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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.
91

Compostos bioativos em óleos e resíduos de sementes de uvas orgânicas e convencionais

Assumpção, Carolina Fagundes January 2014 (has links)
A indústria de alimentos é responsável pela produção de grandes quantidades de resíduos que podem representar altos custos quando não utilizados. Entre estes resíduos estão as sementes oriundas do processamento de uva, uma das frutas mais consumidas no mundo. Além do aproveitamento de resíduos e consequentemente novas formas de consumo, este material tem sido relatado como fonte natural rica em compostos bioativos. Neste contexto, o consumo de alimentos mais saudáveis também tem impulsionado a busca e a preferência por alimentos orgânicos. Assim, para investigar o potencial de utilização de resíduo da indústria de processamento de suco de uva (Vitis labrusca, cv. “Bordô” e “Isabel”) foi analisado o resíduo da obtenção do óleo de sementes de uvas orgânicas e convencionais quanto ao teor de carotenoides e atividade antioxidante em comparação à semente integral. Os resíduos orgânicos e convencionais apresentaram os maiores teores de carotenoides totais, pró-vitamina A e atividade antioxidante por DPPH em relação a semente integral. O resíduo convencional destacou-se pela maior atividade antioxidante por TRAP e pelos teores mais significativos de carotenoides presentes no extrato antioxidante. também foram determinados O conteúdo de compostos bioativos e a estabilidade oxidativa dos óleos obtidos da prensagem das sementes orgânicas e convencionais Bordô e Isabel. Não foi observada diferença significativa entre as amostras quanto à atividade antioxidante por TRAP, porém os óleos Bordôs apresentaram-se mais estáveis ao aquecimento, com teores mais significativos de luteína, α e β-caroteno e α-tocoferol. A fim de investigar a qualidade, estabilidade oxidativa e conteúdo de compostos bioativos nestes óleos, foi realizado o refino do óleo Bordô orgânico. Não foi observada presença de β-caroteno e zeaxantina no óleo refinado e o óleo virgem de mesmo cultivar apresentou maior estabilidade ao aquecimento. Neste contexto, os resultados sugerem o consumo de óleos virgens devido a presença e maior quantidade de compostos bioativos. Não foi observada diferença significativa entre os diferentes modos de cultivo, sugerindo que a preferência por alimentos orgânicos pode restringir-se à motivos como ausência de agrotóxicos e apelo socioambiental. Os resíduos obtidos do processamento de uva, inclusive da obtenção do óleo destacaram-se pela alta atividade antioxidante e quantidade significativa de carotenoides, o que sugere sua inserção na alimentação como fonte natural rica em compostos bioativos. / The food industry is responsible for producing large quantities of waste that may represent high costs when not used. Some of these residues are the seeds derived from the processing of grapes, one of the most consumed fruits worldwide. In addition to the reuse of waste and consequently new forms of consumption, this material has been reported to be rich natural source of bioactive compounds. In this context, the consumption of healthier foods has also driven the search and preference for organic foods. Therefore, to investigate the potential use of grape processing waste (Vitis labrusca, variety “Bordô” and “Isabel”), the residues obtained from the extraction of oil from organic and conventional grape seeds were examined to determine their content of carotenoids and antioxidant activity compared with those found in the whole seed. The organic and conventional residues exhibited higher levels of total carotenoids, provitamin A, and antioxidant activity by DPPH compared with the corresponding whole seeds. The conventional residue presented the highest antioxidant activity by TRAP and the highest levels of carotenoids in the antioxidant extract. The content of bioactive compounds and the oxidative stability of the oils obtained from the pressing of organic and conventional seeds “Bordô” and “Isabel” were also determined. No significant difference in the antioxidant activity by TRAP was observed between the samples, but the “Bordô” oils were more stable when heated and exhibited higher levels of lutein, α and β-carotene, and α-tocopherol. To investigate the quality, oxidative stability, and content of bioactive compounds in these oils, the organic “Bordô” oil was refined. The refined oil did not contain β-carotene and zeaxanthin, and the virgin oil of the same variety showed greater stability to heating. Thus, the results recommend the consumption of virgin oils due to their larger content of bioactive compounds. No significant difference was observed between the different modes of cultivation, suggesting that the preference for organic foods can be restricted to reasons such as the absence of pesticides and environmental appeal. The residues obtained from grape processing, including the residues obtained from the extraction of oil, exhibited high antioxidant activity and a high amount of carotenoids, suggesting their inclusion in foods as a natural source rich in bioactive compounds.
92

Impacto da administração das vitaminas D e E na sensibilidade insulínica, metabolismo oxidativo e aspectos da imunidade em ovelhas no período periparto / Impact of Vitamins D and E administration on insulin sensitivity, oxidative stress and immunity aspects of ewes in the peripartum period

