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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
341

Elaboração e secagem em spray dryer de bebida probiótica formulada a partir da fermentação do suco de caju / Production and spray drying of probiotic beverage made from the fermentation of cashew apple juice

Pereira, Ana Lucia Fernandes January 2013 (has links)
PEREIRA, Ana Lucia Fernandes. Elaboração e secagem em spray dryer de bebida probiótica formulada a partir da fermentação do suco de caju. 2013. 114 f. : Tese (doutorado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Tecnologia de Alimentos, Fortaleza-CE, 2013 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-07T15:22:25Z No. of bitstreams: 1 2013_tese_alfpereira.pdf: 23321259 bytes, checksum: 8664c9c00f28dc1b79e6eb068f4d265d (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-07T15:22:45Z (GMT) No. of bitstreams: 1 2013_tese_alfpereira.pdf: 23321259 bytes, checksum: 8664c9c00f28dc1b79e6eb068f4d265d (MD5) / Made available in DSpace on 2016-07-07T15:22:45Z (GMT). No. of bitstreams: 1 2013_tese_alfpereira.pdf: 23321259 bytes, checksum: 8664c9c00f28dc1b79e6eb068f4d265d (MD5) Previous issue date: 2013 / The objective of this study was to develop a probiotic cashew apple juice ready to drink and in the dehydrated form through spray drying. The first stage of the study was the optimization of Lactobacillus casei NRRL B-442 cultivation in cashew apple juice, to optimize the proper inoculum amount and the fermentation time. The optimum conditions for probiotic cashew apple juice production were: initial pH 6.4, fermentation temperature of 30°C, inoculation level of 7.48 log CFU/mL (L. casei) and 16 h of fermentation process. Cashew apple juice showed to be as efficient as dairy products for L. casei growth. In a second stage, the stability of probiotic cashew apple juice stored for 42 days at 4°C was evaluated. Analyses were conducted in the non fermented cashew apple juice (control), and in the fermented juices with L. casei NRRL B-442, with 8% (w/v) of sucrose (sugar table), after fermentation, and without the addition of sugar. The viability of the probiotic bacteria, sugars and organic acids content, color, antioxidant and enzymatic activity, and sensory characteristics were evaluated during the storage. Viable cell counts increased in the probiotic cashew apple containing sucrose along the storage period. Moreover, the fermentation lead to the preservation of the ascorbic acid content, which had a less intense reduction in the fermented cashew apple juices compared to the non fermented sample. The antioxidant activity and total polyphenolic compounds of cashew apple juice had a similar trend. Browning reactions and nutritional breakdown caused by enzymes were minimized in the fermented samples during storage. In these samples, a higher reduction of the enzymatic activity of polyphenoloxidase and peroxidase activity was observed. During the storage, the increase in the chroma values indicated that yellowness was reinforced, being well accepted by consumers. The sensory attributes (aroma, flavor, acidity and color) of probiotic cashew apple juice were positively influenced by storage under refrigeration for 42 days. In the third stage of the research, the effects of dehydration by spray drying in cashew apple juice containing L. casei NRRL B-442 was assessed and the influence of storage temperature on the viability of L. casei NRRL B-442 and physical properties of the powder were evaluated during 35 days of storage. The drying agents used were: 20% (w/v) maltodextrin or 10% (w/v) maltodextrin + 10% (w/v) arabic gum. The powder of probiotic cashew apple juice showed satisfactory levels of L. casei survival, during drying. During storage, the addition of 10% (w/v) maltodextrin + 10% (w/v) arabic gum kept microbial viability within satisfactory levels when the powder was subjected to cooling at 4°C. However, greater differences in the reconstituted powder color and higher rehydration time were obtained in this condition. On the other hand, the addition of 20% (w/v) maltodextrin provided better yield. In conclusion, cashew apple juice is a good substrate for the probiotic beverage production, and the condition of drying agents 10% maltodextrin + 10% arabic gum is adequate to maintain satisfactory levels of L. casei NRRL B-442 survival for 35 days, in the powder of probiotic cashew juice stored at 4°C. / O objetivo desta pesquisa foi elaborar um produto probiótico à base de suco de caju pronto para beber, como também, na forma desidratada obtida pela secagem por aspersão (spray drying). A primeira etapa da pesquisa consistiu em otimizar as condições de crescimento do Lactobacillus casei NRRL B-442 em suco de caju, a quantidade adequada de inóculo e o tempo de fermentação. As condições ótimas para produção do suco de caju probiótico foram: pH inicial de 6,4, temperatura de fermentação de 30°C, quantidade de inóculo de 7,48 log UFC/mL (L. casei) e 16 h de fermentação. O suco de caju mostrou ser tão eficiente quanto os produtos lácteos para o crescimento de L. casei. Em uma segunda etapa, foi avaliada a estabilidade da bebida probiótica de caju estocada por 42 dias a 4°C. Foram realizadas análises no suco de caju não fermentado (controle) e nos sucos fermentados com L. casei NRRL B-442, adicionado ou não de 8% (p/v) de sacarose depois da fermentação. Durante a estocagem, foram realizadas as determinações de viabilidade de L. casei NRRL B-442, conteúdo de açúcares e ácidos orgânicos, cor, atividade antioxidante e enzimática e aceitação sensorial. Foi observado que o número de células viáveis aumentou no suco de caju contendo sacarose ao longo da estocagem. Além disso, a fermentação proporcionou um efeito conservante no conteúdo de ácido ascórbico que teve uma redução menos intensa, com a estocagem, nos sucos fermentados, quando comparados com o controle. A atividade antioxidante e o conteúdo de polifenóis apresentaram similar tendência. Reações que reduzem o valor nutricional causadas por enzimas foram minimizadas nas amostras fermentadas durante a estocagem. Nessas amostras foi observada maior redução da atividade enzimática da polifenoloxidase e peroxidase. Durante a estocagem, o aumento do croma indicou que a cor amarela foi intensificada, sendo bem aceita pelos consumidores. Os atributos sensoriais (aroma, sabor, acidez e cor) do suco de caju probiótico foram positivamente influenciados pela estocagem sob refrigeração por 42 dias. Na terceira etapa da pesquisa, foi avaliado o efeito da desidratação por spray drying no suco de caju contendo L. casei NRRL B-442, além de avaliar a influência da temperatura de estocagem sobre a viabilidade de L. casei e nas propriedades físicas do pó, durante 35 dias de estocagem. Os agentes de secagem usados foram: 20% (p/v) de maltodextrina ou 10% (p/v) de maltodextrina + 10% (p/v) de goma arábica. O suco de caju probiótico desidratado por spray drying apresentou níveis satisfatórios de sobrevivência de L. casei NRRL B-442, durante a secagem. Durante a estocagem, a adição de 10% (p/v) de maltodextrina + 10% (p/v) de goma arábica manteve a viabilidade microbiana dentro de níveis satisfatórios quando o pó foi submetido à refrigeração a 4ºC. Entretanto, maiores diferenças na coloração do pó reconstituído e maior tempo de reidratação foram obtidos nesta condição. Já a adição de 20% (p/v) de maltodextrina proporcionou melhor rendimento. Em conclusão, o suco de caju pode ser utilizado como substrato para o desenvolvimento de bebida probiótica, e a condição dos agentes de secagem de 10% de maltodextrina + 10% de goma arábica mostra-se adequada para manter os níveis satisfatórios de L. casei NRRL B-442 por até 35 dias, no suco de caju probiótico desidratado estocado a 4°C.
342

