order to control the gas concentrations appropriately. The third study was dedicated to the fruit weight loss during cold storage. A system to continuously monitor weight loss and fruit settlement inside the cold room was developed. A quite simple correlation between fruit weight loss and fruit mass settlement was found, opening the way to a simple continuous monitoring of weight loss. Part C of this thesis includes two studies concerning the fruit quality evolution during shelf life after the cold storage period. In this period physiological changes occur rapidly, with a softening of the fruit and a loss of the organoleptic quality properties. The first study analyzed the relationship between measurable fruit quality parameters and the consumer’s satisfaction provided by sensory analysis. It was found that esters and fruit firmness play a key role in defining the consumer’s acceptance. The best consumer acceptance of pears stored under DCA for 8 months was found at day 3 of shelf life. The second study dealt with the spatial non-uniformity in the fruit flesh of the ripening processes. The spatial distribution of biochemical compounds, physiological activity and VOCs was measured at different flesh locations. It was observed that fructose content decreased inwards, from the skin to the core, while glucose and sucrose increased. Malic acid, together with antioxidant capacity and total phenolic compounds (TPC), had a minimum at mid-point in the flesh between skin and core. It was also found that naturally emitted VOCs could be applied as fungicides being able of inhibiting the growth of the pathogens P. expansum and R. stolonifer. Results from this thesis provide detailed insights that could help to increase the quality of the fruit reaching the final consumer.

This work was conducted to identified the best conditions of conservation (temperature and atmosphere composition) for apples cultivars Fuji, Fuji Suprema and Fuji Kiku. The experiment consited of the following treatments: storage at -0,5ºC without atmosphere modification (RA); 1kPa of O2+<0,5kPa of CO2 at +0,5ºC; 0,8kPa of O2+<0,5kPa of CO2 at -0,5ºC; 1,2kPa of O2+<0,5kPa of CO2 at -0,5ºC; 1kPa of O2+ 2kPa of CO2 at -0,5ºC. The experimental arragment was completely radomized with 4 replicates of 23 fruits. Fruit quality was evaluated after 8 months of cold storage and after 7 days of shelf life at 20ºC. After 8 months of cold storage, and 7 days of shelf life at 20ºC, the fruit firmness, solids soluble concentration (SSC); tritable acidity (TA); totals polyphenols; fruits with diseases and physiological disorders; respiration and ethylene production were evaluated. At harvest the colour of the skin; reductor sugars; anthocyanins and vitamine C were evaluated moreover the variables listed before. The Fuji Suprema cv. had maximum value of anthocyanins and parameter a* of colour measurment. The Fuji Kiku cultivar showed the higher levels of firmness, SST, AT and vitamine C. Before the cold storage and shelf life period, the treatments 1,2kPa of O2 + < 0,5kPa of CO2, and 1kPa of O2 + 2kPa of CO2 showed the best results in relation of the quality especially in deleyed softening in Fuji. The CA treatments preserved the firmness in the other cultivars. SST were no afected by the AC treatments while AT were preserved in this storage conditions. The 1kPa of O2+ 2kPa of CO2 showed the lowest values of respiration and ethylene production. The Fuji cultivar and their mutant Fuji Kiku were sensible to the higher levels of CO2 (2kPa), evidencied for the most incidens of internal breakdow. The total polyphenols stained high and increase in some CA treatment for all the cultivars. No difference beteween -0,5 and + 0,5 º C, of temperature in relation of the quality, in the 1kPa of O2 + < 0,5kPa of CO2 for any of the cultivars evaluated were found.
O presente trabalho teve como objetivo identificar as melhores condições de conservação, em relação à temperatura e composição da atmosfera, de armazenamento que permitam a manutenção da qualidade das maçãs das cultivares Fuji, Fuji Suprema e Fuji Kiku. Os tratamentos avaliados foram: armazenamento a -0,5ºC sem modificação da atmosfera (AR); 1kPa de O2+<0,5kPa de CO2 a +0,5ºC; 0,8kPa de O2+<0,5kPa de CO2 a -0,5ºC; 1,2kPa de O2+<0,5kPa de CO2 a -0,5ºC; 1kPa de O2+ 2kPa de CO2 a -0,5ºC. O delineamento experimental utilizado foi o inteiramente causalizado, com 4 repetições sendo que cada unidade experimental constava de 23 frutos. Após 8 meses de armazenamento refrigerado, e 7 dias de exposição dos frutos à temperatura de 20ºC, foram avaliadas a firmeza da polpa; sólidos solúveis totais (SST), acidez titulável (AT); polifenóis totais; frutos com podridões e distúrbios fisiológicos; produção de etileno e respiração. No momento de colheita, além das variáveis anteriores, foram medidas a cor da epiderme; açúcares redutores; antocianinas totais e vitamina C. A Fuji Suprema apresentou os maiores valores de antocianinas totais e maior valor do parâmetro a* da cor, diferenciando-se estatisticamente das outras, enquanto que a cultivar Fuji Kiku mostrou os maiores valores de firmeza da polpa, SST, AT e vitamina C. De acordo com os resultados obtidos após o período de conservação e vida de prateleira, os tratamentos de 1,2kPa de O2 + < 0,5kPa de CO2, e 1kPa de O2 + 2kPa de CO2 apresentarão os maiores valores em firmeza da polpa em Fuji. Enquanto que os tratamentos de AC permitiram manter a firmeza nas outras cultivares. Não houveram diferenças nos tratamentos de atmosfera controlada (AC), para as variáveis SST mas estes tratamentos permitiram manter a AT. O tratamento de 1kPa de O2 + 2 kPa de CO2, determinou uma menor respiração e produção de etileno nas diferentes cultivares. A cultivar Fuji e sua mutante Fuji Kiku apresentaram susceptibilidade a altos níveis de CO2 (2kPa) manifestando uma maior incidência de degenerescência da polpa. Os polifenóis totais mantiveram-se elevados e inclusive aumentaram em alguns dos tratamentos de AC. Não houve diferenças entre as temperaturas de -0,5 e + 0,5, em relação a qualidade, no tratamento de 1kPa de O2 + < 0,5kPa de CO2 em nenhuma das cultivares.

