Made available in DSpace on 2016-12-09T13:52:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-11-08. Added 1 bitstream(s) on 2016-12-09T13:55:20Z : No. of bitstreams: 1 000793445.pdf: 794571 bytes, checksum: b0bf9d63d28d7da0a2034c160d31312e (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O presente trabalho teve como objetivos avaliar o efeito antioxidante de extratos de pimentas vermelhas in natura do gênero Capsicum e medir a estabilidade oxidativa do óleo de soja adicionado do extrato de pimenta; além de avaliar a retenção dos tocoferóis, naturalmente presentes no óleo de soja, durante os testes de estocagem acelerada em estufa e em temperatura ambiente. Nos extratos hidroalcóolicos liofilizados das pimentas Malagueta, Cumari, Bode e Dedo-de-moça, foram avaliados a atividade antioxidante por meio dos sistemas DPPH· (2,2-diphenyl-1- picrylhydrazyl), β-caroteno/ácido linoleico, FRAP (Ferric Reducing Antioxidant Power) e ABTS·+ (2,2- azino-bis-3- ethylbenzo-thiazoline-6-sulfonic acid), os teores de compostos fenólicos, carotenoides totais e ácido ascórbico. Os tratamentos: Controle (óleo de soja), TBHQ100 (óleo de soja + 100 mg/kg de TBHQ), TBHQ200 (óleo de soja + 200 mg/kg de TBHQ), BHA100 (óleo de soja + 100 mg/kg de BHA), BHA200 (óleo de soja + 200 mg/kg de BHA), Extrato100 (óleo de soja + 100 mg/kg de compostos fenólicos totais de pimenta Malagueta) e Extrato200 (óleo de soja + 200 mg/kg de compostos fenólicos totais de pimenta Malagueta), foram submetidos ao teste acelerado em estufa (60ºC/20 dias) e ao teste em temperatura ambiente (28ºC/9 meses). Os tratamentos foram analisados por meio das medidas de índice de peróxidos, dienos conjugados, índice de estabilidade oxidativa, teores de tocoferóis e ganho de massa (60ºC/30 dias). Os resultados obtidos das determinações analíticas foram submetidos à análise de variância e as diferenças entre as médias foram testadas a 5% de probabilidade pelo teste de Tukey. As pimentas são boas fontes de ácido ascórbico, carotenoides e compostos fenólicos. Estes compostos conferem às pimentas propriedades antioxidantes, mesmo que sejam submetidos a processos de estresse oxidativo. Os extratos da pimenta Malagueta adicionados ao óleo de soja como ... / This study aimed to evaluate the antioxidant capacity of extracts from red peppers of the genus Capsicum in nature and measure the oxidative stability of soybean oil added of pepper extract, as well as evaluating the resistance of tocopherols naturally present in soybean oil during the accelerated storage tests in stove and at room temperature. In the lyophilized hydroalcoholic extracts of Malagueta, Cumari, Bode, and Dedo-de-moça, the antioxidant activity, by means of antioxidant systems DPPH· (2,2-diphenyl-1-picrylhydrazyl), β-carotene/linoleic acid, FRAP (Ferric Reducing Antioxidant Power), and ABTS·+ (radical 2,2-azinobis-3-ethylbenzothiazoline-6- sulfonic acid), and also the levels of phenolics, total carotenoids, and ascorbic acid were evaluated. Treatments: Control (soybean oil-free antioxidants), TBHQ100 (soybean oil + 100 mg/ kg TBHQ), TBHQ200 (soybean oil + 200 mg/kg TBHQ), BHA100 (soybean oil + 100 mg/kg BHA), BHA200 (soybean oil + 200 mg/kg BHA), Extract100 (soybean oil + 100 mg/kg of total phenolic compounds of Malagueta), and Extract200 (soybean oil + 200 mg/kg of total phenolic compounds of Malagueta) were subjected to the accelerated storage test (60°C/20 days) and to the test at room temperature (28°C/9 months). The treatments were analyzed by measuring the peroxide value, conjugated dienes, oxidative stability index, levels of tocopherols, and mass gain (60ºC/30 days). The results of analytical determinations were subjected to analysis of variance and differences between means were tested at 5% probability by Tukey test. The peppers are good sources of ascorbic acid, carotenoids, and phenolic compounds. These compounds provide the peppers with antioxidant properties, even if they are subjected to oxidative stress conditions. Chilli pepper extracts added to soybean oil as natural antioxidants were capable of reducing the changes suffered by soybean oil during the storage process, thus being able to be natural ...