Elaboração e secagem em spray dryer de bebida probiótica formulada a partir da fermentação do suco de caju / Production and spray drying of probiotic beverage made from the fermentation of cashew apple juice

Pereira, Ana Lucia Fernandes January 2013 (has links)
PEREIRA, Ana Lucia Fernandes. Elaboração e secagem em spray dryer de bebida probiótica formulada a partir da fermentação do suco de caju. 2013. 116 f. Tese (Doutorado em tecnologia de alimentos)- Universidade Federal do Ceará, Fortaleza-CE, 2013. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-07-07T17:55:40Z No. of bitstreams: 1 2013_tese_alfpereira.pdf: 24437687 bytes, checksum: 9e9963b2d25536d6bfb0cbe06acecac0 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-07-21T20:24:58Z (GMT) No. of bitstreams: 1 2013_tese_alfpereira.pdf: 24437687 bytes, checksum: 9e9963b2d25536d6bfb0cbe06acecac0 (MD5) / Made available in DSpace on 2016-07-21T20:24:58Z (GMT). No. of bitstreams: 1 2013_tese_alfpereira.pdf: 24437687 bytes, checksum: 9e9963b2d25536d6bfb0cbe06acecac0 (MD5) Previous issue date: 2013 / The objective of this study was to develop a probiotic cashew apple juice ready to drink and in the dehydrated form through spray drying. The first stage of the study was the optimization of Lactobacillus casei NRRL B-442 cultivation in cashew apple juice, to optimize the proper inoculum amount and the fermentation time. The optimum conditions for probiotic cashew apple juice production were: initial pH 6.4, fermentation temperature of 30°C, inoculation level of 7.48 log CFU/mL (L. casei) and 16 h of fermentation process. Cashew apple juice showed to be as efficient as dairy products for L. casei growth. In a second stage, the stability of probiotic cashew apple juice stored for 42 days at 4°C was evaluated. Analyses were conducted in the non fermented cashew apple juice (control), and in the fermented juices with L. casei NRRL B-442, with 8% (w/v) of sucrose (sugar table), after fermentation, and without the addition of sugar. The viability of the probiotic bacteria, sugars and organic acids content, color, antioxidant and enzymatic activity, and sensory characteristics were evaluated during the storage. Viable cell counts increased in the probiotic cashew apple containing sucrose along the storage period. Moreover, the fermentation lead to the preservation of the ascorbic acid content, which had a less intense reduction in the fermented cashew apple juices compared to the non fermented sample. The antioxidant activity and total polyphenolic compounds of cashew apple juice had a similar trend. Browning reactions and nutritional breakdown caused by enzymes were minimized in the fermented samples during storage. In these samples, a higher reduction of the enzymatic activity of polyphenoloxidase and peroxidase activity was observed. During the storage, the increase in the chroma values indicated that yellowness was reinforced, being well accepted by consumers. The sensory attributes (aroma, flavor, acidity and color) of probiotic cashew apple juice were positively influenced by storage under refrigeration for 42 days. In the third stage of the research, the effects of dehydration by spray drying in cashew apple juice containing L. casei NRRL B-442 was assessed and the influence of storage temperature on the viability of L. casei NRRL B-442 and physical properties of the powder were evaluated during 35 days of storage. The drying agents used were: 20% (w/v) maltodextrin or 10% (w/v) maltodextrin + 10% (w/v) arabic gum. The powder of probiotic cashew apple juice showed satisfactory levels of L. casei survival, during drying. During storage, the addition of 10% (w/v) maltodextrin + 10% (w/v) arabic gum kept microbial viability within satisfactory levels when the powder was subjected to cooling at 4°C. However, greater differences in the reconstituted powder color and higher rehydration time were obtained in this condition. On the other hand, the addition of 20% (w/v) maltodextrin provided better yield. In conclusion, cashew apple juice is a good substrate for the probiotic beverage production, and the condition of drying agents 10% maltodextrin + 10% arabic gum is adequate to maintain satisfactory levels of L. casei NRRL B-442 survival for 35 days, in the powder of probiotic cashew juice stored at 4°C. / O objetivo desta pesquisa foi elaborar um produto probiótico à base de suco de caju pronto para beber, como também, na forma desidratada obtida pela secagem por aspersão (spray drying). A primeira etapa da pesquisa consistiu em otimizar as condições de crescimento do Lactobacillus casei NRRL B-442 em suco de caju, a quantidade adequada de inóculo e o tempo de fermentação. As condições ótimas para produção do suco de caju probiótico foram: pH inicial de 6,4, temperatura de fermentação de 30°C, quantidade de inóculo de 7,48 log UFC/mL (L. casei) e 16 h de fermentação. O suco de caju mostrou ser tão eficiente quanto os produtos lácteos para o crescimento de L. casei. Em uma segunda etapa, foi avaliada a estabilidade da bebida probiótica de caju estocada por 42 dias a 4°C. Foram realizadas análises no suco de caju não fermentado (controle) e nos sucos fermentados com L. casei NRRL B-442, adicionado ou não de 8% (p/v) de sacarose depois da fermentação. Durante a estocagem, foram realizadas as determinações de viabilidade de L. casei NRRL B-442, conteúdo de açúcares e ácidos orgânicos, cor, atividade antioxidante e enzimática e aceitação sensorial. Foi observado que o número de células viáveis aumentou no suco de caju contendo sacarose ao longo da estocagem. Além disso, a fermentação proporcionou um efeito conservante no conteúdo de ácido ascórbico que teve uma redução menos intensa, com a estocagem, nos sucos fermentados, quando comparados com o controle. A atividade antioxidante e o conteúdo de polifenóis apresentaram similar tendência. Reações que reduzem o valor nutricional causadas por enzimas foram minimizadas nas amostras fermentadas durante a estocagem. Nessas amostras foi observada maior redução da atividade enzimática da polifenoloxidase e peroxidase. Durante a estocagem, o aumento do croma indicou que a cor amarela foi intensificada, sendo bem aceita pelos consumidores. Os atributos sensoriais (aroma, sabor, acidez e cor) do suco de caju probiótico foram positivamente influenciados pela estocagem sob refrigeração por 42 dias. Na terceira etapa da pesquisa, foi avaliado o efeito da desidratação por spray drying no suco de caju contendo L. casei NRRL B-442, além de avaliar a influência da temperatura de estocagem sobre a viabilidade de L. casei e nas propriedades físicas do pó, durante 35 dias de estocagem. Os agentes de secagem usados foram: 20% (p/v) de maltodextrina ou 10% (p/v) de maltodextrina + 10% (p/v) de goma arábica. O suco de caju probiótico desidratado por spray drying apresentou níveis satisfatórios de sobrevivência de L. casei NRRL B-442, durante a secagem. Durante a estocagem, a adição de 10% (p/v) de maltodextrina + 10% (p/v) de goma arábica manteve a viabilidade microbiana dentro de níveis satisfatórios quando o pó foi submetido à refrigeração a 4ºC. Entretanto, maiores diferenças na coloração do pó reconstituído e maior tempo de reidratação foram obtidos nesta condição. Já a adição de 20% (p/v) de maltodextrina proporcionou melhor rendimento. Em conclusão, o suco de caju pode ser utilizado como substrato para o desenvolvimento de bebida probiótica, e a condição dos agentes de secagem de 10% de maltodextrina + 10% de goma arábica mostra-se adequada para manter os níveis satisfatórios de L. casei NRRL B-442 por até 35 dias, no suco de caju probiótico desidratado estocado a 4°C.
343

