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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.
1

Adapta??o de metodologia de digest?o in vitro e determina??o da bioacessibilidade in vitro de Beta -caroteno em tr?s variedades de batata-doce de polpa alaranjada. / Adaptation of in vitro digestion methodology and determination of in vitro Beta-carotene bioacessibility of three orange sweet potato varieties.

Giori, Fernanda Peixoto 23 February 2010 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-30T14:26:59Z No. of bitstreams: 1 2010 - Fernanda Peixoto Giori.pdf: 2362278 bytes, checksum: a15d423533272c981b15d7f22b714be1 (MD5) / Made available in DSpace on 2016-08-30T14:26:59Z (GMT). No. of bitstreams: 1 2010 - Fernanda Peixoto Giori.pdf: 2362278 bytes, checksum: a15d423533272c981b15d7f22b714be1 (MD5) Previous issue date: 2010-02-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior-CAPES / Brazil was adverted by the World Health Organization (WHO) as a sub-clinical area of serious vitamin A deficiency. Thus, the Brazilian Agricultural Research Corporation (EMBRAPA) is selecting and improving varieties of sweet potatoes with higher levels of Beta-carotene, pro-vitamin A. The carotenoids provitamin A amount of in foods does not necessarily correspond the amount that is absorbed and metabolized by the body. For a better determination of these values and knowledge of the mechanisms of its transport and absorption, it is necessary to understand the factors that lead to the food matrix release, until the absorption and the influence on the promotion and maintenance in human health. In order to perform preliminary studies of its absorption, this study aims to determine the efficiency of micellization of Beta -carotene in orange sweet potato (Ipomoea batatas, Lam), by applying a in vitro digestion as a tool for determining the bioaccessibility, which is the first step for bioavailability determination. This approach aims to simulate the oral, gastric and intestinal stages of human. The digestion was performed with 10 g of fresh samples, homozeneided with 5% (w/w) of canola oil. The extraction was performed with acetone and petroleum ether and the micellar fraction with petroleum ether, NaCl 10% (w / v) and NaSO4 2% (w/v) and involves the use of enzymes as -amylase , pepsin, bile, pancreatin, lipase and mucin, and inorganic compounds such as KCl, KSCN, NaH2PO4, Na3PO4, NaOH, NaCl, CaCl2, HCl, NaHCO3. The physiological variations are reproduced by the heating bath shaker with orbital gyrus (37?C) and centrifugation (5000g, 45 min). Quantification and determination of the profile of carotenoids were performed by high performance liquid chromatography (HPLC) with YCM ? C30 Carotenoid S-3 4.6 x 250mm column. Quantification of total carotenoids was performed by UV-VIs. The whole procedure was performed under controlled temperature (25 ? C) and light. The Beta -carotene was present mainly with levels of 86%, 73% and 82% for access 1, 2 and 3 and after digestion, the profile of Beta -carotene has set levels of 96%, 89% and 100%, respectively. The efficiency of micellization was 23.8%, 28% and 25% for 1.2 and 3 hits, indicating Beta -carotene transfer of the food matrix to micelles, corresponding to bioaccessibility of the compound. This methodology proved to be faster and cheaper, since the in vivo studies are costly, complex and require more time. / O Brasil foi classificado pela Organiza??o Mundial da Sa?de (OMS) como ?rea de car?ncia sub-cl?nica grave de vitamina A. Assim, a Empresa Brasileira de Pesquisa Agropecu?ria (EMBRAPA) v?m selecionando e melhorando variedades de batata-doce com teores maiores de Beta-caroteno, composto pr?-vitamina A. A quantidade de caroten?ides pr?