Orientador: Neuza Jorge / Banca: Agdamar Affini Sufredini / Banca: Débora Maria Moreno Luzia / Resumo: O presente trabalho teve como objetivos avaliar o efeito antioxidante de extratos de pimentas vermelhas in natura do gênero Capsicum e medir a estabilidade oxidativa do óleo de soja adicionado do extrato de pimenta; além de avaliar a retenção dos tocoferóis, naturalmente presentes no óleo de soja, durante os testes de estocagem acelerada em estufa e em temperatura ambiente. Nos extratos hidroalcóolicos liofilizados das pimentas Malagueta, Cumari, Bode e Dedo-de-moça, foram avaliados a atividade antioxidante por meio dos sistemas DPPH· (2,2-diphenyl-1- picrylhydrazyl), β-caroteno/ácido linoleico, FRAP (Ferric Reducing Antioxidant Power) e ABTS·+ (2,2- azino-bis-3- ethylbenzo-thiazoline-6-sulfonic acid), os teores de compostos fenólicos, carotenoides totais e ácido ascórbico. Os tratamentos: Controle (óleo de soja), TBHQ100 (óleo de soja + 100 mg/kg de TBHQ), TBHQ200 (óleo de soja + 200 mg/kg de TBHQ), BHA100 (óleo de soja + 100 mg/kg de BHA), BHA200 (óleo de soja + 200 mg/kg de BHA), Extrato100 (óleo de soja + 100 mg/kg de compostos fenólicos totais de pimenta Malagueta) e Extrato200 (óleo de soja + 200 mg/kg de compostos fenólicos totais de pimenta Malagueta), foram submetidos ao teste acelerado em estufa (60ºC/20 dias) e ao teste em temperatura ambiente (28ºC/9 meses). Os tratamentos foram analisados por meio das medidas de índice de peróxidos, dienos conjugados, índice de estabilidade oxidativa, teores de tocoferóis e ganho de massa (60ºC/30 dias). Os resultados obtidos das determinações analíticas foram submetidos à análise de variância e as diferenças entre as médias foram testadas a 5% de probabilidade pelo teste de Tukey. As pimentas são boas fontes de ácido ascórbico, carotenoides e compostos fenólicos. Estes compostos conferem às pimentas propriedades antioxidantes, mesmo que sejam submetidos a processos de estresse oxidativo. Os extratos da pimenta Malagueta adicionados ao óleo de soja como ... / Abstract: This study aimed to evaluate the antioxidant capacity of extracts from red peppers of the genus Capsicum in nature and measure the oxidative stability of soybean oil added of pepper extract, as well as evaluating the resistance of tocopherols naturally present in soybean oil during the accelerated storage tests in stove and at room temperature. In the lyophilized hydroalcoholic extracts of Malagueta, Cumari, Bode, and Dedo-de-moça, the antioxidant activity, by means of antioxidant systems DPPH· (2,2-diphenyl-1-picrylhydrazyl), β-carotene/linoleic acid, FRAP (Ferric Reducing Antioxidant Power), and ABTS·+ (radical 2,2-azinobis-3-ethylbenzothiazoline-6- sulfonic acid), and also the levels of phenolics, total carotenoids, and ascorbic acid were evaluated. Treatments: Control (soybean oil-free antioxidants), TBHQ100 (soybean oil + 100 mg/ kg TBHQ), TBHQ200 (soybean oil + 200 mg/kg TBHQ), BHA100 (soybean oil + 100 mg/kg BHA), BHA200 (soybean oil + 200 mg/kg BHA), Extract100 (soybean oil + 100 mg/kg of total phenolic compounds of Malagueta), and Extract200 (soybean oil + 200 mg/kg of total phenolic compounds of Malagueta) were subjected to the accelerated storage test (60°C/20 days) and to the test at room temperature (28°C/9 months). The treatments were analyzed by measuring the peroxide value, conjugated dienes, oxidative stability index, levels of tocopherols, and mass gain (60ºC/30 days). The results of analytical determinations were subjected to analysis of variance and differences between means were tested at 5% probability by Tukey test. The peppers are good sources of ascorbic acid, carotenoids, and phenolic compounds. These compounds provide the peppers with antioxidant properties, even if they are subjected to oxidative stress conditions. Chilli pepper extracts added to soybean oil as natural antioxidants were capable of reducing the changes suffered by soybean oil during the storage process, thus being able to be natural ... / Mestre