POTENCIAL TECNOLÓGICO E NUTRICIONAL DE SUBPRODUTOS DO PROCESSAMENTO DE FRUTAS / POTENTIAL TECHNOLOGY AND NUTRITION OF BY-PRODUCTS OF PROCESSING FRUITS

Macagnan, Fernanda Teixeira 22 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The passion fruit peel (CM), apple pomace (BM) and orange bagasse (BL) are by-products generated in large quantities and usually wasted by brazilian industries of juices processing. However have nutritional qualities important for health, as relevant levels of dietary fiber. In this context, the study aimed to characterize the flour of these by-products, study potential nutritional as alternative sources of fiber in diets drawn up for rats, and test the nutritional and sensory quality of honey breads enriched with these flours. In step characterization, it was verified a high content of dietary fiber, which varied 54.82 to 76.84% in dry matter (DM), highlighting the soluble fraction (18.97% to 25.17% in DM), mainly composed of pectin (49.19% to 91.25% of the soluble fiber). Phenolic compounds were also elevated in the samples analyzed (479.71 to 862.11 mg% in DM). The BM stood out for higher fiber content, pectin, condensed tannins and greatest copper binding capacity. The CM presented a high mineral content, very small percentage of fat, high hydration capacity and greater fat binding capacity. The BL was the by-product with higher levels of soluble fiber and phenolic content. In biological assay, conducted for 40 days, it was used 32 male Wistar rats, with 21 days old, randomly distributed (eight animals / treatment) between the following experimental treatments: TC, control treatment with cellulose as a fiber source; TBM; treatment with apple pomace as fiber source; TBL, treatment with orange bagasse as a source of fiber; TCM; treatment with passion fruit peel as a source of fiber.The different sources of fiber did not affect the average consumption, weight gain, feed conversion, gastrointestinal transit time, and neither exerted influence on the weight of the intestine empty, kidney, liver and epididymal fat of animals. There was also not significant difference in the levels of total cholesterol, HDL cholesterol, albumin, total protein and lipids in the liver. However, it was found that the addition of these by-products has enabled significant reductions in serum triglycerides and hepatic cholesterol, and also promote changes in important parameters for gut health (pH, nitrogen and fecal moisture) and play important roles in the control of postprandial glycemia. The fiber derived from BM showed greater potential to reduce the absorption and metabolization of fat for its increased excretion in feces, but it was the only one that did not exercise significant influence on fasting glucose. The fiber from the CM had higher apparent digestibility and the animals fed with BL showed the better postprandial glycemic response. The replacement of 15% of wheat flour standard formulation of honey bread by flours fruit by-products of allowed the reduction of caloric value and the increase in dietary fiber content (from 6.62 to 9.61% in DM to the formulations added BL and BM, respectively) and your soluble fraction. Sensory evaluation of honey breads enriched with flour by-products indicated good acceptability average for all parameters evaluated (color, aroma, flavor, texture, overall acceptability) and favorable purchase intent of these products. Is founded, thus, the rational utilization of these by-products of processing fruits as alternative sources of fiber with potential nutritional and technological to be used in human food. / A casca de maracujá (CM), o bagaço de maçã (BM) e o bagaço de laranja (BL) são subprodutos gerados em grande quantidade e geralmente desperdiçados pelas indústrias brasileiras de processamento de sucos. Contudo possuem qualidades nutricionais importantes, como teores relevantes de fibra alimentar. Nesse contexto, este trabalho objetivou caracterizar as farinhas desses subprodutos, estudar o potencial nutricional como fontes alternativas de fibra em dietas elaboradas para ratos e testar a qualidade nutricional e sensorial de pães de mel enriquecidos com essas farinhas. Na etapa de caracterização, constatou-se alto teor de fibra alimentar, que variou de 54,82 a 76,84% na matéria seca (MS), destacando-se a fração solúvel (18,97% a 25,17% na MS), composta principalmente por pectina. Os compostos fenólicos também foram elevados nas amostras analisadas (479,71 a 862,11 mg % na MS). O BM destacou-se pelo maior teor de fibra, pectina, taninos condensados e superior capacidade de ligação ao cobre. A CM apresentou alto teor de minerais, baixo percentual de gordura, elevada capacidade de hidratação e maior capacidade de ligação à gordura. O BL foi o subproduto com maior teor de fibra solúvel e conteúdo de fenóis. No ensaio biológico, conduzido por 40 dias, utilizou-se 32 ratos Wistar machos, com 21 dias de idade e distribuídos aleatoriamente (oito animais/tratamento) entre os seguintes tratamentos experimentais: TC, tratamento controle com celulose como fonte de fibra; TBM; tratamento com bagaço de maçã como fonte de fibra; TBL, tratamento com bagaço de laranja como fonte de fibra; TCM; tratamento com casca de maracujá como fonte de fibra. As diferentes fontes de fibras não afetaram o consumo médio, ganho de peso, conversão alimentar, tempo de trânsito gastrointestinal e nem exerceram influência no peso do intestino vazio, do rim, do fígado e da gordura epididimal dos animais. Também não foi observada diferença significativa nos níveis de colesterol total, colesterol HDL, albumina, proteínas totais e lipídeos no fígado. Contudo, constatou-se que adição desses subprodutos possibilitou reduções significativas nos níveis de triglicerídeos séricos e de colesterol hepático, além de promover modificações em parâmetros importantes para a saúde do intestino (pH, nitrogênio e umidade fecal) e desempenhar importante ação no controle da glicemia pós-prandial. A fibra oriunda do BM mostrou maior potencial em reduzir a absorção e a metabolização da gordura pela sua excreção aumentada nas fezes, mas foi a única que não exerceu influência significativa na glicemia de jejum. A fibra advinda da CM apresentou maior digestibilidade aparente e os animais alimentados com BL mostraram a melhor resposta glicêmica pós-prandial. A substituição de 15% da farinha de trigo da formulação padrão de pão de mel pelas farinhas dos subprodutos de frutas possibilitou a redução do valor calórico e o incremento no teor de fibra alimentar (6,62 a 9,61% na MS para as formulações adicionadas de BL e BM, respectivamente) e de sua fração solúvel. A avaliação sensorial dos pães de mel enriquecidos com as farinhas dos subprodutos indicou boa média de aceitabilidade para todos os parâmetros avaliados (cor, aroma, sabor, textura, aceitação global) e favorável intenção de compra desses produtos. Fundamenta-se, assim, a utilização racional desses subprodutos do processamento de frutas como fontes alternativas de fibras, que têm potencial nutricional e tecnológico para serem utilizadas na alimentação humana.
344