-vitamina A presentes nos alimentos n?o corresponde necessariamente ?quela quantidade absorvida e metabolizada pelo organismo. Para uma melhor determina??o destes valores e conhecimento dos mecanismos de transporte e absor??o deste composto, faz-se necess?rio, o entendimento dos fatores que levam ? sua libera??o da matriz do alimento, at? a extens?o de sua absor??o, bem como a influ?ncia na promo??o e manuten??o da sa?de humana. A fim de realizar estudos preliminares de sua absor??o, este trabalho visa determinar a efici?ncia de miceliza??o de Beta-caroteno de batata-doce de polpa alaranjada (Ipomoea batatas, Lam.), atrav?s da aplica??o de digest?o in vitro, como ferramenta de determina??o da bioacessibilidade, etapa preliminar para a determina??o da biodisponibilidade. Esta metodologia visa simular as etapas de digest?o oral, g?strica e intestinal humana. Foram pesados 10g de amostra in natura e adicionados 5% (p/p) de ?leo de canola. A extra??o do alimento foi realizada com acetona e ?ter de petr?leo e a da fra??o micelar, com ?ter de petr?leo, NaCl 10%(p/v) e NaSO4 2%(p/v) . Enzimas como: a-amilase, pepsina, bile, pancreatina, lipase e mucina, bem como compostos inorg?nicos, tais como KCl, KSCN, NaH2PO4, Na3PO4, NaOH, NaCl, CaCl2, HCl, NaHCO3. As varia??es fisiol?gicas foram reproduzidas pelo banho de aquecimento com giro orbital (37?C) e centrifuga??o (5000g;45 min). A quantifica??o e determina??o do perfil de caroten?ides foi realizada por cromatografia l?quida de alta efici?ncia (CLAE), com coluna YCM? Carotenoid C30 S-3 de 4,6 x 250mm. A quantifica??o de caroten?ides totais foi realizada por espectrofotometria UV-VIs. Todo o procedimento foi executado sob temperatura (25?C) e luz controlada. O Beta-caroteno estava presente majoritariamente, com teores de 86%, 73% e 82%, para as variedades 1, 2 e 3 e ap?s a digest?o, o perfil do Beta-caroteno passou a configurar teores de 96%, 89% e 100%, respectivamente. A efici?ncia de miceliza??o foi de 23,8%, 28% e 28,9% para as variedades 1,2 e 3, indicando a transfer?ncia do - caroteno da matriz do alimento para as micelas, correspondendo a bioacessibilidade deste composto. Esta metodologia demonstrou-se mais r?pida e mais barata, quando comparada aos estudos in vivo, que s?o mais onerosos, complexos e demandam mais tempo.
2

Caractérisation des différentes formes variétales d'huile de palme de Côte d Ivoire : propriétés antioxydantes / Characterization of Palm Oil Speciies of Côte d Ivoire : antioxident proprieties

Monde, Absalome Ake 28 September 2011 (has links)
La présente étude avait pour objectif de déterminer la composition en acides gras, la teneur en caroténoïdes, en vitamine E, et en polyphénols des huiles extraites de quatre variétés de palmier à huile cultivées en Côte d'Ivoire (variétés parentales : HP1et HP2, variétés hybrides : HP3 et HP4), puis d'étudier les propriétés antioxydantes de leurs extraits polyphénoliques. Les résultats ont montré : une richesse particulière en acides gras insaturés totaux avec une prédominance en acide oléique des variétés HP1 (60%), HP3 (56%) et HP4 (57%) comparée à HP2 (48%). Les concentrations en vitamine E étaient de 864 à 1124 µg/g avec une forte teneur en α- et γ- tocotriénol dans la variété HP2 et les hybrides HP3 et HP4. La variété HP1 et les hybrides ont des taux de caroténoïdes totaux significativement plus élevés que la variété HP2. La teneur en polyphénols totaux était élevée dans les variétés HP1 (0,195mM EAG), HP3 et HP4 (0,191mM et 0,2 mM EAG). Les différents polyphénols identifiés étaient l'acide caféique, l'acide chlorogénique, l'acide coumarique, la rutine et un dérivé non identifié de la quercétine. Ces extraits polyphénoliques avaient un effet inhibiteur sur l'oxydation des LDL de manière dose-dépendante, dans le système d'oxydation au cuivre qu'à l'AAPH. Les activités antioxydantes étaient significativement plus importantes pour HP3 et HP4 comparées à HP1 et HP2. Ces extraits polyphénoliques ont inhibé la production d'O2•― par modulation de la NADPH oxydase au