Dissertations / Theses on the topic 'Postharvest'
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Peck, Leslie Kathryn. "Pre- and Postharvest Practices for Optimizing the Postharvest Quality of Cut Sunflower, Dahlia, and Delphinium." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/73589.
Full textMaster of Science
Daniel, Chanel Karousha. "The effect of garlic extracts on the control of postharvest pathogens and postharvest decay of apples." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86544.
Full textENGLISH ABSTRACT: Apples are an important export commodity for the South African market, and postharvest losses that occur as a result of decay due to infection with pathogenic fungi such as Botrytis cinerea Pers., Penicillium expansum (Link) Thom. and Neofabraea alba (E.J. Guthrie) are of major concern for all parties concerned with fruit production and distribution. Decay control of these fungi is primarily managed through the use of synthetic fungicides; however, pathogen development of resistance to these fungicides and recent worldwide concern over healthier living and a greener environment has called for the discriminate use of synthetic chemicals. This has opened up an avenue for the development of safer and more environmentally friendly alternatives to control postharvest decays. The use of plant extracts and essential oils are favoured as natural sources of antimicrobials whilst still being safe for human consumption and having no negative impact on the environment. Allium sativum (garlic) is one such plant species that is well documented for its value in improving human health and is readily available for consumption not just as a flavour component of food but also to be taken as a daily herbal diet supplement. Given the antimicrobial effectiveness of garlic against human pathogens and ailments, its value as an antifungal agent against postharvest pathogens causing grey mould, blue mould and bull’s eye rot of apples was investigated in vitro and in vivo within this study. Furthermore, an attempt was made to elucidate the chemical components of garlic extracts by gas chromatography-mass spectrometry (GC-MS). All experiments in this study were carried out with garlic extracts prepared from fresh garlic bulbs. For the in vitro experiments, two extract preparations of garlic, one containing ethanol (Extract 1) and one where ethanol had been removed by evaporation (Extract 2), was tested for antifungal action within an amended media experimental design. Both extract preparations were each subjected to two dilution series (0-80% garlic extract) with water and ethanol as diluents. Both extract preparations were successful at retarding pathogen mycelial growth and spore germination; however, concentrations of Extract 2 (ethanol evaporated) and diluted with distilled water provided markedly better inhibition of B. cinerea and P. expansum than the ethanolic dilutions of extract 2. Both extract preparations yielded similar inhibitory results when tested against N. alba. Due to the results achieved in the amended media experiments, the use of a crude garlic extract without ethanol and diluted in water was considered to be the best option for further tests throughout the remainder of the study. In vitro volatile effects of crude garlic extracts at concentrations between 0 and 40% garlic extract were subsequently tested. Garlic volatiles were effective in inhibiting pathogen mycelial growth and spore germination of all three pathogens, at lower concentrations compared to the amended media experiments. In vitro volatile exposure with garlic extracts was more effective at inhibiting N. alba than direct application of the extracts. Curative and protective application of garlic extracts and clove oil for increased fungal inhibition through synergism was tested by direct and volatile exposure to the pathogens in vivo on three economically important apple cultivars; ‘Granny Smith’, ‘Golden Delicious’, and ‘Pink Lady’. Direct exposure of artificially wounded and inoculated fruit to the garlic extract and clove oil revealed that garlic extracts applied curatively but not protectively effectively controlled decay caused by B. cinerea and P. expansum on all apple cultivars. Both curative and protective applications were ineffective in controlling N. alba. In vivo volatile exposure to the garlic extracts and clove oil did not inhibit decay on any of the cultivars and was not effective against any of the three pathogens investigated. A full chemical profile analysis was done by GC-MS analysis of garlic extract samples. The compounds diallyl disulphide, allyl methyl trisulphide, allyl methyl disulphide and dimethyl trisulphide were detected in relatively high amounts. This result suggests that the abundance of sulphur and sulphur related compounds detected may be responsible for the antifungal action noted in the experimental studies. In conclusion, garlic was shown to have antifungal activity against B. cinerea, P. expansum and N. alba. The pathogens used in this study were not compared with each other, but undoubtedly each pathogens reacts differently to exposure to the garlic extracts. It would therefore be advisable to investigate the effects of the extracts on each of the pathogens in a more in-depth study. More investigations into the application of the garlic extracts is required before it may be recommended for use; however, results for the use of garlic extracts against these postharvest pathogens and the postharvest decay they cause are promising.
AFRIKAANSE OPSOMMING: Appels is ‘n belangrike uitvoerproduk vir die Suid-Afrikaanse vrugtebedryf, maar noemenswaardige na-oes verliese word weens bederf deur patogeniese swamme soos Botrytis cinerea Pers., Penicillium expansum (Link) Thom. en Neofabraea alba (E.J. Guthrie) ervaar. Dit raak alle partye betrokke met die produksie en verspreiding van hierdie vrugsoort. Hierdie swamme word hoofsaaklik met behulp van kunsmatige swamdoders beheer, alhoewel weerstand-ontwikkeling en wêreldwye bewusmaking van ‘n gesonder leefstyl en omgewing die gebruik van kunsmatige middels streng aanspreek en die ontwikkeling van veiliger en meer omgewingsvriendelike alternatiewe middels verlang. Plant-ekstrakte en essensiële olies kan dien as sulke middels en is natuurlike bronne van anti-mikrobiese aktiwiteit, is veilig vir menslike verbruik en het ook geen negatiewe invloed op die omgewing nie. Allium sativum (knoffel) is so ‘n plantspesie wat as alternatiewe middel gebruik kan word. Dit is bekend vir sy waarde in die verbetering van menslike gesondheid, is maklik bekombaar en word nie net as ‘n geurmiddel vir voedsel gebruik nie, maar ook as ‘n daaglikse krui-aanvulling. Gegewe die anti-mikrobiese doeltreffendheid van knoffel teenoor menslike patogene en kwale, is die werking (in vitro en in vivo) teen na-oes patogene wat grys skimmel, blou skimmel en teikenvrot in appels veroorsaak, in hierdie studie ondersoek. Bepaling van die chemiese samestelling van die knoffel-ekstrak is ook met behulp van gaschromatografie massa spektrometrie (GK-MS) onderneem.Vars knoffelbolle is vir elke eksperiment in hierdie studie gebruik met die voorbereiding van die knoffel-ekstrak. Vir die in vitro eksperiment is twee knoffel-ekstrakte voorberei, naamlik: ‘n ekstrak wat etanol bevat (Ekstrak 1) en een waarvan die etanol verwyder is met verdamping (Ekstrak 2). Die ekstrakte is getoets vir werking teen fungi in kultuur-medium.. Albei ekstrakte is verdun tot twee konsentrasie reekse (0-80%) met water en etanol as verdunningsmiddels. Albei ekstrakte het suksesvolle werking getoon teenoor die patogene ten opsigte van vertraging van miseliumgroei en spoor-ontkieming, alhoewel konsentrasies van Ekstrak 2, verdun met gesuiwerede water, patogene B. cinerea en P. expansum beter onderdruk het as Ekstrak 2 verdunnings met etanol.. Beide ekstrakte en hul afsonderlike verdunnings met etanol en water het soortgelyke resultate gelewer met onderdrukking van N. alba. Volgens resultate wat verkry is van die kultuur-medium eksperimente, is Ekstrak 2 verdun met gesuiwerde water beskou as die geskikste vir verdere toetse in hierdie studie. Die vlugtige effek van Ekstrak 2 is in vitro getoets by konsentrasies tussen 0 tot 40%. Die vlugtige stowwe van knoffel het al drie patogene se groei en spoor-ontkieming effektief onderdrukby laer konsentrasies as wat gebruik is in die kultuur-medium eksperiment. Dus is in vitro blootstelling van N. alba aan die vlugtige stowwe meer effektief as direkte toediening van die ekstrakte. Die voorkomende en beskermende effek van die knoffel-ekstrak, asook naeltjie-olie, is in vivo ondersoek om te bepaal of die stowwe saam sterker onderdrukking van die patogene kon bewerkstellig. Direkte en vlugtige blootstelling is op drie ekonomies-belangrike appel-kultivars getoets, naamlik: ‘Granny Smith’, ‘Golden Delicious’ en ‘Pink Lady’. Direkte blootstelling met die knoffel-ekstrak en naeltjie-olie aan gewonde en ge-inokuleerde vrugte het aangedui dat B. cinerea- en P. Expansum-bederf net beheer kon word indien knoffel voorkomend toegedien is vir al die ondersoekte appel-variëteite. Voorkomende en beskermende toediening was onsuksesvolle om N. alba te beheer. In vivo blootstelling van die drie patogene aan die knoffel-ekstrak en naeltjie-olie se vlugtige stowwe kon nie enige van die patogene effektief onderdruk nie en was onsuksesvol in bederf-beheer. ‘n Volledige chemiese profiel is saamgestel deur GK-MS ontleding van die knoffelekstrakte. Hoë vlakke van verbindings dialliel disulfied, alliel-metiel-tri-sulfied, alliel-metieldisulfied en dimetiel-trisulfied is bespeur. Die aantal vrye sulfied en sulfied-verwante verbindings in die ekstrak kan moontlik ‘n verduideliking bied vir die anti-swam werking waargeneem gedurende hierdie studie. Ten slotte: knoffel toon ‘n anti-swam werking teenoor B. cinerea, P. expansum en N. alba. Die patogene in hierdie studie is nie met mekaar vergelyk nie, omdat elkeen uniek en uiteenlopend op knoffel reageer het. Alhoewel die huidige studie alreeds belowende resultate gelewer het, moet die ekstrak se effek op elke patogeen onderskeidelik nog in diepte ondersoek word, asook die wyse van die toediening in die na-oes praktyk voordat hierdie middel aanbeveel kan word vir gebruik.
Auret, Erika Elizabeth. "Control strategies for citrus postharvest diseases." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-06192006-084845.
Full textPangaribuan, Darwin H. "Postharvest physiology of fresh-cut tomato slices /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19021.pdf.
Full textHewage, Kalehe Sarananda. "Factors influencing postharvest longevity of Embul bananas." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307677.
Full textGalli, Federica. "RIPENING AND POSTHARVEST MANAGEMENT OF PAWPAW FRUIT." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_diss/507.
Full textVan, Hoorn A. T. (Aaltje Trientje). "Optimisation of blueberry postharvest handling and storage." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/20906.
