Dissertations / Theses on the topic 'Food odour'
To see the other types of publications on this topic, follow the link: Food odour.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 40 dissertations / theses for your research on the topic 'Food odour.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Solina, Marica, University of Western Sydney, of Science Technology and Environment College, and Centre for Advanced Food Research. "Investigations on aroma development in wheat and soy extrudates." THESIS_CSTE_CAFR_Solina_M.xml, 2001. http://handle.uws.edu.au:8081/1959.7/525.
Full textAbstract:
The factors determining the generation of aroma in starch extrudates containing added ingredients with aroma precursors were elucidated. Analyses were performed using headspace analysis of raw materials and extrudates and subsequent analysis by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Olfactometry (GC-O. Study I described the volatile, amino acid and fatty acid profiles of Hydrolised vegetable protein (HVP)and Soy protein isolate (SPI). Studies II, III and IV descibed the volatiles developed from extrusion of different feedstocks under mild and extreme processing conditions. Wheat starch was chosen as the carrier.A comparison of the influence of the three different ingredients HVP, SPI and glucose, added to the starch feed, showed the formation of Strecker aldehydes and Maillard-type compounds were significantly affected by the addition of these ingredients. The work in this thesis demonstrated that the addition of ingredients such as HVP, SPI, glucose, cysteine, cysteine-HCI, modifies the aroma of wheat starch extrudates. Furthermore, it showed the changes in conditions of extrusion and pH will greatly influence the aroma profile of the products.Doctor of Philosophy (PhD)
2
Sörensen, Ida. "Meerkats (Suricata suricatta) are able to detect hidden food using olfactory cues." Thesis, Linköpings universitet, Biologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-151238.
Full textAbstract:
Meerkats are known to strongly rely on chemical communication in social contexts. However, little is known about their use of the sense of smell in food detection and selection. The aim of the present study was therefore to assess whether meerkats are able to (1) detect hidden food using olfactory cues, (2) distinguish the odour of real food from a single food odour component, and (3) build an association between the odour of real food and a novel odour. I employed the buried food test, widely used with rodents to assess basic olfactory abilities, designed to take advantage of the propensity of meerkats to dig. I found that the meerkats were clearly able to find all four food types tested (mouse, chicken, mealworm, banana) using olfactory cues alone and that they successfully discriminated between the odour of real food and a food odour component. In both tasks, the animals dug in the food-bearing corner of the test arena as the first one significantly more often than in the other three corners, suggesting development of an efficient foraging strategy. No significant association-building between a food odour and a novel odour was found within the 60 trials performed per animal. I conclude that meerkats are able to use olfactory cues when foraging and that their sense of smell is well-adapted for recognizing specific odours of behavioural relevance. To the best of my knowledge, this is the first study to successfully employ the buried food test with a carnivore species.
3
Solina, Marica. "Investigations on aroma development in wheat and soy extrudates." Thesis, View thesis, 2001. http://handle.uws.edu.au:8081/1959.7/525.
Full textAbstract:
The factors determining the generation of aroma in starch extrudates containing added ingredients with aroma precursors were elucidated. Analyses were performed using headspace analysis of raw materials and extrudates and subsequent analysis by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Olfactometry (GC-O. Study I described the volatile, amino acid and fatty acid profiles of Hydrolised vegetable protein (HVP)and Soy protein isolate (SPI). Studies II, III and IV descibed the volatiles developed from extrusion of different feedstocks under mild and extreme processing conditions. Wheat starch was chosen as the carrier.A comparison of the influence of the three different ingredients HVP, SPI and glucose, added to the starch feed, showed the formation of Strecker aldehydes and Maillard-type compounds were significantly affected by the addition of these ingredients. The work in this thesis demonstrated that the addition of ingredients such as HVP, SPI, glucose, cysteine, cysteine-HCI, modifies the aroma of wheat starch extrudates. Furthermore, it showed the changes in conditions of extrusion and pH will greatly influence the aroma profile of the products.
4
Marshall, Joanna. "The microbial ecology of the human foot." Thesis, University of Leeds, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328884.
Full text
5
Singleton-Jones, Nicola. "A fundamental study into odour in footwear." Thesis, Nottingham Trent University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389685.
Full text
6
Yiin, Yeh-Min 1975. "Acquisition of odor-cued fasting-anticipatory satiety in rats." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29489.
Full textAbstract:
Animals can associate orosensory characteristics from food with postingestive effects and adjust meal size to prevent energy deficit. By using odor-fasting duration conditioning, two studies were conducted to test the above hypothesis. In the first study, thirteen male and eleven female adult Wistar rats were given 1.5 hours to ingest a casein-based test-meal odorized by either vanilla or chicken flavor prior to a 4-hour short-fast or a 12-hour long-fast. Rats went through the training phase with a pseudo-random sequence of six duplicates of each odor-fasting pairing over four experimental days, followed by an odor preference test. Gender differences may exist regarding hunger perception because only females were capable of adjusting meal size according to the postprandial fast duration. A second study was conducted to examine whether a sugar-rich meal can improve acquisition of anticipatory satiety through memory enhancement. Thirty-two female Sprague-Dawley rats were given either a sugar-rich or a protein-rich test-meal prior to the post-prandial fasts. Rats were conditioned in a similar fashion to the first study except that different odors were used, postprandial fasts were shortened to 3 and 10 hours, whereas training phase was elongated to eleven duplicates and followed by an extinction phase. Both dietary groups acquired the anticipatory satiety. However, probably due to the carbohydrate-induced overeating, the sugar-rich group in contrast to the protein-rich group, exhibited a delayed learning in meal-size adjustment prior to a short fast. The above studies demonstrated the existence of gender and macronutrient differences in food intake regulation.
7
Mahony, Amy. "Effect of color on the odor, flavor, and acceptance properties of foods and beverages." Kansas State University, 2011. http://hdl.handle.net/2097/9188.
Full textAbstract:
Master of ScienceFood Science Institute -- Human Nutrition
Koushik Adhikari
A significant increase in the number of products carried in supermarkets has lead manufacturers to use food color as a way to differentiate their products from competitor’s products or as a form of communication. This report’s overall objective was to review the impact of color on sensory properties of foods and beverages and help product developers understand the multiple sensory properties within a food or beverage that may potentially change by manipulating color. The effect of color on flavor or odor identification, basic taste perception, flavor or odor intensity, quality and refreshment, and consumer acceptance has been extensively researched. Research to date has shown inconsistent findings, although key themes are consistent. Some colors are more appropriate for certain foods and beverages, and product color can be directly linked to palatability. Color cues can be used for flavor identification within a food or beverage, and the presence of certain colors evoke flavor associations within a product. Perceived intensities of basic taste or flavor attributes have increased or decreased merely with color addition. Consumers use color cues to determine quality, therefore color can ultimately affect product acceptance.
8
Carreira, Laura Regula Eustáquio. "Influência do odor de alimentos no proteoma salivar: o caso particular do odor do pão." Master's thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/27215.
Full textAbstract:
Cheirar um alimento desencadeia emoções e a salivação. Contudo, não se sabe que alterações esse estímulo induz na composição proteica da saliva.
Este trabalho tem como objetivo identificar alterações induzidas pelo odor do pão no proteoma salivar, relacionando-as com emoções desencadeadas e avaliando a sua semelhança com a mastigação. As técnicas utilizadas foram: quantificação em proteína total, eletroforese bidimensional, ELISA e determinação de atividade enzimática.
Observaram-se aumentos nos níveis de expressão de spots proteicos de α-amilase e cistatinas, com o cheiro, semelhantes às induzidas pela mastigação do mesmo alimento. Já os níveis de imunoglobulinas não diminuem com o cheiro, ao contrário da mastigação. O desejo desencadeado pelo odor do pão resultou em maiores aumentos de taxa de secreção, cortisol e amilase salivares. Conclui-se que, o proteoma salivar responde ao odor dos alimentos e que algumas alterações são semelhantes às resultantes da mastigação desse alimento; The influence of food odor in salivary proteome: the particular case of bread odor
Abstract:
Smelling food causes emotions and induces salivation. However, it is not known which changes this stimulus causes in the salivary protein composition.
This paper aims to identify changes induced by bread odor in salivary proteome, relating them to perceived emotions and assessing their similarity with changes induced by chewing. The techniques used were: total protein quantification, two-dimensional electrophoresis, ELISA and enzymatic activity quantification.
Increases in expression levels of α-amylase and cystatins’ protein spots, induced by food odor were observed, which were similar to the ones induced by chewing the same food. Immunoglobulin levels do not decrease with odor, by opposition to chewing. The desire caused by the odor of bread resulted in higher increases in salivary secretion, cortisol and amylase rates. It is concluded that salivary proteome responds to food odor and some changes are similar to those resulting from chewing of this food.
9
Kendal-Reed, Martin Stuart. "Human infant olfaction : responses to food odours measured by brain electrical activity mapping (B.E.A.M.)." Thesis, University of Warwick, 1990. http://wrap.warwick.ac.uk/91144/.
