Made available in DSpace on 2017-07-10T17:37:51Z (GMT). No. of bitstreams: 1 Sidiane_Coltro.pdf: 604676 bytes, checksum: eccb769c94921f8082441892d38b80d7 (MD5) Previous issue date: 2012-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The strawberry is a fruit that is highly perishable and are very susceptible to physical damage and fungal attack. The use of fungicides has been the primary method for reducing post-harvest diseases. Accordingly, alternative methods free of chemicals must be used in post-harvest to maintain the quality and prolong the life reduce the incidence of fungi. Therefore, this study aimed to evaluate the effect of heat treatment and post-harvest salicylic acid in the response of strawberry-related activities of the enzymes polyphenol oxidase and peroxidase, the contents of total phenols, anthocyanins and ascorbic acid and the incidence of pathogens during storage of fruits. This study was divided into two experiments. In the first experiment, Dover strawberries were treated thermally in an oven at 45°C for 3 hours and stored at 5°C for 1, 7 and 14 days and analyzed. After these periods, the fruit were removed and transferred to the cooling environment at 20°C for 2 days to be analyzed again. We used a completely randomized in factorial scheme (2x6), with 12 treatments and four replicates of 10 berries per tray. In the second experiment, strawberries Dover were heat treated in an oven with forced air at 45°C for 3 hours and after immersed in a solution of salicylic acid 2.0 mM L-1 for 5 minutes; then they were stored under refrigeration (5°C) and after 1,7 and 14 days and transferred to a room at 20°C for 2 days and the be analyzed. The design was completely randomized in factorial scheme (4x3), with 12 treatments and four replications. Were evaluated the activity of polyphenoloxidase, peroxidase, phenylalanine ammonia-lyase, the incidence of fungi, total phenols, anthocyanins, ascorbic acid, pH, titratable acidity, soluble solid and weight loss. It was found that the metabolism postharvest Dover cv. strawberry has been modified by application of heat treatment, because the results showed that the activity of polyphenoloxidase, peroxidase and phenylalanine ammonia-lyase and ascorbic acid, total phenols and anthocyanins, and the incidence of fungi were lower in heat-treated strawberries. The heat treatment resulted in higher acidity, higher soluble solids and lower mass loss. The heat treatment is not provided, according to the incidence of fungi and weight loss, increased shelf life of strawberries, being limited to seven days of storage. However, the addition of salicylic acid to heat treatment was less effective than other treatments for most variables, indicating that it is disadvantageous. However, heat shock alone was more effective in reducing the activity of peroxidase, polyphenoloxidase showed lower activity compared to the control at 7 +2 days and did not differ from other treatments at 14 +2 days, was effective in maintaining high levels phenolic compounds, anthocyanins and ascorbic acid up to 7 +2 days / O morango é um fruto que apresenta alta perecibilidade e, são bastante suscetíveis a danos físicos e ataque de fungos. O uso de fungicidas químicos tem sido o principal método para reduzir as doenças pós-colheita. Nesse sentido, métodos alternativos livres de produtos químicos devem ser utilizados em pós-colheita para manter a qualidade, prolongar a vida útil e diminuir a incidência de fungos. Assim, o presente trabalho teve por objetivo avaliar o efeito do tratamento térmico pós-colheita e do ácido salicílico na resposta do morango relacionada à atividade das enzimas polifenoloxidase e peroxidase, aos conteúdos de fenóis totais, antocianinas e ácido ascórbico e à incidência de patógenos durante o armazenamento dos frutos. Este estudo foi dividido em dois experimentos. No primeiro experimento, morangos cultivar Dover, foram tratados termicamente em estufa a 45°C por 3 horas e armazenados a 5 ºC por 1, 7 e 14 dias e analisados. Após esses períodos, os frutos foram retirados da refrigeração e transferidos para ambiente a 20 ºC por 2 dias para serem analisados novamente. Foi utilizado o delineamento inteiramente casualizado, em esquema fatorial (2x6), com 12 tratamentos e quatro repetições com 10 morangos por bandeja. No segundo experimento, morangos cultivar Dover foram tratados termicamente em estufa com circulação forçada de ar com 45°C por 3 horas e depois imergidos em solução de ácido salicílico 2,0 mMol L-1 por 5 minutos, depois foram armazenados sob refrigeração (5°C) e após 1, 7 e 14 dias foram transferidos para ambiente a 20 ºC por 2 dias para então serem analisados. O delineamento foi inteiramente casualizado, em esquema fatorial (4x3), com 12 tratamentos e quatro repetições. Foram avaliados a atividade de polifenoloxidase, peroxidase, fenilalanina amônia-liase, incidência de fungos, fenóis totais, antocianinas, ácido ascórbico, pH, acidez titulável, sólidos solúveis e perda de massa. Foi constatado que, o metabolismo pós-colheita de morangos cv. Dover foi modificado pela aplicação de tratamento térmico, pois os resultados mostraram que a atividade de polifenoloxidase, peroxidase e fenilalanina amônia-liase e os teores de ácido ascórbico, fenóis totais e antocianinas e a incidência de fungos foram inferiores em morangos tratados termicamente. O tratamento térmico resultou em maior acidez titulável, maior teor de sólidos solúveis e menor perda de massa. O tratamento térmico não proporcionou, segundo a incidência de fungos e a perda de massa, aumento da vida útil dos morangos, ficando limitado aos sete dias de armazenamento refrigerado. Entretanto, a adição de ácido salicílico ao tratamento térmico, se mostrou menos efetivo que os demais tratamentos para a maioria das variáveis analisadas, indicando ser desvantajoso. Porém, o choque térmico isolado mostrou-se mais efetivo em reduzir a atividade de peroxidase, apresentou atividade inferior de polifenoloxidase comparado ao controle aos 7+2 dias e não diferiu dos demais tratamentos aos 14+2 dias, se mostrou efetivo em manter níveis elevados de compostos fenólicos, antocianinas e ácido ascórbico até 7+2 dias