Full textENGLISH ABSTRACT: By world standards South Africa’s contribution to fresh blueberry production is very small, a mere 0.25 %. This seemingly insignificant and unimpressive statistic is, however, by no means indicative of the impending impressive potential the South African blueberry industry holds. South Africa is encountering a rapid growth phase off a very small base and the current 100-150 ton export crop is expected to increase to a range of 500 to 600 tons or more in the next five years. Consequently, export by sea must be considered as a logistic alternative. Seafreight success relies on controlled atmosphere storage which in turn relies on berries of exceptional quality. To achieve this, fundamental differences between blueberry cultivars must be examined and blueberry handling and storage regimes must be assessed and optimised. This study investigates the storage potential of certain rabbiteye blueberries relative to controlled atmospheres and short pre-cooling delays. Quality assessments were based on external colour, soluble solids, titratible acidity, firmness and decay development. Furthermore, the respiration and ethylene production rates as well as moisture loss, of various cultivars were determined to characterize fundamental differences amongst cultivars and to gain insight into their postharvest behaviour. Lastly the effect of infection on pigment levels of blueberry flesh and peel was examined for the purpose of laboratory experience. Controlled atmosphere storage had the greatest impact on berry firmness and percentage decay. No off flavours were detected during sensory analysis at the CA levels tested. CAstored berries were firmer and incidence of decay was reduced significantly. Significant decay reduction was challenged by the market tolerance of no more than 2 %. Decay suppression and storage extension was insufficient (for the set period), particularly after the shelf life period. Cultivar and seasonal differences as well as picking maturity and inoculum pressure determine blueberry CA storability. CA may be a valuable technology, however advances must first be made in ensuring optimal blueberry quality to warrant export by sea. Short pre-cooling delays (0, 2, 4, 6 h) at 20 ºC had no effect on colour (L, C, H), total soluble solids, titratable acidity and firmness of blueberry cultivars, ‘Centurion’, ‘Premier’ and ‘Tifblue’. Results for percentage decay indicate that prompt cooling becomes more critical as the duration of storage increases, particularly when market specification of no more than 2 % decay must be met. Berries subjected to longer delays appear to be more susceptible to decay. Differences exist among cultivars and knowledge gained from this research can be used to adapt handling and cooling regimes. Information generated will benefit cultivar selection for marketing (local vs. export), storage (short vs. long term) and logistics (air vs. seafreight). Rabbiteye blueberry cultivars differ considerably in terms of their respiration rate, ethylene production and moisture loss. These quality parameters were evaluated for various cultivars at 15 ºC. ‘Climax’ appears to have the highest respiration rate, ethylene production and moisture loss, whilst ‘Premier’ has the lowest respiration rate and ethylene production was too low to be detected by gas chromatography. The lowest moisture loss proportionality constant was found for ‘Tifblue’ and ‘Centurion’. A change in blueberry flesh colour from white to dark red was noted in infected berries. Artificial inoculation with Botrytis cinerea showed a similar result. The colour change was evaluated by comparing anthocyanin pigment levels (determined by spectrophotometry and HPLC) of the peel and flesh. Anthocyanin content of infected flesh doubled, whilst that of infected peel was less than 50 % of the control. Pigment leakage has been reported in blueberries. It would appear that cell disruption, induced by infection may facilitate migration of anthocyanin from the peel to the flesh. The storage potential of blueberries depends on cultivar, maturity at harvest, climatic conditions as well as the inoculum pressure. Under favourable conditions storage life of blueberries can be manipulated effectively. Further cultivar specific research that targets relevant quality issues should be investigated. Reliable techniques should be developed to quantify blueberry firmness changes. Research on inoculum levels may give insight into the reduction of decay pressure and decay suppressing alternatives such as antibacterial pads can be examined. Peel integrity relative to decay susceptibility can also be researched on a cellular level.
AFRIKAANSE OPSOMMING: Suid-Afrika se bydrae tot wêreld bloubessie produksie is baie klein, ‘n skrale 0.25 %. Hierdie onindrukwekkende statistiek weerspieel egter glad nie die indrukwekkende potensiaal van die Suid-Afrikaanse bloubessie bedryf nie. Die bedryf ondervind tans ‘n dramatiese groei met ‘n klein begin vanaf die huidige 100-150 ton opbrengs tot wat volgens verwagting binne die volgende vyf jaar sal styg tot in die orde van 500-600 ton. Na aanleiding van die verwagte toename in produksie, sal seevrag verskeping oorweeg moet word as alternatief vir uitvoer eerder as lugvrag. Die sukses van seevrag lê in die gebruik van beheerde atmosfeer opberging (BA), waarvan die sukses op sy beurt bepaal word deur bessies van hoogstaande kwaliteit. Om steeds aan die verwagtings van die oorsese mark te voldoen moet grondliggende verskille tussen bloubessie kultivars ondersoek word en daaropvolgend moet hantering en opbergingstelsels aangepas en geoptimeer word. Die navorsing bestudeer die opbergingspotensiaal van verskeie rabbiteye bloubessies relatief tot beheerde atmosfere en kort vertragings in verkoeling. Kwaliteit, gebasseer op eksterne kleur, oplosbare deeltjies, titreerbare sure, fermheid en persentasie bederf, is ondersoek. Die respirasie en etileenproduksie tempos sowel as vogverlies van verskeie kultivars was verder bepaal om die fundamentele verskille tussen kultivars te bepaal, sowel as insig te verwerf in na-oes gedrag. Die effek van infeksie op pigment vlakke van bloubessie vlees en skil was ondersoek vir die doel van laboratorium ondervinding. Beheerde atmosfeer opberging het die grootste effek getoon op bessie fermheid en persentasie bederf. Na aanleiding van sensoriese toetse is daar geen wansmaake aangeteken ten op sigte van die BA vlakke wat getoets is nie. Bessies onderworpe aan beheerde atmosfeeriese toestande was fermer en bederfonderdrukking was beduidend. Die markverdraagsaamheid ten opsigte van bessiebederf, is egter 2 %. Hiervolgens was onderdrukking van verval asook opbergingsvermoë, onvoldoende (spesifiek na die rakleeftyd). Kultivar en seisoenale verskille asook plukrypheid en inokulum druk, bepaal ook die sukses van BA opberging. BA word beskou as ‘n waardevolle tegnologie vir verlenging van opberging. Dit blyk egter dat daar eers ‘n vooruitgang gemaak moet word in die versekering van optimale bessie kwaliteit voordat verskeping oorweeg kan word. Kort vertragings (0, 2, 4, 6 uur by 20 ºC) in verkoeling, het geen invloed gehad op kleur, (L, C, H), totale oplosbare vastestowwe, titreerbare suur en fermheid van bloubessie kultivars ‘Centurion’, ‘Premier’ en ‘Tifblue’ nie. Bederfresultate dui daarop dat onmiddelike verkoeling krities is, veral by verlengde opberging, om aan die 2 % bederf drempelwaarde te voldoen. Bessies onderhewig aan langer vertragings voor verkoeling, blyk meer vatbaar te wees vir bederf. Verskille bestaan tussen kultivars en kennis ingewin tydens hierdie navorsing kan toegepas word om hanteringsprosedures en verkoeling aan te pas. Ingeligte besluitneming kan dus ten opsigte van kultivarspesifieke bemarking (plaaslik en uitvoer), opberging (kort- en langtermyn) en vervoer (lug- en seevrag) gemaak word. Rabbiteye bloubessie kultivars verskil aansienlik ten opsigte van hul respirasietempo, etileenproduksie en vogverlies. Laasgenoemde kwaliteitsbepalers is by verskillende kultivars ondersoek by 15 ºC. ‘Climax’ het die hoogste respirasietempo, etileenproduksie en vogverlies getoon, terwyl ‘Premier’ die laagste respirasietempo gehad het, en die etileenproduksie te laag was om met die gaschromatograaf te bepaal. Die laagste vogverlies proporsionaliteitskonstante is waargeneem tussen ‘Tifblue’ en ‘Centurion’. ‘n Verandering is waargeneem in bloubessie vrugvleeskleur van wit tot donkerrooi by besmette bessies. ‘n Soortgelyke resultaat is verkry met kunsmatige inokulering met Botrytis cinerea. Die kleurverskil is geëvalueer deur vergelyking te tref met die antosianienpigment vlakke tussen die skil en die vlees (bepaal deur spektrofotometrie en HPLC). Antosianieninhoud van besmette vrugvlees het verdubbel, terwyl die van besmette vrugskil minder as 50 % van die kontrole groep was. Pigmentlekkasie is al vermeld by bloubessies. Dit wil voorkom of selskade veroorsaak deur infeksie beweging van antosianien vanaf die skil na die vlees kan aanhelp. Die opbergingspotensiaal van bloubessies hang af van kultivar, rypheid by oes, omgewings toestande sowel as inokulum druk. Onder gunstige toestande kan bloubessies se opbergingsvermoë effektief gemanipuleer word. Verder kultivar-spesifieke navorsing wat relevante kwaliteits kwessies aanspreek, kan gedoen word. Verder kan betroubare tegnieke in die meting van bloubessie fermheid veranderinge ondersoek word. Navorsing ten opsigte van inokulum vlakke mag insig gee in terme van bederf-druk vermindering en die gebruik van bederf-onderdrukking alternatiewe soos anti-bakteriese lappies. Skil integriteit relatief tot bederf-vatbaarheid kan ook op sellulere vlak ondersoek word.
Lerud, Ryan M. "Sensors and Portable Instruments for Postharvest Agriculture." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/4994.
Full textMeyer, Celeste. "Carbohydrates and leaf blackening of Protea cut flowers." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53320.
Full textENGLISH ABSTRACT: Protea cut flowers are exported worldwide but the vase life of some species and cultivars is considerably shortened by post-harvest leaf blackening. Research has established carbohydrate depletion to be positively correlated with this disorder. Consequently, a study had been made of the carbohydrate status of various species and cultivars, as well as the effect of supplemental glucose (pre and post-storage) on leaf blackening. Glucose, fructose, sucrose and starch concentrations of various Protea species and cultivars held in water were measured at harvest, and again at leaf blackening initiation. All measured carbohydrates declined significantly in 'Carnival', 'Pink Ice' and 'Sheila'. In 'Cardinal' all carbohydrate concentrations decreased significantly, except the sucrose concentration in the inflorescence. 'Susara' and 'Ivy' had very high initial carbohydrate concentrations in the leaves which decreased significantly. The very high initial carbohydrate concentrations in the inflorescence of 'Ivy' declined significantly. 'Brenda' differed from the other cultivars and species in that glucose concentrations increased over time. Carbohydrate concentrations of most of the tested proteas declined significantly from harvest to the initiation of leaf blackening. This highlighted the dependence of the leaves and inflorescence on the carbohydrate reserves, further substantiating the carbohydrate depletion theory. The inflorescences were characterized by high fructose and glucose concentrations and low sucrose concentrations when compared to the leaves. It was hypothesized that glucose pulsing and cold storage at 1°C for three weeks would significantly reduce leaf blackening. 'Brenda', 'Cardinal', 'Carnival', 'Pink Ice', 'Susara ' and 'Sylvia' had significantly less leaf blackening with glucose treatments of 4 and 10%. Leaf blackening of 'Sheila', P. cynaroides and P. grandiceps was not significantly reduced by glucose pulsing. P. magnifica showed a small, but significant, reduction in leaf blackening in response to the 3, 6 and 9% treatments after 10 days only, but despite this, leaf blackening was unacceptably high. 'Pink Ice' harvested at the soft tip stage had less leaf blackening than those harvested open or closed. Toxicity symptoms on the leaves, and in some instances flowers, were observed at higher glucose concentrations (8 and 10%) onP. grandiceps, P. cynaroides, 'Cardinal' and 'Sheila'. All glucose treatments resulted in toxicity symptoms on P. magnifica. A decrease in nonstructural carbohydrates post-harvest apparently occurs in all proteas but it appears that only members of the Ligulatae respond to glucose. Glucose pulsing followed by cold storage at 1°C for three weeks in combination with post-storage glucose vase solutions, significantly reduced leaf blackening of some Protea cultivars. Glucose (1 and 2%), with hypochlorite, significantly delayed leaf blackening in 'Cardinal' and 'Sylvia' after seven days. Leaf blackening of 'Brenda', 'Carnival', 'Pink Ice' and 'Susara' was not significantly reduced by the glucose vase solutions. Other disinfectants, in combination with the sugar treatments, need to be evaluated since the hypochlorite treatment had a dehydrating effect on all the cultivars and resulted in increased leaf blackening. Carbohydrate supplementation of protea flowers with glucose, pre and post-storage, will help meet the post-harvest carbohydrate requirements of certain Protea cultivars and species to an extent. Glucose treatments must be seen in conjunction with maintaining the cold chain and when combined with cold chain maintenance, can extend the storage and vase life.