Orientador: Adriana Vitorino Rossi / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-20T21:18:58Z (GMT). No. of bitstreams: 1 Souza_PatriciaTononde_M.pdf: 1500158 bytes, checksum: 99c73fcb4e4c8143227e13cef0571323 (MD5) Previous issue date: 2012 / Resumo: Capsaicinóides (CAPS) são substâncias responsáveis pela pungência em pimentas do gênero Capsicum. Quantificar CAPS é relevante devido às aplicações desses compostos na indústria alimentícia, farmacêutica e cosmética, além do uso em armas químicas. Nesse trabalho, foi desenvolvido método espectrofotométrico baseado na reação colorimétrica entre CAPS, Co e 4-(2-piridilazo)resorcinol, PAR, para quantificação de CAPS totais (CCAPS) em diversas espécies de Capsicum. O produto da reação tem proporção estequiométrica Co:PAR:CAPS 1:2:2 e absorção em 510 nm proporcional a CCAPS. A curva analítica apresentou faixa linear entre 0,001 e 0,03 U, limite de detecção = 0,0004 U e limite de quantificação = 0,0005 U (U = mg CAPS/g pimenta) e coeficiente de correlação = 0,9979. Os resultados foram comparados com o método de cromatografia líquida de alta eficiência (HPLC) e não apresentaram diferença significativa com 95% de confiança, além disso, ambos resultados são coerentes com as escalas organolépticas disponíveis na literatura. No aperfeiçoamento das condições para obtenção de extratos etanólicos de CAPS, estabeleceu-se o uso de cachaça (teor alcoólico 39%), proporção pimenta:cachaça 30:50 g/mL e agitação de 30 min. O estudo da conservação dos extratos indicou que é favorável armazená-los a 6°C, a estocagem das pimentas in natura a -11 °C por até três meses não leva a perda significativa de CAPS e a CCAPS aumenta a medida que o estágio de maturação de pimenta é completado / Abstract: Capsaicinoids (CAPS) are substances responsible for pungency in Capsicum. CAPS is relevant to quantify due to the applications of these comounds in food, pharmaceutical and cosmetic industries, and the use of chemical weapons. Inthis work, we developed a spectrophotometric method based on the colorimetric reaction between CAPS, Co and 4-(2-pyridylazo)resorcinol, PAR, for quantification of total CAPS (CCAPS) in several species of Capsicum. The product of the reaction is stoichiometric Co:PAR:CAPS 1:2:2 and absorption at 510 nm proportional to CCAPS. The analytical curve linear range between 0,001 and 0,03 U, detection limit = 0,0004 and limit of quantification U = 0,0005 U (U = mg CAPS/g pepper) and correlation coefficient = 0,9979. The results were compared with the method of high performance liquid chromatography (HPLC) and not significantly different at 95% confidence, moreover, both results are consistent with the organoleptic scales available in the literature. The improvement of conditions for obtaining ethanol extracts of CAPS, established the use of cachaça (alcohol content 39%), proportion pepper:cachaça 30:50 g/mL and stirred for 30 min. The study of the conservation of the extracts indicated that it supports storing them at 6 °C, the storage of in nature peppers at -11 °C for up to three months does not lead to significant loss of CAPS and CCAPS increases as the stage of maturation of pepper is added / Mestrado / Quimica Analitica / Mestra em Química

Orientador: Julian Martínez / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-26T22:24:07Z (GMT). No. of bitstreams: 1 Aguiar_AnaCarolina_D.pdf: 3211663 bytes, checksum: 1dba9003e81cefba0f37a83236458c50 (MD5) Previous issue date: 2015 / Resumo: Neste trabalho a caracterização, a extração e o encapsulamento de extratos de pimentas Capsicum com tecnologia supercrítica foram estudados. Inicialmente, 20 variedades de pimentas foram caracterizadas quanto à concentração de capsaicinoides. Foi observada uma grande variação entre a composição dos capsaicinoides, sendo que a capsaicina e a dihidrocapsaicina foram os compostos majoritários. Com base nos resultados obtidos, foram selecionadas duas pimentas para obtenção de extratos com dióxido de carbono (CO2) supercrítico: a pimenta malagueta para extração de capsaicinoides e a pimenta biquinho para a extração de capsinoides. No que diz respeito à extração supercrítica (SFE) de pimenta malagueta, verificou-se que as concentrações mais elevadas de capsaicinoides foram obtidas com as menores pressões, indicando que pode haver competição entre capsaicinoides e outros