Priscilla Marques do Nascimento 14 March 2018 (has links)
Trinta ovelhas, mestiças (Santa Inês X Dorper), adultas e hígidas foram selecionadas para avaliar o efeito da suplementação intramuscular com as vitaminas D e E no perfil bioquímico, metabolismo energético, metabolismo oxidativo, sensibilidade insulínica e imunidade no periparto. Após confirmação da gestação essas fêmeas foram distribuídas em três grupos de dez animais e no 108&deg; dia de gestação receberam veículo oleoso (grupo controle-GC); ou 70.000 UI/kg de P.V. de vitamina D3 (colecalciferol) (grupo tratado-GD); ou 60UI/kg de P.V. de vitamina E (-tocoferol) (grupo tratado-GE). As amostras de sangue foram coletadas previamente à aplicação da vitamina (-45), quatro (-30); e duas semanas (-15) antes do parto; até duas horas do parto (0), uma (7); duas (15); e quatro semanas após o parto (30). Foram analisadas as concentrações plasmáticas de glicose, beta hidroxibutirato (BHB), ácidos graxos não esterificados (AGNEs) e as concentrações séricas de colesterol, triglicérides, ureia, creatinina, cálcio total, cálcio iônico, proteína total, ácido úrico, aspartato amino transferase (AST), gamaglutamil transferase (GGT), e ainda a creatina quinase (CK). Foram também analisadas as concentrações de insulina e cortisol. Do metabolismo oxidativo foram determinadas as atividades da superóxido dismutase (SOD) e glutationa peroxidase (GSH-Px), a habilidade de redução férrica plasmática (HRFP), substâncias reativas ao ácido tiobarbitúrico (TBARS), bem como o status antioxidante total (TAS). Para avaliar aspectos relacionados à imunidade de monócitos e neutrófilos, por método in vitro, em 24 ovelhas (seis de cada tratamento). As amostras de sangue foram coletadas nos momentos 30; 0; e 30 e avaliadas sem estímulo (burst basal) e com estímulo por DCFH-DA, SaPI e PMA. A imunofenotipagem com anticorpos monoclonais CD8, CD4, CD14, CD16, CD45R, WC1, CD206, foi realizada aos dias -30, -15,0,7 e 30. Foram determinadas as concentrações das vitaminas D e E, nos momentos pré-determinados das coletas e no dia do teste de tolerância à glicose (TTG), realizado para avaliar a sensibilidade insulínica, e foi calculado RQUICKI e RQUICKI BHB. Todas as variáveis estudadas apresentaram efeito de tempo. Houve interação tempo*tratamento em TBARS (P=0,0217) e tendência para vitamina E (0,0811), SOD (0,0886) e GSH-Px (P=0,0643). Houve efeito de tratamento no colesterol (P=0,0088) e vitamina D (P<0,0001) e tendência para TAS (P=0,0830). No TTG, com resultados de AUC de BHB e AGNE apresentaram efeito de número de fetos gestados (P=0,0006 e 0,0005 respectivamente) e o RQUICKIBHB mostrou-se melhor indicador de sensibilidade insulínica do que o RQUICKI em ovelhas. A suplementação com vitamina D influenciou os teores plasmáticos de alfa tocoferol e a resposta imune das ovelhas. A suplementação com vitamina E reduziu a peroxidação lipídica no parto e relacionou-se positivamente com a melhora oxidativa dos monócitos sem estímulo e estimulados por PMA. / Thirty healthy adult ewes were selected to evaluate the effect of supplementation with intramuscular vitamins D and E in peripartum period on the biochemical profile, energetic metabolism, oxidative metabolism, insulin sensitivity and immunity. After pregnancy confirmation these females were distributed into three groups of ten animals treated with intramuscular injection containing oily vehicle (control-to-control group) on the 108th day of pregnancy, (CG); or 70,000 IU / kg of body weight of vitamin D3 (cholecalciferol) (treated group-GD); or 60 IU / kg of body weight of vitamin E (-tocopherol) (treated group-GE). Blood samples were collected before the application of the vitamins and vehicle (-45), four (-30); and two weeks (-15) before lambing; until 2 hours of lambing (0); one (7), two (15) and four weeks postpartum (30). Plasma concentrations of glucose, beta hydroxybutyrate (BHB), non-esterified fatty acids (NEFA) and serum concentrations of cholesterol, triglycerides, urea, creatinine, total calcium, ionic calcium, total protein, uric acid, aspartate amino transferase (AST), gammaglutamyl transferase (GGT), and creatine kinase (CK) were measured. The concentrations of insulin and cortisol, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), plasma ferric reduction ability (FRAP), thiobarbituric acid reactive substances (TBARS), as well as total antioxidant status (TAS) were determinate. Monocytes and neutrophils were assessed by in vitro method to identify aspects related to immunity in 24 ewes (six from each treatment) at -30, 0 and 30. Blood samples were evaluated without stimulus (basal burst), with DCFH-DA, SaPI and PMA stimulus. Immunophenotyping with monoclonal antibodies CD8, CD4, CD14, CD16, CD45R, WC1, CD206 were performed at -30, -15, 0, 7 and 30. The concentrations of vitamins D and E were determinate at the predetermined collection times and on the day of the Intravenous Glucose Tolerance Test (IVGTT), realized to evaluate the insulin sensitivity, as well as RQUICKI and RQUICKI BHB. All variables studied showed time effects. There were interaction time * treatment in TBARS (P = 0.0217) and tendency for vitamin E (0.0811), SOD (0.0886) and GSH-Px 16 (P = 0.0643). Treatment effect on cholesterol (P = 0.0088) and vitamin D (P &lt;0.0001) and tendency for TAS (P = 0.0830) were observed. About of IVGTT, AUC results of BHB and AGNE showed number of fetuses effect (P = 0.0006 and 0.0005 respectively). RQUICKIBHB was a better indicator of insulin sensitivity than RQUICKI in ewes. Vitamin D supplementation influenced the plasma levels of alpha tocopherol and the immune response of ewes. Vitamin E supplementation reduced lipid peroxidation at parturition and was positively related to the oxidative improvement of the monocytes without stimulation and stimulated by PMA. High doses of vitamins D or E administered 45 days before parturition on healthy ewes can be beneficial; however more studies are needed about this topic.
93

Avaliação laboratorial e produtiva de bovinos confinados, alimentados com feno de Brachiaria sp. e suplementados com antioxidantes / Laboratory and productive evaluation of confined cattle feeded with feno of Brachiaria sp. and supplemented with antioxidants