AFRIKAANSE OPSOMMING: Protea snyblomme word wêreldwyd uitgevoer alhoewel die vaasleeftyd van sommige spesies en kultivars beduidend verkort word deur na-oes loof verbruining. Navorsing het koolhidraatverbruik positief gekorreleer met hierdie probleem. Gevolglik is 'n studie gemaak van die koolhidraatstatus van verskeie spesies en kultivars asook die effek van addisionele glukose (voor en na opberging) op loofverbruining. Glukose, fruktose, sukrose en stysel konsentrasies van verskeie Protea spesies en kultivars wat in water gehou is, is bepaal met oes en weer met die eerste tekens van loofverbruining. Al die gemete koolhidraatkonsentrasies het beduidend afgeneem in 'Carnival', 'Pink Ice' en 'Sheila'. In 'Cardinal' het al die koolhidraatkonsentrasies beduidend afgeneem, behalwe vir die sukrosekonsentrasie in die blom. 'Susara' en 'Ivy' het baie hoë begin koolhidraatkonsentrasies in die blare wat beduidend afneem. Die baie hoë inisiële koolhidraatkonsentrasies in die blom van 'Ivy' neem beduidend af met tyd. 'Brenda' verskil van die ander kultivars en spesies deurdat die glukosekonsentrasies toeneem met tyd. Koolhidraatkonsentrasies van die meeste getoetste proteas neem beduidend af vanaf oes totdat die eerste tekens van loofverbruining verskyn. Dit het die afhanklikheid van die blare en blom op die koolhidraatreserwes beklemtoon en daardeur verder die koolhidraatteorie ondersteun. Die blomme is gekarakteriseer deur hoë fruktose- en glukosekonsentrasies en lae sukrosekonsentrasies wanneer dit met die blare vergelyk is.Die hipotese is gestel dat die voorsiening van glukose, vir 'n aantal ure, gekombineerd met koue opberging by 1°C vir drie weke loofverbruining beduidend sal verminder. 'Brenda', 'Cardinal', 'Carnival', 'Pink lee', 'Susara' en 'Sylvia' het beduidend minder loofverbruining met glukose behandelings tussen 4 en 10%. Loofverbruining van 'Sheila', P. cynaroides en P. grandiceps is nie beduidend verminder deur glukose behandelings nie. P. magnifica het 'n klein, maar beduidende verlaging in loofverbruining getoon met die 3, 6 en 9% behandelings na 10 dae, maar ten spyte hiervan was loofverbruining onaanvaarbaar hoog. 'Pink lee' is geoes by die sagte punt stadium en het minder loofverbruining gehad as blomme wat oop of toe geoes is. Toksisiteitsimptome op die blare, en in sommige gevalle blomme, is waargeneem met hoër glukose konsentrasies (8 en 10%) op P. grandiceps, P. cynaroides, 'Cardinal' en 'Sheila'. Alle glukosebehandelings het toksisiteitsimptome tot gevolg gehad op P. magnifica. 'n Afname in nie-strukturele koolhidrate na oes kom waarskynlik voor in alle proteas maar dit wil voorkom of slegs lede van die Ligulatae positief reageer op glukose. Glukosebehandeling gevolg deur koue opberging by 1°C vir drie weke in kombinasie met na-stoor glukose vaasoplossings het loofverbruining van sommige Protea kultivars beduidend verminder. Glukose (l en 2%), saam met hipoehloriet, het loofverbruining beduidend verminder in 'Cardinal' en 'Sylvia' na sewe dae. Loofverbruining van 'Brenda', 'Carnival', 'Pink lee' en 'Susara' is nie beduidend verminder deur die glukose vaasoplossings nie. Ander ontsmettingsmiddels in kombinasie met die suikerbehandelings moet geëvalueer word aangesien die hipoehlorietbehandeling 'n dehidrerende effek op al die kultivars gehad het en 'n toename in loofverbruining tot gevolg gehad het. Byvoeging van glukose by proteablomme, voor en na opberging, sal tot 'n mate help om in die na-oes koolhidraatbehoeftes van sekere Protea kultivars en spesies te voorsien. Glukosebehandelings moet saam met die beheer van die koueketting gesien word en wanneer gekombineerd met koueketting beheer kan dit opberg en vaasleeftyd verleng.
Greeley, M. "Rice in Bangladesh : Postharvest losses, technology and employment." Thesis, University of Sussex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373146.
Full textPorter, Kerry Louise. "The postharvest physiology of Chinese cabbage cv. 'Yuki' /." Title page, table of contents and abstract only, 2003. http://web4.library.adelaide.edu.au/theses/09PH/09php8441.pdf.
Full textCaussiol, Laure. "Postharvest quality of conventionally and organically grown banana fruit." Thesis, Cranfield University, 2001. http://hdl.handle.net/1826/909.
Full textTaverner, Peter D. "Effects of postharvest oils on arthropod pests of citrus /." Title page, contents and summary only, 1999. http://web4.library.adelaide.edu.au/theses/09PH/09pht233.pdf.
Full textSmyrniotaki, Mari. "Postharvest biochemical and textural characteristics of sh2 sweetcorn cobs." Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/7282.
Full textMarais, Evelyn. "Postharvest manipulation of fruit colour in apples and pears." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51878.
Full textENGLISH ABSTRACT: Red colour development on bi-coloured apples and pears ensures better prices for producers. The use of postharvest irradiation to improve colour has been successful on apples, and the objectives of this thesis were to optimise conditions during irradiation for apples and to evaluate the effects of irradiation on pears. 'Cripp's Pink' apples responded to postharvest irradiation with high-pressure sodium (HPS) lights by developing a red blush, whereas the response to irradiation with UV 8 plus incandescent lights was less effective. '8raeburn' apples held at -0.5°C for 4 or 8 weeks prior to irradiation showed a decrease in hue angle and an increase in anthocyanin concentration after 72 hours of irradiation with HPS lamps. In 'Forelle' pears treated in the same way, neither colour development nor anthocyanin synthesis was affected by irradiation. '8raeburn' and 'Cripp's Pink' apples picked weekly for 5 weeks until the optimum harvest date were irradiated with HPS lights. A significant increase in fruit colour was only measured in mature fruit of both cultivars. 'Cripp's Pink' apples were harvested from two production areas with different microclimates, namely, Ceres and Grabouw, and stored for 0, 2 or 5 days at -0.5 °C before irradiation for 120 hours at either 6°C or 20°C. Fruit from Ceres that were irradiated immediately after harvest developed better colour at 6 °C than at 20°C. The differences between fruit irradiated at the two temperatures were no longer significant after 5 days of cold storage prior to irradiation. Fruit from Grabouw consistently developed better colour when irradiated at 6°C than at 20°C. Colour development slightly after 5 days of cold storage prior to irradiation. In another experiment, fruit from both areas were stored at -0.5°C for 20 days before irradiation at either 6°C or 6/20°C. The fluctuating temperature regime resulted in decreases in hue angle of 70° and 65° for the fruit from Grabouw and Ceres, respectively. The decreases were smaller (±200) when fruit were irradiated at 6°C. The hue angle value of well-coloured 'Cripp's Pink' apples held at 3rC under HPS lights for 144 hours increased from 29.3° to 48.3°, and anthocyanin concentration decreased from 739.9 IJg·g·1to 283.6 IJg·g·1. Control fruit held at the same temperature in the dark did not show any change in hue angle value or anthocyanin concentration. 'Bon Rouge' and 'Red d' Anjou', two full red pear cultivars, irradiated with HPS lights for 72 hours, showed no significant changes in hue angle. 'Forelle' pears, harvested with or without attached leaves, were irradiated with HPS at two temperature regimes, 20°C and 200/6°C. The resulting decreases in hue angle were attributed to yellowing and not red colour formation. In conclusion, the response of apples to postharvest irradiation was affected by maturity and temperature, while pears failed to respond at all.
AFRIKAANSE OPSOMMING: Rooikleurontwikkeling van twee-kleur appels en pere verseker beter pryse vir die produsente. Na-oesbestraling om kleur te verbeter is al suksesvol uitgevoer op appels, en die doelwit van hierdie tesis was om die kondisies vir appels gedurende bestraling te optimaliseer en om die effek van bestraling op pere te evalueer. 'Cripp's Pink' appels het reageer op na-oesbestraling met hoëdruk-natriumligte (HDN) deur 'n rooi blos te ontwikkel, terwyl die reaksie op bestraling met UV-B plus gloeilamplig minder effektief was. 'Braebum' appels opgeberg by -O.5aC vir 4 of 8 weke voor bestraling het 'n afname in die kleurskakeringswaarde getoon, asook 'n toename in antosianienkonsentrasie na 72 uur se bestraling met HDN ligte. 'Forelle' pere wat dieselfde behandeling ontvang het, het geen kleurontwikkeling en geen antosianienontwikkeling getoon na bestraling nie. 'Braebum' en 'Cripp's Pink' appels wat weekliks geoes is vir 5 weke tot die optimum oesdatum is bestraal met HDN ligte. Slegs die volwasse vrugte van beide kultivars het 'n betekenisvolle toename in kleur getoon. 'Cripp's Pink' appels is geoes in twee produksie areas met verskillende mikroklimate, naamlik Ceres en Grabouw. Vrugte is opgeberg vir 0, 2 of 5 dae by -O.5aC voor bestraling vir 120 uur by of 6aC of 20aC. Vrugte van Ceres wat onmiddellik na oes bestraal is het beter kleur ontwikkel by 6aC as by 20aC. Kleurontwikkeling by vrugte bestraal by 6 of 20aC het nie verskil wanneer vrugte vooraf opgeberg was by -~5ac vir 5 dae nie. Vrugte van Grabouw het konstant beter kleur pntwikkel wanneer bestraling by 6°C eerder as 20°C plaasgevind het. In die volgende eksperiment, was beide die vrugte van Ceres en Grabouw vir 20 dae opgeberg by -o.soC voor bestraling by 6°C of 6°/20°C. Die flukturerende temperatuur regime het afnames van 70° en 65° in kleurskakeringswaarde getoon vir die vrugte van Grabouw en Ceres, respektiewelik. Die afname was kleiner (±200)wanneer vrugte by 6°C bestraal is. 'Cripp's Pink' appels wat goed gekleur was en opgeberg is by 3rC terwyl dit blootgestel is aan HDN ligte vir 144 uur, het 'n toename van 29.30 tot 48.3° getoon vir die kleurskakeringswaarde, en antosianienkonsentrasie het afgeneem van 739 I'g.g-1 tot 283.6 I1g.g-1. Die kontrole vrugte opgeberg by dieselfde temperatuur in die donker het geen verandering in beide die kleurskakeringswaarde of die antosianienkonsentrasie getoon nie. 'Bon Rouge' en 'Red d' Anjou', twee volrooi peerkultivars, is bestraal met HDN ligte vir 72 uur en het geen betekenisvolle verandering in kleur getoon nie. 'Forelle' pere, geoes met of sonder 'n aangehegte stingelsegment, is bestraal met HDN ligte by twee verskillende temperatuur regimes, nl. 20°C of 20/6°C. Die afname in kleurskakeringswaarde is aan vergeling toegeskryf eerder as aan rooikleurontwikkeling. Ter opsomming, die reaksie van appels op na-oes bestraling is beïnvloed deur rypheid en temperatuur, terwyl pere geen reaksie getoon het nie.