After severe storms timber is often wasted because it cannot be processed before being damaged by fungi and insects and excess oftimber can flood the market causing economic problems. Effective storage of sawlogs is therefore essential. However, this often involves water storage causing problems in environmentally sensitive sites. 'Vater storage also leads to bacterial attack ofthe wood which increases its porosity. A method receiving current interest relies on the exclusion of oxygen by wrapping stacks in plastic film. This method has been shown to be effective on certain species, particularly Norway spruce, in Germany. In this study the method was restricted to Pinus sylvestris in the UK. which is far more susceptible to sapstain. In previous work the oxygen exclusion relied on a perfect seal being maintained during storage. Combining wrapping with biological control micro-organisms and with a strain ofSaccharomyces cerevisiae was also tested. Sapstain development, oxygen and carbon dioxide levels were monitored in laboratory and field tests. In the laboratory, airtight containers were developed using gas piping to test variables prior to field trials. In field trials. wrapping resulted in almost complete control ofbluestain fungi in Pinus sylvestris. 'After over four months storage, in both field trials, the stain on wrapped timber was less than 1 % compared to over 33% in control stacks. In all wrapped stacks the COl levels increased and the 0, concentration decreased, reaching zero within about 14 days. The addition ofyeast aided the depletion ofoxygen and the increase in carbon dioxide in wrapped stacks, although it had no significant effect on stain development. Further trials with even simpler wrapping systems are needed to fully assess the additive effect ofusing Yeasts to help maintain low oxygen levels under such conditions.

Orientador: Benedito Carlos Benedetti
Texto em português e Inglês
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
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Resumo: Botrytis cinerea Pers, causador da doença conhecida como mofo cinzento, é o principal problema para a conservação pós-colheita de uvas de mesa. A utilização do dióxido de enxofre (SO2) é a prática pós-colheita mais comum para o controle desta doença. Pesquisas buscam alternativas a este produto devido às reações que causa em pessoas alérgicas, danos que pode causar nos frutos e às restrições ao seu uso em sistemas de produção orgânico. Foram avaliados os efeitos da aplicação de uma atmosfera de 40% de CO2 por 24 ou 48 horas (pré-armazenagem) combinado com armazenagem em atmosfera controlada (AC) (12% O2 + 12% CO2) no controle de B. cinerea, e nos atributos de qualidade de uvas 'Flame Seedless' e 'Crimson Seedless'. Também foram avaliados, em uvas 'Crimson Seedless', e os efeitos da associação deste tratamentos com aplicações pré-colheita de cloreto de cálcio (CaCl2) ou dióxido de cloro (ClO2). Os tratamentos foram aplicados em uvas orgânicas infectadas de três formas: infectadas naturalmente, superficialmente inoculadas com conídios e inoculadas com uma baga coberta de micélio. Uvas 'Flame Seedless', naturalmente infectadas, tratadas com 40% de CO2 por 48 horas + AC apresentaram redução da podridão pós-colheita, de 22% para 0,6%, após 4 semanas, e de 100% para 7,4%, após 7 semanas. O pré-armazenamento em 40% de CO2 sozinho também limitou a incidência de mofo cinzento em frutos infectados naturalmente e em uvas inoculadas artificialmente, porém foi menos eficaz do que quando seguido pelo armazenamento em AC. A aplicação de CaCl2 ou ClO2 em pré-colheita reduziu a incidência do mofo cinzento em uvas 'Crimson Seedless' inoculadas com uma solução de conídios, porém não houve controle quando os cachos de uva foram inoculados com micélio. A aplicação de CaCl2 e ClO2 reduziram o mofo cinzento de 45% para 23,2% e 15.6%, respectivamente, em cachos inoculados com conídios e avaliados após 6 semanas armazenadas 0oC. O pré-tratamento com 40% CO2 + CA não afetou as características físico-químicas e sensoriais de uvas 'Crimson Seedless' ou 'Flame Seedless'. Em experimentos in vitro os tratamentos com 40% CO2 por 24 ou 48 h limitaram o crescimento micelial até 72 horas após o tratamento. A germinação dos conídios de B. cinerea foi retardada por 12h. Os resultados mostram que o pré-tratamento com 40% CO2 + CA possui grande potencial para ser adotado como prática comercial para conservação de uvas orgânicas
Abstract: Gray mold, caused by Botrytis cinerea Pers, is the main postharvest decay of table grapes. The use of sulfur dioxide (SO2) is the common post-harvest practice for its control. Several researchers are looking for alternative methods of control, because SO2 can cause allergic reactions, damage fruits and also it cannot be applied in organic production system. In this thesis, it was evaluated the effects of applying an atmosphere of 40% CO2 for 24 or 48 hours (pre-storage) combined with controlled atmosphere storage (CA = 12% O2 + 12% CO2) in the control of B. cinerea, and the effects in the quality and sensory attributes of 'Flame Seedless' and 'Crimson Seedless' table grapes. In addition, it was evaluated the efficacy of CaCl2 or ClO2 application in pre-harvest alone or in combination with pre-storage of 40% CO2 for 24 h + CA, to control gray mold on 'Crimson Seedless' table grapes, and the determination of the impact of these treatments on fruit quality. The treatments were applied in certified organic table grapes naturally infected, surface inoculated and nesting inoculated (inoculated with an infected berry). After 4 weeks of storage, the pre-storage in 40% CO2 for 48 hours + CA reduced postharvest rot from 22% to 0.6%, and after 7 weeks, the decay was reduced from 100% to 7.4% in 'Flame Seedless' naturally infected. The pre-storage in 40% CO2 alone also reduced the incidence of gray mold in fruits naturally infected and in artificially inoculated, but it was less effective than combined treatment. The application of CaCl2 or ClO2 pre-harvest reduced the incidence of gray mold on grapes 'Crimson Seedless' inoculated with a spore solution, but there was no control when fruits were nesting inoculated. After 6 weeks at 0oC, the application of CaCl2, and the ClO2 in fruits surface inoculated, reduced the gray mold from 45% to 23.2% and 15.6%, respectively. The pretreatment with 40% CO2 + CA did not affect quality and nor sensory attributes for both varieties tested. In vitro experiments, the treatment with 40% CO2 for 24 or 48 h limited mycelial growth for at least 72 hours after treatment. Conidial germination of B. cinerea was delayed for 12 hours. Our results showed the potential that pre-treatment with 40% CO2 associated with CA has to be adopted in commercial practice for preservation of organic grapes