Full textAbstract:
This thesis addresses the area of human infant olfaction, which has hitherto been a somewhat neglected area in psychology. A review of the available literature showed that a number of different experimental approaches to infant olfaction could be identified. It was concluded from this literature review that infants display a degree of olfactory competence in the weeks after birth. These previous findings are discussed in the light of a model concerned with odour significance. This model is systems-based and suggests an explanation for the apparent olfactory competence of human infants in the first weeks of life. It is argued that this may derive from pre-natal exposure to odorants and consequent acceleration of maturation in the foetal olfactory system. The experiments reported in this thesis concentrated on the cortical reactions of infants to a small range food odours. These reactions were plotted by means of a technique involving electro-encephalography. This technique involves a computerised imaging system which summarises cortical potentials from twenty-eight locations on the scalp and is known as Brain Electrical Activity Mapping (BEAM). It is believed that this is the first time that this method has been used to examine responses to odour in human infants. This study also involved the use of a special low ambient odour testing environment. A parallel study used respiratory plethysmography to test odour response. The major findings of the BEAM research are as follows: 1) The BEAM technique has been shown to be a practical method in the psychophysical measurement of cortical responses to odour in the human infant. 2) Human infants at the age of three months show a pattern of cortical activity in response to a small range of food odours. 3) There is evidence that a limited area of the infant brain is responding to these odours. It was argued that these findings lent some support to the model described above. However, similar findings to that of the BEAM work were not shown by the respiratory plethysmography study. This was explained by problems in data handling techniques. It was concluded that the BEAM method could be used to further knowledge in the area of infant olfactory response. Possible improvements to the experimental technique were discussed which would allow testing of infant response to maternal odour. Such future work could shed considerable light on the role of olfaction in the early infant-mother relationship.
10
White, Peter Richard. "The responses of the saw-toothed grain beetle Oryzaephilus surinamensis to pheromones and food odours." Thesis, University of Oxford, 1987. http://ora.ox.ac.uk/objects/uuid:9b87541d-76a9-4d7d-bf59-9c852cf86708.
Full textAbstract:
The responses of the saw-toothed grain beetle, 0ryzaephilus surinamensis to food odours and pheromones were investigated at both sensory and behavioural levels to give an integrated picture of olfaction, and the importance of odours in this species. The sensory capability of the antenna was assessed by a study of the structure, distribution and function of sensilla using SEM and TEM. Seven different sensilla types, including 3 with an olfactory function, were identified, although the total number of olfactory sensilla was low compared with those for mechanoreception. Antennal responses to odours were studied using both the electroantennogram (EAG) technique and single-cell recordings, whilst a 2-choice pitfall assay and a single-insect arena test were used to investigate behavioural responses. Food-produced volatiles from carob pods were found to produce large amplitude antennal responses and attraction in behavioural assays. Analysis of such volatiles by coupled gas chromatography-electroantennography (GC-EAG) demonstrated at least 3 active components, of which one was identified as hexanoic acid. Attraction to food odour was found to vary with insect age, and this correlated with similar variation in the EAG response, suggesting a role for peripheral receptor sensitivity in modulating insect behaviour. Beetle-produced volatiles also caused antennal responses and attraction of conspecific individuals of both sexes, thus acting as an aggregation pheromone. The active components were identified by GC-EAG as (Z,Z)-3,6-dodecadien-11-olide, (Z,Z)-3,6-dodecadienolide and (Z,Z)-5,8-tetradecadien-13-olide. These act as a multicomponent pheromone, with separate antennal receptors for each component. Although no sexual differences in antennal responses were found, consistently more females than males were attracted to the pheromone. This suggested a partial sex pheromone function, as the pheromone was shown to be male-produced. However, the ratio of females:males attracted was found to vary with the blend ratio tested. Thus if males are able to alter the blend they produce, the pheromone may act at different times as either a sex pheromone or an aggregation pheromone. Finally, the functional and evolutionary importance of odours to this insect are discussed.
11
Li, Zhenfeng 1968 Oct 9. "Aroma detection and control in passive and dynamic food systems for superior product." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=115879.
Full textAbstract:
Passive (static) and dynamic studies have shown aroma to be an important aspect of food quality, which can be used to differentiate, classify, and grade foodstuffs, and in some cases it can be used to predict other quality characteristics. Monitoring and control of food aroma changes during food processing can significantly improve the quality of the final product in terms of flavour, color, taste, and overall appearance. Hence, it is a prominent and urgent field of study in the post production systems.Passive aroma detection of unprocessed foods and dynamic aroma detection during food processing was undertaken using a fast GC analyzer -- zNose. During the study on the passive aroma detection, the aroma of Chinese spirits (Fenjiu) and mango (Mangifera indica L.) fruits, (i.e., liquid and solid states, respectively) was analyzed. In the study of Chinese spirits, aroma profiles of Fenjiu liquor samples of different quality levels were acquired and used for quality classification and prediction. Measurements of dielectric properties of the samples were also conducted to estimate alcohol concentration. In the study of mango fruits, aroma changes of mango samples were monitored during their shelf life and used to evaluate mango quality. Ripening and rots were detected with 80% and 93% accuracy, respectively.
During the study of dynamic aroma detection, a real-time aroma monitoring and control system was developed for use during microwave drying. Aroma signals of a processed food item were detected with zNose and analyzed with a fuzzy logic algorithm to determine the optimal food drying temperature. Phase control was used to adjust the microwave power level to meet temperature requirements. Carrot (Daucus carota L.) and apple (Malus domestica Borkh) were selected as representatives of vegetables and fruits. In carrot drying, samples could be dried in a short time at high temperatures but the interior of some sample cubes was burnt. Drying at a lower temperature extended the drying process, but led to a great loss of aroma in the finished product.' The best results were obtained at 60°C. Based on these results, a fuzzy logic controller was designed and employed to control the drying process according to carrot aroma changes. To investigate the possibility of aroma improvement without zNose assistance, a linear control method was developed whereby a temperature control profile imitated the fuzzy logic control, but aroma control was not included. With these new control strategies, the carrot color and flavour were significantly improved and less time and power were consumed. Similar results were achieved when apple was microwave-dried. Apple aroma was monitored online during microwave drying processes and controlled with similar fuzzy and linear control strategies. Apple color, aroma, and overall appearance remained intact with the new strategies and less time and power were consumed. In contrast to the carrot drying, a different linear temperature profile was required for apple drying in terms of aroma retention.
12
Pratama, Filli, of Western Sydney Hawkesbury University, Faculty of Science and Technology, and School of Food Science. "Imparting aromas into raw milled rice: an experimental study." THESIS_FST_SFH_Pratam_F.xml, 2000. http://handle.uws.edu.au:8081/1959.7/478.
Full textAbstract:
This thesis describes a series of experiments concerned with the production of aromatised rice. The end product showed no visible difference from untreated rice, and the cooked product had a perceivable aroma. The aromatisation process used liquid carbon dioxide as a vehicle to deliver the aroma, and eugenol, isoeugenol, methyl eugenol, cinnamyl alcohol and cinnamaldehyde were used as the principle model aroma components. The aromas penetrated the cores of the rice grains, providing a longer period for the aroma compounds to migrate toward the surface and be lost to the open air. The stability of the injected compounds in aromatised rice was investigated, showing that aroma loss was a first-order process, although some model compounds showed evidence of two binding models, with two distinct phases of aroma loss. The strength of aroma binding to rice was further assessed by means of gas-chromatography columns, and the model aroma compounds interacted best with the rice-flour column. Shelf-life studies demonstrated that eugenol and cinnamaldehyde in aromatised rice showed no significant changes after being stored for 6 months in sealed vacuum aroma-barrier plastic bags, and the aromas could be detected by the human olfactory system after the rice had been cooked by boiling and steamingDoctor of Philosophy (PhD)
13
Hu, Xiaohuan. "Controlling the Production of Off-odor Guaiacol by Alicyclobacillus acidoterrestris in Apple juice or a Microbiological Medium." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461151403.
Full text
14
Patton, Kathleen A. "Storage stability of freeze dried raspberry and blackberry juices." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65392.
Full text
15
Lam, Siu-ping, and 林少萍. "Aroma profiles of soy sauces." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31221105.
Full text
16
Freiberger, Eliza Brito. "Nanocápsulas de poli (L-ácido lático) contendo óleo de café torrado." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/1079.
Full textAbstract:
Capes; CNPqO aroma de café é constituído por uma mistura de componentes voláteis, os quais podem ser encontrados no óleo obtido na torração do café. O café solúvel, em função das condições de processamento, perde parte do seu aroma que, a princípio, poderia ser reincorporado ao produto pela adição do óleo de café diretamente sobre o produto final. Contudo, alguns trabalhos apontam para dificuldades de se obter bons resultados quando se trabalha com o óleo in natura devido à sua volatilidade e à degradação dos aromas. A incorporação de nanocápsulas contendo o óleo de café pode ser uma alternativa para minimizar estas perdas, pois o polímero encapsulante pode agir como barreira de proteção e promover sua liberação de forma controlada. A proposta do trabalho é a obtenção de nanocápsulas de poli(L-ácido lático)(PLLA), contendo o óleo de café torrado pela técnica de miniemulsificação/evaporação do solvente e validar o método para quantificação do óleo de café por espectrofotometria UV-Vis. Os estudos de validação possibilitaram garantir a qualidade dos resultados obtidos. Formulações com diferentes concentrações de PLLA, óleo e tipos de surfactantes foram valiadas quanto ao tamanho e índice de polidispersão frente à recuperação de óleo. Todas as formulações testadas apresentaram valores de recuperação de óleo acima de 80% mostrando que a técnica é adequada e pode ser considerada uma alternativa promissora para produzir nanocápsulas contendo óleo de café. As análises da composição do aroma das nanocápsulas, que indica a qualidade da porção de óleo encapsulada, mostraram que as nanocápsulas contêm frações de todos os compostos encontrados no óleo.