Donetti, Manuela. "Postharvest biochemical and physiological characterisation of imported avocado fruit." Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/7672.
Full textAnselmo, Francisca Deuzenir Marques. "Quality and melon postharvest conservation Cantaloupe "Torreon" for export." Universidade Federal do CearÃ, 2007. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1507.
Full textAvaliou-se a vida Ãtil pÃs-colheita de melÃes Cantaloupe, hÃbrido âTorreonâ, submetidos à aplicaÃÃo pÃs-colheita de 1-MCP em diferentes concentraÃÃes (0, 300 e 600 ppb) e dois perÃodos distintos de exposiÃÃo ao gÃs (6 e 12 horas), colhidos em dois diferentes estÃdios de maturaÃÃo (50 e 75% de rachadura do pedÃnculo) mantidos em armazenamento refrigerado durante 21 dias e 28 dias, visando exportaÃÃo. Os frutos foram colhidos em fazendas de MossorÃ, RN-Brasil, sendo analisados nos LaboratÃrios de Fisiologia e Tecnologia PÃs-colheita da Embrapa AgroindÃstria Tropical e de Frutos Tropicais do Departamento de Tecnologia de Alimentos da Universidade Federal do CearÃ, em Fortaleza- CE. Para o monitoramento da qualidade dos frutos durante a armazenagem, determinaÃÃes quanto à perda de massa acumulada e firmeza externa e interna foram efetuadas, alÃm de avaliaÃÃo visual de aceitaÃÃo segundo escala de notas; onde se atribui notas relativas à cor externa, firmeza, incidÃncia de podridÃes e aparÃncia geral. Foram realizadas as anÃlises fÃsico-quÃmicas de clorofila total, aÃÃcares solÃveis totais, aÃÃcares redutores, carotenÃides totais, coloraÃÃo da polpa, conteÃdo de sÃlidos solÃveis totais, acidez total (AT) e pH. Segundo a avaliaÃÃo visual, a aplicaÃÃo do 1-MCP retardou a perda de firmeza e de coloraÃÃo verde dos frutos, bem como a incidÃncia de podridÃes. A manutenÃÃo da firmeza foi confirmada atravÃs da analise em texturÃmetro. Frutos tratados com 1-MCP apresentaram maior firmeza do que os frutos controle e esse resultado foi mais efetivo com o aumento da dosagem.
It was evaluated useful life postharvest Cantaloupe melons, hybrid `Torreon', submitted to the application postharvest of 1-MCP at different concentrations (0, 300 and 600 ppb) and two periods of exposition to the gas (6 and 12 hours),harvested in two different stadiums of maturation (50 and 75% stalk abscission layer) kept in storage cooled during 21 days and 28 days, aiming at exportation. The fruits were harvested in farms at MossorÃ, RN-Brazil, being analyzed in the Laboratories of Physiology and Technology Postharvest of the Embrapa Tropical AgroindÃstria and of Tropical Fruits of the Department of Food Technology of the Federal University of the CearÃ, in Fortaleza-CE. For the monitoring of the quality of the fruits during storage, its physical characterization how much to the loss of accumulated mass and external and internal firmness beyond visual evaluation acceptance second scale was made notes; in this scale if external color attributes to relative notes Ã, firmness, incidence of podridÃes and general appearance. Physical chemical analysis were performed of total chlorophyll content, soluble sugars, reducing sugars, totals carotenoids, coloration of the pulp, total soluble solid content, totals acidity (AT) and pH. According to visual evaluation, the application of the 1-MCP delayed the loss of firmne ss and green coloration of the fruits, as well as the incidence of rottenness. The maintenance of the firmness was confirmed through analyzes physical in the device texturometer. Fruits dealt with 1-MCP had presented greater firmness of that the fruits have controlled and this result was more effective with the increase of the dosage.
Bagnato, Annunziata Teresa. "Postharvest improvement of Cavendish banana quality and shelf life /." Title page, table of contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09phb147.pdf.
Full textStephens, Iain Andrew. "Leaf blackening of proteas." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/49768.
Full textENGLISH ABSTRACT: Leaf blackening is a particular problem limiting vase life and marketability of Protea cut flowers. This research investigated suppression of Protea leaf blackening with a specific focus on Protea cv. Sylvia (P. eximia x P. susannae) cut flowers. Leaf blackening decreased significantly with decreasing storage temperatures m 'Sylvia' proteas and this was attributed to lower respiration rate and conservation of carbohydrate. Low storage temperatures were beneficial in short term handling procedures encountered during airfreight. However, use of low temperatures alone during the longer sea freight period was unsatisfactory in either maintaining or extending 'Sylvia' protea vase life. Cooling of 'Sylvia' proteas under vacuum significantly suppressed leaf blackening and was of greater benefit than forced air cooling. Although removal of the uppermost leaves delayed leaf blackening in short term storage no significant benefit was found for longer storage periods. Girdling directly beneath the 'Sylvia' protea flowerhead significantly reduced leaf blackening and in combination with low storage temperatures (O°C) enabled a significant extension in both storage and vase life of 'Sylvia' proteas. 'Sylvia' proteas did not exhibit a climacteric respiration peak during 96 h storage at O°C. Exposure to ethylene did not increase Protea leaf blackening or have a detrimental effect on vase life of either proteas or pincushions evaluated. No beneficial response to sucrose supplementation was found in 'Sylvia' proteas. Analysis of the sugar content of both flowerhead and leaves indicated that glucose supplementation might be of benefit and was investigated. Holding solutions of 2.5 % glucose significantly extended vase life due to a significant reduction in leaf blackening. Vase life was terminated due to flowerhead collapse instead of leaf blackening for the first time in 'Sylvia' protea cut flowers. Vase life was significantly extended by 2:3% glucose pulse solutions and leaf blackening significantly suppressed with increasing glucose pulse concentration. Solution uptake was facilitated by use of high intensity PAR lights in the early morning and was attributed to increased stomata opening and a consequent increase in both transpiration and glucose solution uptake. The faster uptake of glucose solutions in shoots harvested in the afternoon was attributed to higher shoot temperatures and consequent transpiration rate to those harvested in the morning. There was a significant reduction in uptake time with increasing pulse temperature, which enabled vacuum cooling to be performed earlier further benefiting storage and vase life extension. Enclosure of 'Sylvia' proteas in polyethylene (PE) lined cartons did suppress leaf blackening in non-pulsed shoots. However, this had no practical significance on useful vase life, which was terminated at this point due to excessive leaf blackening. Water loss appears to have a minimal influence on 'Sylvia' protea leaf blackening. Shading at four and three weeks prior to harvest coincided with a period of significant flowerhead dry mass increase. It is thought that shading at this point, concurrent with an increased carbohydrate demand by the developing flower head resulted in a temporary limitation in carbohydrate supply resulting in the appearance of preharvest leaf blackening. It would appear that proteas do not store large quantities of carbohydrate. Although accentuating winter light conditions by shading did result in a decrease in carbohydrate content the fact that carbohydrate content was already low precluded shading from having a significant impact on postharvest leaf blackening. The finding that glucose was beneficial in extension of both storage and vase life of 'Sylvia' proteas directed research into its use for other Protea and Leucospermum cut flowers. Significant differences in the response to glucose supplementation were found in both Protea and Leucospermum (pincushions). The significant difference in sensitivity to glucose concentration in 'Pink Ice' proteas (phytotoxic at 2:4%) and 'Susara' proteas (no apparent toxicity), in conjunction with a lack of response in 'Cardinal' proteas, a hybrid from the same parents as 'Sylvia' indicates the need to direct future research to individual cultivars. Glucose supplementation had no beneficial effect on vase life of 'Scarlet Ribbon' and 'Tango' pincushions, whilst significantly extending vase life of 'Cordi', 'Gold Dust', 'High Gold' and 'Succession' pincushions.
AFRIKAANSE OPSOMMING: Blaarverswarting is 'n spesifieke probleem wat die vaasleeftyd en die bemarkbaarheid van Protea snyblomme beperk. In hierdie navorsing is ondersoek ingestel na die onderdrukking van Protea blaarverswarting met spesifieke fokus op die snyblomme van die kv. Sylvia (P. eximia x P. susannae). Die voorkoms van blaarverswarting by 'Sylvia' het merkbaar afgeneem tydens die verlaging van bergingstemperature. Hierdie afname is toegeskryf aan 'n laer respirasietempo en die behoud van koolhidrate. Lae bergingstemperature in die korttermyn hantering van die produk tydens lugvrag was voordelig. Die gebruik van lae temperature, slegs tydens die langer verskeepingsperiode, was egter onbevredigend vir vaasleeftyd verlenging en onderhoud van 'Sylvia' protea. Die afkoeling van 'Sylvia' proteas onder vakuum het blaarverswarting in 'n groot mate onderdruk en het beter resultate gelewer as geforseerde lugverkoeling. Alhoewel die verwydering van die heel boonste blare blaarverswarting by korttermynopberging vertraag het, het dit geen merkbare voordele vir langer bergingsperiodes ingehou nie. Ringelering direk onder die blomkop van die 'Sylvia' protea het blaarverswarting aansienlik verminder, en saam met lae bergingstemperature (O°C) het dit 'n merkbare verlenging in beide die bergingstyd en die vaasleeftyd van 'Sylvia' proteas teweeggebring. 'Sylvia' proteas het geen klimakteriese respirasiekruin tydens 'n bergingsperiode van 96 uur teen O°C getoon nie. Blootstelling aan etileen het nie die Protea blaarverswarting laat toeneem of 'n nadelige effek op die vaasleeftyd van die proteas of speldekussings wat geevalueer is, gehad nie. Geen voordelige reaksie op sukrose-byvoeging is in 'Sylvia' proteas gevind nie. 'n Analise van die suikerinhoud van beide die blomkoppe en die blare het aangetoon dat 'n glukose-byvoeging moontlik voordelig kon wees, en hierdie aspek is ondersoek. Met stooroplossings van 2,5 % glukose is die vaasleeftyd aansienlik verleng omdat daar 'n merkbare afname in blaarverswarting was. Vir die eerste keer in die geval van die 'Sylvia' protea, het die vaasleeftyd van die snyblomrne tot 'n einde gekom omdat die blornkoppe uitmekaar gebreek het en nie omdat blaarverswarting ingetree het nie. Die vaasleeftyd is aansienlik verleng met ~ 3% glukose-pulsoplossings, en blaarverswarting is merkbaar onderdruk met die verhoging van hierdie oplossings se glukosekonsentrasie. Die opname van die oplossings is gefasiliteer deur hoe intensiteit PAR (fotosinteties-aktiewe radiasie) ligte vroeg in die oggend, en is toegeskryf daaraan dat meer huidmondjies oopgegaan het. Dit het gelei tot 'n toename in transpirasie en 'n toename in die opname van die glukose-oplossing. Die feit dat glukose-oplossings vinniger opgeneem is deur lote wat in die middag geoes is, is toegeskryf daaraan dat loottemperature dan hoer is as soggens en gevolglik lei tot 'n vinniger transpirasietempo. Daar was 'n merkbare afname in die opnametyd wanneer die temperatuur van die pulsoplossings verhoog is. Vakuumafkoeling kon dus vroeer toegepas word, wat 'n verlenging in bergingstyd en vaasleeftyd tot gevolg gehad het. Verpakking van 'Sylvia' proteas in kartonne wat met poli-etileen uitgevoer is, het blaarverswarting van lote wat nie aan pulsering onderwerp is nie, onderdruk. Hierdie maatreel het egter geen praktiese waarde met betrekking tot vaasleeftyd nie; die vaasleeftyd het tot 'n einde gekom as gevolg van omvangryke blaarverswarting. Dit lyk asof waterverlies weinig invloed het op die blaarverswarting van' Sylvia' proteas. Die vermoede bestaan dat lae koolhidraatvlakke proteas ontvanklik maak vir blaarverswarting. Alhoewel die beklemtoning van winterligtoestande deur beskaduwing gelei het tot 'n afname in koolhidraatinhoud, was hierdie inhoud reeds laag en blaarverswarting na die oes is nie beinvloed nie. Beskaduwing tydens die vier en drie weke voor oestyd het saamgeval met 'n tydperk van aansienlike toename in die droe massa van die blomkop. Die vermoede bestaan dat beskaduwing tydens hierdie fase, saam met die toename in die ontwikkelende blomkop se behoefte aan koolhidrate, aanleiding gegee het tot 'n tydelike beperking in koolhidraatvoorraad wat die voorkoms van blaarverswarting voor die oes tot gevolg gehad het. Die bevinding dat glukose voordelig is vir die verlenging van beide die bergingstyd en die vaasleeftyd van 'Sylvia' proteas het die navorsing gerig om ook ondersoek in te stel na die gebruik daarvan vir ander Protea en Leucospermum snyblomme. Merkbare veranderinge is gevind in die reaksie op glukosebyvoegings in beide Protea en Leucospermum (speldekussings). Die opmerklike verskil in sensitiwiteit vir glukosekonsentrasie in 'Pink Ice' proteas (fitotoksies by ~ 4%) en 'Susara' proteas (geen klaarblyklike toksisiteit), saam met 'n gebrek aan reaksie by 'Cardinal' proteas, 'n hibried van dieselfde ouers as 'Sylvia', dui aan dat verdere navorsing op individuele kultivars toegespits sal rnoet word. Glukosebyvoegings het geen voordelige uitwerking op die vaasleeftyd van 'Scarlet Ribbon' en 'Tango' speldekussings gehad nie, terwyl dit die vaasleeftyd van 'Cordi', 'Gold Dust', 'High Gold' en 'Succession' speldekussingkultivars merkbaar verIeng het.