niveau des cellules THP-1 stimulées au PMA, de manière dose-dépendante. Cette action antioxydante a été confirmée par l'inhibition de l'expression de la sous unité p22phox de 74% pour HP1, 87% pour HP2, 69% pour HP3 et 75% pour HP4. L'huile de palme brute pourrait ainsi être considérée comme une source sûre de composés polyphénoliques, notamment l'huile issue des formes variétales HP3 et HP4, dont les effets protecteurs semblaient être plus marqués. / The purpose of the present study was to determine fatty acid, vitamin E, carotene and polyphenol contents in four oil palm species of Côte d'Ivoire (parental varieties: HP1et HP2, crossing varieties: HP3 and HP4), then to study their polyphenol antioxidant properties. The results showed that palm oil species were characterized by the special richness in polyunsaturated fatty acids composition, with a prevalence in oleic acid, especially the first variety, HP1 (60%), and the two hybrids ensuing from crossing HP3 (56%) and HP4 (57%) compared to HP2 (48%). Total vitamin E content was 864–1124 μg g−1, with a notable higher content of γ -and α-tocotrienol in variety HP2 and hybrids HP3 and HP4. Total carotene content of those varieties was higher, and the β-carotene and α-carotene levels were predominant in HP1, HP3 and HP4. The highest total phenolic contents were found for parental variety HP1, (0.195 mM GAE), the two crossing varieties HP3 and HP4 (0.191mM and 0.2 mM GAE). The main identified phenolic compounds were caffeic, chlorogenic, coumaric acids, rutin, and a non identified quercetin derivative. The antioxidative effects were monitored by Cu2+- or AAPH-induced generation of conjugated dienes (lag-time and oxidation rate) showed that these phenolic compounds inhibit human LDL oxidation in a synergistic manner. The antioxidant activities were significantly more important for HP3 and HP4 varieties compared to HP1 and HP2 varieties. All palm oil polyphenol extracts (compared to control) decreased PMA-stimulated O2•― production by THP-1 cells in a dose dependent manner in the modulation of NADPH oxidase. Using Western blot analysis, we further demonstrated that incubation for 24h of these polyphenol extracts with THP-1 cells led to a significant reduction in the expression of NADPH oxidase subunit p22phox (from 74% for HP1, 87% for HP2, 69% for HP3 and 75% for HP4). Crude palm oil could be considered as a good source of phenolic compounds, in particularly oil resulting from HP3 and HP4 varieties. These protective effects seemed to be more marked with the two crossing varieties in comparison with the two parental varieties.
3

Varia??o no conte?do prot?ico e pigmentar em variantes crom?ticas de Gracilaria domingensis nas popula??es naturais de Rio do Fogo-RN, BRASIL / Variation in protein and pigment content in colour strains of Gracilaria domingensis in the natural populations of Rio do Fogo (RN)

Pereira, Dinaelza Castelo 23 March 2009 (has links)
Made available in DSpace on 2014-12-17T14:01:58Z (GMT). No. of bitstreams: 1 DinaelzaCP.pdf: 982597 bytes, checksum: 8505a456042640660a4eeec39570774f (MD5) Previous issue date: 2009-03-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The seaweed Gracilaria domingensis is a common species in the coast of Rio Grande do Norte. This species lives in the intertidal zone, where colour strains (red, green and brown) co-occur during the whole year. Seaweeds that live in this region are exposed to daily changes and to the rhythm of the tide. During the low tide they are exposed to dissection, hiper-or hipo-osmotic shock, high temperatures and high irradiance. The aim of this study was to analyze whether the pigment and protein content of the colour strains of G. domingensis is affected by some environmental parameters in a temporal scale. The seaweeds were collected during 10 months in the seashore of Rio do Fogo (RN). The total soluble proteins and the phycobiliprotein were extracted in phosphate buffer and the carotenoids were analyzed by a standardized method through HPLC-UV. The pigments analysis showed that phycoerithrin is the most abundant pigment in the three strains. This pigment was strongly correlated with nitrogen and the photosynthetically active radiation. Chlorophyll presented higher concentrations than carotenoids during the whole, but the ratio carotenoid/chlorophyll-a was modified by incident radiation. The most abundant carotenoid was ?