Made available in DSpace on 2017-07-10T17:37:56Z (GMT). No. of bitstreams: 1 2012_Maria_Cristina_Copello_Rotili.pdf: 1512539 bytes, checksum: 0de2ebbb956f5ea7ef24fdd44b97de82 (MD5) Previous issue date: 2012-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The passion fruit is a climacteric fruit and at the phase of the Post harvest suffers important physiological transformations resulting of its own metabolism of ripening and others oxidative stress. The storage conditions of the passion fruit establish determining factor for its conservation. The refrigeration and modified atmosphere have been widely used in fruits, and the yellow passion fruit appears very promising in the use of these techniques, due to high instability of its physical and physiological characteristics post harvest. Therefore, this study was conducted with the objective of to evaluate the biochemical, physicochemical and microbiological of the passion fruit during its storage in modified atmosphere and at different temperatures. The work was divided into two experiments: The first consisted of the evaluation of the effect of storage temperature, where the fruits were stored at 5 º and 24 ºC. And in the second experiment evaluated the effect of modified atmosphere during the storage of the fruits at 5 °C. In both experiments the evaluations occurred at intervals of 10 days for 40 days, being evaluated the antioxidant activity DPPH and TEAC, the content of total phenolic compounds, ß-carotene and ascorbic acid, and physical and microbiological quality of the fruits. In the second experiment were included assessments of total titratable acidity, total soluble solids and enzymatic activity for polyphenol oxidase and peroxidase. In both experiments, it was utilized a completely randomized delineation, with five repetitions. The results showed that the total phenolic compounds, β-carotene and antioxidant activity of passion fruit juice were not affected by storage temperature and the content of total phenolic compounds of the juice increased with storage time. The effects of high temperature during storage were more evident in the appearance of the fruit than at the nutritional quality of the juice. The antioxidant activity of the juice, expressed in kidnapping DPPH radical, decreased during the storage, independent of temperature. Under the conditions of storage at 5 ° C and normal atmosphere, the shelf-life of passion fruit was higher and lasted up to 20 days in good conditions of marketing. The use of modified atmosphere was not able to reduce the losses of antioxidant activity of passion fruit juice during its storage. Total phenolics compounds and ascorbic acid were not affected by the use of modified atmosphere. Up to 30 days of storage there was suppressive effect of the activity of pathogens similarly in the two atmospheres of storage, suggesting that this effect was more related to low temperature. At 40 days of storage the modified atmosphere was more effective in inhibiting the activity of pathogens. The modified atmosphere was effective in reducing fresh mass loss and wrinkling of the rind, evidencing the high sensitivity of the fruit changes involving the loss of water and the importance of the use of modified atmosphere in maintaining their physical quality. Total soluble solids and total titratable acidity decreased during the storage and the modified atmosphere did not affect these results. The use of modified atmosphere during the storage at 5° C provided great conditions for marketing the yellow passion fruit up to 20 days. This study revealed the existence of activities of the polyphenoloxidase and peroxidase enzymes in the yellow passion fruit rind, but they were not identified in the fruit juice / O maracujá-amarelo é um fruto climatérico e na fase pós-colheita sofre importantes transformações fisiológicas decorrentes do próprio metabolismo de maturação e de outros estresses oxidativos. As condições de armazenamento do maracujá estabelecem fator determinante para sua conservação. A refrigeração e a atmosfera modificada têm sido largamente utilizadas em frutos, e o maracujá-amarelo se apresenta muito promissor no uso dessas técnicas, devido à elevada instabilidade de suas características físicas e fisiológicas pós-colheita. Assim, este estudo foi realizado com o objetivo de avaliar as respostas bioquímicas, físico-químicas e microbiológicas do maracujá-amarelo durante o seu armazenamento em atmosfera modificada e em diferentes temperaturas. O trabalho foi dividido em dois experimentos: O primeiro constou da avaliação do efeito da temperatura de