Orientador: Helena Maria Andre Bollini / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-10T02:41:45Z (GMT). No. of bitstreams: 1 Martins_VileneBraga_D.pdf: 1017565 bytes, checksum: 3e2f8c9e34708fbc423f2f9e619b06bd (MD5) Previous issue date: 2008 / Resumo: O cupuaçu, fruta de sabor exótico e agradável, rico em potássio e pectina, é uma das principais e mais promissoras frutas cultivadas na região amazônica, sendo utilizado na produção de polpas, sucos, sorvetes, doces e cosméticos. Devido ao longo período de entresafra e a perecibilidade dos frutos, se faz necessária a busca de técnicas que melhor conservem o produto, como a produção de polpas congeladas, sucos e néctares. Na elaboração de sucos dietéticos ou light, a adição de edulcorantes no lugar da sacarose pode ser fator significativo na qualidade do produto final, já que os açúcares interferem na percepção da acidez e sabor global. Os edulcorantes apresentam comportamento sensorial diferenciado para cada tipo de aplicação, sendo necessária a utilização de diferentes técnicas sensoriais para a escolha do edulcorante mais adequado. Este trabalho teve como objetivo traçar o perfil sensorial do suco tropical de cupuaçu de valor calórico reduzido adoçado com diferentes edulcorantes, tendo a sacarose como referência, através de análises sensoriais. Foram obtidos 6 lotes de suco de cupuaçu a partir de 3 polpas comerciais de cupuaçu supercongeladas. Uma das polpas (P1) foi utilizada como referência para a preparação de sucos adoçados com sacarose e os edulcorantes (sucralose, aspartame e estévia). As polpas P2 e P3 foram adoçadas apenas com sacarose. Foram realizadas determinações físicoquímicas (pH, acidez titulável, sólidos solúveis, sólidos totais, determinação de cor e ácido ascórbico), determinação da doçura ideal e equivalência de doçura para suco de cupuaçu, análise descritiva quantitativa (ADQ), análise tempo-intensidade (ATI, avaliando os estímulos doce, amargo e sabor de fruta), testes de aceitação e mapa de preferência. Os resultados obtidos para a ADQ e a ATI foram avaliados estatisticamente por análise de variância (ANOVA), teste de médias de Tukey e análise dos componentes principais (ACP), utilizando o programa SAS. A doçura ideal determinada para o suco de cupuaçu adoçado com sacarose foi de 8%. A sucralose apresentou a maior potência edulcorante no suco, sendo 500 vezes mais doce que a sacarose, enquanto a estévia apresentou o menor poder edulcorante, apenas 89 vezes mais doce do que a sacarose. Na ADQ, o aspartame e a sucralose exibiram médias semelhantes para todos os atributos, apresentando significativamente as maiores intensidades para o atributo gosto doce. Já a estévia apresentou médias maiores para amargor e amargor residual. Na ATI, a estévia apresentou a maior intensidade máxima para o amargor, persistindo por um longo período, confirmando a presença de amargor residual intenso na amostra. Sacarose, aspartame e sucralose apresentaram médias baixas para intensidade do amargor. Em relação ao estímulo sabor de fruta, a sacarose exibiu a maior intensidade máxima, enquanto a estévia apresentou a menor. O aspartame e a sucralose foram os edulcorantes que mais se aproximaram do comportamento sensorial da sacarose, apresentando maior aceitação e intenção de compra do produto. O mapa de preferência explicou 70,43% das variações observadas. As menores médias de aceitação foram obtidas para a estévia, indicando que a não aceitação do produto está diretamente relacionada ao sabor amargo e amargor residual da amostra / Abstract: Cupuaçu, fruit with an exotic flavour, rich in potassium and pectin, is one of the leading and most pleasant promising fruit grown in the Amazon region, used in the production of pulps, juices, ice cream, conserves and cosmetics. Due to the long period between harvests and the considerable perishability of the fruits, it is necessary to search for techniques that best preserve the product, such as frozen pulps, juices and nectars. In the elaboration of dietetic or light juices, the substitution of sucrose by sweeteners can be a significant factor in final product quality, since the sugars interfere with the perception of acidity and overall flavour. Sweeteners present differentiated sensory behaviour in each type of application, the use of different sensory techniques being required to choose the most adequate one in each case. The objective of the present study was to trace the sensory profile of reduced calorie tropical cupuaçu juice sweetened with various sweeteners, by way of physical-chemical and sensory analyses. The cupuaçu juice was divided into 6 batches, and 3 commercial super-frozen pulps were used. One of the pulps (P1) was used as the reference to prepare juices sweetened with sucrose and the sweeteners (sucralose, aspartame and stevia). Pulps P2 and P3 were only sweetened with sucrose. Physical-chemical analyses (pH, titratable