Chen, Wei-Chun. "EFFECTIVENESS OF POSTHARVEST SANITATION TREATMENTS ON MICROBIAL LOAD OF BLUEBERRIES." MSSTATE, 2008. http://sun.library.msstate.edu/ETD-db/theses/available/etd-10172008-084244/.
Full textDelaporte, Kate Louise. "Eucalypts for ornamental horticulture : selection, interspecific hybridisation and postharvest testing /." Title page, contents and abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09AHP/09hpd338.pdf.
Full textTasneem, Azra. "Postharvest treatments to reduce chilling injury symptoms in stored mangoes." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81444.
Full textExperiments were performed to assess and compare the potential of the above-mentioned postharvest treatments to reduce the CI symptoms on mango cv. Kent. The obtained results indicated that MJ- and DPA-treatments gave significantly greater percentage of marketable fruits.
Experiments were also conducted with mangoes cv. Tommy Atkins treated with MJ and DPA before storing at low temperatures (1, 4, 7 and 10°C). The chemical treatments were successful at reducing CI symptoms of mangoes. Fruit decay was reduced during subsequent ripening. MJ-treated fruits had lower mass loss and higher total soluble solids (TSS) than the control treatment. The overall quality of MJ- and DPA-treated fruits was good with lower surface pitting and scalding compared with the control treatment. The best results were obtained at storage temperatures of 7 and 10°C. Both MJ and DPA postharvest treatments can reduce CI symptoms in mangoes cvs. Kent and Tommy Atkins when the mangoes are stored at below critical temperature.
Van, Wyk Angelique A. (Angelique Ann). "Time-temperature interaction on postharvest rind colour development of Citrus." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16456.
Full textENGLISH ABSTRACT: Rind colour is one of the most important external quality characteristics of citrus fruit and plays an important role in purchasing decisions by consumers. Consumers perceive brightlycoloured fruit to be sweet and mature, whereas citrus with a green rind is perceived to be sour and immature. However, there is a poor correlation between rind colour and internal quality, contradicting what is generally assumed by the fruit-buying public. In general, a bright orange rind colour improves consumer acceptance. Thus, it is important to ensure that the rind of citrus fruit is well-coloured on arrival at the market. Various pre-harvest cultural practices and postharvest techniques can be applied to improve rind colour. Degreening with ethylene gas is the most commonly used postharvest technology to improve rind colour, but has various negative side-effects. Degreened fruit are more prone to decay, have rinds which appear dull and flaccid, have been reported to develop off-flavours and have a shorter shelf-life period. Therefore, it is necessary to find alternatives to ethylene degreening and to extend shelf-life of citrus fruit. Under normal orchard conditions, rind colour development is associated with low night temperatures, usually experienced during autumn or following the passing of a cold front. To simulate cold front conditions, a hydrocooler and cold room were used to rapidly drop fruit temperature to 4 ºC for 6 hours, and then fruit were incubated at 20 to 22 ºC for 72 hours. This “cold shock” treatment of ‘Nules Clementine’ mandarin improved rind colour to a level similar to that of degreened fruit in the 2002 season due to a decrease in chlorophyll content and increase in carotenoid content. However, this result could not be repeated. Storage temperature is one of the most important postharvest factors affecting rind colour. Citrus fruit shipped to export markets requiring low temperatures (-0.6 ºC) for pest disinfestations purposes have been reported to arrive with poor rind colour. Shipping under low temperatures results in poor rind colour of fruit on arrival in the market. To comply with the USA’s phytosanitary requirement for imported citrus, fruit is held at -0.6 ºC for a minimum of 22 days. The effect of shipping at various temperatures (-0.6 ºC or 4.5 ºC), durations and the influence of initial rind colour, “orange” or “yellow”, on fruit colour upon arrival in the market was evaluated. Fruit shipped at a higher temperature (4.5 ºC) had a marginally better rind colour than fruit shipped at -0.6 ºC. The perceived loss of rind colour following shipping at sub-zero temperatures is probably due to carotenoid degradation. Therefore, initial rind colour plays a critical role in final product quality. Depending on market destination and shipping temperature, pale-coloured fruit should not be packed for markets sensitive to rind colour. Holding temperature after shipping can be effectively used to improve the rind colour of fruit arriving in the market with undesirable rind colour. An intermediate holding temperature of between 11 and 15 ºC resulted in the greatest improvement in rind colour after 2 weeks. A high holding temperature (20 ºC) caused colour degradation, whereas a low holding temperature (4.5 ºC) resulted in the maintenance of rind colour. By selecting the correct holding temperature, even after shipping at sub-zero temperatures, final colour can be improved.
AFRIKAANSE OPSOMMING: Tyd-temperatuur interaksie op na-oes skilkleur ontwikkeling by sitrus Skilkleur is een van die belangrikste eksterne kwaliteitseienskappe van die sitrusvrug en spëel ʼn belangrikke rol in wat verbruikers koop. Verbruikers verwag dat heldergekleurde vrugte soet en ryp sal wees, terwyl sitrus met ʼn groen skil geassosieer word met onrypheid en ʼn suur smaak. In teenstelling hiermee is daar egter ʼn swak korrelasie tussen skilkleur en interne kwaliteit. Aangesien ʼn heldergekleurde oranje skil verbruikersaanvaarding verbeter, is dit dus belangrik om te verseker dat die sitrusvrug ʼn goeie skilkleur het teen die tyd wat dit die mark bereik. Verskeie voor-oes bestuurspraktyke en na-oes tegnieke kan toegepas word om die skilkleur te verbeter. Ontgroening met etileen gas is die tegnologie wat mees algemeen gebruik word om skilkleur na oes te verbeter, maar dit het egter verskeie newe effekte tot gevolg. Ontgroende vrugte is meer vatbaar vir bederf en verwelkde skille met ʼn dowwe voorkoms. Afsmaake kan voorkom en ʼn verkorte rakleeftyd is al gerapporteer. Dit is dus noodsaaklik om ʼn alternatief vir etileen ontgroening te ontwikkel en die rakleeftyd van sitrusvrugte te verleng. Onder normale boordomstandighede word skilkleur ontwikkeling geassosieer met lae nag temperature wat gewoonlik in die herfs of na ʼn kouefront ondervind word. Om soortgelyke omstandighede na te boots, was ʼn “hydrocooler” en koelkamers gebruik om die temperatuur vinnig te laat daal tot by 4 °C en dit vir 6 uur daar te hou. Die vrugte was dan by 20 tot 22 °C geinkubeer vir 72 uur. Hierdie “koueskok” behandeling van ‘Nules Clementine’ mandaryn het skilkleur verbeter tot ʼn vlak vergelykbaar met ontgroende vrugte in die 2002 seisoen wat ontstaan het weens ʼn verlaging in chlorofil en ʼn toename in die karotinoïed inhoud van die skil. Opbergingstemperatuur is een van die belangrikste na-oes faktore wat skilkleur beinvloed. Sitrusvrugte wat verskeep word na uitvoermarkte wat lae temperature (-0.6 °C) vir disinfestasie vereis arriveer soms by die mark met ʼn swak skilkleur. Om die fitosanitêre vereistes vir die invoer van sitrus deur die VSA na tekom, was vrugte vir ʼn minimum van 22 dae by -0.6 °C gehou. Die effek van verskeping by verskeie temperature (-0.6 °C of 4.5 °C), tydperke en die invloed van aanvanklike skilkleur, “oranje” of “geel” was geevalueer by aankoms in die mark. Vrugte wat by hoër temperature (4.5 °C) verskeep was het ʼn effens beter skilkleur as vrugte by -0.6 °C getoon. Die verlies in skilkleur wat waargeneem word na verskeping onder vriespunt kan moontlik toegeskryf word aan karotenoiëd afbraak. Daarom speel aanvanklike skilkleur ʼn kritieke rol in finale produk kwaliteit. Die finale mark bestemming en verskepingstemperatuur sal bepaal of swakgekleurde vrugte verpak kan word. Opbergingstemperatuur na verskeping kan effektief gebruik word om die skilkleur van vrugte wat swak gekleur was met aankoms by die mark te verbeter. Matige temperature tussen 11 en 15 °C het na 2 weke die beste verbetering in skilkleur gelewer. Hoër temperature (20 °C) het skilkleur nadelig beinvloed, terwyl lae temperature skilkleur behou het. Deur die korrekte temperatuur te kies, selfs na verskeping by temperature onder vriespunt, kan uiteindelike skilkleur steeds verbeter word.
Novillo, Borrás Pedro. "HARVEST AND POSTHARVEST QUALITY OF PERSIMMON FRUIT:PHYSICOCHEMICAL AND NUTRITIONAL ASPECTS." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/58270.
Full text[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
Siddique, Shaikh. "Cold plasma inhibits growth and germination of avocado postharvest pathogens." Thesis, Siddique, Shaikh (2018) Cold plasma inhibits growth and germination of avocado postharvest pathogens. PhD thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/50154/.