Doutorado
Tecnologia Pós-Colheita
Doutor em Engenharia Agrícola

A goiaba é uma fruta saudável para consumo, oferece níveis elevados de licopeno, vitamina C e fibras e constitui-se numa boa opção ao processamento mínimo. Entretanto, o ponto de colheita e o controle da senescência são questões importantes para o sucesso do processamento. O objetivo do trabalho foi definir o melhor estádio de maturação para o processamento mínimo, em rodelas, de goiabas Kumagai e Pedro Sato, bem como utilizar meios de controlar a senescência desses frutos, como o 1- Metilciclopropeno (1-MCP) e atmosfera modificada. Primeiramente, foi conduzida uma avaliação dos melhores estádios de maturação das goiabas para o processamento mínimo. Os frutos de ambas as variedades foram colhidos em 3 estádios de maturação definidos pela cor da casca em verde, verde-claro e verde-amarelado. Análises físicoquímicas e sensoriais ocorreram no início do experimento e a cada 3 dias durante 9 dias. As goiabas do estádio verde obtiveram notas abaixo do limite de aceitabilidade quanto à aparência durante as avaliações. Porém, nas goiabas dos estádios de maturação mais avançados, foram observados intensa perda de firmeza e escurecimento da polpa na região placentária, características de senescência. No segundo experimento, goiabas dos estádios verde-claro e verde-amarelado foram submetidas, antes do processamento, ao tratamento com 1-MCP por 0, 3, 6 e 12 horas, para escolha do tempo ideal de exposição dos frutos ao produto. As análises físicoquímicas seguiram de acordo com o experimento anterior. A determinação da atividade respiratória e da produção de etileno foram realizadas diariamente durante 9 dias. O pico respiratório e a elevação da concentração de etileno foram evidenciados no dia do processamento em ambas as variedades e em todos os tratamentos. Isto ocorre, provavelmente, devido às injúrias ocasionadas pelo processamento. Contudo os tratamentos em que as goiabas ficaram expostas ao 1-MCP por 12 horas reduziram a atividade respiratória e a produção de etileno das goiabas, mantendo a qualidade físicoquímica durante o armazenamento. No terceiro experimento foram estudados seis materiais de embalagem, os quais foram selecionados em função da manutenção de qualidade dos produtos minimamente processados. As análises físico-químicas ocorreram no início e ao final dos 9 dias de armazenamento. Nesse período, o monitoramento da composição gasosa foi realizado diariamente. As embalagens de polipropileno e polietileno de baixa densidade, sob atmosfera modificada passiva, foram eficientes, permitindo a conservação e manutenção da qualidade das goiabas. No último experimento foi avaliada a combinação dos melhores resultados obtidos anteriormente. O processamento mínimo das duas variedades ocorreu simultaneamente, com objetivo de se obter um mix de goiabas brancas e vermelhas, proporcionando, assim, um visual mais atrativo. Goiabas do estádio verde-amarelado, minimamente processadas, tratadas por 12 horas com 1-MCP e embaladas com filme de polipropileno de 52µm conseguiram manter sua qualidade, viabilizando, assim, a combinação das técnicas de controle da senescência.
The guava is a healthy fruit, offer high levels of lycopene, vitamin C and fibers, being a good option to the minimal processing. However, the harvest point and senescence control are important for the processing success. The objective of this work was to define the best ripening stage for the minimal processing, in round slices, of Kumagai and Pedro Sato guavas, as well as means of controlling the senescence of theses fruits, as the 1-methylcyclopropene (1-MCP) and modified atmosphere. Firstly, the evaluation of the best ripening stages was conducted. The fruits of both varieties were harvested at 3 ripening stages defined by the skin color in green, light-green and yellowish-green. In the beginning of the experiment, physical-chemical and sensorial analyses took place every 3 days during 9 days. The green ones obtained low acceptability grades as to their appearance during evaluations. However, the yellowishgreen ones lost their firmness and gained a browning flesh. In the second experiment, the light-green and yellowish-green guavas were submitted, before the processing, to treatment with 1-MCP per 0, 3, 6 and 12 hours, in order to choose the best time of exposure of the fruit to the product. The physical-chemical analyses were equal to the previous experiment. The respiratory activity and ethylene production were achieved daily during 9 days. The respiratory peak and the increase of ethylene concentration were observed in the day of the processing in both varieties as well as in all treatments, probably due to injuries caused by the cuts. However, the treatment in which the guavas were exposed to 1-MCP for 12 hours had their respiratory activity and ethylene production reduced, thus keeping the physical-chemical qualities storage. In the third experiment, six packaging materials were studied, being selected according to the quality of the guavas. The physical-chemical analyses took place in the beginning and the end of the 9 days of storage. In this period the monitoring of gas composition was accomplished daily. The packagings of polypropylene and low density polyethylene films, under passive modified atmosphere, were efficient in keeping the quality of guavas. In the last experiment, the combination of the best results of the previous experiments was evaluated. The minimal processing of the two varieties was performed simultaneously, obtaining a mix of white and red guavas, thus achieving a more attractive look. Yellowish-green guavas treated with 1-MCP per 12 hours and packed with polypropylene film (52µm) the keeping the quality, thus enabling the combination of two techniques of senescence control.