Costa, Gustavo Lage 22 December 2014 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-01-29T11:11:37Z No. of bitstreams: 2 Tese -Gustavo Lage Costa - 2014.pdf: 4404595 bytes, checksum: 914021b79a6b38b0b2af9d94eebc4c97 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-01-29T11:13:18Z (GMT) No. of bitstreams: 2 Tese -Gustavo Lage Costa - 2014.pdf: 4404595 bytes, checksum: 914021b79a6b38b0b2af9d94eebc4c97 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-01-29T11:13:18Z (GMT). No. of bitstreams: 2 Tese -Gustavo Lage Costa - 2014.pdf: 4404595 bytes, checksum: 914021b79a6b38b0b2af9d94eebc4c97 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-12-22 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The grass Brachiaria sp. brought to Brazil in the green revolution, came with the goal of increasing the Brazilian livestock production. The introducing of the grass, starts emerging problems such as leaf hopper pastures and hepatogenous photosensitization. The etiology of photosensitization caused by Brachiaria sp. is still controversial. But not even knowing for sure rightly if the cause is the steroidal saponins or the fungus Phytomices chartarium, it is known that they occur and cause damage to livestock. The described laboratory abnormalities are increased activity of enzymes aspartate aminotransferase (AST) and gamma glutamyl transferase (GGT), bilerrubinemia and jaundice, and evidence of insufficient functionof.liver. Histopathological examination can demonstrate a cholangiohepatitis and presence of foamy macrophages. The presence of these cells is important because its quantification was negatively correlated with the gain in cattle weight. Thus this study evaluated 40 Nelore young bulls, with the Brachiaria sp hay consumption adjusted to the maximum amount of forage (84%), with the goal of reproducing the hepatic abnormalities described in cases of photosensitization. Therefore, the aim of this study was to evaluate the possible liver changes, by the metabolic and histological profile of the liver and lymph nodes, and also check if the offered antioxidants would be able to minimize these changes, promoting greater weight gain and improving carcass characteristics of feedlot cattle. As a result, the braquiaria hay with low amounts of saponin and fungal spores did not induce clinical signs of liver damage in young bulls, but laboratory assessments indicate evidence of chronic inflammatory liver change with the presence of foamy macrophages. The antioxidant supplementation did not alter the metabolic profile of the animals, but reduced the amount of foamy macrophages in the liver. However this decrease did not improve weight gain of cattle, carcass characteristics and the final quality of the meat. / O capim Brachiaria sp. trazido para o Brasil na revolução verde, veio com o objetivo de aumentar a produção pecuária brasileira. Juntamete com o capim, começararam a surgir problemas, como a cigarrinha das pastagens e a fotossenssibilização hepatógena. A etiologia da fotossenssibilização causada pelo capim Brachiaria sp. ainda é controversa. Mas mesmo não sabendo ao certo se o causador é as saponinas esteroidais ou o fungo Phytomices chartarium, sabese que elas ocorrem, e causam prejuízos à pecuária. As alterações laboratoriais descritas são o aumento de atividade das enzimas aspartato aminotransferase (AST) e gama glutamiltransferase (GGT), bilerrubinemia e icterícia, além de indícios de insuficiência da função hepática. Os exames histopatológicos podem demonstrar uma colangiohepatite e presença de macrófagos espumosos. A presença destas células é importante, pois a sua quantificação foi correlacionada negativamente com o ganho em peso de bovinos. Desta forma, o objetivo deste estudo foi avaliar 40 tourinhos nelore, com o consumo de feno de Brachiaria sp. ajustado para a maior quantidade possível de volumoso (84%), no intuto de reproduzir as alterações hepáticas descritas em casos de fotossensibilização hepatógena, que foram monitoradas por meio de testes como o perfil metabólico e histológico do fígado e linfonodos, e ainda verificar se os antioxidantes ofertados seriam capazes de minimizar estas alterações, promovendo maior desenvolvimento ponderal e melhorando as características da carcaça de bovinos confinados. Como resultados, o feno de braquiaria com baixas quantidades de saponina e de esporos do fungo, não induziram sinais clínicos de lesão hepática nos tourinhos. Porém as avaliações laboratoriais indicam evidencias de alteração hepática inflamatória crônica com presença de macrófagos espumosos. A suplementação com antioxidantes não alterou o perfil metabólico dos animais, mas reduziu a quantidade dos macrófagos espumosos no fígado. Essa diminuição não melhorou o desenvolvimento ponderal dos bovinos, as características de carcaça e a qualidade final da carne.
94

Avaliação da estabilidade oxidativa do biodiesel (B100) comercial na presença de antioxidantes naturais da casca de romã / Estimate of oxidative stability of commercial biodiesel (B100) in the presence of natural antioxidants from pomegranate peel

Witt, Elaine de Paula 11 September 2018 (has links)
Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2018-11-12T22:46:53Z No. of bitstreams: 1 Elaine_Witt_2018.pdf: 2791531 bytes, checksum: 048d2ad0555e9f07d9ad80e05214ce75 (MD5) / Made available in DSpace on 2018-11-12T22:46:56Z (GMT). No. of bitstreams: 1 Elaine_Witt_2018.pdf: 2791531 bytes, checksum: 048d2ad0555e9f07d9ad80e05214ce75 (MD5) Previous issue date: 2018-09-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Biodiesel is a sensible fuel to the oxidation, because it presents in its chemical composition some free radicals. To raise its oxidative stability it is necessary to add synthetic or natural antioxidants. Among the natural antioxidants there is a variety of plants that may be used with the function to avoid or to detain the chain reactions of oxidation, which are capable to promote or inactivate the free radicals interrupting the reaction in the biofuel chain. In the pomegranate peel is possible to detect some phenolic compounds and antioxidants compounds beyond several bioactive compounds with some mechanisms of action that are similar to the vitamin C, vitamin E and beta-carotene. The aim of this study was to evaluate the biodiesel oxidative stability in the presence of some natural oxidants which were extracted from the pomegranate peel by the conventional method of extraction (Soxhlet and the grease and oils extractor – Goldfish) and by the supercritical extraction with CO2 in a condition of constant pressure (200 bar), some variation in the temperature (35, 45 and 55 oC) and in the presence of the cosolvent ethanol (0, 2,5 and 5 mL). The extracts were measured in relation to the antioxidant activity by the DPPH• radical inhibition. The extract obtained by the Soxhlet method with ethyl acetate presented 94,16% of inhibition in the 1000 µg.mL-1 concentration. The phenolic compound content was used with the FolinCiocalteu reagent, which was evaluated for the extracts. The sample obtained by the grease and oils extractor – Goldfish with an ethanol solvent, showed a density of 98,62mg of EAG/g of the extract. The commercial biodiesel was additive with some extract of the pomegranate peel and with the synthetic antioxidants BHA and BHT and submitted to the oxidative stability test in the Rancimat. A test that indicates the time of the oxidation in the Exploratory Differential Calorimetry (DSC) equipment. It was analyzed the effects in the temperature and the addition of the ethanol cosolvent in the extract yield. The best tenses of induction obtained were for the additive biodiesel with some extracts obtained by the conventional method, both with the ethyl acetate solvent, which took 11,13 hours for the extract obtained in the grease and oils extractor (ExtAcet) and 11,01 hours for the extract obtained in the Soxhlet (SoxAcet). It was checked that these values are higher than the other ones which were found for the additive biodiesel with the synthetic antioxidants BHA (6,91h) and BHT (7,86). Among the extracts obtained by the supercritical extraction, it was highlighted the condition of 35 °C with 5 mL of ethanol (8,01 h) and 55 °C with 5 mL of ethanol (7,77 h).Except the supercritical extract in the temperature of 35 oC without the addition of ethanol, all the extracts presented a time of induction higher than the obtained in the control (4,38 h), however only threeextracts that were added to the biodiesel showed a higher value which is demanded in the Resolution n45/2014 and it predicts oxidative stability of 8h for the test in Rancimat. For the DSC test, the samples that presented a higher time of oxidation were for the ExtAcet (31,42 min) and the supercritical extraction in the condition of 35 °C with 5mL of ethanol (31,25 min). The biodiesel oxidative stability was in the most part higher when it was added to thepomegranate peel in comparison to the pure biodiesel showing efficiency in its utilization as a natural antioxidant. / Biodiesel é um combustível sensível a oxidação devido a sua composição química. Para elevar sua estabilidade termo oxidativa é necessário acrescentar antioxidantes sintéticos ou naturais. Dentre os antioxidantes naturais existe uma variedade de plantas que podem ser utilizadas com a finalidade de evitar ou retardar reações de oxidação. Estes são capazes de promover ou inativar os radicais livres interrompendo a reação em cadeia de oxidação do biocombustível. Na casca de romã é possível encontrar compostos fenólicos, compostos antioxidantes além de diversos compostos bioativos, com mecanismo de ação semelhante ao da vitamica C, Vitamina E e betacaroteno. O objetivo deste trabalho foi avaliar a estabilidade oxidativa do Biodiesel na presença de antioxidantes naturais extraídos da casca da romã pelo método de extração convencional (Soxhet e extrator de óleos e gorduras-Goldfish) e pela extração Supercrítica com CO2 supercrítico em condições de pressão constante (200 bar) e variação de temperatura (35, 45 e 55 oC) e cossolvente etanol (0 mL, 2,5 mL e 5 mL). Os extratos foram avaliados quanto à atividade antioxidante pela inibição do radical DPPH•, sendo o extrato obtido pelo método Soxhlet com acetato de etila o que apresentou 94,16% de inibição na concentração de 1000 µg.mL-1. O Teor de Compostos Fenólicos utilizando o reagente FolinCiocalteu foi avaliado para os extratos e a amostra obtida pelo equipamento extrator de óleos de gorduras-Goldfish com solvente etanol apresentou uma concentração de 98,62 mg de EAG/g de extrato. O biodiesel comercial foi aditivado com os extratos de casca de romã e com os antioxidantes sintéticos BHA e BHT e submetidos ao teste de estabilidade oxidativa em Rancimat e teste para indicar o tempo de oxidação em equipamento de Calorimetria Diferencial Exploratória (DSC). Foram avaliados os efeitos da temperatura e da adição de cossolvente etanol no rendimento do extrato. Os melhores tempos de indução obtidos foram para o Biodiesel aditivado com os extratos obtidos pelo método convencional, ambos com solvente acetato de etila, sendo 11,13 horas para o extrato obetido no extrator de óleos e gorduras (ExtAcet) e 11,01 horas para o SoxAcet. Ainda verificou-se que esses valores são superiores aos encontrados para o biodiesel aditivado com os antioxidantes sintéticos BHA (6,91 h) e BHT (7,86 h). Entre os extratos supercríticos destacou-se a condição de 35 °C com 5 mL de etanol (8,01 h) e 55 °C com 5 mL de etanol (7,77 h). Com exceção do extrato supercrítico na temperatura de 35 oC sem adição de etanol, todos os extratos apresentaram um tempo de indução superior ao obtido no controle (4,38 h), no entanto apenas três extratos aditivados ao biodiesel apresentaram valor superior ao exigido pela Resolução 45/2014 a qual prevê estabilidade oxidativa de 8 horas para o teste em Rancimat. Para o teste DSC, as amostras que apresentaram maior tempo de oxidação foi para o ExtAcet (31,42 min) e extração supercrítica na condição de 35 °C com 5 mL de etanol (31,25 min). A estabilidade oxidativa do biodiesel foi, em sua maioria, superior quando acrescido dos extratos de casca de romã, em comparação ao biodiesel puro, mostrando eficiência na sua utilização como antioxidante natural.
95