Full textNelson, Jacob A. "Postharvest Degradation of Microalgae: Effect of Temperature and Water Activity." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4458.
Full textRAJESTARY, RAZIEH. "Management of postharvest decay of strawberies by using natural compounds." Doctoral thesis, Università Politecnica delle Marche, 2020. http://hdl.handle.net/11566/274578.
Full textPostharvest losses of fruit and vegetables amounted up to half of the production through the chain from the field to the customer table. Therefore, the investigations on sustainable approaches to minimize postharvest decay and food losses would be the goal of research in the next years. In order to reduce the presence of pathogens, the application of chemical fungicides was used, however, due to potential environmental and health issues, this practice need to be evaluated carefully. Alternative approaches such as the use of edible coatings, essential oils (EOs), salts, and natural compounds (plant extracts) were emerging technologies to manage postharvest decay of fresh fruit. The aim of this work was to investigate the effectiveness of natural compounds known as plant defense inducers on postharvest decay. In the first work, we used the meta-analyses approach to investigate the potential effect of 1% chitosan on postharvest fungal pathogens, summarizing 13 years of data related to disease incidence, mycelium growth of Botrytis cinerea, Rhizopus stolonifer, Penicillium spp., Colletotrichum spp., Alternaria spp. and the activity of enzymes linked to host defense mechanisms. This meta-analysis confirmed chitosan antimicrobial and eliciting activity. The other works were focused on testing, the effectiveness of the control of postharvest decay of strawberry following the application of commercial compounds, mainly chitosan-based coating and plants essential oils. The preharvest application of (‘Chito Plant powder’,’KiForce’ ‘Prev-Am Plus’ compounds) and postharvest application of (‘Chito Plant powder’, ‘Chito Plant solution’, ‘Kaitosol’, ‘OII-YS’, ‘MeJA’, ‘3 Logy’, ‘DF-100 Forte’, ‘Prev-Am Plus’, ‘Humic acid’ compounds and bergamot, rosemary, mentha EOs, combine under hypobaric environment at 50 kPa, were tested. Gray mold, caused by B. cinerea, and Rhizopus rot, caused by R. stolonifer, were monitored after incubating fruits at 20±1 °C or 7 day storage at 4±1 °C following two days shelf life at 20±1 °C. Besides, the changes of qualitative parameters in preharvest application was analyzed. Our results showed the effectiveness of the different compounds on strawberry decay, however, among the chitosan-based coating ‘Chito Plant powder’ was the most effective compound at both pre and postharvest application at cold storage condition and in maintaining fruit quality. Rosemary and mentha EOs, combine under hypobaric environment, and sweet orange EOs with commercial formulation Prev-Am Plus following grapefruit seed extract EOs with commercial formulation DF-100Forte were the most effective compounds against gray mold infection at room temperature. Our results showed that the application of these innovative compounds was a suitable approach for strawberry postharvest decay management.
Bokshi, A. I. "POSTHARVEST DISEASE CONTROL OF MELONS USING SYSTEMIC ACQUIRED RESISTANCE AND OTHER." Thesis, The University of Sydney, 2008. http://hdl.handle.net/2123/3938.
Full textBokshi, A. I. "POSTHARVEST DISEASE CONTROL OF MELONS USING SYSTEMIC ACQUIRED RESISTANCE AND OTHER." University of Sydney, 2008. http://hdl.handle.net/2123/3938.
Full textThe goal of this research was to test commercially viable alternative methods to fungicides for controlling storage diseases of melons that are safe for human health and the environment. Initially, experiments were conducted on melons to develop a protocol for optimum conditions of disease development during storage for different pathogens and for different stages of fruit maturity. For all pathogens tested, the study found that humidity greater than 90% and temperatures above 20° C support infection and rapid growth of disease. Differences in the rate of infection and extent of disease development after the inoculation of different storage pathogens was observed between rockmelon and honeydew melons, indicating differences in host pathogen interactions. Among the tested pathogens, Alternaria spp. was the least aggressive in infection and disease severity, growing considerably slower than Fusarium acuminatum which was moderately aggressive and Rhizopus spp. which was very aggressive, in comparison. Green half-slip melons showed greater resistance to pathogen attack than green full-slip fruit, while yellow full-slip melons were highly susceptible to pathogen attack. Therefore, the laboratory experiments for postharvest treatments of rockmelons were performed using green full-slip fruit challenged with F. acuminatum. Evaluation of physical and safe chemical methods of postharvest treatment to control postharvest diseases of melons showed that none of the treatments alone was as effective as the commercially available fungicide. Hot water solutions of safe compounds considerably increase their efficacy against postharvest rots, however, symptoms of phytotoxicity on the rind after dipping made their use unacceptable. Iodine was the only safe chemical tested which did not cause any phytotoxicity on melons. When combined with hot water, iodine showed the best control of storage rots and was as good as the fungicides carbendazim or guazatine. Hot water iodine dipping of fruit also delayed ripening and fruit were firmer during storage for a longer period of time. Systemic acquired resistance (SAR) was evaluated as a method of controlling powdery mildew in glasshouse grown rockmelon seedlings by treating with the activators 2,6-dichloroisonicotinic acid (INA) or benzothiadiazole (BTH) or water. Increased resistance due to application of INA or BTH, was observed by the reduction of powdery mildew on pre-inoculated detached leaves and also on intact leaves from natural infections. Heightened resistance due to spraying with elicitors of SAR, was further evident by the increased activities of the pathogenesis related proteins (PR proteins), peroxidase and accumulation of phenolics or antifungal compounds during and after challenge inoculation. Field grown rockmelons were treated with INA or BTH or BABA (β-aminobutyric acid) or water at various stages of plant growth and evaluated for increased resistance against pre and postharvest diseases. Both powdery mildew and downy mildew were significantly less on the SAR elicitor treated plants. Preharvest treatment with SAR elicitors also reduced storage diseases of the harvested rockmelon fruit. The reduction in postharvest disease was similar whether plants were treated once, three weeks before harvest, or given four sprays during the growing season beginning at anthesis. A further postharvest dip with 500 ppm of guazatine gave substantial reduction of storage rots of melons. Enhanced activities of chitinase and peroxidase, two major PR-proteins, compared to the control, indicated induction of defence had occurred in the foliage and fruit as a result of SAR. Over the course of four field and one glasshouse experiments slight phytotoxicity was observed in plants frequently sprayed with INA or BTH, but no phytotoxicity was seen after a single spray during the late stages of fruit development. The combination of SAR elicitor treatment and use of a safe postharvest dip provided substantial control of storage rots of rockmelons. The best treatment for control of storage rots involved application of BTH (50 ppm) two weeks before harvest, combined with a hot iodine dip (55° C) of fruit, achieving equivalent or better disease control than use of guazatine fungicide dip.
Valentyn, Aatika. "Orthodox and alternative strategies to control postharvest decay in table grapes." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/351.
Full textBahuguna, Devesh. "Postharvest windthrow and recruitment of large woody debris in riparian buffers." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/3326.
Full textThanaraj, Thiruchelvam. "Understanding the changes in Sri Lankan mango fruits during postharvest ripening." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/7795.
Full textMagwaza, Lembe Samukelo. "Non-destructive prediction and monitoring of postharvest quality of citrus fruit." Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85578.
Full textENGLISH ABSTRACT: The aim of this study was to develop non-destructive methods to predict external and internal quality of citrus fruit. A critical review of the literature identified presymptomatic biochemical markers associated with non-chilling rind physiological disorders. The prospects for the use of visible to near infrared spectroscopy (Vis/NIRS) as non-destructive technology to sort affected fruit were also reviewed. Initial studies were conducted to determine the optimum condition for NIRS measurements and to evaluate the accuracy of this technique and associated chemometric analysis. It was found that the emission head spectroscopy in diffuse reflectance mode could predict fruit mass, colour index, total soluble solids, and vitamin C with high accuracy. Vis/NIRS was used to predict postharvest rind physico-chemical properties related to rind quality and susceptibility of ‘Nules Clementine’ to RBD. Partial least squares (PLS) statistics demonstrated that rind colour index, dry matter (DM) content, total carbohydrates, and water loss were predicted accurately. Chemometric analysis showed that optimal PLS model performances for DM, sucrose, glucose, and fructose were obtained using models based on multiple scatter correction (MSC) spectral pre-processing. The critical step in evaluating the feasibility of Vis/NIRS was to test the robustness of the calibration models across orchards from four growing regions in South Africa over two seasons. Studies on the effects of microclimatic conditions predisposing fruit to RBD showed that fruit inside the canopy, especially artificially bagged fruit, had lower DM, higher mass loss, and were more susceptible to RBD. The study suggested that variations in microclimatic conditions between seasons, as well as within the tree canopy, affect the biochemical profile of the rind, which in turn influences fruit response to postharvest stresses associated with senescence and susceptibility to RBD. Principal component analysis (PCA) and PLS discriminant analysis (PLS-DA) models were applied to distinguish between fruit from respectively, inside and outside tree canopy, using Vis/NIRS signal, suggesting the possibility of using this technology to discriminate between fruit based on their susceptibility to RBD. Results from the application of optical coherence tomography (OCT), a novel non-destructive technology for imaging histological changes in biological tissues, showed promise as a potential technique for immediate, real-time acquisition of images of rind anatomical features of citrus fruit. The study also demonstrated the potential of Vis/NIRS as a non-destructive tool for sorting citrus fruit based on external and internal quality.
AFRIKAANSE OPSOMMING: Die studie het ten doel gestaan om nie-destruktiewe meeting metodes te toets en ontwikkel wat die interne en eksterne-kwaliteit van sitrusvrugte kan voorspel. In ʼn litratuuroorsig is biochemies verandering in die skil en wat geassosieer word met die ontwikkeling van fisiologies skildefekte geïdentifiseer, asook is die moontlikheid ondersoek om Naby Infrarooi spektroskopie (NIRS) as ‘n nie-destruktiewe tegnologie te gebruik om vrugte te sorteer. Eerstens was die optimale toestande waarby NIRS meetings van sitrusvrugte geneem moet word asook die akkuraatheid van die toerusting en chemometrika data-ontleding beproef. Daar is gevind dat die uitstralings-kop spektrofotometer in diffusie-weerkaatsings modus vrugmassa, skilkleur, totale opgeloste stowwe asook vitamien C akkuraat kan voorspel. Daarna van NIRS gebruik om na-oes fisies-chemiese eienskappe wat verband hou met skilkwaliteit en vatbaarheid vir skilafbraak van ‘Nules Clementine’ mandaryn. Deur gebruik te maak van “Partial least squares” (PLS) statistieke was gedemonstreer dat die skilkleur, droë massa (DM), totale koolhidrate en waterverlies akkuraat voorspel kon word. Chemometriese analises het ook getoon dat optimale PLS modelle vir DM, sukrose, glukose en fruktose verkry kan word deur modelle te skep wat gebaseer is op “Multiple scatter correction” (MSC) spektrale voor-verwerking. ʼn Belangrike stap in die ontwikkeling van NIRS gebaseerde indeling is om die robuustheid van die kalibrasiemodelle te toets en was gedoen deur vrugte te meet en sorteer van vier boorde en oor twee seisoene. ʼn Verder eksperiment om die impak van mikroklimaat op die skil se vatbaarheid vir fisiologiese defekte te ontwikkel het getoon dat vrugte wat binne in die blaardak ontwikkel (lae vlakke van sonlig) ʼn laer DM, hoër gewigsverlies het en was ook meer vatbaar vir skilafbraak. Die resultate dui daarop dat verskille in mikroklimaat oor die seisoen asook in die blaardak die skil se biochemiese profiel beïnvloed, wat lei tot ʼn negatiewe reaksie op na-oes stres en verhoogde voorkoms van fisiologiese skilafbraak. Die ontwikkelde “Principal component analysis” (PCA) en PLS-diskriminant analise modelle was daarna suksesvol toegepas om vrugte te skei na NIRS meetings, op die basis van vrugpossies in die blaardak. Nuwe, nie-destruktiewe tegniek, nl. “Optical coherence tomography” (OCT) was suksesvol getoets as manier om ʼn fotografiese beeld te skep van histologiese veranderinge in die skil. Die resultate dui op die potensiaal van die onontginde tegnologie om intak biologiese-materiaal te analiseer. Hierdie studie het getoon dat daar wesenlike potensiaal is om NIRS verder te ontwikkel tot ʼn tegnologie wat gebruik kan word om vrugte te sorteer gebaseer op eksterne (skil) asook interne (pulp) eienskappe
AraÃjo, Karina CrisÃstomo. "Postharvest conservation Lippia sidoides Cham and Alpinia zerumbet for family agriculture." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=10376.