Salmonella sp. é um dos principais microrganismos causadores de surtos de enfermidades transmitidas por alimentos associados ao consumo de ovos e de alimentos formulados com este ingrediente. Ovos desidratados são largamente utilizados pelas indústrias de alimentos, por oferecer maior praticidade e maior padronização em relação ao produto \"in natura\". Apesar do processo tecnológico de desidratação do ovo incluir uma etapa de pasteurização, existe um risco de haver microrganismos sobreviventes, já que a pasteurização é feita em temperatura branda. Além disso, a pasteurização pode destruir os fatores intrínsecos antimicrobianos presentes na clara, possibilitando a multiplicação de microrganismos que sobreviveram ao processo de pasteurização ou que contaminaram o produto após a pasteurização. O controle da Aa do produto desidratado e o tempo de armazenamento são, portanto, fatores fundamentais para o controle da multiplicação de microrganismos indesejáveis. Nesse estudo, avaliou-se a cinética de multiplicação de Salmonella experimentalmente adicionada a ovo em pó Aa ajustada para 0,4, 0,6, 0,8 e 0,9, durante o armazenamento em quatro temperaturas: 8°C, 15°C, 25°C e 35°C. Os resultados indicaram que S. Enteritidis é capaz de sobreviver por longo tempo (pelo menos 56 dias) em ovo em pó com Aa próximo de 0,4 quando armazenado a 8°C, 15° e a 25°C. Essa sobrevivência é menor (até 28 dias) quando o armazenamento é feito a 35°C. No ovo em pó com Aa em tomo de 0,6 ou 0,8, S. Enteritidis sobrevive por menos tempo do que no produto com Aa de cerca de 0,4, independentemente da temperatura de armazenamento. No produto com Aa de cerca de 0,9, há grande multiplicação de S. Enteritidis quando o armazenamento é feito a 15°C, 25°C ou 35°C. Nesse produto, o armazenamento a 8°C impede a multiplicação do patógeno. Verificou-se também que Salmonella Radar, resistente a diversos antibióticos, apresentou o mesmo comportamento que S. Enteritidis nas amostras de ovo estudadas.
Salmonella is one of the major foodborne pathogens associated to the consumption of eggs and foods containing eggs. Powdered eggs are widely used in the food industry because they are more convenient and uniform than the in natura product. Despite the existence of a pasteurization step in the drying process, Salmonella can survive because the pasteurization of eggs should be done under mild temperature. Moreover, pasteurization can destroy the intrinsic antimicrobial components of the albumen, making the multiplication of Salmonella possible when the time and temperature of storage are not appropriate. Thus, the water activity (Aw) of the product and the storage time and temperature are essential factors in the control of Salmonella. In this work, we evaluated the growth kinetics of Salmonella in experimentally inoculated powdered egg, adjusted to different Aw values (0.4, 0.6, O.S and 0.9) during storage at 8°C, 15°C, 25°C and 35°C, up to 8 weeks. The results indicated that Salmonella Enteritidis is able to survive for long time in powdered eggs (at least 56 days) when the Aw is dose to 0.4 and the temperature is 8°C, or 15°C or 25°C. The survival is lower when the temperature is 35°C. When the Aw is dose to 0.6 or to 0.8, the pathogen survives for less time than in the product with Aw 0.4, regardless the storage temperature. When the Aw is dose to 0.9, there is an intensive growth of the pathogen when the storage is done at 15°C, 25°C or 35°C. However, storage at 8°C inhibits the growth of Salmonella at this Aw. Salmonella Radar, resistant to several antibiotics, presented the same growth partem as S. Enteritidis.

[EN] In recent years, persimmon crop has become very relevant in Mediterranean Spain, where the production of this fruit centres on only one variety, persimmon cv. Rojo Brillante, majorly located in the Valencian Community. The main postharvest disorders manifested by 'Rojo Brillante' persimmons are flesh browning, which is associated with mechanical damage and chilling injury displayed after low-temperature storage. Previous research has determined the postharvest conditions that lead fruit to develop such alterations. However, the biochemical process behind flesh browning and chilling injury disorders is still unknown. Currently, there is special interest in introducing cultivars from other countries to broaden the varietal range. Besides, prolonging the fruit storage period to supply the markets according to the demand is one of the main challenges. In this context, the present Thesis approached three main objectives: 1) Studying the biochemical process implied in the main physiological postharvest disorders manifested in persimmon fruits by focusing on changes in the fruit redox state; 2) Evaluating postharvest treatments to preserve fruit quality during cold storage; 3) Assessing the physico-chemical and nutritional quality of persimmon cultivars introduced from other countries to increase the varietal range. Biochemical, chromatographic and microstructural studies have revealed that flesh browning manifested by fruits submitted to mechanical damage after removing astringency is associated with a tannins oxidation process caused by a stress oxidative situation. A new flesh disorder, "pinkish bruising", has been described on fruits submitted to mechanical impacts while showing high astringency levels. Sensitiveness to the flesh browning disorder has also been evaluated on different cultivars introduced from other countries. The implication of the redox system in the chilling injury manifestation on 'Rojo Brillante' persimmon has been determined. Moreover, we described the changes in this system associated with chilling injury alleviation by 1-MCP treatment. The effect of a controlled atmosphere based on 4-5% O2 + N2 to prolong the storage of cultivars 'Rojo Brillante' and 'Triumph' has been seen to strongly depend on variety. The results were highly positive on cultivar 'Triumph', in which the evaluated atmosphere extended the storage period up to 3 months. The use of short-term high CO2 treatments was another technology assayed to alleviate chilling injury in non-astringent cultivar 'Fuyu'. This treatment significantly reduced the main chilling injury symptom manifested by this cultivar, which is flesh gelling. This effect was related to cell structure preservation. Recent studies have shown that ethyl formate treatment is highly effective for pest control of persimmon 'Fuyu'. However, this treatment induces fruit softening, which causes quality loss. This Thesis revealed that ethyl formate treatment induces the activity of ethylene synthesis-related genes and that flesh softening is mediated by this hormone. It also demonstrated that by applying 1-MPC pretreatment, fruit softening associated with ethyl formate can be controlled. Therefore, the combined used of both treatments is seen as a potential treatment to disinfect persimmon fruits while preserving quality. Finally, the study of ten cultivars introduced from other countries helped select the most interesting cultivars to broaden the varietal range according to their maturation date and their response to deastringency treatment. The main nutritional compounds of persimmon and how they are affected by CO2 deastringency treatment are described.