acidity, soluble solids, total solids, colour determination and ascorbic acid) were carried out, and also the determination of the ideal sweetness and sweetness equivalence for cupuaçu juice, quantitative descriptive analysis (QDA), timeintensity analysis (TIA, evaluating the stimuli of sweet, bitter and fruity taste), acceptance tests and preference map. The results obtained in the QDA and TIA were statistically analysed using ANOVA, Tukey¿s means test and PCA, using the SAS programme. The ideal sweetness for cupuaçu juice sweetened with sucrose was shown to be that produced with 8% added sucrose. Sucralose presented the greatest sweetening power in the juice, being 500 times sweeter than sucrose, whereas stevia showed the lowest sweetening power, only 89 times sweeter than sucrose. In the QDA, aspartame and sucralose showed similar means for all the attributes, showing significantly greater intensities for the attribute of sweet taste. On the other hand, stevia showed significantly higher means for bitter taste and aftertaste, differing significantly from all the other samples (p<0.05). In the TIA, stevia presented the greatest maximum intensity for bitter taste, which persisted for a long period, confirming the presence of a strong bitter aftertaste in the sample. Sucrose, aspartame and sucralose showed low means for the intensity of bitter taste in the cupuaçu juice. With respect to the fruity taste stimulus, sucrose showed the highest maximum and stevia the lowest value. Aspartame and sucralose showed the closest sensory behaviour to that of sucrose, presenting the highest product acceptance and buying intention. The preference map explained 70,43% of the variations in sample acceptance observed. The lowest acceptance means were obtained with stevia, indicating that the non-acceptance of the product was directly related to the bitter taste and aftertaste of the sample / Doutorado / Consumo e Qualidade de Alimentos / Doutor em Alimentos e Nutrição

Made available in DSpace on 2016-05-02T13:55:33Z (GMT). No. of bitstreams: 1 AlanKardecdeSouza-dissertacao.pdf: 422059 bytes, checksum: ea2c6f1ec1d26f3446d1eeee444a6292 (MD5) Previous issue date: 2012-08-24 / Goat's milk is a complete food, rich in proteins, fats, vitamins and minerals. Having very small lipid molecules, it is highly digestible when compared to other types of milk. One of the great challenges for the popularization of goat milk is that many potential consumers reject it because of its odor, flavor and high price when compared to pasteurized cow milk. This study aimed at analyzing the quality of the milk commercialized in Alfenas, MG, Brazil and evaluating the effect of pasteurization and freezing on its microbiological, physico-chemical and sensory characteristics. During 270 days, 3 batches of raw, pasteurized, and pasteurized and frozen goat milk were analyzed. Each batch was assessed every 90 days. The data were submitted to ANOVA and the Tukey test. The results showed that the slow pasteurization was effective in improving the microbiological quality of the milk, while no change was found in freezing it for 90 days. The physico-chemical and sensory characteristics of the milk was not changed by pasteurization and 90-day freezing. It was concluded that the goat milk commercialized in Alfenas, MG, Both pasteurized and pasteurized and frozen, have microbiological, physico-chemical and sensory quality within the standards established by law. / O leite de cabra é um alimento completo, rico em proteínas, gorduras, vitaminas e sais minerais, possui moléculas de gordura de tamanho reduzido, apresentando alta digestibilidade comparado aos demais tipos de leites. Um dos maiores desafios para a popularização do leite de cabra é a grande rejeição por parte do público consumidor em potencial, devido ao forte odor, sabor e preço elevado comparado ao leite de vaca pasteurizado. Este trabalho objetivou analisar a qualidade do leite de cabra comercializado na cidade de Alfenas-MG e avaliar o efeito da pasteurização e do congelamento sobre suas características microbiológicas, físico-químicas e sensoriais. Durante 270 dias, foram realizadas análises microbiológicas, físico-químicas e sensoriais de 3 lotes de leite de cabra cru, pasteurizado e pasteurizado e congelado. Cada lote foi analisado a cada 90 dias. Os dados obtidos foram submetidos à análise de variância e teste de Tukey. Verificou-se que a pasteurização lenta foi eficiente para melhorar a qualidade microbiológica do leite e que o congelamento por 90 dias não a alterou. As características físico-químicas e sensoriais não foram alteradas pela pasteurização e nem após o congelamento por 90 dias. Concluiu-se que o leite de cabra, pasteurizado e pasteurizado e congelado, comercializado na cidade de Alfenas-MG possui qualidade microbiológica, físico-química e sensorial dentro dos padrões estabelecidos pela legislação.