Full textThere is a large concentration of plants with medicinal potential in the Caatinga are widely incorporated in folk medicine for the local community. This region holds vast natural pharmacopoeia based on empirical knowledge. For small farmers in this region the commercial production of medicinal plants is an alternative economic interest, whose production can be based on agroecological production system grounded in sustainability, to reduce the risk of species extinction pharmacological important that the system of extractive production imposes. Thus, the aim of this work was to evaluate the influence of storage time and different packaging on postharvest pepper and rosemary colony seeking knowledge of methodologies accessible to family farming. The experiments were conducted at the Experimental Farm Curu Valley (FEVC) at Pentecost - Ce, using plant species colony pepper and rosemary. Initially, seedlings were made from arrays of proven genetic origin, belonging to the Garden of Medicinal Plants of the Experimental Farm Curu Valley. After six months of seedling transplanting the plant materia l was collected manually with the help of pruning shears at eight o'clock in the morning, then was weighed and washed in a solution consisting of sodium hypochlorite and water in proportion to 200 ppm, and put to dry the shadow on the screen bottom trays to increase air circulation, allowing a uniform drying. The trays were placed in natural hair, remained for three days. The plant material was harvested rosemary pepper consists of branches with leaves and after drying were separated from the branches. But the plant material consisted only of the colony of sheets after drying were ground to facilitate the packaging procedure. After drying the material was packaged and stored in an appropriate room, accommodated on shelves and subjected to temperature and hum idity. Every three months were performed extractions of essential oil as well as the quantification of the moisture content. The experiment was conducted in a completely randomized following a 3x4 factorial design consisting of three types of packaging (paper, plastic and plastic + paper) and storage period (0, 3, 6 and 9 months). The variables studied were yield of essential oil and moisture content. It was found that for pepper rosemary plastic casing provided better preservation of essential oil content of the plant material, about 2 mL more than the other two packages tested, and can be stored for a period of three months. To the colony, the plastic was crucial to the conservation of the essential oil of the material, the plant material can be stored for up to nine months without excessive losses in oil revenue. The behavior of the variable moisture content was similar for both materials, being observed a reduction in moisture content throughout the storage period.
Bordoh, Paa Kwesi. "Integrated postharvest management of anthracnose in dragon fruits using plant extracts." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/48293/.
Full textMontesinos, Herrero Clara Isabel. "Evaluation of alternatives to synthetic fungicides to control citrus postharvest diseases." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/63662.
Full text[ES] Los cítricos (Citrus spp. fam. Rutaceae) son la fruta más consumida a nivel mundial y se cultivan en más de un centenar de países. Durante el manejo en poscosecha, la mayor parte de las pérdidas se deben a enfermedades fúngicas, que durante décadas se han controlado mediante tratamientos con fungicidas de síntesis. Sin embargo, su uso está continuamente más restringido por parte de los distribuidores y cadenas de supermercados, que reducen el Límite Máximo de Residuos (LMR) a un tercio del establecido o incluso prohíben el uso de ciertos fungicidas. Esto ha provocado la pérdida de eficacia de los tratamientos y el desarrollo de cepas de patógenos resistentes a los fungicidas. Se necesitan pues alternativas para sustituir o combinar con el uso de fungicidas de síntesis. El objetivo de este trabajo fue evaluar tratamientos alternativos contra las podredumbres verde y azul, causadas por Penicillium digitatum (Pers.: Fr.) Sacc. y Penicillium italicum Wehmer, respectivamente. Aditivos alimentarios y sustancias GRAS se probaron en test in vivo preliminaries contra los mohos verde y azul. El benzoato sódico (BS; Capítulo 1) y el sorbato potásico (SP; Capítulo 2) fueron los más eficaces. Baños de 60 s en 3% (p/v) BS sobre 50°C redujeron en un 90% la incidencia de las podredumbres verde y azul en naranjas 'Valencia Late' tras 7 días a 20°C. Estos tratamientos fueron también efectivos en naranjas 'Lanelate', limones 'Fino' y mandarinas híbridas 'Ortanique', pero no en mandarinas 'Clemenules'. La combinación de baños calientes de BS con dosis bajas de imazalil (IMZ) fueron sinérgicas. Un nuevo método colorimétrico que empleó la extracción del SP de la fruta macerada, seguido de una reacción con ácido 2-tiobabitúrico (Capítulo 3) mostró que en naranjas tratadas con SP almacenadas a 15°C, los residuos descendieron rápidamente al inicio y lentamente más tarde, hasta que dejaron de descender tras 6 días. Un doble aclarado rápido con agua corriente inmediatamente después de la inmersión de limones en SP al 2% (p/v), eliminó más del 90% del residuo de SP. Los choques gaseosos a 33ºC y 15kPa CO2 durante 24 h o 30 kPa O2 durante 48 h controlaron de manera eficaz las podredumbres verde y azul tras 7 días de incubación a 20ºC, pero el control de las dos podredumbres descendió tras 15 días (Capítulo 4). En almacenamiento en frío, tras 14, 28 y 42 días, la incidencia de moho verde en mandarinas 'Clemenules' y 'Ortanique' tratadas con baños con SP y 30kPa O2 durante 48h se redujo en un 100, 96 y 68%, y 100, 97 y 79%, respectivamente. De nuevo, una fuerte sinergia se observó entre los tratamientos (Capítulo 5). Las podredumbres verde y azul se controlaron eficazmente mediante la fumigación de limones y naranjas durante 6 h a 22ºC con dos dosis de 3000 ¿L L-1 amoniaco, inyectadas al inicio del tratamiento y 2 h después (Capítulo 6). El tratamiento con amoniaco controló una cepa de P. digitatum resistente a IMZ. Cuando la fruta se bañó en 10 o 30 mg L-1 IMZ (un 10% de la dosis comercial) antes de la fumigación con amoniaco, una sola aplicación con 1500 ¿L L-1 amoniaco fue suficiente para controlar las dos podredumbres, y el incremento en la eficacia fue aditivo o sinérgico. Todos estos tratamientos, a diferentes niveles, podrían sustituir a los fungicidas de síntesis o aumentar la eficacia de los tratamientos con IMZ en el manejo poscosecha de los cítricos. El desarrollo de las podredumbres verde y azul en las especies y variedades de cítricos más importantes comercialmente se evaluó durante cuatro campañas consecutivas y se relacionó con los parámetros de calidad de la fruta (Capítulo 7). La susceptibilidad de los cultivares en orden creciente fue Nova, Sanguinelli, Ortanique, Lanelate, Navelate, Fortune, Clemenules, Valencia, W. Navel, Oronules, Clemenpons, Marisol, Salustiana, Hernandina, y Nadorcott. Las características de la corteza fueron los parámetros de calidad
[CAT] Els cítrics (Citrus spp. fam. Rutaceae) son la fruita més consumida a nivell mundial i es cultiven en un centenar de països. Durant la poscollita, la major part de les pèrdues es deuen a malalties fúngiques, que durant dècades s'han controlat mitjançant tractaments amb fungicides de síntesi. No obstant, l'ús d'aquestes pràctiques està contínuament més restringit per part dels distribuïdors y cadenes de supermercats, que redueixen el Límit Màxim de Residus (LMR) a un terç del permès per la legislació o inclús prohibeixen l'ús d'alguns fungicides. Açò ha provocat la minora de l'eficàcia dels tractaments poscollita i el desenvolupament de soques dels patògens resistents als fungicides. Es necessari per lo tant trobar i implementar alternatives per a substituir o combinar l'ús de fungicides de síntesi. L'objectiu d'aquest treball ha sigut avaluar tractaments alternatius contra les podridures verda i blava, causades per Penicillium digitatum (Pers.: Fr.) Sacc. i Penicillium italicum Wehmer, respectivament. Additius alimentaris i substàncies GRAS es provaren en test in vivo preliminars contra les podridures verda i blava. El benzoat sòdic (BS; Capítol 1) i el sorbat potàsic (SP; Capítol 2) foren els més eficaços. Solucions calentes de BS combinades amb baixes dosis d'imazalil (IMZ) foren sinèrgiques. Esta combinació va reduir l'incidència de les podridures verda i blava en quasi el 100% en taronges 'Valencia Late' després de 8 setmanes a 5°C i 7 dies a 20°C. En assajos semicomercials mandarines 'Marisol', la combinació SP+IMZ a 20°C va permetre una baixada significativa de la dosis de IMZ sense perdre eficàcia contra la podridura verda. Un nou mètode colorimètric que inclou l'extracció del SP de la fruita macerada, seguit d'una reacció amb àcid 2-tiobabitúric (Capítol 3) mostrà que en taronges tractades amb SP conservades a 15°C, els residus descendiren ràpidament al inici i lentament mes tard, fins que deixaren de descendir després de 6 dies. Un doble rentat ràpid amb aigua corrent immediatament després de d'immersió de llimones en SP al 2% (p/v), eliminà més del 90% del residu de SP. Els xocs gasosos a 33ºC i 15kPa CO2 durant 24 h o 30 kPa O2 durant 48 h controlaren de manera eficaç les podridures verda i blava després de 7 dies d'incubació a 20ºC, però el control de les dos podridures descendí després de 15 dies (Capítol 4). La combinació de banys amb SP i xocs gasosos mostrà un efecte sinèrgic, que mantingué l'eficàcia dels tractaments combinats durant 15 dies. En conservacions en fred, després de 14, 28 i 42 dies, d'incidència de podridura verda en mandarines 'Clemenules' i 'Ortanique' tractades en banys amb SP i 30kPa O2 durant 48h es reduí en un 100, 96 i 68%, i 100, 97 i 79%, respectivament. De nou, una forta sinergia s'observà entre els tractaments (Capítol 5). Les podridures verda i blava es controlaren eficaçment mitjançant la fumigació de llimones i taronges durant 6 h a 22ºC amb dos dosis de 3000 ¿L L-1 amoníac, injectades al inici del tractament i 2 h després (Capítol 6). El tractament amb amoníac controlà una soca de P. digitatum amb un alt nivell de resistència a IMZ. Tots estos tractaments, a diferents nivells, podrien substituir als fungicides de síntesis o augmentar l'eficàcia dels tractaments amb IMZ en el maneig poscollita dels cítrics. El desenvolupament de les podridures verda i blava en les especies y varietats de cítrics més importants comercialment s'avaluà durant quatre campanyes consecutives i es relacionà amb els paràmetres de qualitat de la fruita (Capítol 7). La susceptibilitat dels distints cultivars en ordre creixent fon Nova, Sanguinelli, Ortanique, Lanelate, Navelate, Fortune, Clemenules, Valencia, W. Navel, Oronules, Clemenpons, Marisol, Salustiana, Hernandina, i Nadorcott. Les característiques de la pell foren els paràmetres de qualitat més influents en la susceptibilitat dels cítrics a les pod
Montesinos Herrero, CI. (2016). Evaluation of alternatives to synthetic fungicides to control citrus postharvest diseases [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/63662
TESIS
Chiputula, Jonathan. "Evaluating mechanical damage of fresh potato during harvesting and postharvest handling." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0041361.