Coffee flavor is a mixture of volatile components found in the oil obtained from the roasted coffee. Soluble coffee loses part of its aroma due to processing conditions which could be reintroduced to the product by the direct addition of the coffee oil. However, some studies point out difficulties in obtaining good results when working with in natura oil because of the high volatility and the flavor degradation. The incorporation of nanocapsules containing coffee oil could be an alternative to minimize these losses, because the encapsulating polymer could act as a protecting barrier and promote its controlled release. The aim of this work is obtain PLLA nanocapsules containing roasted coffee oil by the miniemulsification/solvent evaporation technique. The spectrophometric UV- Vis method used to quantify the coffee oil was validated. Formulations with different PLLA and oil concentrations and kind of surfactant were evaluated in respect to the average nanocapsules size and polydispersion index and oil recovery. All formulations demonstrated oil recovery values above 80 % demonstrating that the technique is adequate and can be consider a promising alternative to coffee oil nanocapsules production. Flavor analysis nanocapsules composition, which indicates the quality of the encapsulated oil, showed that the nanocapsules contain fractions of all the substances found on the in natura oil.
17
Pratama, Filli. "Imparting aromas into raw milled rice: an experimental study." Thesis, View thesis, 2000. http://handle.uws.edu.au:8081/1959.7/478.
Full textAbstract:
This thesis describes a series of experiments concerned with the production of aromatised rice. The end product showed no visible difference from untreated rice, and the cooked product had a perceivable aroma. The aromatisation process used liquid carbon dioxide as a vehicle to deliver the aroma, and eugenol, isoeugenol, methyl eugenol, cinnamyl alcohol and cinnamaldehyde were used as the principle model aroma components. The aromas penetrated the cores of the rice grains, providing a longer period for the aroma compounds to migrate toward the surface and be lost to the open air. The stability of the injected compounds in aromatised rice was investigated, showing that aroma loss was a first-order process, although some model compounds showed evidence of two binding models, with two distinct phases of aroma loss. The strength of aroma binding to rice was further assessed by means of gas-chromatography columns, and the model aroma compounds interacted best with the rice-flour column. Shelf-life studies demonstrated that eugenol and cinnamaldehyde in aromatised rice showed no significant changes after being stored for 6 months in sealed vacuum aroma-barrier plastic bags, and the aromas could be detected by the human olfactory system after the rice had been cooked by boiling and steaming
18
Marcello, Gregory James. "The Effects of Predation and Supplemental Food on Foraging and Abundance of White-Footed Mice (Peromyscus Leucopus) in Relation to Forest Patch Size." Oxford, Ohio : Miami University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1123179821.
Full text
19
Aineslahti, Emmi. "Training of spider monkeys in a food-rewarded two-choice olfactory discrimination paradigm and assessment of olfactory learning and memory performance." Thesis, Linköpings universitet, Biologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-157124.
Full textAbstract:
There is little knowledge about olfactory learning in primates, even though primates are known to use olfaction in several behaviors including food selection and territorial defense. Therefore I assessed the olfactory learning and memory performance in five adult spider monkeys (Ateles geoffroyi) using a food-rewarded two-choice olfactory discrimination paradigm. The spider monkeys acquired the initial odor discrimination in 530-1102 trials and in a series of intramodal transfer tasks they needed 30-510 trials to reach the learning criterion. There was a significant negative correlation between the number of trials needed to reach the learning criterion and the number of transfer tasks completed. Thus, as a group, the animals displayed olfactory learning set formation. The number of trials that the spider monkeys needed in initial olfactory learning was comparable to that of other primate species tested previously but higher compared to that of other mammals such as dogs and rats. The learning speed of the spider monkeys in intramodal transfer tasks was similar to that of other mammals tested, suggesting that primates are less prepared to use olfactory cues in the initial solving of a problem but that once they learn the concept, their learning speed with novel odor discrimination problems is not generally slower than that of non-primate mammals. All spider monkeys tested reached the learning criterion in the memory tasks straight on the first testing day, that is: within 30 trials, suggesting similar long-term odor memory capabilities in spider monkeys and other mammals such as dogs, mice and rats.
20
Van, Eeden Petrus Rabe. "Chemical, sensory and consumer analysis of cork taint in South African wines." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2092.
Full textAbstract:
Thesis (MSc Food Sc (Food Science))--University of Stellenbosch, 2009.This study focused on a serious quality-related problem in the global wine industry, including the South African Wine Industry, namely cork taint in wine. Annually, large financial losses are incurred by cork suppliers and wine producers, as a result of cork-tainted wine. Although contaminated new unused corks are frequently implicated as the origin of this taint, contaminated cellar equipment and water can also be the source of the problem. An explorative investigation into the incidence of cork taint in South African wines showed that 3.8% of the 133 wines tested, contained 2,4,6-trichloroanisole (TCA) concentrations of 3.5 ng/L and higher, as determined by gas chromatography coupled with electron capture detection (GC-ECD). TCA concentrations higher than 1 ng/L were found in 18% of the wines tested. All affected wines were sealed with solid or agglomerate cork stoppers. These wines were sourced from various wineries in the Western Cape region, South Africa and were of different cultivars. None of the wines sealed with synthetic closures had any detectable TCA, 2,4,6-tribromoanisole (TBA) or pentachloroanisole (PCA) levels and only very low 2,3,4,6- tetrachloroanisole (TeCA) levels (1 ng/L or less). Another group of 28 wines that were rejected by the official South African wine regulatory body on the basis of the presence of mouldy taint during wine certification, was also included in this study. GC-ECD analysis showed that 30% of the wines in this group contained TCA at concentrations of 3.5 ng/L and higher. These results pointed to a relative high incidence of TCA in the wines investigated, especially those sealed with cork stoppers. Although no general conclusions should be made on the incidence of cork taint in the wider wine industry based on the results found within this explorative investigation, these findings confirmed the presence of cork taint in South African wines. Detection threshold values were determined for TCA, TeCA, TBA and PCA in three wine cultivars using the standard ASTM method. Results indicate that factors relating to the wine cultivar seemed to affect threshold values considerably. Our research proposes a detection range rather than an average detection threshold. Detection ranges established for TCA, TeCA, TBA and PCA in Chenin blanc, Pinotage and Shiraz coincide with reported values in literature. This result can be regarded as a valuable expansion of the existing knowledge of detection threshold values. Descriptive sensory analysis indicated significant (P 0.05) changes in the aroma profile of Chenin blanc, Pinotage and Shiraz after TCA, TeCA, TBA or PCA was added to the respective base wines that contained no detectable levels of the haloanisoles. The mouldy taint induced by these haloanisoles were described as mouldy, mouldy-chemical, mouldychlorine, as well as mouldy-acidic. In Chenin blanc, additions of TCA, in the concentration range 1 to 17 ng/L, resulted in a marked increase in the mouldy aroma and was accompanied by an immediate decrease in fruitiness. This change was already evident at added TCA concentrations of 1 ng/L. Similar trends were observed in Pinotage, while the addition of low levels of TCA to Shiraz (2 ng/L) resulted in a significant (P 0.05) decrease in the herbaceous character of the wine. The aroma changes observed were prominent enough to render the wine totally unacceptable in comparison to its original character. Consumers’ degree of liking did not seem to be affected by very low concentration levels of TCA in Chenin blanc, Pinotage or Shiraz, but rejection increased as the concentration increased beyond detection threshold level. A slight gender effect was also noticed. Female consumers appeared to be more sensitive to increasing levels of TCA, whereas male consumers did not respond as negatively to higher concentration levels of TCA. This study makes an important contribution towards understanding the sensory impact of especially TCA contamination in wine, through the establishment of concentration ranges at which these compounds exert a noticeable detrimental effect on the aroma profile of wine. Additional insight into cork taint in wine is provided by the consumer preference studies, where the effects of the taint on the product acceptance by consumers are demonstrated. The development of a modus operandi to ensure that sensory panels provide reliable data, can be regarded as an important contribution to wine-related research. This study is one of the first where advanced sensometric techniques were applied in sensory studies on cork tainted wines.
21
Akpolat, Hacer. "The Effect of pH and Temperature on Cabbage Volatiles during Storage." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1427734475.
Full text
22
Leobet, Elenir Lila. "Influência dos parâmetros de processo na formação do aroma e sabor indesejado de cereal em café aglomerado." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/785.