Microencapsulação de tocoferóis em matrizes lipídicas advindas de gorduras low trans interesterificadas quimicamente / Tocopherols microencapsulation with chemistry interesterify low trans fat matrix

Diaz Gamboa, Oscar Wilfredo 19 August 2018 (has links)
Orientador: Lireny Aparecida Guaraldo Gonçalves / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T08:12:03Z (GMT). No. of bitstreams: 1 DiazGamboa_OscarWilfredo_D.pdf: 1876345 bytes, checksum: 56e9f8f4f7650f56a9f3dd8d60c68957 (MD5) Previous issue date: 2011 / Resumo: O presente projeto visou estabelecer condições ideais de obtenção de um produto que poderá ser disponibolizado para comercialização no Brasil tendo como foco a encapsulação para aplicação na área alimentícia. Tocoferóis são antioxidantes naturais que podem ser utilizados para enriquecimento de alimentos. Contudo há a necessidade de proteção desse agente ativo por métodos especiais como a microencapsulação. No presente estudo foram desenvolvidos sistemas compostos por micropartículas obtidas por ¿spray chilling" utilizando lipídios interesterificados sem isômeros trans com óleo de soja totalmente hidrogenado na relação de 70:30% m/m respectivamente, com ponto de fusão na faixa de 40-65 °C para formação das matrizes. Alfa-tocoferol foi utilizado como principio ativo a ser encapsulado. Para a obtenção das micropartículas matrizes lipídicas foram fundidas e mantidas em banho à temperatura de 65 °C . O a-tocoferol foi adicionado nas misturas lipídicas que em seguida foram homogeinizados em ultraturrax. As soluções foram pulverizadas em atomizador duplo fluido aquecido também a 65 °C e pressão de ar de 0,25 MPa, com a a tomização efetuada dentro de uma câmara resfriada a 10 °C. Foi realizado um p lanejamento DCCR (Delineamento Central Rotacional) com 2 variáveis independentes: a velocidade de homogeneização (3000 a 11000 rpm) e a concentração de tocoferol (5-25 g/100g). A quantificação do princípio ativo encapsulado foi realizada utilizando técnica isocrática de cromatografia líquida de alta eficiência (CLAE). Os tratamentos foram caracterizados em relação à eficiência de encapsulação, morfologia, tamanho médio, estabilidade e liberação do princípio ativo. Para o estudo da estabilidade os tratamentos foram submetidos à estocagem por 180 dias em três diferentes temperaturas (ambiente 25°C ±5 °C, em estufa 22 °C e freezer a -18°C). Medidas de difração de raios-X (0 , 60, 120, 180 dias) e medidas calorimétricas (tempo zero) foram efetuadas. Foi realizada a incorporação das micropartículas em um produto comercial (Iogurte), que foi avaliado sensorialmente. De forma geral, as partículas lipídicas obtidas neste trabalho apresentaram bons resultados quanto à eficiência de encapsulação e apresentando forma esférica, com paredes contínuas, porém rugosas. Os termogramas, obtidos por calorimetria diferencial de varredura (DSC), em tempo zero, não apresentaram diferenças entre os ensaios. Os difratogramas foram muito semelhantes entre os tratamentos e constatou-se a presença de 3 picos principais que parecem estar associados à forma polimórfica ß. As micropartículas de liberação apresentaram boa capacidade de controle da liberação do composto ativo, mostrando-se potenciais para o uso futuro na indústria de alimentos. Finalmente os resultados da análise sensorial de aceitação não foram estatisticamente significativos para os atributos avaliados / Abstract: This project aimed to establish optimal conditions for obtaining a product that will be commercially available in Brazil, focusing on encapsulation for use in the food industry. Tocopherols are natural antioxidants that can be used for food enrichment.However, there is the need for protection of active agent by special methods, such as microencapsulation. The present study developed systems composed of microparticles obtained by "spray chilling" using an interesterified fat with no trans isomers with fully hydrogenated soybean oil in the ratio of 70:30% w/w respectively, with a melting point in the range of 40-65°C for the formation of matrices to encapsulate a-tocopherol as active principle.To obtain small particles a lipid matrices were melted in a water bath at a temperature of 65°C. The a-tocopherol was added to the lipid mixtures and then homogenized in Ultra Turrax for 5 min.The solutions were sprayed in double-fluid atomizer also heated to 65°C and air pressure of 0.25 MPa, the atomization performed inside a chamber cooled to 10°C. Were conducted a CCR design (Central Compo site Rotational Design) with two independent variables: the speed of homogenization (3000 to 11000 rpm) and the concentration of tocopherol (5-25 g/100 g).The quantification of the active ingredient encapsulated was performed using isocratic HPLC technique. The treatments were characterized with respect to encapsulation efficiency, morphology, average size and stability of the microparticles and release of active ingredient.For the stability study treatments were subjected to storage for 180 days at three different temperatures (ambient 25°C ± 5°C , 22°C in an oven and freezer -18°C).Since x-rays diffraction measurements (0, 60, 120, 180 days) and calorimetric measurements (time zero) were made. Were performed the incorporation of the microparticles in a commercial product (yogurt), which was evaluated using the sensory evaluation.In general, the lipid particles studied in this work showed good results in terms of encapsulation efficiency showing spherical shape, with solid rough walls. The thermograms obtained by DSC at time zero did not differ between trials.The XRD patterns were very similar among treatments and found the presence of three major peaks that are associated with the polymorphic form ß. The microparticles showed good ability to control the release of the active principle, showing potential for future use in the food industry. Finally the results of an smooth sensory acceptance indicated that the tested samples did not differ statistically from the standard sample for evaluated attributes / Doutorado / Tecnologia de Alimentos / Doutor em Tecnologia de Alimentos
96