Made available in DSpace on 2014-12-17T15:01:21Z (GMT). No. of bitstreams: 1 MariaFB_DISSERT.pdf: 1170846 bytes, checksum: 98c54baa49841a83467430bc92e8e41c (MD5) Previous issue date: 2010-02-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Milk from different animals can be used for dairy production. Yoghurt is a popular fermented milk product and considered to be one of the greatest importance in terms of consumer acceptance and consumption. The present research deals with the production of strawberry set-type yoghurt by mixing goat and buffalo s milk and it has the objective of taking advantage of the intrinsic characteristics of each milk to produce a final product with desirable attributes. It was conducted by analyzing five experimental groups with different proportions of goat and buffalo s milk: C 100% goat s milk; 7C3B - 70% goat s milk and 30% buffalo s milk, 5C5B - 50% goat s milk and 50% buffalo s milk, 3C7B 30% goat s milk and 70% buffalo s milk; B - 100% buffalo s milk. Each group was evaluated for total solids content and the acidification profile was monitored every 30 minutes by pH analysis. The yoghurt samples were analyzed for physical-chemical (pH, acidity, protein, fat, total and reducing sugars, ash and total solids), rheological (syneresis and viscosity) and sensory characteristics (appearance, odor, consistency and flavour). Samples with higher percentual of bubaline milk reached Vm faster, but the time necessary for pH 4.6 (Te) were similar between groups. Statistical differences (p<0.05) were observed for fat and total solids content of yoghurt, with superior values for groups higher proportions of buffalo s milk. The parameters of behavior reached by the model of Ostwald of Waale pointed yoghurt samples as non-Newtonian and pseudoplastic fluids. Yoghurt made only with goat s milk (C) had higher values (p<0.05) for syneresis, which can be explained by its fragile coagulum. Additionally, this group also had the lowest sensory scores for the attributes consistence and taste, while bubaline yoghurt (B) obtained the best acceptance indexes for all of the appraised parameters / O leite de diversos animais pode ser mat?ria-prima para produ??o de diferentes tipos de produtos l?cteos existentes no mercado. Dentre eles est? o iogurte, o qual ? considerado como um dos produtos de maior aceita??o e consumo. O presente trabalho visa estudar o processo de elabora??o de iogurte a partir de misturas de leite de cabra e de b?fala com adi??o de sabor morango. Pretende-se com isso aliar caracter?sticas intr?nsecas distintas dos dois tipos de leites de forma a obter um produto de elevada aceita??o com caracter?sticas f?sico-qu?micas e organol?pticas desej?veis. A presente pesquisa foi desenvolvida a partir de cinco grupos experimentais com diferentes propor??es de leite caprino e bubalino: C - 100% leite de cabra, 7C3B - 70% leite de cabra e 30% leite de b?fala, 5C5B - 50% leite de cabra e 50% leite de b?fala, 3C7B - 30% leite de cabra e 70% leite de b?fala, B - 100% leite de b?fala. Inicialmente cada grupo foi avaliado quanto ao teor de s?lidos totais e foi determinado o pH das amostras retiradas a cada 30 minutos para acompanhamento da acidifica??o. Os iogurtes foram caracterizados quantos aos atributos f?sico-qu?micos (pH, acidez, prote?na, gordura, AR, ART, cinzas e s?lidos totais), reol?gicos (sinerese e viscosidade) e sensoriais (apar?ncia, odor, consist?ncia e sabor). As amostras com maior percentual de leite bubalino alcan?aram a taxa m?xima de acidifica??o (Vm) mais rapidamente, mas o tempo necess?rio para alcan?ar pH 4,6 foi similar entre os grupos. Diferen?as estat?sticas entre os grupos estudados foram percebidas no percentual de gordura e s?lidos totais, os quais apresentaram valores superiores para as formula??es com maior presen?a de leite de b?fala. Os ?ndices de comportamento alcan?ados pelo modelo de Ostwald de Waale apontam que os iogurtes s?o fluidos pseudopl?sticos. Al?m disso, o comportamento das curvas de fluxo e viscosidade aparente em fun??o da taxa de cisalhamento indicam que os iogurtes se classificam como fluidos n?o Newtoniano. Os iogurtes obtidos a partir de leite de cabra (grupo C) apresentaram valores estatisticamente superiores (p< 0,05) para sinerese, o que pode ser conseq??ncia do fr?gil co?gulo formado. Adicionalmente, esse grupo, ao ser comparado com os demais, apresentou escores mais baixos para os atributos consist?ncia e sabor, enquanto o iogurte produzido apenas com leite bubalino (grupo B) obteve os melhores ?ndices de aceita??o para todos os par?metros avaliados