armazenamento, onde os frutos foram armazenados em temperatura de 5º e 24ºC. E no segundo experimento foi avaliado o efeito da atmosfera modificada durante o armazenamento dos frutos a 5 ºC. Em ambos os experimentos as avaliações ocorreram em intervalo de 10 dias durante 40 dias, sendo avaliada a atividade antioxidante DPPH e TEAC, os teores de compostos fenólicos totais, ß-caroteno e ácido ascórbico e a qualidade física e microbiológica dos frutos. No segundo experimento foram incluídas as avaliações de acidez total titulável, sólidos solúveis totais e a atividade enzimática para polifenoloxidase e peroxidase. Em ambos os experimentos, foi utilizado o delineamento inteiramente casualizado, com cinco repetições. Os resultados mostraram que os compostos fenólicos totais, β-caroteno e atividade antioxidante do suco do maracujá-amarelo não foram influenciados pela temperatura de armazenagem e o conteúdo de compostos fenólicos totais do suco aumentou com o tempo de armazenagem. Os efeitos da elevada temperatura durante o armazenamento foram muito mais evidentes na aparência do fruto do que na qualidade nutricional do suco. A atividade antioxidante do suco, expressa em sequestro do radical DPPH, diminuiu durante o armazenamento, independente da temperatura. Nas condições do armazenamento a 5 ºC e em atmosfera normal, a vida-de-prateleira do maracujá-amarelo foi superior e se estendeu até 20 dias em boas condições de comercialização. O uso da atmosfera modificada não foi capaz de reduzir as perdas de atividade antioxidante do suco do maracujá-amarelo, durante o seu armazenamento. Compostos fenólicos totais e ácido ascórbico também não foram influenciados pelo uso da atmosfera modificada. Até 30 dias de armazenamento houve efeito supressor da atividade de patógenos similarmente nas duas atmosferas de armazenagem, sugerindo que este efeito esteve mais relacionado à baixa temperatura. Aos 40 dias de armazenamento a atmosfera modificada foi mais eficiente em inibir a atividade de patógenos. A atmosfera modificada foi eficaz na redução da perda de massa fresca e do enrugamento da casca, ficando evidente a alta sensibilidade dos frutos à alterações envolvendo a perda de água e a importância do uso da atmosfera modificada na manutenção da sua qualidade física. Sólidos solúveis totais e acidez total titulável diminuíram durante o armazenamento e a atmosfera modificada não influenciou estes resultados. O uso da atmosfera modificada durante o armazenamento a 5 ºC proporcionou condições ótimas para comercialização do maracujá-amarelo até 20 dias. Este estudo revelou a existência de atividade das enzimas polifenoloxidase e peroxidase na casca do maracujá-amarelo, mas não foram identificadas no suco do fruto

Made available in DSpace on 2017-05-12T14:47:05Z (GMT). No. of bitstreams: 1 Adriana Sbardeloto Di _Domenico.pdf: 3233687 bytes, checksum: 1957cd3e9f309d6954a03c673b9b5592 (MD5) Previous issue date: 2014-02-28 / Brazil is one of the largest producers of grains, and maize is the second most produced grain in the country. As this cereal is directly related to human and animal food basis, many matters appear on the maintenance of their post-harvest quality, especially during storage, due to the increased attention to food safety. Despite this importance, maize is often stored on farms in inappropriate conditions, exposed to quantitative and qualitative losses, the development of toxigenic fungi and aflatoxin contamination, a substance capable of causing severe damage to human and animal health, as well as many agribusiness losses. The objective of this research was evaluating storage alternatives viable to farms through two storage experiments (2012 winter crop 2012/2013 summer harvests), for assessment of the quality of stored maize in different packings for 12 months. The experimental design was a 4 x 5 factorial, whose factors were four types of packaging storage (conventional sacks, bags hermetically sealed, metallic silo and cobs) and five time periods (0, 3, 6, 9 and 12 months). Two maize hybrids (2B688RR, 30K73Hx) cultivated in the region of the town of Dois Vizinhos were used, in the southwest of Paraná. The storage was conducted in ambient conditions and the following parameters were evaluated: water content, ash, protein, fat, grains without defects, volumetric weight, one-thousand grains weight, counting of Aspergillus sp, Fusarium sp, Penicillium sp, total of molds and yeasts and occurrence of aflatoxins (B1, B2, G1 and G2). The results obtained in each experiment, when attended the presuppositions of the mathematical model, were evaluated by use of analysis of variance and differences between means (p<0.05) by Tukey test at 5% significance level, and when not attended them, by Kruskal-Wallis also at 5% significance level. Furthermore, the Principal Component Analysis (PCA) was done to determine which of the variables evaluated was responsible for the largest variations in the quality of stored maize. It was found in both storages that maize kernels placed in sealed bags presented the lowest water content. Also that regardless of packaging and hybrid maize, there were an increase in ash content of grains and the decrease of the percentage of grains without defects and volumetric weight. It was detected the incidence of Aspergillus sp. Fusarium sp. and Penicillium sp., respectively 20.37, 86.11 and 94.44% of the samples of