Full textAbstract:
O café solúvel aglomerado é produto da aglomeração do café solúvel em pó. A sua produção envolve etapas de processo cujas variações térmicas modificam qualitativamente e quantitativamente a fração de compostos voláteis responsáveis pelo aroma e sabor do produto acabado. A indústria de bebidas de café considera o sabor e aroma de cereal como um defeito na produção de café solúvel aglomerado. Desta forma, este trabalho objetivou aplicar o planejamento experimental para avaliação dos parâmetros de processo da produção de café solúvel aglomerado em escala industrial. Os efeitos destes parâmetros nos componentes voláteis do café e na intensidade do gosto de cereal foram avaliados através do planejamento fracionário 24-1 com resolução IV. As variáveis independentes estudadas foram temperatura do queimador (TQ), fluxo de ar de processo (FA), temperatura da seção quente do leito (TL) e pressão de vapor (PV). Os resultados do planejamento experimental deram-se pela utilização de análise sensorial conduzida por equipe treinada para a detecção do aroma e sabor indesejado. Adicionalmente, os compostos voláteis foram extraídos pela técnica microextração em fase sólida com amostragem no headspace (HS-MFES), identificados e quantificados por cromatografia gasosa acoplada a espectrometria de massa (CG-EM). O efeito dos fatores estudados foi avaliado mediante análise de variância (ANOVA) com nível de significância de 90% e os resultados expressos por gráficos de pareto. A análise de componentes principais (ACP) foi realizada com o intuito de identificar dentre os compostos que podem conferir sabor e aroma de cereais aqueles tem a maior contribuição e quais as condições de processo ideias para evitar a formação do sabor e aroma de cereal. De acordo com ACP foi constatado que piridina, 2-metoxi-4-vinilfenol, 2,3-dimetilpirazina, 2,5-dimetilpirazina, 2,6-dimetilpirazina, 4-metiltiazol, pirazina, 2-metoxifenol, 4,5-dimetiltiazol contribuem para formação do sabor e aroma de cereal. Também indicou que a aglomeração deve ocorrer conforme TQ=215ºC, FA=250rpm, TL=120ºC e PV=1,2 x100KPa.The agglomerated instant coffee is the product of the powder instant coffee agglomeration. Its production involves stages of processes whose thermal variations change qualitatively and quantitatively the volatile compounds fractions responsible for the aroma and flavor of the finished product. The coffee beverage industry considers the cereal like flavor and aroma as a fault in the production of the agglomerated instant coffee. In this way, this study had as the aim to apply experimental plan to evaluate the parameters of the processes of the agglomerated instant coffee production on an industrial scale. The effects of those parameters in the coffee volatile components and in the intensity of the cereal taste were evaluated through the fractional 24-1 with resolution IV. The independent variables studied were the burner temperature (BT), the process air flow (AF), the temperature of the fluidized bed hot section (LT) and the steam pressure (SP). The results of the experimental plan were made by the use of sensory analysis performed by a trained team for the detection of the undesired aroma and flavor. Additionally, the volatile compounds were extracted by solid-phase microextractiontechniquewithsampling in theheadspace (HS-SPME), identified and quantified by gas chromatography coupled to mass spectrometry (GC-MS). The effect of the factors studied was evaluated by variance analysis (ANOVA) with significance level of 90% and the results showed by Pareto charts. The principal components analysis (PCA) was made with the aim to identify, among several compounds, those that implies on more cereal flavor and aroma, those which major contribution and which ideal process conditions could be used to reduce the cereal flavor and aroma development. According to PCA, it was found that pyridine, 2-metoxi-4-vinylphenol, 2,3-dimethylpyrazine, 2,5-dimetylpyrazine, 2,6-dimethylpyrazine, 4-methyltiazol, pyrazine, 2-methoxyphenol, 4,5-dimethylthiazol contribute to the development of the cereal flavor and aroma. It was also found that the agglomeration must be according to TQ = 215°C, AF=250 rpm, LT=120°C and EPV = 1,2 x 100 KPa.
23
Ferreira, Maresa Custodio Molinari. "Aplicação de técnicas analíticas instrumentais e físio-químicas com quimioterapia para avaliação da qualidade e discriminação de óleos vegetais e azeites de oliva extra virgem." Universidade Tecnológica Federal do Paraná, 2016. http://repositorio.utfpr.edu.br/jspui/handle/1/2193.
Full textAbstract:
CAPESGarantir a qualidade de produtos alimentícios como óleos vegetais é de grande importância para indústrias e pesquisas relacionadas à área de alimentos. Óleos vegetais podem ter sua composição adulterada ou suspeita devido à presença de outros óleos de menor valor comercial. Além disso, problemas relacionados à conservação durante o armazenamento, como, o desenvolvimento de ácidos graxos de cadeia curta e ácidos graxos livres, podem ser desencadeados por processos de degradação. Alterações na composição de óleos podem ser detectadas a partir do uso de cromatografia, enquanto técnicas titulométricas como índice de acidez e saponificação auxiliam na verificação da estabilidade durante a cadeia de distribuição e consumo. Essas técnicas aliadas à espectroscopia e a métodos de análise estatística multivariada permitem, portanto, determinar a qualidade e realizar a discriminação de óleos vegetais. Foram utilizadas 38 amostras de óleos vegetais sendo: 10 de óleo de soja, 6 de milho, 6 de girassol, 6 de canola, 9 azeites de oliva extra virgem e 1 óleo misto de soja e canola. Foram obtidas as composições em ácidos graxos utilizando-se cromatografia gasosa com detector de ionização de chama, índice de acidez, índice de saponificação e índice de iodo de acordo com as metodologias propostas pela Amerian Oil Chemists Society e foram obtidos os espectros na região do infravermelho médio utilizando-se a espectroscopia no infravermelho com transformada de Fourier. A partir dessas análises obteve-se, portanto, três tabelas de dados (cromatográficos, físico-químicos e espectroscópicos) que, por sua vez, foram submetidos à análise estatística. Análise de componentes comuns e pesos específicos foi aplicada às tabelas de dados para discriminação e avaliação da qualidade das amostras. Amostras apresentaram índice de acidez e saponificação elevado em relação a outros estudos. Óleos de soja, milho e girassol possuem maior teor de ácidos graxos polinsaturados, principalmente ácido linoleico em sua composição, enquanto óleos de canola e azeites de oliva extra virgens apresentam maior teor de ácidos graxos monoinsaturados como ácido oleico. A espectroscopia no infravermelho médio permitiu observar a presença de bandas intensas de absorção demonstrando a presença de grupamentos específicos de ácidos orgânicos como estiramento de carbonos unidos por ligações duplas como isômeros cis, metil e metileno, bandas relacionadas à carbonilas dos triacilgliceróis e ausência de ácidos graxos trans por não apresentarem absorções em 3025 e 968 cm-1. A partir da análise de componentes comuns e pesos específicos foi possível separar os dados em três dimensões comuns contendo 56,44, 34,74 e 8,77% da variância dos dados, as quais foram influenciadas majoritariamente pelas análises cromatográficas, físico-químicas e espectroscópicas, respectivamente. De acordo com o perfil de agrupamento das amostras foi possível realizar a discriminação das amostras em relação às matrizes de extração e observado ausência de adulterações. Cromatografia gasosa foi essencial na discriminação das amostras, análises físico-químicas na avaliação da qualidade enquanto os dados espectroscópicos apresentaram baixa influência nos dados, não colaborando efetivamente para a discriminação das amostras. Por fim, análise de componentes comuns e pesos específicos pode ser aplicada de forma eficaz na discriminação de óleos vegetais.
Ensure the quality of food products such as vegetable oils have great importance to industry and researches related to food. Vegetable oils can have their composition adulterated or suspected due to the presence of other oils with lower commercially value. In addition, problems related to preservation during storage as the development of short chain and free fatty acids can be initiated by degradation processes like rancidity. Alterations in composition can be detected by the use of chromatography while titrimetric techniques assists in the verification of stability during storage. These techniques combined to spectrocopy and multivariate statistical methods allow determine the quality and realize the discrimination of vegetable oils. 38 samples of vegetable oils were used being: 10 soybean, 6 corn, 6 sunflower, 6 canola, 9 extra virgin olive oil and 1 mixed canola and soybean oil. It was obtained the fatty acid composition using gas chromatography (GC-FID), acid, saponification and iodine value according to American Oil Chemists Society methods and the spectra in the mid-infrared region were obtained using Fourier transform infrared spectroscopy. From these analyses it was obtained three data tables (chromatographic, physicochemical and spectrocopic) that, in its turn, were submitted to statistical analysis. Common components and specific weights analysis were applied to the data tables to discrimination and evaluation of the quality of samples. Samples presented acid and saponification values high in relation to other studies. Soybean, corn and sunflower oil have higher contend in polyunsaturated fatty acid, mainly linoleic acid in their composition while canola and extra virgin olive oils presented higher amount of monounsaturated fatty acids as oleic acid. The mid-infrared spectrocopy permitted observe the presence of intense absorption bands demonstrating the presence of specific groups of organic acids like carbon stretch united by double bonds with cis isomers, methyl and methylene, bands related to carbonyls of triacylglycerols and the absence of trans isomers by not present absorptions in 3025 and 968 cm-1. From common components and specific weights analysis was possible separate data in three common dimensions containing 56,44, 34,74 and 8,77% of the data variance which were influenced mainly by chromatographic, physicochemical and spectroscopy analyses, respectivetly. According to the cluster profile of the samples was possible to realize the discrimination of the samples in relation to the extraction matrices and it was observed the absence of adulterations. Gas chromatography was essential to the discrimination and physicochemical analyses to the evaluation of the quality of the samples while the spectrocopic data presented low influence to the data, not contributing effectively to the discrimination of the samples. At last, common components and specific weichts analysis can be applyed efficiently to discrimination of vegetable oils.
24
Mignot, Coralie. "Modulation des activations cérébrales par des odeurs subliminales : une étude en IRM fonctionnelle." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAJ023/document.