-carotene and zeaxanthin, which had higher concentrations in the higher radiation months. The concentration increase of zeaxanthin in this period indicated a photoprotective response of the seaweed. The three strains presented a pigment profile that indicates different radiation tolerance profile. Our results pointed that the green strain is better adapted to high irradiance levels than the red and brown strains / A macroalga Gracilaria domingensis ? comumente encontrada no litoral do Rio Grande do Norte. Esta esp?cie habita a zona intertidal, onde linhagens crom?ticas (vermelha, verde e marrom) co-ocorrem durante todo o ano. Algas que vivem nesta regi?o est?o submetidas a mudan?as diurnas e ao ritmo da mar?. Durante a mar? baixa elas ficam expostas a disseca??o, choque hiper ou hipo-osm?tico, altas temperaturas e elevada irradi?ncia. Este trabalho teve como objetivo geral o estudo do perfil prot?ico e pigmentar das variantes crom?ticas de G. domingensis e a altera??o deste perfil em fun??o dos par?metros ambientais em uma escala temporal. As algas foram coletadas mensalmente, durante 10 meses, nas parias de Rio do Fogo-RN. As prote?nas totais sol?veis e as ficobiliprote?nas foram extra?das em tamp?o fosfato e os caroten?ides foram analisados em um m?todo padronizado por HPLC-UV. A an?lise dos pigmentos mostrou que a ficoeritrina ? o pigmento mais abundante nas tr?s linhagens. Este pigmento esteve fortemente correlacionado com o nitrog?nio e a PAR. Os pigmentos caroten?ides apresentaram concentra??es inferiores as da clorofila-a durante todos os meses, mas a raz?o caroten?ides/clorofila-a foi modificada com o aumento da radia??o. O caroten?ide mais abundante foi o ?-caroteno, seguido da zeaxantina, que esteve em maiores concentra??es nos meses de maior radia??o. O aumento na concentra??o da zeaxantina nesse per?odo indicou uma resposta fotoprotetora da alga. As tr?s linhagens apresentaram um perfil pigmentar que remete a diferentes padr?es de toler?ncia a radia??o. A linhagem verde mostrou ser melhor adaptada a elevados n?veis de irradi?ncias do que a vermelha e a marrom
4

Caracteriza??o nutricional, f?sico-qu?mica e sensorial de polpa de tomates cultivados em sistema org?nico

Rosa , C?ntia Let?cia da Silva 31 March 2011 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-26T14:00:38Z No. of bitstreams: 1 2011- C?ntia Let?cia da Silva Rosa.pdf: 3366742 bytes, checksum: 280ece7f9ee6afde0d927d4a7dd0c3ef (MD5) / Made available in DSpace on 2016-08-26T14:00:38Z (GMT). No. of bitstreams: 1 2011- C?ntia Let?cia da Silva Rosa.pdf: 3366742 bytes, checksum: 280ece7f9ee6afde0d927d4a7dd0c3ef (MD5) Previous issue date: 2011-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This study aimed to evaluate accessions of tomato 'heirloom' whose cultivation is still little known in Brazil, grown organically, and its physical-chemical, nutritional and sensory characteristics after processing to obtain concentrated pulp. We used the non-hybrid tomatoes (Lycopersicum esculentum Mill) San Marzano, Chico Grande, Amish Paste and called EUA 05. The fruits were produced in the period from May to September 2010, the sector of Horticulture Department of Plant Science, of UFRRJ. In fresh fruit were analyzed total soluble solids (TSS), acidity (TTA), pH, quantification and identification of carotenoids, color of skin and pulp, texture