maize season winter storage, and in 83.3, 91.6 and 90.07% of the samples from the summer season storage. Aspergillus sp. was only detected after 3 months of storage in the first experiment, while in the second since harvesting. The occurrence of Fusarium sp. tended to decrease during storage, and Penicillium sp. was higher in corn conditioning in cobs. There was no influence of types of packaging and storage time on the occurrence of Aspergillus sp. and aflatoxins in maize season winter storage. However, the conditioning in maize cobs of season storage summer had the lowest count of Aspergillus sp. and did not present aflatoxin. Aflatoxins (B1+B2+G1+G2) detected ranged from 2.77 to 14.45 &#956;g kg-1 and from 3.03 to 197.51 &#956;g kg-1 respectively in the maize storage winter and summer. Besides this, none of the samples of the first storage showed contamination higher than 20 &#956;g kg-1, while in the second 41 samples presented higher values. The results are due to the different climatic conditions of the periods of cultivation of hybrid maize (summer and winter seasons) and storage experiments, the disparity in the incidence of Aspergillus sp. and aflatoxin contamination. The conclusion is that by ACP all variables assessed in this study are important for the quality of stored maize. / O Brasil é um dos maiores produtores mundiais de grãos e o milho é o segundo grão mais produzido no país. Como este cereal está diretamente relacionado à base alimentar humana e animal, surgem muitas preocupações a respeito da manutenção de sua qualidade no pós-colheita, em especial ao longo do armazenamento, com aumento das atenções à segurança alimentar. Apesar disso, muitas vezes o milho é armazenado nas propriedades rurais, em condições inadequadas, exposto a perdas quantitativas e qualitativas, ao desenvolvimento de fungos toxigênicos e à contaminação por aflatoxinas, substância capaz de causar graves danos à saúde humana e animal, além de inúmeros prejuízos agropecuários. Assim, o objetivo deste trabalho foi avaliar alternativas de armazenagem, viáveis a propriedades rurais, através de dois experimentos de armazenagem (safra de inverno 2012 e safra de verão 2012/2013), nos quais se avaliou a qualidade do milho armazenado em diferentes acondicionamentos, por 12 meses. O delineamento experimental utilizado foi um fatorial 4 x 5, cujos fatores foram quatro tipos de acondicionamentos de armazenagem (sacarias convencionais, bolsas seladas hermeticamente, silo metálico e espigas) e cinco períodos de tempo (0, 3, 6, 9 e 12 meses). Utilizaram-se dois híbridos de milho (2B688RR, 30K73Hx) cultivados na microrregião de Dois Vizinhos, sudoeste do Paraná. A armazenagem foi realizada em condições ambientais e os parâmetros avaliados foram: teor de água, cinzas, proteínas, lipídios, grãos sem defeitos, peso volumétrico, peso de mil grãos, contagem de Aspergillus sp., Fusarium sp., Penicillium sp., total de bolores e leveduras e ocorrência de aflatoxinas (B1, B2, G1 e G2). Os resultados obtidos em cada experimento, quando atendiam às pressuposições do modelo matemático, eram avaliados pelo emprego da análise de variância e as diferenças entre as médias (p < 0,05) pelo teste de Tukey, a 5% de significância, quando não, pelo teste de Kruskal-Wallis, também a 5% de significância. Além disso, realizou-se a análise dos componentes principais (ACP) para verificar quais das variáveis avaliadas, eram responsáveis pelas maiores variações na qualidade do milho armazenado. Verificou-se, em ambos os armazenamentos, que os grãos de milho acondicionados em bolsas herméticas apresentaram o menor teor de água. Independente do acondicionamento e do híbrido de milho houve aumento do conteúdo de cinzas dos grãos, redução da percentagem de grãos sem defeitos e do peso volumétrico. Constatou-se a incidência de Aspergillus sp., Fusarium sp. e Penicillium sp., respectivamente, em 20,37, 86,11 e 94,44% das amostras de milho do armazenamento safra de inverno; em 83,3, 91,6 e 90,07% das amostras do armazenamento safra de verão, respectivamente. O Aspergillus sp. foi detectado somente aos 3 meses de armazenagem no primeiro experimento, enquanto no segundo desde a colheita. A ocorrência de Fusarium sp. tendeu a diminuir durante a armazenagem e a de Penicillium sp. foi maior no milho acondicionado em espigas. Não houve influência dos tipos de acondicionamentos e do tempo de armazenagem na ocorrência de Aspergillus sp. e de aflatoxinas no milho do armazenamento safra de inverno. Já o milho acondicionado em espigas do armazenamento safra de verão apresentou a menor contagem de Aspergillus sp. e não apresentou aflatoxinas. Os níveis de aflatoxinas (B1+B2+G1+G2) detectados variaram de 2,87 a 14,45 &#956;g kg-1 e de 3,03 a 197,51 &#956;g kg-1, respectivamente no milho dos armazenamentos safra de inverno e safra de verão, além disso, nenhuma das amostras do primeiro armazenamento apresentou contaminação acima de 20 &#956;g kg-1. No segundo armazenamento, 41 amostras apresentaram contaminação. Resultados atribuídos, principalmente, às diferentes condições climáticas dos períodos de cultivo dos híbridos de milho (safra de verão e safra de inverno) e dos experimentos de armazenagem, a disparidade na incidência de Aspergillus sp. e na contaminação por aflatoxinas. Conclui-se, pela ACP, que todas as variáveis aferidas neste trabalho têm importância na qualidade do milho armazenado.