[ES] El caqui es un cultivo de gran relevancia en el área mediterránea de España, estando la producción centrada en una única variedad, el cv. Rojo Brillante, y localizada principalmente en la Comunidad Valenciana. Las principales alteraciones presentadas por el caqui 'Rojo Brillante' durante el periodo postcosecha son el pardeamiento de la pulpa asociado a los daños mecánicos y los daños por frío manifestados tras la conservación a bajas temperaturas. Las investigaciones previas han determinado las condiciones de manejo bajo las cuales se desarrollan dichas alteraciones, sin embargo los procesos bioquímicos involucrados en la manifestación de estos desórdenes no se conocen en profundidad. Actualmente uno de los principales retos es la introducción de nuevas variedades que permitan ampliar la gama varietal, así como prolongar los periodos de conservación del caqui con el fin de poder escalonar la puesta en el mercado en función de la demanda. En la presente Tesis se han abordado tres objetivos principales: 1) Estudiar los procesos bioquímicos implicados en los principales desórdenes postcosecha del caqui, prestando especial atención a los cambios en el sistema redox del fruto; 2) Evaluar diferentes tratamientos postcosecha para preservar la calidad del fruto durante la conservación frigorífica; 3) Evaluar la calidad físico-química y nutricional de diferentes variedades de caqui introducidas desde otros países para ampliar la gama varietal. Estudios bioquímicos, cromatográficos y microestructurales, han revelado que el pardeamiento de la pulpa o "browning", manifestado por la fruta que ha sufrido daños mecánicos tras la eliminación de la astringencia está asociado a un proceso de oxidación de taninos motivado por una situación de estrés oxidativo. Además se ha descrito una nueva alteración de la pulpa, "pinkish bruising", manifestada por los frutos sometidos a daño mecánico con alto nivel de astringencia. También se ha evaluado la sensibilidad al pardeamiento de diferentes variedades introducidas desde otros países. Con el objetivo de prolongar la conservación del fruto se ha ensayado el uso de la atmósfera controlada basada en 4-5% O2 + N2 sobre las variedades 'Rojo Brillante' y 'Triumph', observándose que la respuesta a esta tecnología depende de manera muy importante de la variedad. Los resultados fueron especialmente positivos en el caso del cultivar 'Triumph', en el que la atmósfera ensayada permitió prolongar la conservación frigorífica hasta tres meses. Otra tecnología ensayada para el control de los daños por frío fue la aplicación de choques con altas concentraciones de CO2 en el cultivar no astringente 'Fuyu'. Este tratamiento alivió el principal síntoma de daño por frío manifestado por esta variedad, la gelificación de la pulpa. Este efecto se ha relacionado con la preservación de la estructura celular de la pulpa del fruto. Estudios recientes han mostrado que el tratamiento con etil formato es altamente efectivo en el control de insectos durante la conservación y comercialización del caqui 'Fuyu', sin embargo este tratamiento provoca un ablandamiento del fruto mermando su calidad. En esta Tesis se ha demostrado que las aplicaciones de etil formato activan los genes de síntesis de etileno, siendo está hormona mediadora del ablandamiento. Los estudios también revelaron que la aplicación de un tratamiento previo con 1-MCP reduce el ablandamiento del fruto asociado al etil formato, por lo que el uso combinado de ambos tratamientos puede ser considerado una alternativa para la desinfección de los frutos sin detrimento de su calidad. Por último, el estudio de diez variedades introducidas desde otros países permitió seleccionar en base a su momento de maduración y respuesta al tratamiento de desastringencia aquellas variedades de mayor interés para ampliar la gama varietal. Además, se identificaron los principales compuestos nutricionales del caqui y
[CAT] El caqui s'ha convertit en els últims anys en un cultiu de gran rellevància en l'àrea mediterrània d'Espanya, estant la producció centrada en una única varietat, el cv. Rojo Brillante, i localitzada principalment a la Comunitat Valenciana. Les principals alteracions presentades pel caqui 'Rojo Brillante' durant el període postcollita són l'enfosquiment de la polpa associat als danys mecànics i els danys per fred manifestats després de la conservació a baixes temperatures. Les investigacions prèvies han determinat les condicions de maneig sota les quals es desenvolupen estes alteracions, però els processos bioquímics involucrats en la manifestació d'estos desordres no es coneixen en profunditat. D'altra banda, actualment un dels principals reptes és la introducció de noves varietats que permetin ampliar la gamma varietal, així com prolongar els períodes de conservació del caqui per tal de poder escalonar la posada en el mercat en funció de la demanda. En este context, en la present Tesi s'han abordat tres objectius principals: 1) Estudiar els processos bioquímics implicats en els principals desordres postcollita del caqui, posant especial atenció als canvis en el sistema redox del fruit; 2) Avaluar diferents tractaments postcollita per preservar la qualitat del fruit durant la conservació frigorífica; 3) Avaluar la qualitat fisicoquímica i nutricional de diferents varietats de caqui introduïdes des d'altres països per ampliar la gamma varietal. Estudis bioquímics, cromatogràfics i microestructurals, han revelat que l'enfosquiment de la polpa o "Browning", manifestat per fruita que ha patit danys mecànics després de l'eliminació de l'astringència està associat a un procés d'oxidació de tanins motivat per una situació d'estrès oxidatiu. A més s'ha descrit una nova alteració de la polpa, "pinkish bruising", manifestada pels fruits sotmesos a dany mecànic amb alt nivell d'astringència. També s'ha avaluat la sensibilitat a l'enfosquiment de diferents varietats introduïdes des d'altres països. Amb l'objectiu de perllongar la conservació del fruit s'ha assajat l'ús de l'atmosfera controlada basada en 4-5% O2 + N2 sobre les varietats 'Rojo Brillante' i 'Triumph', observant-se que la resposta a esta tecnologia depèn de manera molt important de la varietat. Els resultats van ser especialment positius en el cas del cultivar 'Triumph', en què l'atmosfera assajada va permetre prolongar la conservació frigorífica fins a tres mesos. Una altra tecnologia assajada per al control dels danys per fred va ser l'aplicació de xocs amb altes concentracions de CO2 en el cultivar no astringent 'Fuyu'. Este tractament va alleujar el principal símptoma de dany per fred manifestat per esta varietat, la gelificació de la polpa. Este efecte s'ha relacionat amb la preservació de l'estructura cel¿lular de la polpa del fruit. Estudis recents han mostrat que el tractament amb etil format és altament efectiu en el control d'insectes durant la conservació i comercialització del caqui 'Fuyu', però este tractament provoca un estovament del fruit minvant la seua qualitat. En esta Tesi s'ha demostrat que les aplicacions d'etil format activen els gens de síntesi d'etilè, sent esta hormona mediadora de l'estovament. Els estudis també van revelar que l'aplicació d'un tractament previ amb 1-MCP redueix l'estovament del fruit associat a l'etil format, per la qual cosa l'ús combinat de tots dos tractaments pot ser considerat una alternativa per a la desinfecció dels fruits sense detriment de la seua qualitat. Finalment, l'estudi de deu varietats introduïdes des d'altres països va permetre seleccionar en base al seu moment de maduració i resposta al tractament de desastringència aquelles varietats de més interès per ampliar la gamma varietal. A més, es van identificar els principals compostos nutricionals del caqui i es va avaluar l'efecte del tractament de desastringència amb CO2 sobre els mat