instrumental and analysis of pesticides. Access San Marzano was not processed because of bacterial contamination in the field. The process was composed of the stages of pre-washing, washing / screening, milling, pulping, concentration, filling, exhaustion, closing, heat treatment / cooling and storage. It were added in the formulation of 1% salt, 0.4% sugar and citric acid for pH correction for microbial control. It was performed viscosity and pre-commercial sterility analyses in addition to those cited in the fresh tomato, both in the pulps in this study as six commercial brands on the market. For the sensorial analysis of the product manufactured was performed the Quantitative Descriptive Analysis (QDA) with trained judges and acceptance test with consumers. With respect to the TSS in tomatoes fresh, the Chico Grand and San Marzano showed the highest values (5.2? Brix). Access Chico Grande showed greater balance between acidity and sugar content in fruit, established by the TSS / TA (? Brix /%) of 19.2. Regarding the content of lycopene, access San Marzano had a higher average level of 6029 ?g/100g and more red coloration observed in the amount of a *= 29.68. No pesticide residues were found in the samples for organochlorine and organophosphorus pesticides. Results for the SST of pulps showed that accessions Amish Paste and EUA 05 stood out with values of 10.1 ? Brix. Regarding ATT access Amish Paste showed higher citric acid (1.445 g/100g) and lower pH value (3.66), which can lead to an impairment of sensory quality. The efficiency of the processing of pulp was 73% for access Chico Grande, Amish Paste 72% and 81% for EUA 05. After analyzing the lycopene content of the samples, we observed that the sample Amish Paste (3346.0 ?g/100g) and EUA 05 (3375.0 ?g/100g) showed the highest values with no statistical difference between them, corroborating the red color represented by lower values of hue angle. With respect to viscosity, the samples Chico Grande (246cP) and EUA 05 (235cP) stood out by the highest maximum viscosity. The results found in ADQ characterized the pulps by the attributes of astringency, taste salty, sour and acid flavor, and the commercialpulps by the attributes sweet aroma and sweet taste, flavor and aroma of tomato pulp. With respect to acceptance, the lowest scores were attributed to pulp in this study. However, samples Chico Grande (4.41) and the EUA 05 (4.48) had the highest score for overall acceptability with statistically significant differences with regard to the sample Amish Paste (3.06). It can be concluded with respect to fresh tomatoes that tomato 'heirloom' evaluated showed good quality in relation to balance acidity/sugar, and lycopene content. In pulps prepared from the three accessions 'heirloom' studied, concentrated pulp obtained from tomato Amish Paste and USA 05 showed the best characteristics for the food industry, with respect to soluble solids, lycopene content and red color. However, access Chico Grande showed higher viscosity when compared to other accessions. After the sensory analysis concluded that there was a rejection by the majority of consumers with regard to all the pulps obtained from tomatoes 'heirloom' due to significant changes in aroma and taste sour, salty taste as well as during the preparation / Este trabalho teve como objetivo geral avaliar acessos de tomate ?heirloom? cujo cultivo ainda ? pouco conhecido no Brasil, cultivados no sistema org?nico, e suas caracter?sticas f?sicoqu?micas, nutricionais e sensoriais ap?s o processamento para obten??o de polpa concentrada. Foram utilizados os tomates n?o h?bridos (Lycopersicum esculentum Mill) San Marzano, Chico Grande, Amish Paste e o denominado EUA 05. Os frutos foram produzidos no per?odo de maio a setembro de 2010, no setor de Horticultura do Departamento de Fitotecnia, da UFRRJ. Os frutos in natura foram caracterizados pelas an?lises de s?lidos sol?veis totais (SST), acidez total titul?vel (ATT), pH, quantifica??o e identifica??o dos caroten?ides, cor da casca e da polpa, textura instrumental e an?lise de pesticidas. O processamento e as an?lises foram realizados na Embrapa Agroind?stria de Alimentos, Rio de Janeiro-RJ. O processamento foi composto pelas etapas de pr?