compostos solúveis no CO2 supercrítico à pressões mais elevadas. O maior rendimento global foi obtido nas maiores pressões devido ao aumento da densidade do solvente. A pimenta biquinho apresentou uma concentração considerável de capsinoides. O processo de SFE com CO2 resultou em baixos rendimentos globais de extração quando comparado com os resultados obtidos empregando métodos a baixa pressão. Por outro lado, o extrato obtido com a menor densidade do CO2 apresentou uma alta concentração de capsinoides, sugerindo que o CO2 supercrítico sem cossolventes pode ser empregado para a obtenção destes compostos. Adicionalmente, foi realizada uma estimativa de custos de manufatura dos extratos supercríticos de pimenta malagueta nas condições otimizadas de extração (15 MPa e 40 °C) e o resultado obtido foi comparado com o valor comercial de um extrato com as mesmas características. Verificou-se que o processo de SFE de oleorresina de pimenta malagueta pode ser economicamente viável. Em uma segunda etapa, uma unidade de precipitação pelos métodos Antissolvente Supercrítico (SAS) e Extração Supercrítica de Emulsões (SFEE) foi desenvolvida e avaliada quanto ao desempenho de precipitação do poli(ácido lático) (PLLA) puro e coprecipitação de PLLA e ?-caroteno por SAS, e formação de partículas em suspensão de Hi-Cap 100® de oleorresina de pimenta malagueta por SFEE. Os ensaios de SAS para precipitação do PLLA puro e coprecipitação do PLLA com ?-caroteno resultaram em partículas com distintas morfologias em função das condições operacionais empregadas. Embora não tenha sido possível avaliar a influência dos parâmetros operacionais nas partículas obtidas por SAS, a realização dos experimentos foi fundamental para atestar o funcionamento da unidade desenvolvida. As emulsões formadas por ultrassom apresentaram alta estabilidade e a partir dos ensaios cinéticos determinou-se que o tempo apropriado de injeção na coluna de precipitação era de 10 min após a emulsificação. Os ensaios de SFEE resultaram em suspensões com baixa porcentagem de retenção de capsaicinoides, possivelmente devido à alta taxa de extração desses compostos durante a SFE e à perda de oleorresina verificada no frasco de coleta. Quanto ao teor de solvente residual, observou-se que quanto menor a perda de oleorresina, maior a concentração de solvente na suspensão. O diâmetro médio das partículas em suspensão apresentou pouca variação em relação ao diâmetro médio das emulsões injetadas, indicando que o tamanho de partícula está mais relacionado com o tamanho e natureza das gotículas de emulsão do que com as condições de transferência de massa do processo / Abstract: The characterization, extraction and encapsulation of extracts from Capsicum peppers with supercritical technology were studied. Initially, 20 varieties of peppers were characterized in terms of concentration of capsaicinoids. A large variation in the composition of capsaicinoids was observed, whereas capsaicin and dihydrocapsaicin were the major ones. Based on these results, two peppers were selected to obtain extracts with supercritical carbon dioxide (CO2): malagueta for capsaicinoids extraction and biquinho to capsinoids extraction. Regarding the supercritical fluid extraction (SFE) of malagueta pepper, higher concentrations of capsaicinoids were obtained at lower pressures, indicating that there may be competition between capsaicinoids and other compounds soluble in supercritical CO2 at higher pressures. The global yield was greater at higher pressures due to the increase of the solvent density. The extracts from biquinho pepper showed a considerable concentration of capsinoids. The SFE process with CO2 resulted in global extractions yields lower than those obtained using low pressure extraction methods. Moreover, the extract obtained at lower CO2 density had a high concentration of capsinoids, which suggests that supercritical CO2 without cosolvents may be employed to obtain these compounds. Additionally, an estimate of the manufacturing cost of supercritical extracts of malagueta peppers at the optimized conditions (15 MPa and 40 °C) was performed and the result was compared with the commercial value of an extract with the same characteristics. It was found that the SFE process of malagueta pepper oleoresin may be economically viable. In a second stage, a unit of precipitation by Supercritical Antisolvent (SAS) and Supercritical Fluid Extraction of Emulsions (SFEE) methods was developed and evaluated in terms of the precipitation performance of pure PLLA and coprecipitation of poly(lactic acid) (PLLA) and ?