Novillo Borrás, P. (2015). HARVEST AND POSTHARVEST QUALITY OF PERSIMMON FRUIT:PHYSICOCHEMICAL AND NUTRITIONAL ASPECTS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/58270
TESIS

Le stockage de chaleur dans des géostructures énergétiques telles que des remblais est réalisable en installant des échangeurs horizontaux au sein des différentes couches de sol compacté. Dans ce système, l'énergie thermique qui est injectée en été via un fluide caloporteur circulant dans les échangeurs de chaleur, peut être extraite en période hivernale. Dans ces conditions, lors de la mise en service, le sol compacté est soumis à des variations de température quotidiennes et saisonnières. Ces variations pourraient modifier les performances thermo-hydro-mécaniques du sol compacté. Ainsi, le but de cette étude est d'étudier les performances thermiques et mécaniques d'un sol compacté lorsqu'il est soumis à des variations de température monotones et cycliques. Le sol étudié est un limon fréquemment utilisé dans les constructions de remblais en France. Le comportement thermique et mécanique du sol est étudié à un état de compactage correspondant aux propriétés thermiques optimales. Dans cet état, le sol compacté est non saturé ce qui complexifie l'estimation de ses propriétés thermiques. Pour pallier à ces difficultés, dans cette étude, un modèle inverse est proposé pour estimer les propriétés thermiques du sol compacté. L’efficacité du modèle est testée sur un jeu de données acquises dans la gamme de 20 à 50 °C dans un modèle réduit en laboratoire. Les valeurs obtenues sont ensuite comparées à des mesures classiques en laboratoire (méthodes en régime transitoire et en régime permanent). Cette méthode pourrait permettre de suivre l’évolution des propriétés thermiques du stockage et ainsi assurer son efficacité tout au long de sa durée de vie. La question de la stabilité à long terme de ces structures soumises à des variations thermiques monotones (5, 20 et 50 °C) et cycliques (5 à 50 °C) est ensuite abordée à l'aide d'essais oedomètriques et d’essais de cisaillement direct à température contrôlée. Les résultats des essais de compressibilité ont montré que l'effet de la variation de température est plus prononcé sous une contrainte verticale supérieure à la pression de préconsolidation. Les indices de compression et de gonflement peuvent être considérés comme indépendants des variations de température. Donc le tassement global du remblai dû aux variations thermiques pourrait être considéré comme négligeable. Les résultats des essais de cisaillement direct ont montré que les variations de température (monotones ou cycliques) augmentent la cohésion ce qui est avantageux pour la capacité portante et la stabilité des pentes des remblais. Dans la phase de conception d'un remblai de stockage, ces résultats seraient utiles au dimensionnement du système si des trajectoires thermomécaniques similaires à celles de cette étude sont respectées. Dans une dernière partie, une simulation numérique prenant en compte l'interaction sol-atmosphère est réalisée afin d’évaluer la performance thermique de ce sol compacté en conditions naturelles. Différentes profondeurs d'installation de boucles d'échangeurs de chaleur sont testéss ainsi que différents scénarios de stockage. Les résultats ont montré que le sol compacté augmente de 8.5% les performances du système par rapport à l'installation d'une boucle horizontale dans le sol naturel (non compacté). Les résultats de deux scénarios différents ont montré qu’en été avec un fluide ayant une température d'entrée de 50 °C augmente significativement la performance du système. De plus, une installation plus profonde des boucles horizontales améliore également la performance du système. Il convient de noter que le remblai est en interaction avec l'atmosphère depuis ses surfaces supérieure et latérale, l'efficacité thermique de la structure pourrait être affectée en raison des pertes de chaleur. Par conséquent, il est préférable de placer les échangeurs de chaleur loin des surfaces supérieures et latérales
Nowadays, thermal energy storage in geostructures like embankments can be possible by installing the horizontal heat exchangers in different layers of compacted soil. In this system, the thermal energy is stored in summer via a fluid, circulating in the heat exchangers, to be extracted in the demand period. When the serviceability of embankment as a medium to store the thermal energy starts, the compacted soil will be subjected to the daily and seasonally temperature variations. These seasonal temperature variations could modify the thermo-hydro-mechanical performance of the compacted soil. Thus, the aim of this study is to investigate the thermal and mechanical performances of a compacted soil when it is subjected to monotonic and cyclic temperature variations. The studied soil is a sandy lean clay that is frequently used in embankment constructions in France. The thermal and mechanical behavior of the soil are investigated at a compaction state corresponding to the optimal thermal properties. However, this compacted soil is unsaturated and the estimation of its thermal properties is complex. In this study, an inverse analytical model is proposed to estimate the thermal properties of the soil using temperature monitoring in the range of 20 to 50 °C in a soil compacted in a large container. The estimated thermal parameters were compared to classical laboratory measurements (transient and steady-state methods). The comparison showed that the estimated values were close to the results obtained in transient laboratory method. Using this method, the thermal efficiency of the compacted soil can be verified in the lifetime of the storage system. To ensure the structure stability, long-term mechanical response of these systems subjected to monotonic and cyclic temperature variations should be investigated. To achieve this aim, using temperature-controlled oedometric and direct shear devices, consolidation and shear parameters of the studied soil at different monotonic (5, 20, and 50 °C) and cyclic (5 to 50 °C) temperatures were investigated. The results of temperature-controlled