Recuperação de tocoferois do destilado da desodorização do oleo de palma : fracionamento com dioxido de carbono supercritico

Peixoto, Camila Arantes 13 July 2004 (has links)
Orientadores: Fernando Antonio Cabral, Luiz Ferreira de França / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T21:38:30Z (GMT). No. of bitstreams: 1 Peixoto_CamilaArantes_M.pdf: 600363 bytes, checksum: 95564747a5d85efcd82a01c07b415291 (MD5) Previous issue date: 2004 / Resumo: O óleo de palma e seus subprodutos são fontes de tocoferóis. Os tocoferóis, por sua vez , são compostos de grande importância para a indústria alimentícia, farmacêutica e cosmética. Eles agem no organismo como vitaminas lipossolúveis essenciais na nutrição humana por inibirem a formação de radicais livres e seus efeitos nocivos sobre o organismo. Além disso, possuem aplicação tecnológica em alimentos pois são antioxidantes naturais, prevenindo e retardando a rancidez oxidativa dos óleos e também de alimentos com alto teor de lipídios.No refino do óleo de palma, a etapa de desodorização é responsável pela perda em 33% dos tocoferóis totais presentes no óleo, e o destilado formado (DDOP), não tem aplicação tecnológica nem valor comercial. A extração com fluido supercrítico utilizando CO2 como solvente tem sido considerada como uma alternativa para substituir os tradicionais processos de separação que utilizam solvente orgânico. Com a finalidade de verificar a possibilidade de extração de tocoferóis do DDOP utilizando CO2 supercrítico, foram realizados neste trabalho experimentos em um sistema de extração na forma estática para obtenção de dados experimentais de equilíbrio de fases deste sistema multicomponente. Foram realizadas medidas de solubilidade nas condições operacionais de 60 a 90ºC; 20 a 35MPa e tempo de equilíbrio de 6h, de acordo com os testes preliminares realizados. Foi determinada a composição em tocoferóis individuais e totais dos extratos e feita análise da seletividade do CO2 supercrítico em separar os tocoferóis do DDOP em função da temperatura e da pressão.A solubilidade do DDOP em CO2 supercrítico mostrou forte dependência de acréscimos na pressão para cada temperatura estudada. As maiores solubilidades obtidas para o sistema multicomponente foram de 144,85 e 172,19 g/KgCO2 para as condições operacionais de 80ºC e 35MPa e 90ºC e 35MPa; respectivamente. O dióxido de carbono comprovou ser efetivo no fracionamento do DDOP. Observou-se que a seletividade do CO2 supercrítico apresentou valores muito abaixo da unidade, e diminuiu com incrementos nas condições operacionais de temperatura e pressão, o que evidencia que é possível concentrar os tocoferóis na fase pesada mas não recuperá-los do DDOP. Os melhores resultados de seletividade foram obtidos nas condições mais drásticas de temperatura e pressão adotadas, ou seja, para as temperaturas de 80 e 90ºC e para as pressões de 30 e 35MPa, tanto para os tocoferóis totais quanto para os individuais. Os compostos d-Tocotrienol e g-Tocotrienol foram os menos solúveis e o composto a-Tocotrienol foi o mais solúvel em CO2 supercrítico / Abstract: The palm oil and its by-products are source of tocopherols. The tocopherols, in turn, are compounds of great importance for food, pharmaceutical, cosmetic industries. They act in the organism as essential lipossoluble vitamins in human nutrition inhibiting the formation of free radicals and its harmful effect in the organism. Moreover, in food, tocopherols have technological application because of their action as natural antioxidant, preventing and delaying the oxidation of oils and food with high content of lipids. In the refining of palm oil, the stage of desodorization is responsible for the loss in 33% of the total tocopherols present in the oil, and the formed distilled (PFAD) do not have technological application, nor commercial value. The extration with supercritical fluid using CO2 as solvent has been considered as an alternative to substitute the traditional processes of separation that use organic solvent. With the purpose to verify the possibility of extraction of tocopherols of PFAD using supercritical CO2, the experiments were carried out in a static analytical apparatus for the attainment of experimental data of phase equilibria of this multicomponent system. Measures of solubility were carried out in the operational conditions of 60 to 90°C; 20 to 35MPa, and 6 hours of equilibrium time, in accordance with the preliminary tests realized. The composition of the extracts in individual and total tocopherols was determinated and it was analyzed the selectivity of supercritical CO2 in separate the tocopherols of PFAD in function of the temperature and pressure. The solubility of PFAD in supercritical CO2 showed high dependence of additions in the pressure for each studied temperature. The higher solubilities gotten for the multicomponent system were 144,85 and 172,19g/Kg CO2 for the operational conditions of 80ºC and 35MPa and 90ºC and 35MPa, respectively. The supercritical carbon dioxide proved to be effective in the fractionization of PFAD. It was observed that the values of selectivity of supercritical CO2 were below the unit and diminished with the increments in operational conditions of temperature and pressure, what evidenced that is possible to concentrate the tocopherols in heavy phase, but not to recover them of PFAD. The best results of selectivity were gotten in the most drastic conditions of temperature and pressure studded, or either, for the temperatures of 80 and 90ºC and of pressure of 30 and 35MPa, as much for the total tocopherols, how much for the individuals ones. The compounds d-Tocotrienol and g-Tocotrienol were the less soluble, and the compound d-Tocopherol was the most soluble in supercritical CO2 / Mestrado / Mestre em Engenharia de Alimentos
97