Forced convective drying using a wind turbine mechanically connected to a ventilation fan was hypothesized for low cost and rapid grain drying in developing countries. The idea was tested using an expandable wind turbine blade system with variable pitch, at low wind speeds in a wind tunnel. The design was based on empirical and theoretical models embedded in a graphical user interface (GUI) created to estimate airflow-power requirements for drying ear corn. Output airflow (0.0016 - 0.0052 m3kg-1s-1) increased within the study wind speed range (2.0 - 5.5 m/s). System efficiency peak (8.6%) was observed at 3.5 m/s wind speed. Flow resistance was overcome up to 1m fill depth in 0.5 m x 0.5 m wide drying bin. Drying study at different airflow rates (no forced convection, 0.002 m3kg-1s-1 and 0.008 m3kg-1s-1) were conducted in a controlled environment at 35oC and 45% relative humidity with mean drying time; 40.3, 37.9 and 22.9 h respectively, that reduced with increasing airflow while drying the ear corn from 22% to 15% moisture content. The overall result supports the hypothesis that the wind convection system increased grain drying rates and should be further developed.

Active packaging systems can offer significant advantages in preventing quality loss in horticultural products through control of microbial and/or physiological activity. By delivering and sustaining volatile active agents at effective levels in a package atmosphere, significant shelf life extension can thus be achieved. Design of these systems is complicated by the number of possible package, product, active agent and carrier combinations that can be employed and the significant interactions that may occur between these components. Mathematical modelling can be used to simplify system design and reduce the number of experimental trials required to achieve optimal active packaging systems. In this study a generalised modelling methodology was developed and validated to facilitate the design of active controlled volatile release packaging systems for horticultural products. The modelling methodology was developed using an example system which comprised tomatoes packed under a modified atmosphere (MA; 5 % (v/v) CO2 and 10 % (v/v) O2) in a LDPE bag with a polymer film sealed sachet containing silica gel pre-saturated with the antifungal agent hexanal. Experimental trials showed that for this system a target sustained hexanal concentration of 40-70 ppm was required. This was shown to be (i) the minimum inhibitory concentration (MIC) for controlling Botrytis cinerea growing on tomatoes stored at 20°C and ~99%RH, (ii) to have only a relatively minor influence on the postharvest quality of tomatoes under these active MA conditions, and (iii) to promote only a small apparent uptake of hexanal from the atmosphere by the tomatoes. The effective hexanal permeabilities of Tyvek , LDPE and OPP sachet films were characterised using the isostatic method and shown to exhibit a dependence on both temperature (10 and 20°C) and concentration (over a range of 0.01-0.22 mol m[superscript -3). Average permeabilities decreased in the order of Tyvek > LDPE > OPP, respectively, at all temperatures at comparable hexanal partial pressures. Hexanal sorption isotherms for silica gel at both 10 and 20ºC were determined using the gravimetric method and were reasonably well described by the Langmuir equation. The equilibrium amount adsorbed was significantly reduced at the higher temperature but the pre-adsorption of water vapour on hexanal uptake on silica gel showed no uniform trend on the sorption characteristics suggesting that multicomponent sorption is complex. A generalised modelling methodology was developed through conceptualising key mass transfer processes involved in these active MA packaging systems. Quantitative methods for deciding the relative importance of each process were established together with guidelines for when simplifying assumptions could be made. This information was formalised into a decision tree to allow appropriate assumptions to be made in model formulation without unacceptable loss of model accuracy. Methods to develop generalised equations from these assumptions to describe changes in the sachet, package headspace and outer bag film with respect to an active agent and MA gases were then identified. The mathematical modelling methodology was applied to the example hexanal release active MAP tomato packaging system. For these systems there was a high initial peak in package headspace concentration during the first 24 h which