-lavagem, lavagem/sele??o, tritura??o, despolpamento, concentra??o, envase, exaust?o, fechamento, tratamento t?rmico/resfriamento e armazenamento. O acesso San Marzano n?o foi utilizado devido ? contamina??o bacteriana no campo. Foram adicionados na formula??o 1% de sal, 0,4% de a??car e ?cido c?trico para corre??o do pH para controle microbiol?gico. As mesmas an?lises realizadas no tomate in natura e ainda as an?lises de viscosidade, coliformes a 45?C, salmonelas, pr?-esterilidade comercial e avalia??o sensorial foram realizadas nas polpas concentradas e em seis marcas comerciais do mercado. Para realiza??o da an?lise sensorial utilizou-se a An?lise Descritiva Quantitativa (ADQ) com equipe treinada e Teste de Aceita??o com consumidores. Com rela??o ao teor de SST nos tomates in natura os acessos Chico Grande e San Marzano apresentaram os maiores valores (5,2 ?Brix). O acesso Chico Grande apresentou maior balan?o entre acidez e o teor de a??cares no fruto, estabelecido pela rela??o SST/ATT (?Brix/%) de 19,2. Com rela??o ao teor de licopeno o acesso San Marzano apresentou maior teor m?dio de 6029 ?g/100g, bem como colora??o mais vermelha observada pelo par?metro instrumental a*=29,68. N?o foram encontrados res?duos de agrot?xicos organofosforados e organoclorados em nenhuma das amostras. Nas polpas concentradas os resultados encontrados para a an?lise SST demonstraram que os acessos Amish Paste e EUA 05 se destacaram com valores de 10,1?Brix. O acesso Amish Paste apresentou maior valor de acidez (1,445g/100g), bem como menor valor de pH (3,66), o que levou a um comprometimento da sua aceita??o sensorial. O rendimento ap?s despolpamento dos tomates foi de 73% para o acesso Chico Grande, 72% para Amish Paste e de 81% para EUA 05. Ap?s a an?lise do teor de licopeno das amostras, observou-se que a amostra Amish Paste (3346,0?g/100g) e EUA 05 (3375,0?g/100g) apresentaram os maiores valores sem diferen?a estat?stica entre si, corroborando com a colora??o vermelha representada pelos menores valores do ?ngulo hue (?h). As polpas Chico Grande (246cP) e EUA 05 (235cP) se destacaram pelos maiores valores de viscosidade m?xima. A avalia??o sensorial (ADQ) caracterizou as polpas obtidas pelos atributos adstring?ncia, gosto salgado, gosto ?cido e aroma ?cido; e as polpas comerciais pelos atributos aroma doce, gosto doce, sabor e aroma caracter?stico de polpa de tomate. Com rela??o ? aceita??o, as menores notas foram atribu?das ?s polpas deste estudo. No entanto, as amostras Chico Grande (4,41) e EUA 05 (4,48) apresentaram a maior nota de aceita??o global com diferen?a estat?stica significativa com rela??o ? amostra Amish Paste (3,06). Pode-se concluir com rela??o ao tomate in natura que os acessos de tomate ?heirloom? avaliados apresentaram boa qualidade com rela??o ao equil?brio acidez/a??cares e teores de licopeno. Nas polpas elaboradas dos tr?s acessos ?heirloom? estudados, a polpa concentrada obtida do tomate EUA 05 e Amish Paste apresentaram melhores caracter?sticas para a ind?stria de alimentos, com rela??o ao teor de s?lidos sol?veis, teor de licopeno e colora??o vermelha. No entanto, o acesso Chico Grande apresentou valores maiores de viscosidade quando comparados aos outros acessos. Ap?s an?lise sensorial concluise que houve uma rejei??o pela maioria dos provadores com rela??o a todas as polpas obtidas dos tomates ?heirloom? devido a altera??es significativas no aroma e sabor ?cido, bem como no gosto salgado, decorrentes de sua formula??o.

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