Estudo da reidrata??o do feij?o verde (Vigna unguiculata L. Walp) desidratado por micro-ondas com e sem pr?-tratamento osm?tico

Queiroga, Priscila Vanini Dantas de Medeiros 19 March 2012 (has links)
Made available in DSpace on 2014-12-17T15:01:54Z (GMT). No. of bitstreams: 1 PriscilaVDMQ_TESE.pdf: 3706825 bytes, checksum: a3b44c4a57772c9356ce81d22bdb9174 (MD5) Previous issue date: 2012-03-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The green bean has organoleptic and nutritional characteristics that make it an important food source in tropical regions such as the Northeast of Brazil. It is a cheap source of protein and important for nutrition of rural population contributing significantly in subsistence farming of the families from Brazil s northeast. It is consumed in entire region and together with the dry meat and other products composes the menu of typical restaurants, being characterized as an important product for economy of Northeast. The green bean is consumed freshly harvested and has short cycle, being characterized as a very perishable food, which hampers your market. The drying method is an alternative to increase the lifetime and provide a reduction volume of this product making easier your transportation and storage. However is necessary to search ways of drying which keep the product quality not only from the nutritional standpoint but also organoleptic. Some characteristics may change with the drying process such as the coloring, the rehydration capacity and the grains cooking time. The decrease of drying time or of exposure of the grains to high temperature minimizes the effects related with the product quality loss. Among the techniques used to reduce the drying time and improve some characteristics of the product, stands out the osmotic dehydration, widely used in combined processes such as the pretreatment in drying food. Currently the use of the microwaves has been considered an alternative for drying food. The microwave energy generates heat inside of materials processed and the heating is practically instantaneous, resulting in shorter processing times and product quality higher to that obtained by conventional methods. Considering the importance of the green beans for the Northeast region, the wastefulness of production due to seasonality of the crop and your high perishability, the proposal of this thesis is the study of drying grain by microwaves with and without osmotic pretreatment, focusing on the search of conditions of processes which favor the rehydration of the product preserving your organoleptic characteristics. Based on the analysis of the results of osmotic dehydration and dielectric properties was defined the operating condition to be used in pretreatment of the green bean, with osmotic concentration in saline solution containing 12,5% of sodium chloride, at 40?C for 20 minutes. The drying of green bean by microwave was performed with and without osmotic pretreatment on the optimized condition. The osmotic predehydration favored the additional drying, reducing the process time. The rehydration of dehydrated green bean with and without osmotic pretreatment was accomplished in different temperature conditions and immersion time according to a factorial design 22, with 3 repetitions at the central point. According to results the better condition was obtained with the osmotically pretreated bean and rehydrated at a temperature of 60?C for 90 minutes. Sensory analysis was performed comparing the sample of the green bean in natura and rehydrated in optimized conditions, with and without osmotic pretreatment. All samples showed a good acceptance rate regarding the analyzed attributes (appearance, texture, color, odor and taste), with all values above 70%. Is possible conclude that the drying of green bean by microwave with osmotic pretreatment is feasible both in respect to technical aspects and rehydration rates and sensory quality of the product / O feij?o verde apresenta caracter?sticas organol?pticas e nutricionais que fazem dele uma importante fonte aliment?cia em regi?es de clima tropical como o Nordeste do Brasil. ? uma fonte de prote?na barata e importante para a nutri??o da popula??o rural contribuindo significativamente na agricultura de subsist?ncia das fam?lias nordestinas. ? consumido em toda a regi?o e comp?e junto com a carne de sol e outros produtos o card?pio dos restaurantes t?picos, caracterizando-se assim como um produto importante para a economia da Nordeste. O feij?o verde ? consumido rec?m-colhido e apresenta ciclo curto, sendo caracterizado como um alimento de alta perecibilidade, o que dificulta a sua comercializa??o. A secagem desse produto se caracteriza como uma alternativa para o aumento da vida ?til deste alimento, al?m de proporcionar uma redu??o de volume facilitando seu manuseio no transporte e armazenagem. Todavia necess?rio se faz buscar formas de secagem que preservem a qualidade do produto n?o s? sobre o ponto de vista nutricional como organol?ptico. Dentre as caracter?sticas que se alteram com o processo de secagem, destacam-se a colora??o, a capacidade de reidrata??o e o tempo de cozimento dos gr?os. A diminui??o do tempo de secagem, ou de exposi??o dos gr?os a elevadas temperaturas minimizam os efeitos relacionados com a perda de qualidade do produto. .Dentre as t?cnicas empregadas para minimizar o tempo de secagem e melhorar algumas caracter?sticas do produto, destaca-se a desidrata??o osm?tica, muito utilizada em processos combinados como pr?-tratamento na secagem dos alimentos. Atualmente a utiliza??o do micro-ondas tem sido apontada como uma alternativa para a secagem de alimentos. A energia de micro-ondas gera calor no interior dos materiais processados e o aquecimento ? praticamente instant?neo, o que resulta em tempos de processamento mais curtos e qualidade do produto superior ? obtida pelos m?todos convencionais. Considerando a import?ncia do feij?o verde para a regi?o Nordeste, o desperd?cio da produ??o devido a sazonalidade da safra e sua alta perecibilidade, foi proposto nesta tese o estudo da secagem dos gr?os em micro-ondas com e sem pr?-tratamento osm?tico, tendo como foco principal a busca das condi??es de processo que favore?am a reidrata??o do produto, com preserva??o de suas caracter?sticas organol?pticas. A partir da an?lise dos resultados da desidrata??o osm?tica e propriedades diel?tricas foi definida a condi??o operacional a ser utilizada no pr?-tratamento do feij?o verde, com concentra??o osm?tica em solu??o salina contendo 12,5% de cloreto de s?dio, a 400C por 20 minutos. A secagem do feij?o verde por micro-ondas foi realizada sem e com pr?-tratamento osm?tico na condi??o otimizada. A pr?-desidrata??o osm?tica favoreceu a secagem complementar, reduzindo o tempo de processo. A reidrata??o do feij?o verde desidratado com e sem pr?-tratamento osm?tico foi realizada em diferentes condi??es de temperatura e tempo de imers?o de acordo com um planejamento fatorial 22, com 3 repeti??es no ponto central . De acordo com os resultados a melhor condi??o, foi obtida com o feij?o pr?-tratado osmoticamente e reidratado a uma temperatura de 600C por 90 minutos. Realizou-se a an?lise sensorial comparando-se as amostra de feij?o verde in natura e reidratado nas condi??es otimizadas, com e sem pr?-tratamento osm?tico. Todas as amostras apresentaram um bom ?ndice de aceita??o referente aos atributos analisados (apar?ncia, textura, cor, odor e sabor), estando todos os valores acima de 70%. Conclui-se que a secagem do feij?o verde por micro-ondas com pr?-tratamento osm?tico ? vi?vel, tanto em rela??o aos aspectos t?cnicos como aos ?ndices de reidrata??o e a qualidade sensorial do produto
345