-carotene by SAS, and particle formation in suspensions of Hi-Cap 100® and malagueta pepper oleoresin by SFEE. The SAS experiments for precipitation of pure PLLA and coprecipitation of PLLA with ?-carotene resulted in particles with different morphologies when comparing the operating conditions. Although it was not possible to evaluate the influence of operating parameters on the particles obtained by SAS, the experiments were important to demonstrate the operation of the assembled precipitation unit. The emulsions formed by ultrasound showed high stability, and from kinetic experiments it was determined that the appropriate injection time in the precipitation column was 10 min after emulsification. The SFEE experiments resulted in suspensions with low retention percentage of capsaicinoids, possibly due to the high rate of extraction of these compounds during the SFE and the loss of oleoresin verified in the collection flask. Regarding the residual solvent content in the suspensions, it was observed that the smaller the loss of oleoresin, the higher the solvent concentration in the suspension. The average mean diameter of the particles in suspension showed little variation from the average mean diameter of the injected emulsion, indicating that the particle size is more related to the size and nature of the emulsion droplets than to the mass transfer conditions of the process / Doutorado / Engenharia de Alimentos / Doutora em Engenharia de Alimentos

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Three hydrocolloid-lipid emulsion coatings were developed using Humkote brand partially hydrogenated cottonseed and vegetable oil, and one of three combined hydrocolloid bases: xanthan gum and propylene glycol alginate (xanthan coating), locust bean gum and xanthan gum (locust bean gum coating), and maltodextrin. Sensory testing using a ranking preference test indicated that these coatings had acceptable appearance and palatability. Quality characteristics of green bell peppers (Capsicum annum L. cv. King Arthur) measured during the 5-week storage period included: respiration rates, chlorophyll content, surface color, puncture force, pectin (uronic acid) content, ascorbic acid (AA) and dehydroascorbic acid (DHA) content, and cumulative weight loss. No significant differences between coated and uncoated peppers were noted in tests for respiration, puncture force, hue angle, chlorophyll content, and AA content. Uncoated peppers had significantly inferior moisture retention (p<0.05), which caused them to be unsaleable after 8 days, while coated groups were saleable for an additional 6 to 8 days. Uncoated fruits also had greater uronic acid breakdown (p<0.05) and higher DHA content (p<0.06) than coated peppers. Significant weekly changes (all treatment groups combined) included linear increases in respiration rates (p<0.01) and moisture loss (p<0.01), increasing linear and quadratic trends in uronic acid content (p<0.01 for both trends), increasing quadratic trends for both chlorophyll and AA content (p<0.05, p<0.01, respectively), and decreasing linear and quadratic (p<0.05 for both trends) in DHA content. The only significant difference between coated groups was in chroma value, with maltodextrin coated peppers appearing less vivid than locust bean coated peppers. Overall, all three coatings performed equally well during the storage study. However, coatings with higher lipid content, which included xanthan gum and locust bean gum groups, withstood humidity changes better than the maltodextrin coated peppers. Coating application provided the greatest benefits in terms of texture maintenance through water retention and prevention of pectin breakdown, despite the lack of differences observed in puncture force. Coatings may also have prevented AA oxidation as demonstrated by the higher DHA content in uncoated groups, however AA patterns do not confirm this concept. Future research should be directed toward further minimizing textural changes and maximizing coating durability. / Ph. D.