L’impact de l’oxygène a été suivi pendant 4 mois pour 3 vins de Merlot d’IPT 61, 63 et 76. Le vin d’IPT 63 était enrichi par une fraction d’ellagitannins de bois de chêne. Les vins ont été ajustés à pH 3, pH 3,5 et pH 4. Pour chaque pH, des doses de 0, 2, 8 et 20 mg/L d’oxygène ont été fournies à l’aide d’oxygène pur, puis des analyses mensuelles ont permis de suivre les évolutions chimiques et sensorielles des vins afin d’apprécier les impacts liés à l’oxygène.Les résultats montrent pour tous les vins, que la consommation de l’oxygène augmente de 2 à 4 fois plus lorsque l’on passe de pH 3 à pH 4. La présence d’ellagitannins dans le vin favorise la consommation d’oxygène, ainsi qu’en solutions modèles hydro-alcooliques de fractions phénoliques. Les teneurs en tannins totaux sont globalement stables. Les polymérisations analysées par la méthode DMACH se produisent majoritairement à pH 3 et pH 3,5 pour le vin d’IPT 61, alors que les différences liées à l’oxygène sont moins fortes sur le vin d’IPT 76. Pour le vin d’IPT 63 + ellagitannins, les polymérisations sont favorisées à pH 3. Les teneurs en anthocyanes totales et moléculaires montrent généralement des diminutions en fonction du temps, de l’oxygène ainsi que de l’acidité. Pour le vin d’IPT 76 et d’IPT 63 + ellagitannins, les anthocyanes se polymérisent davantage aux tannins polymères en présence d’oxygène, et à pH plus acide. 13 pyranoanthocyanes ont pu être identifiées et quantifiées, dont deux molécules de pyranomalvidine-di-(épi)catéchine quantifiées pour la première fois dans des vins rouges secs qui peuvent être considérées comme des marqueurs en lien avec l'apport en oxygène subi par le vin. Les analyses sensorielles réalisées sur le vin d’IPT 76 en fonction des pH montrent que l’amertume est plus forte à pH 4, et pH 3,5 dans une moindre mesure. Cette tendance se retrouve aussi sur la perception d’oxydation.Pour les deux autres vins, d’IPT 61 et d’IPT 63 enrichi par une fraction d’ellagitannins, l’intensité du fruité diminue globalement avec les doses d’oxygène, tandis que le caractère oxydé est bien corrélée avec les doses croissantes d’oxygène, ainsi que l’amertume dans une moindre mesure. / The impact of oxygen has been followed-up during 4 months for 3 Merlot red wines of TPI 61, 63 anf 76. The wine of TPI 63 was supplied by a fraction of ellagitannin from oak wood. Wines have been adjusted at pH 3, pH 3.5 and pH 4. For each pH, quantities of 0, 2, 8 and 20 mg/L of pure oxygen have been added. Then, anlyses have been performed each month to follow the wine chemical and sensory evolutions in order to determine the impact of oxygen.For all wines, the results show that oxygen consumption is 2 to 4 fold higher from pH 3 to pH 4. The presence of ellagitannin in wine favors oxygen consumption, as well as in wine model solutions with phenolic fractions. Total tannin contents remain quite constant. Polymerisations analysed by DMACH index occur mainly at pH 3 and pH 3.5 for the wine of TPI 61, while the differences related to oxygen are less important in the wine of TPI 76. For the wine of TPI 63 + ellagitannins, polymerisations are favored at pH 3. Total and molecular anthocyanins contents generally show a decrease according to time, oxygen and acidity. For the wines of TPI 76 and TPI 63 + ellagitannins, the anthocyanins polymerise more to polymers of tannins with oxygen and acidity. 13 pyranoanthocyanins have been identified et quantified. Among them, two molecules of pyranomalvidin-di-(epi)catechin quantified for the first time in a dry red wine. They can be considerated as marker related to oxygen amount consumed by wine. Sensory analyses realized on wine of TPI 76 according to pH show that bitterness is higher at pH 4, and pH 3.5 in a lesser extent. There is the same trend with the oxidation perception.For the two other wines, of TPI 61 and 63 with ellagitannin fraction, fruity intensity globally decreases with oxygen quantities, while the oxidized parameter is well related to increasing oxygen amounts, as wella s bitterness in a lesser extent.