oedometric tests showed that the effect of the temperature variation is more pronounced under vertical pressures higher than the preconsolidation pressure. The compression and swelling indexes could be considered independent of temperature variations. Therefore, the overall settlement of the embankment due to thermal variation near the heat exchangers could be considered negligible. The results of temperature-controlled direct shear tests showed that the temperature variations (monotonic heating or cooling, or temperature cycles) increased the cohesion which is beneficial for the bearing capacity and slope stability of embankments. These results can be directly used in the design of embankments to store thermal energy exposed to similar thermo-mechanical paths. Finally, the thermal performance of the compacted soil is verified using a numerical simulation considering the soil atmosphere interaction. Different depths installation of heat exchanger loops and different heat storage scenarios were simulated. The results showed that the compacted soil increases 8.5% the systems performance compared to the horizontal loop installation in the local soil. The results of two different scenarios show that an inlet fluid temperature of 50 °C in summer increases highly the system performance (13.7% to 41.4%) while the improvement is less significant (0% to 4.8%) for the ambient inlet temperature. Moreover, a deeper installation of horizontal loops increases the system performance. From the numerical simulation results can be concealed that the embankment is in interaction with the atmosphere from its upper and lateral surfaces, the thermal efficiency of the structure could be affected due to heat losses. Therefore, it is preferable to place the heat exchangers away from the top and side surfaces

碩士
國立臺灣大學
園藝學系
81
The respiration rate of water convolvulus (Ipomoea aquatica Forsk.) correlates positively with storage temperature. At higher temperature ranges (20C and 28C), there were a climacteric-like rise in respiration. At 15C and 10C, the respiration rates increased slightly after 10 days. At 5C and 1C the respiration rates declined slowly just like that of the non- climacteric type of respiration. When stored at different temperatures, the retention of leaf chlorophyll correlates negatively with temperature. By using the criterion that when the chlorophyll content of the basal three leaves of the water convolvulus shoot has dropped to less than 50% of its original value is considered as the end of marketing period, the estimate storage life of water convolvulus at different temperatures were as follows : at 20C, 3 days; at 15C, 6 days; at 10 , 10 days, at 5C and 1C, chilling injury symptoms appeared after 10 and 4 days respectively. At 5C, the shoot tip turned brown and at 1C, the whole stem turned brown. It appears that 10C is a better temperature for water convolvulus storage. When water convolvulu was stored in pure nitrogen environment for 36 hours, its respiration rate did not increase, indicating that anaerobic respiration was not operating at this point. When stored at various concentrations of oxygen, the retention of leaf chlorophyll correlates negatively with oxygen concentration.

A computer simulation program, Controlled Atmosphere Simulation (CAS), was written in Microsoft Visual Basic 3.0, Professional Edition to evaluate energy use by three type of atmosphere generators used in fruit storage warehouses. The program consists of pulldown time and energy use models for a membrane air separator, an ammonia fractionating burner, and a catalytic oxygen burner. Predicted results subsequently became input to an interactive computer program, Fruit Storage Refrigeration Energy Simulation (FruSTRES), which was developed to simulate energy use by cold storage ammonia refrigeration systems. The resulting model package was then used to predict overall annual energy use in fruit storages, based on number and size of rooms, building construction, equipment operation (both refrigeration and CA), commodity stored, storage period(s), and weather conditions. The CAS accurately predicted the pulldown time of each type of equipment under normal operation. The resulting model package (CAS and FruSTRES), will be an invaluable tool in design and analyses of ammonia refrigeration and atmosphere generation systems used in common and controlled atmosphere fruit storages.
Graduation date: 1998

碩士
國立臺灣大學
園藝學研究所
87
The effects of temperature and controlled atmosphere (CA) on the postharvest physiology and quality of cucumber fruit during storage were studied. The optimum temperature of cucumber for storage was 15℃, which maintained better appearance and texture, more total chlorophyll and ascorbic acid content, and longer storage life than other temperatures. Lower temperature reduced its respiration rate, however, the temperature below 10℃ may adversely raise ethylene production rate. The temperature below 10℃ or above 20℃ accelerated skin yellowing, texture softening, loss of chlorophyll content, and deterioration. The storage life of cucumber were about 1 week at 10℃, 18 days at 15℃and 3days to 1 week at 20℃. Oxygen concentrations below 10 % or carbon dioxide concentrations higher than 1% but , all reduced the respiration rate of cucumber and kept better storage quality than air storage. The optimum oxygen and carbon dioxide levels were 5% O2 and 5% CO2 , respectively. A combination of 5% O2 and 5% CO2 reduced respiration and ethylene production rates of cucumber more significantly and kept better storage quality than either 5% O2 or 5% CO2 alone. It is recommended that the best condition for controlled atmosphere storage of cucumber is 5% O2 + 5% CO2 at 15℃.

A two year experiment demonstrated electrical energy savings through evaporator fan cycling in part of a full-sized refrigerated controlled atmosphere apple storage facility in Yakima, Washington. Room cooling demand and evaporator fan operation was controlled by the bulk fruit temperature. Refrigerant temperature was regulated by a computer controlled ramping sequence and a weighted average of three thermistors rather than a room thermostat. Evaporator fans remained off 60-65% of the time during periods of fan cycling operation. Seasonal average fan energy savings approached 50-55% when the product remained in storage for a typical length of time. Room environment conditions, product mass loss, and fruit quality were not compromised. Bulk fruit temperature was exceptionally stable as compared to fruit stored in non-fan cycled rooms controlled by traditional means. Less fan motor heat input in the fruit storage space also results in compressor energy savings. Total electrical energy savings were projected to an 18 room fruit storage facility implementing computer controlled evaporator fan cycling. Projected electrical energy savings achievable through evaporator fan cycling for the state of Washington were made based on reported apple storage capacity.