Full textAbstract:
Certaines études ont montré que des odeurs subliminales – odeurs d'intensité très faible activant le système olfactif mais non perçues consciemment – peuvent impacter le comportement alimentaire. Cependant, les mécanismes sensoriels et cognitifs impliqués dans le traitement des odeurs subliminales demeurent mal connus. Ce travail de thèse avait pour but d'explorer les activations cérébrales induites par des odeurs subliminales au moyen de l'Imagerie par Résonance Magnétique fonctionnelle. Durant les acquisitions IRM, les participants sont exposés à leur insu à deux odeurs présentées à intensité subliminale puis supraliminale. Quatre réseaux cérébraux mis en évidence par Analyse en Composantes Indépendantes s’avèrent spécifiques de la condition subliminale. Ces réseaux ne sont pas propres au traitement des odeurs et semblent liés à des processus attentionnels et de contrôle exécutif. La modulation de leur activité par des odeurs subliminales apporte des éléments nouveaux pour comprendre l’impact de ces odeurs sur le comportement, et suggère des applications possibles d'utilisation de ces odeurs pour réguler le comportement alimentaireSome studies showed that subliminal odours – odours of very low intensity which activate the olfactory system but are not consciously perceived – can impact food behaviours. However, the sensory and cognitive mechanisms involved in subliminal odours processing remain poorly known. This work aims exploring cerebral activity induced by subliminal odours by the means of functional Magnetic Resonance Imaging. During MRI acquisitions, participants were unknowingly exposed to two odours presented at subliminal intensity and then at supraliminal intensity. Four cerebral networks highlighted by Independent Component Analysis (ICA) prove to be specific to the subliminal condition. These networks are not particular to olfactory processing and seem to be linked to attentional and executive control processes. The modulation of their activity by subliminal odours brings new elements to understand the impact of these odours on behaviour, and suggests possible applications for using these odours to regulate food behaviour
25
Oldfield, Anthony Charles. "Food odour preference behaviour in three Australian Pteropus species (Chiroptera: Pteropodidae)." Phd thesis, 1996. http://hdl.handle.net/1885/109270.
Full textAbstract:
This thesis reports an investigation into the olfactory preferences of three Australian Megachiropteran species, Pteropus poliocephalus, P. scapulatus and P. alecto, for a variety of plant-derived odours. Methodologies were devised for investigating odour preference behaviour, involving equipment design, development of new applications for existing statistical techniques for the analysis of preference data, and analysis of odorous headspace in test mixtures and from flowers in the field. Initially, preliminary behavioural observations (Section II) indicated that all three bat species exhibited positive approach behaviours in response to fruit-derived odours and that they responded both within and between species to different quantities of test odour, 0.5mL of test odour distillate at a decision distance of 125mm producing the optimal responses in P. poliocephalus and P. scapulatus, with P. alecto responding with equal intensity to all odour quantities. A common behavioural ethogram was devised for Pteropus, and applied to more detailed analyses of preference responses. These revealed that within each species, bats expressed different degrees of preference for different odours under controlled conditions. When odour preferences within a species were ranked on a decision axis, odour pairs with low separation values were more likely to change in rank position than those further apart. Not only then was each species able to detect fruit odours, but also they could discriminate between different odour types. Patterns of preference for the same test odour stimuli were not the same when compared across species. P. poliocephalus and P. scapulatus preference hierarchies had distinct regions of clustering of odours where the outcomes of pair-wise choices were variable. In contrast, odour comparisons on P. alecto ranks produce more definitive outcomes, with the most significant agreement in preference patterns across individual bats. The existence of preference intransitivity in all three species indicated that these bats employ a comparative method of odour evaluation as opposed to an absolute utility method often described for foragers with transitive preferences. Thus for these bats the 'value' of odours is dependent upon the context within which the odour comparisons are made. Those odours with low levels of separation on the preference hierarchies were more frequently associated with preference intransistivity. Furthermore, the more generalist feeder P. alecto appeared to have the highest sensitivity to variation in odour concentrations, suggesting that dietary specialisation does not necessarily coincide with olfactory acuity. These bats did not select odours on the basis of absolute concentration or intensity, but on qualitative characteristics. The potential for the development of odour-active agents to interfere with bats' odour preference behaviour, in relation to reducing bat damage is substantial. The continuation of Gas Chromatographic - Olfactometric (GCO) investigation of odours involved with high incidences of preference intransitivity is strongly recommended, as is further study of bat-flower volatile interactions. Until now it has not been possible to state with absolute confidence that non-echolocating Megachiropterans are capable of detecting and discriminating between food-related odours. The speculation regarding Pteropus using their sense of smell to locate food odours, and the potential for developing odour deterrents can now end. Further studies on these topics are now warranted and feasible with the use of the techniques here developed.
26
Gupta, Rajni. "Effect of cyclodextrins on the flavour of goat milk and its yoghurt." 2004. http://hdl.handle.net/10292/426.
Full textAbstract:
A previous study showed that addition of β-cyclodextrin to goat milk made a difference to its flavour, but in an undescribed way. Cyclodextrins (CDs, comprising α- β- and γ-CD) may be able to bind the free branched chain fatty acids in goat milk responsible for the largely undesirable ‘goaty’ flavour. The primary aim was to test the effect of CDs on this flavour in goat milk and its products with a view to marketing goat milk products with reduced flavour intensity. A secondary aim was to test the effect of β-CD on skatole flavour, a characteristic flavour of milk from pasturefed ruminants. Study design and methods: The present study evaluates addition of mainly β-CD to goat milk, cow milk and their products to reduce undesirable flavours. The methods applied were mainly ranking and hedonic assessment in sensory experiments. The tests done were with CDs added to buffers and milks, some of which were flavour-enhanced with 4-methyloctanoic acid as a representative goaty fatty acid, or with skatole. Goat milk yoghurts were also tested. Free fatty acid concentrations, which may be affected by CD binding, were measured after separating cream and skim milk. The methods applied were standard dairy procedures: titration of free fatty acids in milk fat and the copper-salt method for measuring fatty acids in skim milk. A fungal lipase was added to milks to accelerate fat hydrolysis (lipolysis). This was done to increase the concentration of free fatty acids for several experimental purposes. Some minor experiments studies were also done, for example the comparative effect of lipases on goat milk and cow milk, and the lipolytic activity at different temperatures over different times. Results: The results of skatole experiments were inconclusive. The odour of 4-methyloctanoic acid was reduced in acidic buffers by addition of α- and β-CD, particularly the former. Alpha and β-CD were both effective in goaty flavour reduction in goat milk. γ-CD was not effective. In all this work differences were statistically significant to varying levels. Goaty flavour was reduced by addition of β-CD to goat milk yoghurt, but only when added before fermentation (P < 0.001), not after (P = 0.09). The liking scores for goat milk yoghurts for both plain and flavoured yoghurts increased with β-CD treatment (both P < 0.001 for 59 panellists). The chemistry experiments revealed a reduction of free fatty acid concentration in the fat phase when β-CD treatment was added to full cream cow milk. However, analysis of skim milk did not show a corresponding increase in concentration. Further experiments are required to reveal the fate of the ‘missing’ fatty acids. Conclusion: Overall it was shown that under certain conditions, CDs were effective in reducing goaty flavour in milk and yoghurts. Whereas CDs are approved for addition to foods in many countries – including the bellwether U.S.A. – formal approval by Food Standards Australia New Zealand has not yet been finalized. When it is, the way should be clear to market a range of more consumer-acceptable goat milk products in New Zealand as a primary market. In short, this research has significant commercial relevance.
27
Lin, Chun-Yu, and 林純伃. "The Study of Low Odor Food Waste Composting process." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/06270287978914933388.
Full textAbstract:
碩士國立高雄海洋科技大學
海洋環境工程研究所
99
This research is aiming to minimize odor emission during the food waste composting processes via the method of pH control. During the food waste composting process, nitrogen element will convert into NH3 or CH3NH2 in an anaerobic condition, thus cause the odor emission problems. It is known that NH3 is a base material, can be neutralized by the organic acid during the initial stage of the composting processes. As the pH increasing during the composting processes, the neutralization capability decreased as well. When the pH is approaching the neutral condition (pH=7), the NH3 will not be soluble in the water content of the compost, and will emit freely as NH3 gas, thus cause the odor problem. Our creative approach is to use organic acid (such as acetic acid) to adjust the compost pH to maintain at the pH5, pH6, pH7 level; and to compare which situation is the best for NH3 odor emission control. And to select the best pH turning point for setting up the future odor control standard operation procedure (SOP). Also to optimize the organic acid usage amount to evaluate the most feasible approach. During the study, total accumulated amount of NH3 emitted will monitored via the NH3 automatic monitoring instrument and via NH3 dragger tube. During the experiment period, the pH, temperature, ammonia and moisture content of each pile were continually monitored. The result showed: (1) increase mature compost quantity are more, the initial of pH value is higher; The NH3 gas produces early, so the NH3 had the time also early to finish; When pH<6, NH3 not yet Obvious emission, therefore detect the NH3 value not to be high; When pH rise to between 6~7, NH3 starts to emission obviously; when pH>7, NH3 emission to increase suddenly; When pH>8.0, the NH3 emission achieves the peak, this time is odor most serious stage in compost system ; Then NH3 emission has to drop, when compost complete mature, NH3 no longer produces, the pH value also returns drops to between 7.0~7.5. May judge change of the pH value be possible initially to do is the NH3 stink emissions against system the optimal parameter. (2) the fficiency of NH3 control eexperiment knowing, has not increased comparison of the acetic acid to pile, gauges NH3 early, and NH3 presents the crest value to need the date number to be few, the NH3 emission is also high. After that increases (the fat pile of pH value according to the fat pile of increase acetic acid content to be low), NH3 presents density of the crest value to be low, and presents time of the crest value also to postpone. The entire journey ammonia delivers the total quantity respectively is in order pH5 (9,732ppm) < pH6 (17,007ppm) < pH7 (22,493 ppm) < has not adjusted control of the pH value to pile (28,102 ppm). NH3 has the decrement result respectively is when pH5 reduce NH3 enission 65%, pH6 reduce NH3 enission 40%, and when pH7 reduce NH3 enission 20%. If our proposed ideal is to be supported for practical application, we still have to make sure that the added organic acid or mineral acid should not affect on the bioactivity of the compost degradation bacteria; thus, a complete stabilization of the compost can be approached. If this approach can be approved, the absorbed NH3 will indeed enhance the N fixation rate, thus, increase the N fertilization content. And this expectation can be easily proved by total N analysis of the final compost products. Finally, if the proposed ideal can be proved, we can not only minimize the NH3 odor emission problems, but also increase the compost fertilization. This will become a perfect win-win solution to the food waste composting industry.