declined to a quasi steadystate concentration over a period of days. The quasi steady-state headspace concentrations were generally in the MIC range and were well predicted by the model. Interactions between water vapour and silica gel may have been responsible for the relatively higher hexanal concentration at the onset of release from the Tyvek sachet (a highly porous material). However the influence of water vapour (>95% RH in the MA bag containing tomatoes) during the quasi steady-state period appeared to be insignificant for all sachet films. The model was successfully applied to a range of packaging configurations and storage temperatures. A lack of fit was evident between model predictions and experimental trials during the initial (unsteady-state) stages of the release pattern for both headspace vapour concentrations and adsorbed mass on the silica gel. These differences were attributed to (i) model input uncertainties, chiefly with regard to the estimated coefficients of both the Langmuir isotherm equation and film permeability, and (ii) overestimated effective permeability values predicted by extrapolation of the concentration dependence of film permeability beyond the conditions for which the permeability was measured. These results suggest improved models for the effective permeabilities of the films, quantified under a range of vapour concentrations and concentration gradients, are required for better describing fluxes across the sachet film. Despite these limitations, the model did describe the general release pattern. The model was then used to pose a range of ‘what-if’ scenarios investigating the release patterns predicted for different active packaging designs. This analysis gave useful insights into how sorption isotherm shape and package/sachet design parameters can be manipulated to achieve different volatile release platforms. The work clearly demonstrated the importance of accurate data for permeability of volatile compounds through polymer films and for sorption of the active agent on the carrier phase. More work on characterising these systems is recommended to further improve modelbased design methods for active MAP systems. Overall the generalised methodology developed can be confidently adopted for constructing a mathematical model that provides sufficient accuracy and simplicity to be implemented for designing active packaging systems for horticultural and food products.

Gulf oysters are harvested and consumed year-round, with more than 90% consumed in a raw, unprocessed state. A chief concern of policymakers in recent years is the incidence of Vibrio vulnificus infection following raw seafood consumption. V.vulnificus refers to a halophilic bacterium naturally occurring in brackish coastal waters, which concentrates in filter-feeding oysters. Proposed FDA legislation requiring processing of all raw Gulf oysters sold during warmer summer months threatens the Gulf oyster industry, as little to no research regarding demand for post-harvest processing (PHP) has preceded the potential mandate. This research endeavors to examine the relationship between oyster consumers' fears of V.vulnificus infection and their willingness-to-pay (WTP) for processing of an oyster meal. The psychological model of Protection Motivation Theory (PMT) is employed alongside the economic framework of contingent valuation (CV) to result in an analysis of oyster processing demand with respect to threats and efficacy. A survey administered to 2,172 oyster consumers in six oyster producing states elicits projected consumption and PMT data. Principal Component Analysis is used to reduce the number of PMT variables to a smaller size, resulting in five individual principal components representing the PMT elements of source information, threat appraisal, coping appraisal, maladaptive coping, and protection motivation. Using survey data, the marginal willingness-to-pay (MWTP) for PHP per oyster meal is also calculated, and the five created PMT variables are regressed on this calculation using four separate OLS models. Results indicate significant correlation for four of the five created PMT variables. In addition, a mean MWTP for PHP of $0.31 per oyster meal is determined, contributing to the demand analysis for processing of Gulf oysters. The findings suggest a strong relationship between the fear elements and the demand for processing, and support arguments in favor of further research on specific PHP treatments and the necessity for a valid PMT survey instrument.

No description available.