Graduation date: 1993

博士
國立臺灣大學
園藝學系
82
The respiration rate and quality of bamboo shoot (Bambusa oldhami Munro) were greatly influenced by temperature. The respiration was measured 10 hours after harvest, it was 457mg CO2/kg*hr at 30C, 247mg CO2/kg*hr at 20C, while only 31mg CO2/ kg*hr at 5C and 0C. The color change of cutting surface showed that "L" value decreased very rapidly at 30C, "a" value and "b" value at 30C increased 5-6 times that of at 5C and 0C, thus the browning occurred very rapidly at high temperature. The ascorbic acid, alcohol soluble solid, sucrose, starch and organic acid all decreased and the crude fiber increased at high temperature and the quality changed slowly under low temperature. There is correlation between the cut surface measured by rheometer and lignification observed by fluorescent observation. To measure the cut force and to observe the response of fluorescent in vascular bundle could be a marker for the lignification of bamboo shoot. The ethylene evolution was affected by temperature, the maximum evolution was measured at 18 hours after harvest. The ACC content and ethylene evolution increased rapidly within 2 hours after wounding of sliced bamboo shoot. The treatment of CoCl2, AOA and AVG could retard the ethylene evolution and toughness, NBD could enhance the ethylene evolution but it could retard the toughness of bamboo shoot. The treatment of C2H4 enhanced the toughness. Under 10C and 20C, the 3% O2 was the extinction point of bamboo shoot, low oxygen could reduce browning. Through the quality analyzation and sensory evaluation, the best combination was 3%O2 +10%CO2 for controlled atmosphere storage of bamboo shoot. Low oxygen and high carbon dioxide could retard the production of ethylene, also the enzyme activity of PAL, PODandPPO. With short- term treatment of low oxygen and high CO2 for 24 hours, then packaged with PE bag stored in 10℃ also had the above effects.

碩士
國立屏東科技大學
科技管理研究所
106
This study uses Taiwan and China's agricultural product controlled atmosphere storage technology patent information as the object of analysis, and understands the development trend and layout of Taiwan and China, which is used as a reference for companies in research and development and business strategy. In terms of patent strategy, the search date is locked in the patents retrieved from 1986 to February 2018. The keywords used in the literature review are the types of agricultural products and gas-conditioning technology and equipment. The number of patents is Taiwan. 23 pens and 684 pens in mainland China were the subject of this study. The results of the analysis show that Taiwan is mainly individuals in the application and research and development of patents, while foreign applicants are conducted by enterprises and teams; China academic institutions are the main applicants, and will apply with the research and development of patents with Private enterprise. This study found that Taiwanese technology is concentrated in transportation and operation equipment. Mainland China technology is concentrated on preservation and ripening. Although the number of applications for detection devices is not more than that of modified atmosphere packaging and control systems, in the application trend, in 2008 After gradually getting attention. It is recommended that the government promote relevant measures and policies, encourage the concentration of technical resources, and comply with the importance of smart agriculture for the research and development of detection systems.

Apples stored onshore in Australia and New Zealand, are maintained at optimal storage conditions with the aid of low temperatures; controlled atmospheres (CA) and new technologies that retard the production or effect of ethylene (AVG and 1-MCP respectively). These technologies allow distribution of the highest quality apples to local and export markets on a year round basis. However, during distribution, maintenance of optimal storage conditions may be lost due to refrigeration system breakdown, operational constraints or management decisions. This thesis quantifies the influence of commercially realistic breaks in optimal storage conditions (temperature and CA) on fruit physiology and quality, both at the time of the break and in subsequent optimal storage conditions. The ‘Cripps Pink’ (‘Pink Lady™’) apple cultivar was chosen for consideration in this thesis because it is a high value cultivar that is of considerable importance to the Australian apple industry. The knowledge of the behaviour of ‘Cripps Pink’ apples in coolstorage conditions (in air and CA) was confirmed through comparison of physiological and quality change behaviour of fruit from three harvests collected in this research and those reported recently by other authors. The investigation of the influence of breaks in temperature control during storage in air at 0°C, revealed that preclimacteric apples exposed to a break in temperature control, were advanced towards the establishment of the climacteric. Postclimacteric apple, responded by doubling ethylene production a short time after return to coolstorage. Harvest maturity, timing of break during coolstorage, length of break of temperature control and multiple breaks in temperature control, had little influence on the increase ethylene production response. Quality factors (firmness, background hue angle, and titratable acidity) were all reduced as a result of exposure to warmer temperatures, but on return to coolstorage temperatures rates of loss in these quality factors were not influenced by the increased ethylene production. Short-term (3-day) breaks in CA while fruit remained at refrigerated temperatures were shown to have no substantial effect on fruit physiology or quality, either during the period of the break in CA or in subsequent CA storage. Breaks in temperature control in combination with breaks in CA were observed to cause a doubling of ethylene production on CA stored apples regardless of being returned to 0°C in air or CA. Those apples that were exposed to a break in temperature control and returned to air storage at refrigerated temperature lost quality (firmness and background hue angle) more rapidly than apples not exposed to breaks in temperature control and transferred to air storage. This result strengthened the knowledge of the influence of ethylene on changes in apple quality, as found for many other apple cultivars. The influence of the decision to transport fruit in CA or air atmosphere shipping containers was initially investigated with a laboratory simulation. Physiology (respiration rate and ethylene production) of air shipped fruit was found not only to be more rapid, but more variable between fruit, than for apples shipped in CA. This more rapid and larger variation of possible fruit physiologies, suggests that in addition to losing quality at a faster rate, the variation in the quality of fruit shipped in air will also enlarge during shipment. This hypothesis was confirmed with data pooled from treatments subjected to 0°C and 3°C, simulating the likely temperature variability within a shipping container. Validation of the influence of shipping atmosphere on delivered fruit quality, was conducted in the commercial environment. This trial found that the length of time to ship fruit from Australia and New Zealand to European markets was not sufficient to induce commercially significant differences between ‘Cripps Pink’ apples shipped in the two atmospheres. Finally, as ethylene production was influenced by fluctuations in temperature control and subsequently affected quality of apples previously stored in CA, an investigative attempt to model ethylene production in temperature variable scenarios was conducted. Published models of ethylene production in apples were adapted to the variable temperature storage scenario and a new model was proposed. Unfortunately, none of the models investigated were able to predict all of the consistent behaviours of ethylene production observed during the experimental work, indicating that more knowledge of the ethylene production pathway is required, before modelling of ethylene production and subsequently apple quality can be conducted successfully.