Alfarroba como substituto do cacau no desenvolvimento de bebida sem lactose: otimizaÃÃo, perfil sensorial e comportamento reolÃgico / Carob as cocoa substitute in the development of lactose free beverage: optimization, sensory profile and rheological behaviour

Ana Cristina da Silva Morais 10 April 2015 (has links)
nÃo hà / Diversos efeitos benÃficos sÃo associados ao consumo de cacau em pÃ, como propriedade antioxidante e efeito cardioprotetor. No entanto, devido a algumas desvantagens como amargor e presenÃa de substÃncias estimulantes e alergÃnica, vÃrios produtos tÃm sido testados como substitutos do cacau, dentre os quais se destaca a alfarroba em pÃ. O produto nÃo apresenta tais desvantagens, alÃm de ser naturalmente adoÃada e fonte de fibras. Diante do exposto, o objetivo desta pesquisa foi verificar a viabilidade de substituiÃÃo total do cacau em pà pela alfarroba em pà em bebida sem lactose a base de amÃndoas da castanha de caju (ACC) e avaliar as alteraÃÃes das caracterÃsticas sensoriais, da aceitabilidade e do comportamento reolÃgico da bebida otimizada. A pesquisa foi realizada em duas fases, onde na primeira adotou-se um planejamento fatorial do tipo 2 para avaliar, atravÃs de superfÃcie de resposta, os efeitos da substituiÃÃo do cacau por alfarroba em pà (concentraÃÃo total de 2 g/100 mL), do teor de sacarose e de carragena no pH e no teor de sÃlidos solÃveis da bebida. Na segunda fase, as amostras otimizadas foram submetidas Ãs anÃlises microbiolÃgicas e à determinaÃÃo de atividade de Ãgua (aw), visando garantir a inocuidade para as anÃlises sensoriais. Aplicou-se a anÃlise descritiva quantitativa (ADQ) para verificar as principais propriedades sensoriais da bebida. Na medida de aceitabilidade das amostras, utilizaram-se os testes com escala hedÃnica e escala relativa ao ideal. O comportamento reolÃgico foi avaliado a 10 ÂC utilizando reÃmetro com placas paralelas. A proporÃÃo de cacau/alfarroba influenciou sutilmente somente o pH da bebida. Desta forma, decidiu-se pela substituiÃÃo total do cacau pela alfarroba em pÃ. As contagens microbianas estavam em nÃveis baixos aceitÃveis, garantindo a seguranÃa do produto, e a atividade de Ãgua situou-se em torno de 0,9838-0,9958. As propriedades sensoriais que apresentaram maior variaÃÃo entre as amostras foram cor marrom, aparÃncia viscosa, aroma de torrefaÃÃo, gosto doce e textura encorpada. As sete formulaÃÃes alcanÃaram boa aceitaÃÃo sensorial. No entanto, as duas amostras com menores teores de sacarose apresentaram menor aceitaÃÃo indicando a grande influÃncia da doÃura para a aceitaÃÃo da bebida. Recomenda-se 16% de sacarose para obter a doÃura ideal. As amostras apresentaram comportamento nÃo Newtoniano. Conclui-se que a substituiÃÃo do cacau pela alfarroba em pà na bebida de ACC (2 g/100 mL) à viÃvel, resultando em um produto de boa aceitaÃÃo sensorial. / Several benefits are associated with cocoa powder consumption as antioxidant properties and cardioprotective effect. However, due to some disadvantages, such as bitterness and the presence of stimulating and allergenic substances, many other products have been tested as a cocoa substitute, and among them carob powder has stood out. The product does not have the same disadvantages of cocoa, besides being naturally sweetened and source of fiber. According to the informations presented, the objective of this research was to investigate the feasibility of full replacement of cocoa powder by carob powder in lactose-free beverage cashew nut almond (CNA)-based as well as to evaluate changes in sensory characteristics, acceptability and rheological behaviour of the optimized beverage. The survey was conducted in two phases, in the first phase a factorial planning type 2 was carried out in order to evaluate, through response surface, the effects of cocoa replacement by carob powder (total concentration of 2 g/100 mL), of sucrose and carrageenan content in the pH and also in the soluble solids content of the beverage. As for the second phase, the optimized samples were subjected to microbiological analyzes, just as well to the determination of water activity (aw), in order to ensure safety for the sensory analysis. A quantitative descriptive analysis (QDA) was applied to verify the main sensory properties of the beverage. Tests with hedonic scale and just about right scale were used to verify the acceptance level of the samples. The rheological behaviour was evaluated at 10 ÂC with a rheometer with parallel plates. The proportion of cocoa/carob just slightly influenced the pH of the beverage. Thus, it was decided to full substitution of the cocoa by carob powder. Microbial counts were in low acceptable levels, ensuring product safety, and water activity stood at around 0.9838 to 0.9958. The sensory properties which presented greater variation among the samples were brown color, viscous appearance, roasting aroma, sweet taste and thickness. The seven formulations achieved good sensory acceptance. However, the two samples with lower sucrose levels presented a lowers acceptance indicating the great influence of sweetness level to the acceptance of the beverage. It is recommended the use of 16% sucrose for optimal sweetness. The samples presented a non-Newtonian behaviour. Finally it was possible to conclude that the replacement of cocoa by carob powder (2 g/100 mL) in lactose-free beverage CNA-based is feasible, resulting in a product of good sensory acceptance.
346