Solanaceous crops such as peppers and more commonly tomatoes have been linked to Salmonella outbreaks that have occurred in the United States. The source of contamination for some of these outbreaks was traced back to the preharvest environment. Sources of contamination at the preharvest level of production often include irrigation water, soil, and the use of biological soil amendments of animal origin (BSAAO). This dissertation aims to (i) determine how factors such as the use of BSAAO's, Salmonella strain, soil type, and irrigation influence the survival of Salmonella in agricultural soils and (ii) determine the risk of Salmonella internalization in to transplanted solanaceous crops (tomatoes and bell peppers) and identify factors that influence internalization through the roots such as mode of contamination, soil contamination level, and root damage. Sandy loam (SL) and clay loam (CL) soils both unamended and amended with poultry litter (PL), irrigated either daily or weekly were inoculated with one of twelve strains of Salmonella enterica and monitored for growth and survival until no longer detected. Tomato plants were transplanted into one of three contamination treatments: contaminated soil (A) or irrigation water administered either once (B, single exposure event) or for 7 d following transplantation (C, repeated exposure event). Plants were sampled 1, 2, 3, 7 and 90 d post-transplantation for Salmonella internalization. Pepper plant roots were left intact, damaged, or removed and placed in inoculated water (6.2 log CFU/ml). Pepper plants in the soil contamination study, were transplanted into soil inoculated with Salmonella at different contamination levels (High, Mid, and Low). Samples were collected 1, 2, 3, and 7d post-transplant. Plants were surface sanitized and enumerated for Salmonella internalization by plant section. Strains in soils treated with PL survived significantly (P<0.05) longer (56 and 112 days for SL and CL respectively), than Salmonella strains in unamended soils. In PL amended SL and CL soils, most strains grew significantly (P<0.05) within the first week following inoculation and ranged from 84 to 210 days in the point it was last detected. Strains survival increased significantly (P<0.05) in soil irrigated weekly compared to soils irrigated daily, weekly irrigation increased survival by 140 to 224 and 42 to 168 days in SL and CL soils respectively depending on the strain. Root sections in the tomato plants of treatment A had significantly (P<0.05) higher recovery of Salmonella internalization compared to the other treatments. No tomato fruit sampled were positive for Salmonella internalization. Pepper plants with damaged roots had significantly higher (P<0.05) Salmonella internalization in the stem than plants with intact roots, while plants with no root stalk had significantly higher (P<0.05) Salmonella internalization in the stem and leaves of plants with intact and damaged roots. Pepper plants exposed to high concentrations of Salmonella had significantly more internalization occur in the roots than plants exposed to mid and low concentrations of Salmonella. Due to the results of these studies assessing the risk of using PL and irrigation regime should be considered in the Salmonella growth and survival in agricultural soils. Though it is unlikely, steps should be considered to limit Salmonella contamination of soil and irrigation water and root damage to prevent the internalization of Salmonella in tomato and bell pepper plants through intervention measures such as composting, water treatment, and effective transplanting techniques. / Doctor of Philosophy / Produce such as tomatoes and peppers has commonly been associated with Salmonella outbreaks in the United States. Fresh produce may be contaminated during the growing period by irrigation water, soil, or manure contaminated with Salmonella. This dissertation aims to (i) determine