South Africa has over 19 500 different indigenous plant species. Most of these are of ethnobotanical significance and are still used by local rural communities as medicine, food and for making beverages. The relatively little research that has been conducted on indigenous plant species has focused mainly on their medicinal potential. However, in view of the rapidly growing size of the global and local beverage industry and their constant search for new products, beverage-making indigenous plant species may have commercial development potential. To date, no detailed studies have been conducted on these plants, especially in the species-rich Limpopo province. The aim of this study was, therefore to evaluate the potential of indigenous plants for commercial beverage production. In order to achieve this, a survey was conducted in the Limpopo province to identify beverage-making plants and to document beverage preparation methods. Selected beverages were analysed and evaluated for their nutrient and sensory characteristics and a market product acceptability survey was conducted to identify those beverages with the greatest potential for development. Sixty three different beverage-plant species were identified in three study areas within the Limpopo province. These were used for the preparation of teas, fruit juices and alcoholic beverages. Plants that received further research attention were selected on the basis of their status as indigenous plants, frequency of use, nature of harvesting methods and availability. Some of the selected beverages were found to be rich in nutrients, especially with respect to vitamin C and mineral content. Furthermore, sensory analyses and market surveys indicated that four species, namely, Doyvalis caffra, Garcinia livingstonei, Grewia flavescens and Englerophytum magalismontanum have potential for further development for the beverage industry while Athrixia phylicoides has commercialisation potential as a herbal tea. However, further research is required to improve and refine preparation methods and to ensure compliance with quality standards. The availability of sufficient plant material for the industry must also be ensured. This research has indicated that South African indigenous plants have untapped market potential for the beverage industry which, if developed sustainably, could contribute to economic growth of the rural parts of South Africa. / Environmental Sciences / D. Ed. (Environmental Management)

South Africa has over 19 500 different indigenous plant species. Most of these are of ethnobotanical significance and are still used by local rural communities as medicine, food and for making beverages. The relatively little research that has been conducted on indigenous plant species has focused mainly on their medicinal potential. However, in view of the rapidly growing size of the global and local beverage industry and their constant search for new products, beverage-making indigenous plant species may have commercial development potential. To date, no detailed studies have been conducted on these plants, especially in the species-rich Limpopo province. The aim of this study was, therefore to evaluate the potential of indigenous plants for commercial beverage production. In order to achieve this, a survey was conducted in the Limpopo province to identify beverage-making plants and to document beverage preparation methods. Selected beverages were analysed and evaluated for their nutrient and sensory characteristics and a market product acceptability survey was conducted to identify those beverages with the greatest potential for development. Sixty three different beverage-plant species were identified in three study areas within the Limpopo province. These were used for the preparation of teas, fruit juices and alcoholic beverages. Plants that received further research attention were selected on the basis of their status as indigenous plants, frequency of use, nature of harvesting methods and availability. Some of the selected beverages were found to be rich in nutrients, especially with respect to vitamin C and mineral content. Furthermore, sensory analyses and market surveys indicated that four species, namely, Doyvalis caffra, Garcinia livingstonei, Grewia flavescens and Englerophytum magalismontanum have potential for further development for the beverage industry while Athrixia phylicoides has commercialisation potential as a herbal tea. However, further research is required to improve and refine preparation methods and to ensure compliance with quality standards. The availability of sufficient plant material for the industry must also be ensured. This research has indicated that South African indigenous plants have untapped market potential for the beverage industry which, if developed sustainably, could contribute to economic growth of the rural parts of South Africa. / Environmental Sciences / D. Ed. (Environmental Management)