Análise sensorial: terminologia, desenvolvimento de padrões e treinamento de painelistas para avaliação de produtos cosméticos / Sensory analysis: terminology, standards development and panel training for evaluation of cosmetics products

Gisely Spósito Vieira 13 August 2015 (has links)
A análise sensorial é uma metodologia científica utilizada para mensurar, avaliar e interpretar reações relacionadas às características de produtos tais como são percebidas através dos sentidos, respondendo à bem mais que simplesmente à preferência por algum produto em detrimento de outros. Métodos científicos específicos têm sido desenvolvidos para medir ou estimar objetivamente, com precisão e reprodutibilidade, as respostas humanas aos estímulos a que são submetidos. Os testes descritivos, que compõem parte da análise sensorial, exigem controle cuidadoso das possíveis variáveis capazes de interferir no resultado, tais como ambiente do teste, armazenamento das amostras, condições da pele dos painelistas, seleção e treinamento de atributos do produto a serem avaliados. A filosofia do treinamento é proporcionar uma mesma experiência sensorial aos painelistas através do uso de uma ampla variedade de amostras de referências, conceitos, terminologias, protocolos e escalas, o que é essencial para estabelecer um quadro comum de referências, cujo propósito é remover a conotação \"subjetiva\" desta metodologia sensorial. Ao fazer uso desta metodologia, obtivemos respostas coerentes, similares e com pequenos desvios padrão após treinamento de três meses com o painel, o qual foi capaz de diferenciar sete produtos comerciais hidratantes nos atributos estudados / Sensory analysis is a scientific method used to measure, analyze and interpret reactions related to product characteristics such as perceived through the senses, responding to much more than simply preference for one product over another. Specific scientific methods have been developed to measure or estimate objectively, accurately and reproducibility human responses to stimuli that they are submitted. Descriptive tests, which are part of sensory analysis, require careful control of possible variables that can affect the results, such as test environment, sample storage, skin conditions of the panelists, product attributes selection and training. The training philosophy is to provide the same sensory experience to panelists through the use of a wide variety of references samples, concepts, terminology, protocols, and scales, which is essential to establish a common frame of reference, whose purpose is to remove the\"subjective\" connotation from this sensory methodology. By using this methodology, we achieved consistente, similar and with small standard deviations answers, after three months of training with the panel, which was able to distinguish seven moisturizers commercial products into the studied attributes
347

Effect of plant growth regulator applications on phenolic quality of red grape berry skin and wine Vitis vinifera L., cvs Cabernet Sauvignon and Carmenère / Effet de l'application des régulateurs de croissance végétale sur la qualité phénolique de la pellicule du raisin et du vin rouge Vitis vinifera L., cépages Cabernet Sauvignon et Carmenère

Gonzalez Rojas, Alvaro 30 May 2012 (has links)
La composition phénolique du vin rouge détermine fortement sa qualité: couleur, goût, texture et la plupart des bienfaits pour la santé. Les conditions ambiantes de la vigne modulent l'équilibre hormonal endogène et l'expression de gènes qui contrôlent la voie de synthèse des composés flavonoïdes, en déterminant la composition phénolique finale du raisin. Même s'ils ont été étudiés, les effets des applications des régulateurs de croissance végétale sur l'équilibre hormonal endogène et la qualité du raisin, les effets de ces substances sur la composition et la qualité du vin sont pauvrement documentés. Le traitement des raisins destinés à la vinification avec des régulateurs de croissance végétale est un outil potentiel pour modifier la qualité des raisins et du vin rouge. Ce projet de thèse a pour objectif d’étudier l’impact d'applications de régulateur de croissance végétale sur la composition phénolique des raisins de Vitis vinifera L. cépages Cabernet Sauvignon et Carménère. L’acide abscissique, l’acide indole-3-acétique et l'acide 2-chloroethilphosphonique ont été appliqués à divers stades phénologiques du raisin, doses et conditions environnementales: Les essais ont été menés à Maipo et Cachapoal au Chili et à Bordeaux en France, dans des vignobles commerciaux et expérimentaux ainsi que sur des plantes cultivées en pots. Il a été examiné l'effet de ces traitements sur le contenu interne d'hormones, sur l'expression de gènes structuraux et régulateurs de la synthèse de composés flavonoides et sur la qualité des raisins, en particulier la composition phénolique de sa pellicule. De plus, des vinifications ont été réalisées à partir de raisins traités pour déterminer l'effet des traitements sur la composition chimique et phénolique du vin, ainsi que sur des attributs qualitatifs tels que les arômes et la texture des vins, jugés par un panel d'évaluation sensorielle. / Phenolic composition strongly determines red wine quality: color, taste, texture and most health benefits. Vineyard environmental conditions modulate endogenous hormonal balance and gene expression which control the flavonoid biosynthetic pathway leading to final grape phenolic composition. Even when the effects of plant growth regulator applications on grape endogenous hormonal balance and quality have been studied, the effect of these substances on wine composition and quality is poorly documented. The treatment of wine grapes with plant growth regulators is a potential tool in order to modify red wine phenolic composition and quality. This thesis project describes six experiments on plant growth regulator applications on developing grapes of Vitis vinifera L., cvs Cabernet Sauvignon and Carménère. Abscisic acid, Indole-3-acetic acid and 2-chloroethylphosphonic acid were applied in different phenological stages, doses and environmental conditions: Maipo and Cachapoal regions in Chile and Bordeaux region in France, commercial and experimental vineyards and plants in containers. The effect on changes in the internal hormonal content, expression of flavonoid biosynthetic and regulatory genes and grape quality, in particular grape skin phenolic composition were examined. In addition, winemaking was performed in order to assess the effect of treatments on wine chemical and phenolic composition and on wine aroma and texture attributes judged by a sensory panel.
348

L'amélioration de la qualité nutritionnelle est-elle compatible avec le maintien de la qualité sensorielle ? : l'exemple des biscuits / Is the improvement of the nutritional quality compatible with the maintenance of the sensory quality? : the example of biscuits