Desenvolvimento e estudo de estabilidade de preparações com papaí- na para debridamentos de feridas

Duarte, Letícia de Souza Guimarães 13 March 2017 (has links)
Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-03-13T18:50:12Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Duarte, Letícia de Souza Guimarães [Dissertação, 2016].pdf: 2499210 bytes, checksum: 961dab593ba2ea593fadba0a224c15cc (MD5) / Made available in DSpace on 2017-03-13T18:50:12Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Duarte, Letícia de Souza Guimarães [Dissertação, 2016].pdf: 2499210 bytes, checksum: 961dab593ba2ea593fadba0a224c15cc (MD5) / A papaína, que corresponde a um complexo de enzimas extraídas do vegetal Carica papaya L., tem sido utilizada pela sua propriedade proteolítica em desbridamento enzimático de feridas. Diversos estudos descrevem o uso da papaína na forma de pó, solução, gel e creme sobre feridas, porém a baixa estabilidade da enzima nesses meios limita sua utilização em larga escala. O objetivo principal do trabalho consiste em desenvolver e avaliar formulações de papaína 10%(p/p) em gel carbômero, contendo antioxidantes como acetato de alfa-tocoferol e metabissulfito de sódio, associados a outros adjuvantes que permitam melhor estabilidade da enzima. As formulações iniciais para o estudo foram planejadas segundo desenho experimental fatorial 23, sendo as variáveis independentes representadas pelas concentrações de cisteína, de polissorbato 80 e de antioxidante (acetato de alfa-tocoferol ou metabissulfito de sódio). As amostras, mantidas sob refrigeração (5°C ± 3) por 7 dias, foram submetidas a ensaios de espectrofluorimetria para avaliação da atividade enzimática. Os resultados iniciais revelaram que as amostras que continham metabissulfito de sódio associado às maiores concentrações de polissorbato 80, apresentaram as melhores condições para manutenção da atividade proteolítica, enquanto que as amostras contendo alfa-tocoferol não foram capazes de manter a atividade. Sendo assim, realizou-se estudo de estabilidade com preparações contendo concentrações fixas de papaína 10% (p/p), polissorbato 80 2,0% (p/p), com variações nas concentrações de cisteína de 0,10, 0,13 e 0,16% (p/p) e metabissulfito de sódio de 0,50, 0,75 e 1,00% (p/p). Durante o período estudado, as amostras apresentaram aspecto homogêneo, sem mudanças na coloração e no odor. Na avaliação de pH não houve variação significativa dos valores (p>0,05). A variação de potencial Zeta foi menor que ǀ10ǀmV, não havendo diferença estatisticamente significativa em função do tempo (p>0,05). A partir dos resultados obtidos, novo desenho fatorial 23 foi traçado considerando como variáveis independentes: o tempo, as concentrações de metabissulfito e de cisteína. A presença de metabissulfito 0,5% ou 1,0% (p/p) associado a cisteína 0,16%(p/p) e polissorbato 80 2,0% (p/p), proporcionaram os menores valores de decaimento na concentração de papaína ativa nas formulações testadas por 28 dias. / Papain, which corresponds to a complex of enzymes from the plant Carica papaya L., has been used for its proteolytic property in enzymatic wound debridement. Several studies describe the use of papain as powder, solution, gel and cream forms over wounds; however, the low stability of the enzyme in the media limits its use in large scale. The main objective of this work is to develop and evaluate formulations with papain 10% (w/w) at carbomer gel, containing antioxidants as alpha-tocopherol acetate and sodium metabisulphite, associated with other adjuvants that enable better stability of the enzymes. The early formulations for the study were planned in a factorial experimental design 23, with the independent variables represented by cysteine, polysorbate 80 and antioxidant (alpha-tocopherol or sodium metabisulphite) concentrations. The samples, kept under refrigeration (5°C ± 3) for 7 days, were submitted to spectrofluorimetry essays for enzyme activity evaluation. Initial findings showed that the samples containing sodium metabisulphite associated with higher concentrations of polysorbate 80, presented the best conditions for proteolytic activity maintenance, whereas the samples containing alpha-tocopherol were not able to maintain activity. Thus, stability study was carried out with preparations with fixed concentrations of papain 10% (w/w), polysorbate 80 2.0% (w/w), with variations in the concentrations of cystein 0.10, 0.13 and 0.16% (w/w) and sodium metabisulphite 0.50, 0.75 and 1.00% (w/w). During the studied period, the samples showed a homogeneous appearance, without color or odor changes. At pH evaluation there was no significant change in values (p> 0.05). Zeta potential have varied less than |10|mV, with no statistically significant difference over time (p> 0.05). From the results, a new factorial design 23 was traced, considering as independent variables: time, metabisulphite and cystein concentrations. The presence of metabisulphite 0.5 % or 1.0 % (w/w) associated with cysteine 0.16 % (w/w), and polysorbate 80 2.0% (w/w), showed the lowest decay values of active papain concentration in the formulations tested for 28 days.
98

Evolution of New Lipids and Molecular Gelators : Syntheses, Aggregation Properties and Applications