28
Lopetcharat, Kannapon. "Sub-threshold effects on the perceived intensity of recognizable odorants : the roles of functional groups and carbon chain lengths." Thesis, 2002. http://hdl.handle.net/1957/27222.
Full textAbstract:
Sub-threshold effects were studied in binary and tertiary mixtures
comprising a panel-recognition-concentration odorant and sub-threshold odorant(s).
Sub-threshold condition was maintained by controlling the sub-threshold
concentration as percentages of subjects' individual detection threshold. The
perceived intensities (overall intensity and several descriptors) of recognizable
odorants were rated using magnitude estimation.
Sub-threshold suppression was common and concentration independent in
mixtures comprising odorants with different functional groups. Suppression was
observed at the lowest sub-threshold concentration tested (30% level). At sub-threshold
concentrations, acetic acid suppressed the perceived intensity of acetaldehyde and ethanol but not vice versa. Acetaldehyde and ethanol, however,
suppressed each other when one was at sub-threshold concentrations in binary
mixtures. Enhancement was observed in tertiary mixtures containing acetaldehyde
at panel recognition concentration and was dependent on sub-threshold
concentrations of acetic acid and ethanol.
In mixtures that contained aliphatic acids with different carbon chain
lengths (acetic acid, propanoic acid and n-butanoic acid), sub-threshold
enhancement and suppression depended on concentrations and molecular similarity
of mixture components. Sub-threshold effects were not observed when the acids
were two carbon-atoms different. 50% and 70% sub-threshold levels caused sub-threshold
enhancement; however, higher concentrations caused decrease in
intensity. Sub-threshold suppression was observed in mixtures containing n-butanoic
acid as a recognizable odorants with propanoic acid at a 10% level in a
binary mixture and acetic acid and propanoic acid in a 30%-30% combination in
the tertiary mixture.Graduation date: 2003
29
Vignovich, Martin Nicholas. "Integration of Taste and Odor in Agranular Insular Cortex." Thesis, 2019. https://doi.org/10.7916/d8-qdv7-q834.
Full textAbstract:
Our perception of the world is limited by the senses we are endowed with. In the case of taste, its functional fidelity is so critical for our survival that we come into the world with innate preference for sweet and disgust for bitter. These stereotyped behaviors are hardwired at the lowest levels of taste processing and they support the view that taste serves as an arbiter of the chemical world, passing judgement before permitting ingestion. Yet our experience of foods is manifold. This complexity results from distinct contributions from the sights, sounds and smells of the foods we consume. Of these, odors are a co-equal component of flavor and the impairment of olfaction can disrupt enjoyment of eating and alter patterns of consumption. The goal of this thesis is to identify the neural basis of odor-taste perception and to characterize how neural activity is affected by odor-taste integration. In contrast to the discrete and innate categorization performed by the taste system, the sense of smell enables discrimination of thousands of unique odor percepts which have no innate value. At the level of olfactory cortex, odor representations are randomly distributed and have been shown to be conditioned through association with other stimuli. The act of eating produces near simultaneous taste and odor transduction originating from the same source. Yet despite ultimately projecting to neighboring cortical regions, taste and odor pathways are anatomically segregated prior to reaching the cortex. Using viral tracing strategies, we identified Agranular Insular cortex (AIc) as a putative site of odor-taste integration. We then used in vivo two-photon Ca2+ Imaging to characterize odor and taste responsive neurons and identify changes in population activity when these stimuli were simultaneously presented. We next asked whether specific flavor experiences altered activity in AIc compared to naive animals. Finally, we developed a behavioral task to test whether silencing AIc disrupted perception of a flavor compound.
30
Salvatore, Liliana. "Instrumental and sensory analysis of volatile organic compounds in porcine adipose tissue." Thesis, 2003. https://vuir.vu.edu.au/30248/.
Full textAbstract:
Boar taint has a major economic impact on the pig industry. A rapid method for the
identification of malodour was also required by the pig industry. Electronic nose technology
was thought to be a possible means for the detection of the complete odour profile of samples
of boar fat. However, this was unsuccessful due to a humidity-related problem in the
instrument. A more traditional method of GC-MS analysis compared with human sensory
analysis was then conducted. The most widely held view is that the compounds skatole and
androstenone are the main contributors to boar taint. However various studies have found
that these compounds appear to differ in their contribution to boar taint and they have not
always accounted for all malodour detected. A possible reason for this fact is that not all
compounds have been accounted for when the analyses were made. The GC-MS analysis has
confirmed that skatole and androstenone are significant contributors to boar taint, but further
analysis was also conducted to determine the nature and ·extent of the effect of other
compounds detected in the odour profile. This has shown that three other compounds
contribute significantly to the odour of pork upon cooking. These have been identified
tentatively from their mass spectra. Two of these, pentadecanal and 3-nonen-1-ol have been
found to make a positive contribution to the odour profile, whilst the other 2-nonadecanone
contributes in a negative manner. If only androstenone and skatole are taken into
consideration when correlating chemical and sensory analysis, this accounts for only 3 7% of
the variation. However when all five compounds (androstenone, skatole, pentadecanal, 2-
nonadecanone and 3-nonen-1-ol) are used in the correlation, then one can account for 87% of
the variation. The hitherto omission of these compounds may account for the variation in the
comparison of chemical and sensory analysis of boar taint, seen in previous studies.
31
Ke, Chih-hua, and 柯志樺. "Ozonation of waste gas from food-cooking operations for odor removal." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/40962089375268355318.
Full textAbstract:
碩士國立中山大學
環境工程研究所
104
Characteristics of fumes and odorous compounds emitted from commercial cooking operations depend mainly on the types of cooked food and used seasoning materials, edible oil, as well as cooking operations. An oxidation-reduction-in-series scrubbing process using an aqueous solution containing hypochlorous acid as an oxidant and an aqueous alkaline solution containing hydrogen peroxide as a reductant or oxidant has been developed and successfully applied to the removal of odorants in gases emitted from commercial cooking operations. However, studies on using ozone and/or H2O2 as an oxidant or oxidants to the odorant reduction were limited. In the present study, an oxidation-oxidation-in-series scrubbing process using ozone and aqueous alkaline H2O2 solutions as oxidants was tried to the removal of cooking-gas odorants. Waste gas samples for test were collected from the vent hole of an oven which contains heated samples of food materials (sausage and shrimps) with high odor intensities when heated. Results indicate that with no ozone addition to the odorous gas, no apparent odor removal occurred with a solution of less than 2,000 mg/L hydrogen peroxide at pH > 12. With ozone concentrations of 1 and 2 ppm, hydrogen peroxide was the major oxidant for the odor removal. With ozone of 5 and 20 ppm and hydrogen peroxide of 330-660 mg/L, both ozone and hydrogen peroxide were responsible for the odor removal. Laboratory data indicate that for the effective removal of odors and THCs (total hydrocarbons) form 1,000 m3 of the test gases, the total chemicals were estimated to cost NT $ 48-66. With an optimal condition of 20 ppm ozone and 660 mg/L H2O2, odor concentration (dilution ratio to the odor threshold) of the influent gas could be reduced from 5500 to 550.
32
Lohe, Adrienne. "The role of two anatomically separate olfactory bulbs in shark food odor tracking." Thesis, 2017. https://hdl.handle.net/2144/20706.
Full textAbstract:
Most sharks have well-developed olfactory systems and depend to a large degree on odor information to locate food, home and navigate, and possibly detect predators and mates. The aim of this investigation is to determine the behavioral function of two paired bilateral olfactory bulbs in the smooth dogfish shark, Mustelus canis. The paired olfactory bulbs are a rare and unique feature among elasmobranchs and are absent in bony fishes. Given that the olfactory system of bony fishes contains lateral and medial nerve bundles with behavioral functions in feeding and social behavior respectively, we hypothesize that sharks have an elaborate functional division in which the medial bulb is processing social odors and the lateral bulb food odors. This functional division would parallel the division into an olfactory and an accessory olfactory system, also known as the vomeronasal organ or Jacobson’s organ, which evolved in tetrapods. Our study is based on the behavioral effects of selective transection of the two olfactory tracts to reveal how the brain is processing input from two anatomically distinct olfactory systems. The results show that animals with lateral tract transections showed impaired ability to track a food odor plume while those with medial transections showed no change. Attempts to identify a reliable social odor (pheromone) were not successful, preventing us from determining the deficits expected from medial tract lesions.
33
Wayne-Chen and 陳文川. "The study to establish an innovative odor removaldevice for food waste compost facility." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/90941046444228934113.