Biguzzi, Coralie 15 February 2013 (has links)
Plusieurs fabricants de biscuits et gâteaux français se sont engagés à mettre sur le marché des produits de meilleure qualité nutritionnelle. Ce travail de thèse a eu pour objectif de déterminer si cette amélioration de la qualité nutritionnelle était compatible avec le maintien de la qualité sensorielle. La première étude portait sur l’impact des réductions en lipides et/ou en sucres sur l’appréciation et la perception sensorielle de neuf catégories de biscuits et gâteaux. Les résultats montrent que les enfants perçoivent peu de différences et apprécient généralement autant les variantes réduites que les variantes standards. Pour les produits réduits sans ajout de polyols, les adultes déprécient principalement les variantes qui sont perçues moins sucrées et parfois également moins grasses et/ou différentes d’un point de vue textural. De plus, les réductions en sucres sont plus perceptibles que les réductions en lipides et à taux de réduction proches, les produits réduits en lipides sont moins dépréciés que ceux réduits en sucres. Les produits réduits avec ajout de polyols ne sont pas dépréciés et ne sont pas tous perçus moins sucrés.La deuxième étude s’est intéressée à deux leviers pour faire mieux accepter les produits réduits en lipides ou sucres. En exposant quasi-quotidiennement des consommateurs à des biscuits réduits d’environ 30 % en lipides ou en sucres, l’appréciation de ces produits augmente après un mois, mais davantage pour les lipides. En revanche, une exposition progressive ne montre pas d’effet sur un mois. Par ailleurs, une allégation nutritionnelle indiquant une réduction ne semble pas être un levier pour l’appréciation de biscuits et gâteaux réduits en lipides ou sucres / French biscuit producers are willing to improve the nutritional composition of their products. The objective of this work was to determine whether it was possible while maintaining the sensory quality of the reduced product.The first study dealt with the impact of fat and sugar reduction on liking and sensory perception of 9 types of biscuits and cakes. Results show that children perceived almost no difference and liked equally the standard and the fat- and/or sugar-reduced variants for most types of biscuits. For products reduced without adding polyols, adults less liked fat- or sugar-reduced variants than standard ones mainly when they were perceived as less sweet, and to a lesser extent as less fatty and/or as different in terms of textural aspects. Furthermore, a reduction in fat content was more difficult to perceive than a reduction in sugar content. With similar levels of reduction, fat-reduced products were less disliked than sugar-reduced ones. Sugar-reduced biscuits with an addition of polyols were not disliked and some of them were not perceived as less sweet than standard biscuits.The second study was about two strategies to promote consumer acceptance for fat- or sugar-reduced products. On the one hand, some consumers were exposed almost daily to -30 % fat- or sugar-reduced biscuits. After a month of exposure, reduced variants were more appreciated than before exposure, but it was more significant for fat reduction. On the other hand, no difference of liking was observed after a month of stepwise exposure. Besides, a nutritional claim indicating the fat or sugar reduction does not seem to be efficient to increase liking for fat- or sugar-reduced biscuits and cakes
349

Préservation de l'arôme dans un jambon cuit non nitrité / Preservation of aroma in a nitrite-free cooked ham

Thomas, Caroline 10 December 2014 (has links)
Le nitrite est un ingrédient essentiel à la fabrication du jambon cuit, pourtant les risques sanitaires dont il est accusé remettent en question son utilisation. L’emploi de cet unique additif permet de remplir de nombreuses fonctions comme la protection antioxydante et antimicrobienne mais aussi le développement de la couleur et de l’arôme. C’est sur cette dernière fonction que ce travail de thèse s’est focalisé avec pour objectif la suppression du nitrite dans la fabrication du jambon cuit. La mise en œuvre de plusieurs techniques complémentaires de chromatographie en phase gazeuse couplées à l’olfactométrie a permis dans une première partie d’identifier le 2-methyl-3-furanthiol, 2-methyl-3-(methyldithio)furan, et le bis(2-methyl-3-furyl)disulfide comme les molécules soufrées responsables de l’arôme du jambon cuit. Il est apparu qu’en l’absence de nitrite et par conséquent en absence de protection antioxydante, les composés odorants issus de l’oxydation sont produits massivement et ont tendance à perturber l’arôme global du jambon cuit. Afin de restaurer l’arôme en l’absence de nitrite, l’étude a été organisée selon 2 axes : le premier visant à favoriser la production des molécules soufrées clés de l’arôme et le second visant à limiter la formation des composés d’oxydation perturbateurs de l’arôme grâce à l’utilisation d’antioxydants naturels. Les recherches ont été conduites sur des mini-jambons cuits modèles. La thiamine a été identifiée comme précurseur majoritaire du 2-methyl-3-furanthiol, du 2-methyl-3-(methyldithio)furan, et du bis(2-methyl-3-furyl)disulfide dans les conditions de fabrication du jambon cuit et des extraits d’acérola, de canneberge, d’oignon et de thé ont été sélectionnés pour leurs propriétés antioxydantes. L’évaluation en parallèle de l’oxydation et de l’arôme a montré que ces quatre extraits utilisés en mélange permettaient, non seulement d’égaler les performances antioxydantes du nitrite, mais aussi de rehausser la note aromatique « jambon cuit » par rapport à la formulation non nitritée de référence. L’association de la thiamine et des extraits végétaux a finalement permis de réaliser des jambons non nitrités qui, en termes d’arôme et d’oxydation, se rapprochent fortement d’un jambon nitrité. Les formulations réalisées constituent donc une première piste satisfaisante pour répondre à la problématique de la suppression du nitrite dans le jambon cuit. La protection antimicrobienne des nouvelles formulations doit être validée et la restauration de la couleur rose du jambon demeure une problématique organoleptique. / Sodium nitrite is an essential ingredient in the cooked ham production process, yet its use is under challenge due to food safety concerns. Sodium nitrite is a multifunctional additive used for its ability to act on several fronts—from inhibiting oxidation and preventing microbial growth to giving desirable colour and aroma. This study focused on the aroma function under a wider objective to reduce nitrite use in cooked ham processing. Using several complementary methods with gas chromatography–olfactometry, we first identified 2- methyl-3-furanthiol, 2-methyl-3-(methyldithio)furan and bis(2-methyl-3-furyl)disulfide as the odour- active sulphur-compounds responsible for cooked ham flavour. It emerged that in the absence of nitrite—and therefore the absence of inhibited oxidation—the massive formation of an array of odour-active compounds produced by oxidative breakdown tended to disrupt the overall aroma of the final cooked ham. Next, in an effort to restore this aroma in the absence of nitrite, the study was organized into two strands, where the first strand aimed to promote the production of key aroma-active sulphur-compounds while the second strand aimed to minimize the formation of aroma-disruptive oxidation compounds by using natural antioxidants. This research was led on model cooked mini-hams. We identified thiamine as the major precursor of 2-methyl-3-furanthiol, 2-methyl-3-(methyldithio)furan and bis(2-methyl-3-furyl)disulfide under cooked ham production conditions, and we selected acerola, cranberry, onion and tea extracts as natural antioxidants. The coupled evaluations of oxidation and aroma showed that the formulated mixture of these four extracts not only equalled the antioxidant performances of added sodium nitrite but also lifted the “cooked ham” head note compared to the reference no-added-nitrite formulation. The association of thiamine and vegetal extracts ultimately made it possible to produce no-added-nitrite hams that, in terms of aroma and oxidation levels, proved almost identical to nitrite-added ham. The engineered formulations thus offer a good research track to suppress the sodium nitrite in cooked ham. The problem of how to restore the distinctive pink colour of cooked ham is an issue that remains to be resolved, and the ability of these new formulations to inhibit microbial growth needs to be validated.
350