Maiti, Bappa January 2015 (has links) (PDF)
The thesis entitled “Evolution of New Lipids and Molecular Gelators: Syntheses, Aggregation Properties and Applications” elucidates the design, synthesis, aggregation properties and application of new lipids based on α-tocopheryl backbone and also with triazacyclononane (TACN) moiety. This thesis also elucidates the synthesis and aggregation properties of molecular gelators based on pyrene-pentapeptide and naphthalene diimide (NDI) moiety. The work has been divided into five chapters. Chapter 1: Introduction: Self-assembled Molecular Aggregates and their Potential Applications This chapter describes the importance of different self-assemble mainly lipids and molecular gelator. Lipids mediated gene delivery, drug delivery and metal ion induced interaction are discussed. For liposomal gene delivery here we mainly describe example of cationic gemini lipids. This chapter also gives a comprehensive account of the research towards the development of novel liposomal drug delivery containing tocopheryl backbone. It also includes the utilization of liposome which could coordinate with metal ions and their interaction with different biological analyte. Here we also discuss a wide range of molecular gelator mainly based on NDI and amino acid or peptide. Chapter 2A: Physicochemical Characterization of Bilayer Membranes Derived from (±) α-Tocopherol Based Gemini Lipids and their Interaction with plasmid-DNA and Phosphatidylcholine Bilayers In this sub-chapter we discuss the membrane formation and aggregation properties of a series of (±) α-tocopherol based cationic gemini lipids (Figure 1) varying polymethylene spacer length (TnS; n = 3, 4, 5, 6, 8 and 12) are studied extensively while comparing with corresponding properties of monomeric counterpart (TM). Liposomal suspensions of all cationic lipids are characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential measurements and small angle x-ray diffraction studies. Aggregation properties of the gemini lipids are highly dependent on the spacer length and were significantly distinct from that of monomeric lipid (TM). Figure 1. Molecular structures of (±) α-tocopherol based cationic monomeric and six gemini lipids that differ in polymethylene spacer length. Stable monolayer formation at air water interface formation of each amphiphile is studied by Langmuir film balance technique. Interaction of liposome with plasmid DNA is studied by ethidium bromide (EB) intercalation assay. Micellar sodium dodecyl sulphate (SDS) mediated release of the plasmid DNA from various pre-formed lipoplex is also studied. Structural transformation of pDNA upon complexation with liposome is characterized by circular dichroism (CD) spectroscopy. Interaction of all tocopheryl lipids with a model phospholipid, L-α-dipalmitoyl phosphatidylcholine (DPPC) derived vesicles is thoroughly examined by differential scanning calorimetry (DSC) and DPH fluorescence anisotropy measurements. Succinctly, we perform a detailed physicochemical characterization on cationic monomeric and gemini lipids bearing tocopherol as their hydrophobic backbone. Chapter 2B: Physicochemical Characterization of Bilayer Membranes Derived from (±) α-Tocopherol Based Gemini Lipids Containing Hydroxyethyl Functionality in the Headgroups and their Interaction with plasmid-DNA and Phosphatidylcholine Bilayers This sub-chapter describes the synthesis and aggregation properties of series of tocopheryl-based monomeric and gemini cationic lipids with hydroxyethyl functionality (Figure 2) in the headgroup region. Gemini lipids of this given series differ in their polymethylene spacer -(CH2)n- chain lengths between cationic headgroups. All monomeric and gemini lipids are found to generate stable suspensions in aqueous media. Average hydrodynamic diameter and surface charge of liposome are characterized by DLS and zeta potential measurements. Atomic force microscopy and transmission electron microscopic studies show that all lipids form vesicular Figure 2. Molecular structures of (±) α-tocopherol based cationic monomeric and five new lipids with hydroxyethyl functionality in the headgroups that differ in polymethylene spacer length aggregates in aqueous media. XRD studies with the cast films of lipids reveal interdigitated bilayer arrangement of liposome. pDNA binding and release studies show that the interactions between gemini lipids and DNA depend upon the nature of head group as well as the length of the spacer between cationic head groups. Circular Dichroism (CD) spectra of lipoplex are measured to characterize structural transformation of pDNA upon complexation with liposome. DPH anisotropy and DSC studies of the DPPC-cationic lipid co-aggregates show that ~20 mol-% of of the tocopheryl gemini lipids is enough to abolish phase transition of DPPC membranes whereas more than 20 mol-% is required in case of their monomeric counterparts. Furthermore thermotropic properties of co-aggregates depend upon the length of the spacer of gemini lipid included in the mixture. Chapter 2C: Transfection Efficacies of α-Tocopherol Based Cationic Gemini Lipids with Hydroxyethyl Containing Headgroups. In this sub-chapter, we demonstrate transfection efficiency of five α-tocopheryl gemini lipid with hydroxyethyl containing headgroups (Figure 3). Co-liposomal formulations with helper lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) form highly stable formulations in water. Co-liposomal formulations with high molar ratio of DOPE (1.5:1 and 2:1) show higher transfection efficiency than liposome with low DOPE content liposome. Co-liposome of gemini lipids with longer spacer (n = 8 and 12) have higher level of luciferase expression in HepG2 cell line. In A549 and MCF-7 cell lines also co-liposomes of TH8S (2:1) are proved to be better than other co-liposome. N/P ratios of highest transfection are 1-1.5. These formulations are more potent than L2K in all three cancer cell line. The comparison with gemini lipid (T8T) without Figure 3. Molecular structures of (±) α-tocopherol based cationic gemini lipids that differ in polymethylene spacer length and helper lipid DOPE. hydroxylethyl group also proves the importance of hydroxyethyl functionalities. High serum stability of DOPE-gemini lipid formulation is attributed to tocopherol backbone and also hydroxyethyl functionalities. Circular dichroism data also show that lipoplex of DOPE-TH8S (2:1) have different conformation than the other. Relatively moderate binding efficiency and easy release of pDNA is also observed with DOPE-TH8S (2:1) in the EB-displacement assay which could be plausible reason for high transfection efficiency. Chapter 2D: Reduction Responsive Nanoliposomes of α-Tocopheryl-Lipoic Acid Conjugate for Efficacious Drug Delivery to Sensitive and Resistant Cancer Cells In this sub-chapter, we present lipid conjugates derived from biologically relevant molecules, i.e., tocopherol and lipoic acid (Figure 4). These conjugates (TL1 and TL2) are able to form stable nanoliposomes (~100 nm) that respond to the reducing environment of cells as shown by the treatments of 1,4-Dithiothreitol (DTT) and Glutathione (GSH). Figure 4. Molecular structures of tocopheryl-lipoic acid conjugates, TL1 and TL2 Nanoliposomes could efficiently load the drug (DOX) molecules and release them in response to the stimulus. Nanoliposomes are stable enough in the presence of serum and could deliver DOX inside drug sensitive and drug resistant cells in an efficient manner that is even better than the drug alone treatments as shown by means of flow cytometry and confocal microscopy analysis. DOX loaded nanoliposomal formulations show relatively less cell viability counts than those drug alone treatments. Chapter 3A: Interaction of Nickel (II) and mida ole it Triazacyclononane Modified Chelator Amphiphiles: A Potential Substrate for Immobilization of His-tag Protein on Hydrophilic Surface This sub-chapter describes two chelator amphiphiles based on 1, 4, 7-traiazaclonone (TACN) (Figure 5). These compounds could bind efficiently Ni2+ ion. Self-assemble of these amphiphiles form vesicular aggregates. Their packing properties of these amphiphiles are influence by Ni2+ and imidazole. Also influence of Ni2+ and imidazole in Langmuir monolayer isotherm of these amphiphiles at air-water interface are also studied. Figure 5. Molecular structures of TACNA chelator amphiphiles. These studies show the newly synthesized amphiphiles could immobilize histidine tagged protein on both bilayer and monolayer surface. One of these compounds with Ni2+ (C16TACNA-Ni2+) is used to transfer a His-tagged protein nucleolin on hydrophilicobic glass surface by Langmuir-Blodgett transfer technique. So, these compounds with Ni2+ could be very useful to attach different His-tagged protein or polypeptide of interest on the bilayer (liposome) or monolayer surface. Chapter 3B: Supramolecular Hosts for Enhancing the Selectivity of TACN Based Probes towards Copper (II): Differential Output Signals for Cysteine and Histidine In this sub-chapter, we have developed a new amphipathic probe compound 1 having TACN as the binding site and dansyl as signaling moiety (Figure 6). As TACN is known for its’ unspecific interaction with multiple ions, the probe shows response with most of the transition metal ions. However, incorporation into different supramolecular hosts (like micelle and vesicles) drastically improves the selectivity of compound 1 towards Cu2+ (diminution of bright green fluorescence) in water. Then we Figure 6. Molecular structures of dansylated TACN chelator amphiphiles. have also employed the Cu2+ complex of compound 1 for selective estimation of amino acids. Addition of cysteine regains the green emission of compound while histidine exhibits blue intense emission upon formation of ternary conjugate. Chapter 4: Transforming a β-Sheet Pyrenylated-VPGKG Sequence into pH Tolerent, Thixotropic Hydrogel by Arene-Perfluoroarene Interactions and Visualized Sensing of Calcium (II) Ion In this chapter we discuss self-assembly studies of a novel thermoresponsive, lipidated, pyrene-appended peptide, PyP (Figure 7). Size of the vesicular aggregates of the β-sheet forming peptide, PyP, strongly depends on the temperature of the solution in water. Further pyrene-octafluoronaphthalene (OFN) pair has been used as supramolecular synthon to induce hydrogelation of PyP in presence of equimolar amount of OFN via complementary quadrupole-quadrupole interactions. The gel shows excellent pH tolerant as well as thixotropic behavior. Detailed studies suggested the lamellar packing of the gelator in a right-handed helical fashion yielded vesicular aggregates. The sticky vesicles form gel via inter- Figure 7. Molecular structure of the Pyrenylated-VPGKG peptide (PyP) and octafluoronapthalene (OFN). Ca2+ ion reinforces the mechanical strength and also reduces the critical gelator concentration of the native gel through coordination with the free -COO- group of the gelator. Therefore, this present system could be used as a visualized sensor of Ca2+ ion. Chapter 5: First Report of Naphthalenediimide Based Metallo(organo)gel In this chapter, we have demonstrated synthesis of a novel asymmetric bolaamphiphilic (Figure 8). NDI derivative is capable of self assemble into stable gel in EtOH. Detailed studies reveal the gelator molecule of 1 adopt a parallel alignment in the lamellae during self-aggregation as nanoscopic spherical assemblies. In addition, dried gel of 1 shows nematic liquid crystalline phase. Further, we synthesize a novel metal-ligand discrete complex 2 in a nearly quantitative yield by reacting equimolar amount of 1 and PdCl2(PhCN)2. Figure 8. NDI derivative, 1, and its discrete metal complex 2. Complex 2 has been found to yield stable gel in dichloromethane (DCM) or chloroform (CHCl3) through the formation of high aspect ratio fibers. ROESY NMR experiment of Complex 2 has been found to yield stable gel in dichloromethane (DCM) or chloroform (CHCl3) through the formation of high aspect ratio fibers. ROESY NMR experiment of
99