Full textAbstract:
碩士國立高雄海洋科技大學
海洋環境工程研究所
98
Main objective of this research is to establish a cost effective odor removal device using ammonia as a probe for study. The established odor removal device was designed based on a cyclone impacting theory. Absorbing fluid utilized was water (or pH controlled water). The cycling turbulence was created via a vacuum pump. With proper impacting design, numerous tiny water droplets were created in the high speed cycling movement. Parameters such as absorbing fluid pH, gas flow rate, operating temperature, electricity consumption, as well as inlet and outlet ammonia concentration were monitored.
34
Su, He-Cheng, and 蘇合成. "Food odor preference and slug mucus trailing behavior of Taiwan slug snake, Pareas formosensis." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/72010737506911541290.
Full textAbstract:
碩士國立臺灣師範大學
生命科學研究所
93
Food searching is an common and important behavior in snakes. Taiwan slug snake (Pareas formosensis), an endemic species in Taiwan, is a specialist, which prey on slugs and snails. In this study, I checked the preference of the snakes to prey orders, and tested whether they could follow the mucus-trail of a slug. The snakes preferred the chemical scents of slugs which were smeared on the cotton swabs. The correct trailing rates of snakes to slug’s venter mucus in Y-maze were significantly higher than the rate of random (50%). The correct trailing rates in dark condition were not significantly different from that of dim (1-2 lux) condition. This suggested that, the snakes might utilize the chemical but not visual cues from mucus to trail the prey. The snakes could trail the mucus both in straight and curved shape. The correctly trailing rates of snakes to mucus of slug’s venter which has been ventilated at 50% RH, 20 ± 2C for 15 or 30 mins were significantly lower than fresh mucus. However, there was no significant difference of trailing slugs’ backside mucus among different ventilation times.
35
Wetherwax, Peter B. "Scent-making by nectar collecting honey bees." Thesis, 1993. http://hdl.handle.net/1957/35698.
Full textAbstract:
Honey bees mark artificial flowers with scents that
advertise about the previous history of the flower to
subsequent foragers. Unrewarding flowers are marked with a
scent, after a single visit, that makes the flower less
attractive to subsequent foragers. Previously rewarding
flowers are initially less attractive than unvisited
flowers but become more and more attractive with each
rewarding visit. Flowers that have rewarded bees four
times are more attractive than unvisited flowers. This
attractant is applied by the bees in response to the
presence of nectar and is not, as has been suggested by
other researchers, inadvertently applied to anything on
which the bee lands.
Similar scent-markings are applied to a real flower,
Lotus corniculatus. One visit was enough to make a flower
less attractive to subsequent foragers but flowers that
consistently offered high amounts of nectar became more
attractive than unvisited flowers. Repellents may be used
by bees to avoid revisiting recently emptied flowers while
attractants may be applied to flowers within a patch that
consistently offer high rewards.
The possible selective pressures responsible for the
evolution of scent-marking was investigated by doing an
energetic analysis. The presence of scent-markings in a
patch results in a 33% increase, over an unmarked patch, in
the amount of sugar obtained per time.
The attractive scent-marking was extracted from a glass
flower and maintained its biological activity when applied
to a clean glass flower. The extract was chemically
analyzed using gas chromatography-mass spectrometry. Four
chemicals were identified; none of the chemicals has
previously been found in honey bees. Mandibular glands
were analyzed as a possible source of the attractant.
Although none of the components was found in the gland
extracts, two previously unidentified chemicals were found.Graduation date: 1994
36
Karyadi, Kenny. "The effects of alcohol odor cues on food and alcohol attentional bias, cravings, and consumption." Thesis, 2015. http://hdl.handle.net/1805/7986.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)In order to elucidate the role of classical conditioning in food and alcohol co-consumption, the present study examined: (1) the effects of alcohol odor cues on alcohol and food cravings and attentional bias (bias in selective attention toward either food or alcohol pictures relative to neutral pictures); and (2) the role of alcohol odor cue elicited cravings and attentional biases on subsequent consumption. Participants (n = 77; mean age = 30.84, SD = 9.46; 51.9% female, 83.1% Caucasian) first completed the lab portion of the study. In this portion, they were exposed to alcohol and neutral odorants, after which their food and alcohol cravings and attentional bias were assessed. Participants then received an online survey the next day, on which they reported their level of food and alcohol consumption following the lab portion of the study. Using repeated measures analysis of covariance, alcohol odor cues were differentially effective in increasing food and alcohol attentional bias and cravings (Fs= 0.06 to 2.72, ps= 0.03 to 0.81). Using logistic and multiple regressions, alcohol odor cue elicited alcohol attentional bias, food attentional bias, and food cravings were associated with later alcohol consumption, but not with later food consumption or concurrent consumption (βs = -0.28 to 0.48, ps = 0.02 to 0.99; Exp(B)s = 0.95 to 1.83, ps = 0.33 to 0.91). Overall, alcohol odor cues can become conditioned stimuli that elicit conditioned food-related and alcohol-related responses, both of which persist long enough to motivate later alcohol consumption; however, these conditioned responses might not persist long enough to motivate later food or concurrent consumption. These findings serve as a first step in clarifying the role of classical conditioning in concurrent consumption. In particular, they suggest that additional empirical investigations are needed to: (1) clarify the classical conditioning mechanisms underlying concurrent consumption; and (2) examine whether interventions targeting classical conditioning mechanisms are effective for reducing alcohol use.
37
Lee, Shi-Jing, and 李世經. "Study of Chemical Scrubber Technology for Removal of Toluene and Odor Emissions from Food and Cooking Processes." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/68656436700098576017.
Full textAbstract:
碩士國立雲林科技大學
環境與安全工程系碩士班
93
Odor emissions from cooking processes are one of the air pollutants which will come under the control of the Air Pollution Control Ordinance in the near future. It is necessary for owners and operators of restaurants and food business to take appropriate measures to minimize these emissions and prevent causing any objectionable odor noticeable at any sensitive receptor in the vicinity or creating other forms of pollution. Chemical oxidation and air washers have a better performance in odor control than electrostatic precipitators but neither one of them alone can effectively reduce odor to an acceptable level. It is now an innovative design to couple these two kinds of technologies together as chemical scrubber that can give a reasonable performance in odor control. The optimum design and operation parameters of chemical scrubber are developed in treating odor problem from cooking processes. This study developed chemical scrubber technology to remove toluene gas using plate column and to control odorous emission from food and cooking processes using packed column. The plate column consisted of a scrubber column ( 220 cm H × 20 cm L × 5 cm W) and a oxidation column ( 200 cm H × 15 cm-dia. ). The study included semi-batch and pilot-plant continuous operations. The packed column consisted of a lampblack pro-treated device ( 45 cm H × 20 cm L × 20 cm W ), a scrubber ( 150 cm H × 30 cm-dia. ) and a oxidation tank ( 60 cm H × 80 cm L × 60 cm W ). The kinetic constant in various combinations such as blank, ozone and UV/ O3 process are conducted individual to better understand the removal efficiency of each mechanism. The field study of the odor problem at six different restaurants was investigated. Four of them were Chinese style restaurants, one of them was Japanese style restaurant, and the last one was a fast food restaurant. The results of field investigation indicated that the species of odor included H2S、DMS、DMDS、NH3、and R-NH2 etc. The species and their concentration ranges at the Chinese style restaurants were THC (4.4 - 7.2 ppm), H2S (0.9 - 8.9 ppm), NH3 (0.3 - 8.5 ppm) and R-NH2 (0.5 - 5 ppm). The content and their concentration at the Japanese style restaurants were THC: (28 ppm), NH3 (2.4 ppm), and R-NH2 (2 ppm). The snack bar was THC (9.2 ppm) and NH3 (0.1 ppm). The fast food restaurant was THC (5.1 ppm), H2S (8.9 ppb), NH3 (0.3 ppm) and R-NH2 (0.4 ppm). THC is used as indicator of pollution. The result of the THC concentration from the Japanese style restaurant is the highest and the Chinese style restaurant has the highest amine emission. Toluene is used as the target pollutant to evaluate the performance of chemical scrubber. The order of toluene removal in semi-batch study were UV/O3, O3, stripping, and UV. All those removal followed the first-order reaction and had the following order KOH > KO3 > KUV. According to mass balance estimation, the removal of 1 g of toluene requires 4.5 g ozone in the ozone process whereas the removal of 1 g of toluene using a combination of UV and ozone need 1.5 g ozone. he toluene removal efficiency in the pilot-scale ozone chemical scrubber were about 90% under the following conditions: gas flow rate of 50 L/min, toluene concentration range of 500 ~ 800 ppm, liquid and air ration (L/G) of 100 L/m3 and ozone dosage of 5.5 g/hr. No others toxic derivatives found in the composition analysis of wastewater. According to regression analysis. The results showed that suitable operational conditions for odor removal in the oxidation tower are L/G = 8.3 L/m3 ( 25 LPM / 3 CMM ), ozone dose = 1.5 g/hr, and height of the packed section = 120 cm. The odorous removal efficiency achieved about 80% and the THC concentration in the food and cooking process could be reduced to below 1-2 ppm. The operating cost fore 12 operation period were NT$ 25 or NT$ 6.9/(1000 m3 waste gas).
38
Brana-Varela, Diego. "Technologies to reduce nutrient excretion and odor production in swine /." 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3242798.
Full textAbstract:
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006.Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6121. Adviser: Peter James Garlick. Includes bibliographical references (leaves 72-89) Available on microfilm from Pro Quest Information and Learning.
39
Reddy, Vijaya P. "The identification of the precursor of off odor causing compounds, produced during storage of ground pearl millet (Pennisetum americanum (L) Leeke)." 1985. http://hdl.handle.net/2097/27539.