Effet de l’obturateur sur l’évolution de la qualité sensorielle du vin / Effect of closures on the evolution of the sensorial quality of wine

Silva, Maria Adélaide 16 December 2011 (has links)
L’évolution des vins lors de la conservation en bouteille est un processus lent et complexe où les obturateurs jouent un rôle fondamental, conséquence directe de leur perméabilité à l’oxygène mais aussi des interactions physico-chimiques avec les constituants du vin.Dans un premier temps nous avons étudié l’effet de la conservation en bouteille des vins de Sauvignon blanc après 24 mois d’embouteillage. Dans cette étude, la combinaison des conditions de mise en bouteille et des taux de transfert d'oxygène à travers les bouchons ont eu un effet significatif sur le développement du Sauvignon après l'embouteillage. Les vins fermés hermétiquement en bouteille « ampoule » ou avec des obturateurs à très faible taux de transfert d'oxygène comme les capsules à vis, présentent les plus fortes concentrations en dioxyde de soufre, en acide ascorbique, et en thiols variétaux, mais aussi des niveaux élevés de sulfure d’hydrogène (H2S), qui ont complètement masqué le fruité des vins, par rapport au caractère réduit dominant. Les plus fortes concentrations en 3-sulfanyl-hexanol (3SH) ont été trouvées pour les vins présents dans les bouteilles « ampoules » suivi des bouteilles scellées avec des bouchons à vis saran et des bouchons agglomérés. Les teneurs les plus faibles en 3SH ont été trouvées pour les bouteilles scellées avec des bouchons synthétiques (Nomacorc classic). Le développement du vin à partir de deux mois semble être plutôt lié aux propriétés de perméabilité des différents obturateurs utilisés.Dans un deuxième temps nous avons voulu étudier l’incidence de sept types d’obturateurs (bouchon en liège : naturel, naturel colmaté, microaggloméré, ciré, bouchons synthétiques, capsules à vis : saran et saranex) sur des marqueurs chimiques d’oxydation et de réduction, sur les teneurs en oxygène du vin, ainsi que sur la composition phénolique et aromatique des vins issus de cinq cépages (Merlot, Cabernet Sauvignon, Syrah, Sauvignon blanc et Riesling). Nous avons vérifié que la concentration d’oxygène dans l’espace de tête après embouteillage varie selon le type d’obturateurs, celle-ci peut être jusqu’à trois fois plus importante dans le cas des capsules à vis. Les teneurs en oxygène apportées lors de la mise en bouteille pourraient être responsables de l’absence de discriminations des paramètres chimiques entre les différentes modalités d’obturateurs, après 24 mois de conservation en bouteille. Nous avons mis en évidence une évolution de la composition des vins, avec une diminution importante des concentrations de certains composés (certaines anthocyanes telles que la malvidine et la cyanidine-3-O-glucoside ont diminuées de 60%, des flavanols monomères et dimères présentent des diminutions de l’ordre de 20%) pour les cépages rouges et une augmentation pour d’autres composés, comme l’H2S ou la 3-méthyl-2,4-nonanedione (MND, augmentation de 10%) ou le 1,1,6-triméthyl-1,2-dihydronaphtalène (TDN), dans le cas du Riesling; il est intéressant de remarquer que l’évolution de ce dernier semble être dépendante du type de bouchon, alors que les taux d’autres composés comme le sulfure de diméthyl (DMS) ne semblent pas être affectés par l’obturateur.L’étude des interactions entre les différents obturateurs et les composés soufrés du vin, tel que le sulfure d’hydrogène, responsables des odeurs désagréables couramment appelés « odeurs de réduction » a été réalisée. Nous constatons pour la première fois l’existence d’une sorption/ « scalping » de 75% d’ H2S ou de DMS en solution, après 25 jours de macération par les bouchons en liège. Nous montrons que certains des obturateurs étudiés peuvent sorber/scalper ces molécules, en milieu modèle hydroalcoolique, ouvrant ainsi les portes à des futures expérimentations portant sur l’obturateur en tant que constituant actif d’un emballage jouant un rôle dans la composition, l’évolution et la perception sensorielle du vin. / Wine post-bottling evolution is a slow and complex process where the closures play a fundamental role as a consequence of their permeability to oxygen and of physicochemical interactions with the constituents of wine.Initially we studied the effect of conservation in bottle of Sauvignon Blanc wines after 24 months of bottling. In this study, the combination of the bottling conditions and rates of oxygen transfer through closures have had a significant effect on the development of Sauvignon after bottling. Wine stored in an airtight bottle or under closures allowing very low oxygen transfer, such as screw caps, had the highest concentrations of sulfur dioxide, ascorbic acid, and varietal thiols; these wines also had the highest levels of hydrogen sulfide (H2S) with dominant reduced off-flavours masking their fruity character. The highest concentrations of 3-sulfanyl-hexanol (3SH) were found in wines contained in the airtight bottles followed by those sealed with screw caps saran and agglomerated corks. The lowest levels were found in bottles sealed with synthetic corks (Nomacorc classic). The development of wine after two months seems to be related to the permeability properties of the different plugs used.Secondly, we studied the impact of seven types of closures (natural cork, colmated cork, microagglomerated cork, natural cork with wax, synthetic, screw caps: saran and saranex) on oxidation and reduction chemical markers, on oxygen contents, as well as phenolic and aromatic composition of wines from five grape varieties (Merlot, Cabernet Sauvignon, Shiraz, Sauvignon Blanc and Riesling). We observed that the oxygen concentration in the headspace after bottling varies with the type of closure, being up to three times higher in the case of screw caps. The oxygen introduced during bottling may be responsible for the lack of overall discrimination between chemical parameters of the different modalities of closures after 24 months of storage. We have demonstrated a change in the composition of wines, with a significant decrease in concentrations of certain compounds (anthocyanins like malvidin and cyanidin-3-O-glucoside were reduced by 60%, flavanol monomers and dimers decreased about 20%) for red grape varieties and an increase of other compounds such as H2S or 3-methyl-2,4-nonanedione (MND), with an increase of 10% or 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN), in the case of Riesling. The evolution of the latter appears to be dependent on the type of closure, while rates of other compounds such as dimethyl sulfide (DMS) remain unaffected.The interactions between different closures and sulfur compounds, such as hydrogen sulfide, responsible for the “reduction” off-flavours in wine were studied. We see for the first time the existence of a sorption/scalping, by cork stoppers, of 75% of H2S or DMS in solution, after 25 days of maceration. We show that some of the closures studied can sorb/scalp these molecules in wine-like media. This may have an impact on the composition, the development and sensory perception of wine, opening the door to future experiments regarding closures as active packaging constituents

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