The seafood industry is of considerable importance to both the New Zealand and global economies and therefore tissue preservation technologies that increase product quality and/or prolong shelf life have the potential to add significant value. Technologies for maintaining the viability of isolated tissues also have a wide range of other medical and industrial applications. This thesis examines the relationship between metabolic function, oxidation and cell death and the resulting stability of the non-viable tissues during long term storage in chinook salmon (Oncorhynchus tshawytscha) red and white skeletal muscle tissue. This research also looks at the role of the aquatic anaesthetic AQUI-S™, in which the active ingredient is isoeugenol (a lipid soluble antioxidant), and other antioxidant compounds in preserving metabolic function in viable tissues and tissue stability in nonviable tissues. Perfusion of salmon tails at 15℃ over 5 or 10 hours with oxygen saturated saline resulted in significant increases in protein and lipid oxidation (protein carbonyl and TBARS concentrations respectively) in the red muscle, but not the white muscle. The introduction of ascorbic acid and uric acid into the saline did not reduce the oxidation in the red muscle despite significantly increasing their respective concentrations in the tissue. This indicates the difficulties associated with attempting to extend tissue viability by delivering free oxygen to the tissue and also highlights the difference in susceptibility of the two muscle types to oxidation. Tail fillets from salmon harvested in both rested and exhausted physiological states using AQUI-S™, and fillets from exhausted salmon harvested without AQUI-S™, were exposed to air at 15℃ for up to 96 hours. Protein carbonyls increased in a roughly linear fashion over the entire 96 hours in all three groups. Both lipid peroxides (TBARS) and uric acid concentrations began to increase in the exhausted group after 30 hours. In contrast, no significant increases in lipid peroxides or uric acid was seen in the fillets from either group harvested using AQUI-S™. Vitamin E concentrations reduced slowly but did not change significantly despite the oxidation that was evident in the tissue. These processes also occurred in salmon tail fillets during storage at 6℃. The measurement of ATP related compounds provides an effective indicator of both the metabolic state of the tissue post-harvest and the quality. The breakdown of these compounds is also associated with the production of ammonia and hydrogen peroxide. Fresh rested salmon fillets had high concentrations of ATP and creatine phosphate, which were both depleted after 12 hours storage at 15℃. This indicates that cell viability lasted a number of hours following harvesting. These metabolites were depleted in exhausted fillets and metabolic potential appeared to be immediately compromised. The concentration of the taste enhancing compound IMP was significantly reduced in fresh rested tissue, but increased during storage, and was significantly higher than in exhausted tissues following 12 hours of storage at 15℃. This indicates that some properties of rested tissues may improve with limited storage times. The accumulation of uric acid - the metabolic end point for ATP related compounds - was also significantly reduced in rested tissue and increases in K-value were slowed. AQUI-S™ showed an ability to preserve tissue function through its anaesthetic action allowing tissue to be harvested in a rested state, and to reduce late stage lipid oxidation in stored salmon tail fillets. The antioxidant action of isoeugenol in salmon fillets may be mediated through its ability to chelate transition metals released during tissue degradation. This research shows that during reperfusion and during fillet storage there is a significant level of oxidative stress, which needs to be minimized while maintaining basic tissue metabolism to prolong tissue and cellular viability. The development of future technologies to preserve tissue viability may depend on the development of a synthetic oxygen carrying compound with properties similar to red blood cells. This may allow more control over oxygen delivery, potentially reducing the oxidative stress associated with high concentrations of free oxygen in solution. However, preserving cell viability will also require the maintenance of endogenous antioxidant function and there is also the potential to use iron chelating compounds including plant derived flavonoids to preserve non-viable tissues. Future research in these areas is necessary.

Resumo: O processamento mínimo de frutas é uma das principais técnicas em ascensão no mercado, seguindo a tendência mundial do consumo de produtos in natura ou mais próximo possível destes. Por outro lado, as frutas minimamente processadas ainda são um desafio, devido à falta de conhecimento a respeito do comportamento fisiológico e bioquímico desses produtos. Com isso o trabalho tem como objetivo obter informações sobre goiaba minimamente processada, nas cultivares Século XXI, Sassaoka e Paluma, bem como embalagens mais adequadas no processo. O experimento foi conduzido no laboratório de Tecnologia de Alimentos, localizado na Universidade Estadual Paulista "Júlio de Mesquita Filho" (Unesp), Campus de Ilha Solteira - SP. Foram utilizados frutos de goiabas, no estádio de vez, de três cultivares Paluma, Sassaoka e Século XXI, os frutos foram levados ao laboratório onde foram lavados e desinfectados, e posteriormente descascados e cortados em fatias de um centímetro. Os tratamentos foram: embalagem PET e em bandeja de isopor com filme plástico (14 μm), em quatro tempos de armazenamento. Foram armazenadas durante seis dias sob temperatura de 8ºC e umidade relativa de 80%. A cada dois dias de armazenamento refrigerado foram retiradas três amostras de cada tratamento para as avaliações. Foram avaliados a perda de massa, pH, sólidos solúveis, acidez titulável, vitamina C e aparência visual. O delineamento experimental utilizado foi inteiramente casualizado (DIC), em esquema fatorial 3 x 2 x 4 (cultivar x embalagem x época). A embalagem de isopor (bandeja) com filme plástico proporcionou melhor conservação quando comparadas com a embalagem PET, mantendo os frutos em boas condições por até quatro dias após processados. Enquanto que a embalagem PET apresentou tendência de acumular água dentro da embalagem, desde o segundo dia de armazenamento, sendo inadequada... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Minimal processing of fruit is one of the main techniques on the rise in the market following the global trend of consumption of raw or as close to these. Moreover, minimally processed fruits are still a challenge due to lack of knowledge about the physiological and biochemical behavior of these products. With this work aims to obtain information on minimally processed guava plants, in the Século XXI, and Paluma Sassaoka as well as packaging the most appropriate process. The experiment was conducted in the laboratory of Food Technology, located in the Universidade Estadual Paulista "Julio de Mesquita Filho (Unesp), Campus de Ilha Solteira - SP. Fruits of guava, the stage of time, from Paluma cultivars, Sassaoka and Século XXI, the fruits were taken to the laboratory where they were washed and disinfected, and then peeled and cut into slices one inch. The treatments were: PET and polystyrene trays with plastic wrap (14 μm) at four times the storage. Were stored for six days at a temperature of 8 º C and relative humidity of 80%. Every two days of storage three samples were taken from each treatment for evaluation. The loss of mass, pH, soluble solids, acidity, vitamin C and visual appearance. The experimental design was completely randomized (CRD) in factorial 3 x 2 x 4 (cultivar x package x time). The styrofoam packing (tray) with plastic wrap provided better preservation compared to the PET packaging, keeping the fruit in good condition for up to four days after processing. While PET showed a tendency to accumulate water in the package, since the second day of storage, and was inadequate for this purpose. Paluma cultivars and Século XXI are the most suitable for minimal processing in styrofoam trays with plastic wrap, with a small loss of weight, higher soluble solids and top scores for visual appearance. The highest levels of vitamin C, after processing, were found in cv. Século XXI / Orientador: Aparecida Conceição Boliani / Coorientador: Luiz de Souza Corrêa / Banca: Jacira dos Santos Isepon / Banca: Omar Jorge Sabbag / Mestre

Made available in DSpace on 2016-08-12T19:15:26Z (GMT). No. of bitstreams: 1 GEORGE FAGNER.pdf: 234473 bytes, checksum: 5420749a8c2e87f6e7ab26164467f3ca (MD5) Previous issue date: 2008-04-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Anthracnosis is a serious disease that limits the production of healthy and marketable mangos (Mangifera indica). Due to the serious nature of this disease, a study was undertaken to test the efficacy of azoxystrobin as compared to different fungicides commonly utilized for the control of this disease, in two experiments. Each experiment consisted of ten treatments with four replicates. The plots were consisted of three plants of cv. Tommy Atkins. The products tested were azoxystrobin + difenoconazole WG (200; 300; 400 e 600 mL ha-1p.c.); azoxystrobin (120 mL ha-1p.c.); chlorothalonil WP (1500 e 2000 mL ha-1p.c.); difenoconazole (300 e 500 mL ha-1p.c.), and an unsprayed control. A total of four applications were performed at 15 days intervals, the first one performed at panicle plain flux. 40 days after the last application were collected 25 fruits for plot. The same ones were conditioned in cardboard boxes and stored at ambient temperature during 15 days, when the evaluated of anthracnosis incidence was accomplished. In the first experiment, the with azoxystrobin in its composition didn t differ between then. In the second experiment, the treatments with fungicides were similars, althought these had differed from the unsprayed control. The analysis of regression pointed azoxystrobin + difenoconazole 600 mL ha-1p.c. as the most efficient in the control of anthracnosis in both experiments / A antracnose da mangueira (Mangifera indica), causada pelo fungo Colletotrichum gloeosporioides, é um dos fatores limitantes à produção de frutos sadios e comercializáveis. Conhecendo-se o problema e consciente das perdas resultantes do ataque do fungo na cultura, avaliou-se a eficiência de diferentes fungicidas no manejo da antracnose da manga, em dois ensaios. Cada ensaio constou de dez tratamentos, com quatro repetições. Sendo que as unidades experimentais foram constituídas por três plantas de manga da cv. Tommy Atkins. Os produtos utilizados foram Azoxystrobin + difenoconazole SC 200 + 125 (200; 300; 400 e 600 mL.ha-1p.c.) Azoxystrobin GrDa 500 (120 mL.ha-1p.c.); Chlorothalonil SC 720 (1.500 e 2.000 mL.ha-1p.c.); Difenoconazole CE 250 (300 e 500 mL.ha-1p.c.), e uma testemunha absoluta. Foi realizado um total de quatro aplicações com intervalos de 15 dias, sendo estas iniciadas no momento da floração plena da panícula. Aos 40 dias após a última pulverização foram coletados 25 frutos por parcela. Os mesmos foram acondicionados em caixas de papelão e armazenados a temperatura ambiente durante 15 dias, quando foi realizada a avaliação de incidência de antracnose. No primeiro ensaio os tratamentos que apresentaram azoxystrobin na sua composição não diferem entre si, já no segundo ensaio não houve diferença significativa entre os tratamentos com aplicação de fungicidas, tendo estes diferido datestemunha. A análise de regressão apontou Azoxystrobin + difenoconazole na dosagem 600 mL.ha-1p.c. como o mais eficiente no controle da antracnose nos dois ensaios