Full textMüller, Ines. "Relationships between preharvest soybean oil application and postharvest behaviour of apples." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Dissertations/Spring2005/i%5Fmuller%5F042805.pdf.
Full textPlatania, Claudia. "New sustainable approaches for control of postharvest diseases of citrus fruit." Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/1220.
Full textParafati, Lucia. "Biological control of postharvest phytopathogenic molds promoted by food-isolated yeasts." Doctoral thesis, Università di Catania, 2016. http://hdl.handle.net/10761/3993.
Full textFATCHURRAHMAN, DANIAL. "Increasing Knowledge on Postharvest Handling of Goji Berries (Lycium barbarum L.)." Doctoral thesis, Università di Foggia, 2022. https://hdl.handle.net/11369/425271.
Full textLu, Jianbo. "Quantifying non-uniformity in hot air treatment using tomato as a test material for postharvest quality and disease control." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=115694.
Full textSingle-temperature heat treatment was most effective in limiting pathogen development and varied according to the parameter measured: 38°C for hypersensitive response (HR), 36°C for tissue breakdown, 36°C, 38°C or 39°C for mycelium abundance, and 38°C or 39°C for lesion size. Bilateral differences in temperature across the fruit significantly affected disease control: decreasing temperature differences significantly improved the uniformity of disease control.
Some of the effects of heat treatment on tomato quality, such as color development and resistance to CI, appear to be localized. A significant difference in redness was identified between heated parts and unheated parts of tomato fruits immediately after treatment; and the differences persisted during storage. Differences in lightness and chroma were noted on day 4. Delay in ripening caused by heat treatment was confirmed through the higher TA and TSS values of heated tomatoes or heated portion of partially heated tomatoes.
The heated parts of tomatoes showed a stronger resistance to chilling injury. The effective temperature control range for CI was wide, but temperatures higher than 39.5°C for 23 h hot air treatment could lead to adverse effects.
Differences in physiological effects between hemispheres in two chambers was reduced by directly decreasing the temperature difference between upper and lower chambers or relatively increasing the heating air flow rate, highlighting the importance of improving the uniformity of air flow around each individual treated fruit.
de, CHIARA MARIA LUCIA VALERIA. "Use of Titanium Oxide (TiO2) to Decompose Ethylene during Storage of Horticultural Crops." Doctoral thesis, Università di Foggia, 2014. http://hdl.handle.net/11369/331737.
Full textBeach, Shannon Elizabeth. "Shipping and nitrogen toning effects on postharvest shelf life of vegetative annuals." Texas A&M University, 2005. http://hdl.handle.net/1969.1/4340.
Full textSchofield, Rex Andrew. "Evaluation of postharvest quality of iceberg lettuce by chlorophyll fluorescence and firmness." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0007/MQ43217.pdf.
Full textMekbib, Sissay Bekele. "Identification of citrus (Citrus sinenses) postharvest pathogens from Ethiopia and their control." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-06082007-152035.
Full textTahir, Ibrahim. "Control of pre- and postharvest factors to improve apple quality and storability /." Alnarp : Dept. of Crop Science, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200635.pdf.
Full textO'Grady, Lizanne. "Effects of postharvest handling on nutritional quality of pomegranate (Punica granatum) Arils." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71973.
Full textENGLISH ABSTRACT: The aim of this study was to investigate the effects of storage temperature and duration on the proximate composition, physico-chemical properties and selected bioactive components (vitamin C, anthocyanins and β-carotene) of arils from three pomegranate cultivars (‘Arakta’, ‘Bahgwa’ and ‘Ruby’). Pomegranates were hand-peeled and stored at three different temperatures (1°, 4° and 8°C) at 95% relative humidity (RH) for 14 days, with an additional day at ambient conditions (~21°C). Physico-chemical attributes, anthocyanins, ascorbic acid and proximate composition was measured on day 0, 7, 14 and 15. O2 consumption and CO2 production increased at elevated temperatures. No visual mould growth was detected in ‘Arakta’ and ‘Bahgwa’ arils after 14 days at 1°C 95% RH and after 7 days at 4°C 95% RH. Higher storage temperature negatively affected the proximate composition, physico-chemical attributes and bioactive components. The physico-chemical properties and selected bioactive components (anthocyanins, ascorbic acid, β-carotene) of pomegranate arils (‘Arakta’, ‘Bahgwa’ and ‘Ruby’) packed in three punnets made of polyethylene terephthalate (PET1 - clampshell; PET2 - tub and lid) or polypropylene (PP - tub and lid) material were studied for a period of 14 days at 5°C 95% RH. Packaging did not have a major effect on the physico-chemical and bioactive components of pomegranate arils, although PET2 had relatively stable headspace gas composition within the punnets. Storage duration caused a rise in pH and a decline in titratable acidity irrespective of packaging type. No visual mould growth was detected in ‘Arakta’ arils after 7 days irrespective of the type of packaging, while mould growth was detected in all ‘Ruby’ in all types of packaging. The earlier onset of visual microbial growth lead to a baseline microbiological study evaluating the effect of pre-storage water dipping of whole fruit on the microbiological quality of pomegranate arils stored for 8 days at 5°C 95% RH. Freshly harvested pomegranate fruit (‘Bahgwa’) were dipped in distilled water and air-dried (dipped fruit) or stored without postharvest dipping (dry fruit) at 7°C 95% RH for 15 weeks. Arils were extracted, packaged and stored at 5°C 95±8.34% RH for 8 days. Total viable aerobic mesophillic bacteria, yeasts and moulds, Escherichia coli and Staphylococcus aureus were enumerated. After 8 days at 5°C 95% RH no microbial growth was detected on arils from ‘dry fruit’, while ‘dipped fruit’ showed increased yeast and mould counts (4.74 log cfu.g-1) and total viable aerobic mesophillic bacteria count (3.73 log cfu.g-1). In conclusion storage temperature affects the nutritional quality of pomegranate arils and is best maintained at 1°C for 14 days or 4°C for 7 days at 95% RH. Current South African packaging used to market pomegranate arils don’t have a major effect on the nutritional quality of pomegranate arils, although the headspace gas composition was most stable in PET2 packaging. Pre-storage water dipping of whole pomegranates should be avoided as this could reduce the shelf life of extracted pomegranate arils.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die gevolge van bergingstemperatuur en -tydperk op die proksimale samestelling, fisies-chemiese eienskappe en geselekteerde bio-aktiewe komponente (vitamien C, antosianiene en β-karoteen) van granaatpitte van drie kultivars ('Arakta’, ‘Bahgwa’ en ‘Ruby’) te ondersoek. Granaatpitte is geberg by drie temperature (1°, 4° en 8°C) 95% RH vir 14 dae plus ‘n addisionele dag by kamertemperatuur (~21°C). Fisies-chemiese eienskappe, antosianiene, askorbiensuur en proksimale samestelling is gemeet op dag 0, 7, 14 en 15. Die granaatpitte se O2-verbruik en CO2-produksie het toegeneem by hoër bergingstemperature. Geen swamgroei was sigbaar na 7 dae by 1°C 95% RH sowel as 14 dae 4°C 95% RH. Hoër bergingstemperatuur het die proksimale samestelling, fisies-chemiese eienskappe en bio-aktiewe komponente negatief beïnvloed. Die fisies-chemiese eienskappe en geselekteerde bio-aktiewe komponente (antosianiene, askorbiensuur, β-karoteen) van granaatpitte ('Arakta’, ‘Bahgwa’ en ‘Ruby’) is verpak in drie bakkies vervaardig van polyethyleentereftalaat (PET1 – klamp-bakkie, PET2 – bakkie en deksel) of polipropileen (PP – bakkie en deksel) en bestudeer vir 14 dae by 5°C 95% RH. Heel granate was onderworpe aan 10-14 weke bergingstydperk by 7°C 95% RH voor die granate geskil en verpak is. Die bakkie tipe het nie 'n duidelike uitwerking op die fisies-chemiese en bio-aktiewe komponente van die granaatpitte gehad nie, alhoewel die gas samestelling in die kopspasie van PET2 bakkies relatief onveranderd gebly het. Gedurende die bergingstydperk het die pH gestyg en die titreerbare suur gedaal ongeag die bakkie tipe. Geen visuele swamgroei was sigbaar in ‘Arakta’ granaatpitte na 7 dae by 5°C 95% RH terwyl ‘Ruby’ granaatpitte wel swamgroei getoon het ongeag die bakkie tipe. Die vroeë aanvang van sigbare swamgroei het tot ‘n verdere mikrobiologiese basislynstudie gelei. Die uitwerking van voorbergingswaterdompeling van heel granate is geëvalueer op die mikrobiologiese gehalte van die granaatpitte wat gestoor was vir 8 dae by 5°C 95% RH. Vars ge-oesde ‘Bahgwa' granate is in water gedompel en gelugdroog (gedompelde granate) of glad nie in water gedompel nie (droë granate) en geberg by 7°C 95% RH vir 15 weke. Granate is ontpit, verpak en geberg by 5°C 95±8.34% RH vir 8 dae. Totale lewensvatbare aërobiese mesofilliese bakterieë, giste en swamme, Escherichia coli en Staphylococcus aureus telling is vervat. Granaatpitte van ‘droë granate’ was vry van enige mikrobiese groei na 8 dae. Die ‘gedompelde granate’ het ‘n toename in giste en swamme (4,74 log cfu.g-1) en totale lewensvatbare aërobiese mesofilliese bakterieë (3,73 log cfu.g-1) getoon. Hierdie studie maan dus teen waterdompeling van heel granate voor ‘n bergingsperiode van 10-15 weke. Ten slotte word die voedingswaarde van granaatpitte wel beïnvloed deur ‘n hoër bergingstemperatuur en sal die granaatpitte se gehalte behou word by 1°C vir 14 dae of 4°C vir 7 dae by 95% RH. Die voedingswaarde van granaatpitte word nie beïnvloed deur kommersiële verpakking wat tans in Suid-Afrika gebruik word om granaatpitte te adverteer nie, alhoewel PET2 bakkies se gas samestelling in die kopspasie onveranderd gebly het. Waterdompeling van heel granate voor ‘n verlengde bergingstydperk moet eerder vermy word aangesien dit die raklewe van granaatpitte verminder.
Leatherwood, William Roland. "Managing the postharvest physiology of unrooted cuttings to enhance shipping and postharvest quality." 2008. http://www.lib.ncsu.edu/theses/available/etd-03202008-110930/unrestricted/etd.pdf.
Full textBlakey, Robert John. "Management of avocado postharvest physiology." Thesis, 2011. http://hdl.handle.net/10413/7893.
Full textThesis (Ph.D.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.