Full text
40
"Identification of odorous compounds in commercial chaw tofu and evaluation of the quality of model broths during fermentation." 2005. http://library.cuhk.edu.hk/record=b5892345.
Full textAbstract:
Cheung Hiu-Ming.Thesis (M.Phil.)--Chinese University of Hong Kong, 2005.
Includes bibliographical references (leaves 140-150).
Abstracts in English and Chinese.
ABSTRACT --- p.i
ACKNOWLEDGEMENTS --- p.vi
LIST OF FIGURES --- p.xiii
LIST OF TABLES --- p.xv
Chapter CHAPTER 1 --- LITERATURE REVIEW --- p.1
Chapter 1.1 --- Introduction --- p.2
Chapter 1.2 --- Soybeans --- p.3
Chapter 1.2.1 --- Chemistry and nutritional value of soybeans --- p.3
Chapter 1.2.2 --- Protein composition of soybeans --- p.4
Chapter 1.2.3 --- Volatile compounds in soybeans --- p.4
Chapter 1.3 --- Food fermentation --- p.5
Chapter 1.4 --- Chaw tofu --- p.6
Chapter 1.4.1 --- Preparation of tofu --- p.7
Chapter 1.4.2 --- Preparation of chaw tofu --- p.7
Chapter 1.4.3 --- Microorganisms involved in fermentation of chaw tofu --- p.8
Chapter 1.4.4 --- Volatile components in chaw tofu --- p.11
Chapter 1.4.5 --- Proteolytic activity of chaw tofu --- p.12
Chapter 1.5 --- Stinky brine broth --- p.13
Chapter 1.5.1 --- The pH value of stinky brine broth --- p.13
Chapter 1.5.2 --- The salt percentage of stinky brine broth --- p.14
Chapter 1.5.3 --- Volatile components of stinky brine broth --- p.14
Chapter 1.5.4 --- Parameters affecting ammonia production of stinky brine --- p.15
Chapter 1.6 --- Other fermented soy products --- p.16
Chapter 1.6.1 --- Microorganisms involved in the fermentation --- p.16
Chapter 1.6.1.1 --- Fermentation of soybean by bacteria --- p.17
Chapter 1.6.1.1.1 --- Natto --- p.17
Chapter 1.6.1.1.2 --- Kinema --- p.18
Chapter 1.6.1.1.3 --- Soy daddawa --- p.19
Chapter 1.6.1.1.4 --- Hawaijar --- p.20
Chapter 1.6.1.1.5 --- Thua nao --- p.21
Chapter 1.6.1.2 --- Fermentation of soybean by moulds --- p.21
Chapter 1.6.1.2.1 --- Tempe --- p.21
Chapter 1.6.1.2.2 --- Sufu --- p.22
Chapter 1.6.1.2.3 --- Soy sauce --- p.22
Chapter 1.6.1.2.4 --- Soy paste --- p.23
Chapter 1.6.2 --- Formation of volatile compounds during Bacillus fermentation --- p.24
Chapter 1.6.3 --- Biochemical changes during fermentation --- p.21
Chapter 1.7 --- Methods of flavor analysis --- p.30
Chapter 1.7.1 --- Headspace Analysis --- p.31
Chapter 1.7.2 --- Aroma characterization --- p.32
Chapter CHAPTER 2 --- IDENTIFICATION OF ODOROUS COMPOUNDS IN COMMERCIAL CHAW TOFU BASED ON ODOR ACTIVITY EVALUATION --- p.42
Chapter 2.1 --- Introduction --- p.43
Chapter 2.2 --- Materials & Methods --- p.46
Chapter 2.2.1 --- Experimental samples --- p.46
Chapter 2.2.2 --- Headspace-Gas Chromatography-Mass Spectrometry (GC-MS) --- p.46
Chapter 2.2.3 --- Conditions of the Gas Chromatography-Mass Spectrometry (GC-MS) --- p.47
Chapter 2.2.4 --- Compound identifications --- p.48
Chapter 2.2.5 --- Quantification of compounds --- p.48
Chapter 2.2.6 --- Statistical analysis --- p.48
Chapter 2.2.7 --- Calculation of odor activity value (OAV) --- p.49
Chapter 2.3 --- Results & Discussion --- p.50
Chapter 2.3.1 --- Odor activity value (OAV) --- p.51
Chapter 2.3.2 --- Volatile compounds in fresh samples --- p.51
Chapter 2.3.2.1 --- Comparison of odorous compounds in fresh samples among different locations --- p.52
Chapter 2.3.3 --- Volatile compounds in deep-fat fried samples --- p.53
Chapter 2.3.3.1 --- Comparison of odorous compounds in deep-fat fried samples among different locations --- p.54
Chapter 2.3.4 --- Comparison between fresh and deep-fat fried samples --- p.55
Chapter 2.3.5 --- Odorous compounds of chaw tofu based on OAVs --- p.56
Chapter 2.3.6 --- Possible ways for formation of odorous compounds --- p.58
Chapter 2.3.6.1 --- Protein degradation --- p.58
Chapter 2.3.6.2 --- Lipid degradation --- p.59
Chapter 2.3.7 --- Comparison between volatile compounds in chaw tofu and others fermented soybean products --- p.60
Chapter 2.4 --- Conclusion --- p.61
Chapter CHAPTER 3 --- IDENTIFICATION OF ODOROUS COMPOUNDS IN COMMERCIAL CHAW TOFU BASED ON GAS CHROMATOGRAPHY-OLFACTOMETRY --- p.67
Chapter 3.1 --- Introduction --- p.68
Chapter 3.2 --- Materials & Methods --- p.71
Chapter 3.2.1 --- Experimental samples --- p.71
Chapter 3.2.2 --- Gas Chromatography-Mass Spectrometry-Flame Ionization Detection-Olfactometry (GC-MS-FID-O) --- p.71
Chapter 3.2.3 --- Conditions of the Gas Chromatography-Mass Spectrometry --- p.72
Chapter 3.2.4 --- Detection of odor active compounds --- p.73
Chapter 3.2.5 --- Compound identifications --- p.73
Chapter 3.3 --- Results & Discussion --- p.74
Chapter 3.3.1 --- "Fecal, rancid and putrid odor" --- p.74
Chapter 3.3.2 --- "Cabbages, sulfurous and meaty odor" --- p.76
Chapter 3.3.3 --- Green odor --- p.77
Chapter 3.3.4 --- Other odor contributing compounds --- p.77
Chapter 3.3.5 --- Odor generate during deep-fat frying --- p.78
Chapter 3.3.6 --- Comparison between GC-O and OAVs --- p.79
Chapter 3.3.7 --- Comparison between volatile compounds in chaw tofu and others fermented soybean products --- p.80
Chapter 3.4 --- Conclusion --- p.82
Chapter CHAPTER 4 --- EVALUATION OF CHAW TOFU MODEL FERMENTATION BROTH --- p.86
Chapter 4.1 --- Introduction --- p.87
Chapter 4.2 --- Materials & Methods --- p.90
Chapter 4.2.1 --- Model fermentation broth preparation --- p.90
Chapter 4.2.2 --- Tofu sample preparation --- p.91
Chapter 4.2.3 --- Gas Chromatography-Mass Spectrometry --- p.91
Chapter 4.2.3.1 --- Conditions of Gas Chromatography-Mass Spectrometry (GC-MS) --- p.92
Chapter 4.2.3.2 --- Compound identification --- p.93
Chapter 4.2.3.3 --- Quantification of compounds --- p.93
Chapter 4.2.4 --- Viable cell counts --- p.93
Chapter 4.2.5 --- pH value and soluble content --- p.94
Chapter 4.2.6 --- Proteolytic activity --- p.94
Chapter 4.2.7 --- Statistical analysis --- p.95
Chapter 4.3 --- Results & Discussion --- p.96
Chapter 4.3.1 --- Headspaces analysis --- p.96
Chapter 4.3.1.1 --- Changes in volatile composition in model fermentation broths --- p.97
Chapter 4.3.1.2 --- Comparison of volatile compositions between the broths --- p.98
Chapter 4.3.1.3 --- Comparison of volatile compositions among the three deep-fat fried fermented tofu with different broths --- p.101
Chapter 4.3.1.4 --- Comparison of volatile compositions of deep fat fried fermented tofu with that of the commercial chaw tofu --- p.102
Chapter 4.3.2 --- Liquid samples analysis --- p.104
Chapter 4.3.2.1 --- "Changes in viable cell counts, pH values, protease activities and soluble solid contents within model fermentation broths during fermentation" --- p.106
Chapter 4.3.2.2 --- Viable cell counts --- p.107
Chapter 4.3.2.3 --- Soluble solid content --- p.108
Chapter 4.3.2.4 --- Proteolytic activity --- p.106
Chapter 4.3.2.5 --- pH value --- p.110
Chapter 4.4 --- Conclusion --- p.112
Chapter CHAPTER 5 --- GENERAL CONCLUSION --- p.127
APPENDIX --- p.130
IDENTIFICATION OF MICROORGANISMS PRESENTED IN THE MODEL CHAW TOFU FERMENTATION BROTHS BY MICROBIAL IDENTIFICATION SYSTEM (MIDI) --- p.130
Materials & Methods --- p.130
Model fermentation broth preparation --- p.130
Viable cell counts --- p.131
Microbial Identification System (MIDI) --- p.131
Results --- p.133
Suggestion on further investigation --- p.134
REFERNECES --- p.141