how factors such as poultry litter, Salmonella strain, soil type, and irrigation affects the survival of Salmonella in agricultural soils and (ii) identify the capability of Salmonella uptake through the roots of tomato and bell pepper plants, and identify factors that facilitate the uptake of Salmonella such as how the plant is contaminated, the Salmonella population level in the soil, and root damage. Sandy loam and clay loam soils untreated and treated with poultry litter, irrigated daily or weekly, were contaminated with one of twelve strains of Salmonella and tested for Salmonella levels until it was no longer detected in the soils. Tomato plants were planted into one of three treatments: Salmonella contaminated soil (A) or irrigated with Salmonella contaminated water once after planting (B, single exposure event) or for 7 days following planting (C, repeated exposure event). Tomato plants were tested for Salmonella uptake within the first week or 90 days following planting. The roots of pepper plants were either left intact, damaged, or removed and placed into Salmonella contaminated water. Pepper plants in the Salmonella contaminated soil study were planted into soil containing one of three different Salmonella contamination levels (high, mid and low). Plants were tested for Salmonella uptake within the first week following planting. Factors such as the use of poultry litter and irrigation influenced the growth and presence of Salmonella in both soil types. The uptake of Salmonella of tomato plants in contaminated soil was observed in the roots more than the roots of plants irrigated with contaminated irrigation water. No tomatoes tested were found positive for Salmonella internalizing. The uptake of Salmonella in the stems and leaves of pepper plants was highly dependent on root damage and the presence of the roots. Pepper plants that were exposed to high levels of Salmonella in the soil had more instances of Salmonella uptake than plants with lower levels of Salmonella in the soil. Based on these results, the use of poultry litter and irrigation should be considered in the potential risk of Salmonella contamination during the growing stage of produce. Though the uptake of Salmonella in tomato and pepper plants is unlikely, precautions should be taken to limit the potential contamination of soil and irrigation water with Salmonella and prevent root damage from occurring to prevent possible uptake of Salmonella.

Two lipid-based edible coatings, Apex B (AC Humko, Memphis, TN) and Durafresh (Pacrite, Ecoscience Produce Systems, Orlando, Fl) were evaluated for their ability to preserve post harvest quality changes in green bell peppers (Capsicum annum L. cv. King Arthur). Post harvest storage quality conditions tested included respiration rates, weight, color and texture changes, and stability of ascorbic acid (AA) and dehydroascorbic acid (DHA) content. Results indicated that no appreciable changes between days or treatment groups occurred in three of the parameters tested: weight, texture, and hue angle (p>0.05 for all parameters). Significant weekly changes were seen in respiration rates, dehydroascorbic acid content, and chromaticity values. Respiration rates and DHA were significantly higher during the last two weeks of the study (p=0.0001, p=0.0001 respectively). Chromaticity values were significantly lower, indicating a more faded color on the 14th day of the study alone (p=0.0097). Initial AA levels were much lower than expected (average initial content=78.72mg/100g). Significant differences between coated and uncoated pepper groups were seen in AA and DHA levels. AA content was found to be significantly lower in coated peppers (p=0.0279), while DHA levels were significantly higher in coated groups (p=0.0126). Overall, coated groups differed little from uncoated counterparts, except in the area of vitamin content in which the coated peppers showed an increase in vitamin breakdown. Despite the results, modifications of lipid coatings are needed, such as creating bilayer and composite coatings that contain either polysaccharide or protein constituents to enhance coating effectiveness. / Master of Science