Compostos bioativos em óleos e resíduos de sementes de uvas orgânicas e convencionais

Assumpção, Carolina Fagundes January 2014 (has links)
A indústria de alimentos é responsável pela produção de grandes quantidades de resíduos que podem representar altos custos quando não utilizados. Entre estes resíduos estão as sementes oriundas do processamento de uva, uma das frutas mais consumidas no mundo. Além do aproveitamento de resíduos e consequentemente novas formas de consumo, este material tem sido relatado como fonte natural rica em compostos bioativos. Neste contexto, o consumo de alimentos mais saudáveis também tem impulsionado a busca e a preferência por alimentos orgânicos. Assim, para investigar o potencial de utilização de resíduo da indústria de processamento de suco de uva (Vitis labrusca, cv. “Bordô” e “Isabel”) foi analisado o resíduo da obtenção do óleo de sementes de uvas orgânicas e convencionais quanto ao teor de carotenoides e atividade antioxidante em comparação à semente integral. Os resíduos orgânicos e convencionais apresentaram os maiores teores de carotenoides totais, pró-vitamina A e atividade antioxidante por DPPH em relação a semente integral. O resíduo convencional destacou-se pela maior atividade antioxidante por TRAP e pelos teores mais significativos de carotenoides presentes no extrato antioxidante. também foram determinados O conteúdo de compostos bioativos e a estabilidade oxidativa dos óleos obtidos da prensagem das sementes orgânicas e convencionais Bordô e Isabel. Não foi observada diferença significativa entre as amostras quanto à atividade antioxidante por TRAP, porém os óleos Bordôs apresentaram-se mais estáveis ao aquecimento, com teores mais significativos de luteína, α e β-caroteno e α-tocoferol. A fim de investigar a qualidade, estabilidade oxidativa e conteúdo de compostos bioativos nestes óleos, foi realizado o refino do óleo Bordô orgânico. Não foi observada presença de β-caroteno e zeaxantina no óleo refinado e o óleo virgem de mesmo cultivar apresentou maior estabilidade ao aquecimento. Neste contexto, os resultados sugerem o consumo de óleos virgens devido a presença e maior quantidade de compostos bioativos. Não foi observada diferença significativa entre os diferentes modos de cultivo, sugerindo que a preferência por alimentos orgânicos pode restringir-se à motivos como ausência de agrotóxicos e apelo socioambiental. Os resíduos obtidos do processamento de uva, inclusive da obtenção do óleo destacaram-se pela alta atividade antioxidante e quantidade significativa de carotenoides, o que sugere sua inserção na alimentação como fonte natural rica em compostos bioativos. / The food industry is responsible for producing large quantities of waste that may represent high costs when not used. Some of these residues are the seeds derived from the processing of grapes, one of the most consumed fruits worldwide. In addition to the reuse of waste and consequently new forms of consumption, this material has been reported to be rich natural source of bioactive compounds. In this context, the consumption of healthier foods has also driven the search and preference for organic foods. Therefore, to investigate the potential use of grape processing waste (Vitis labrusca, variety “Bordô” and “Isabel”), the residues obtained from the extraction of oil from organic and conventional grape seeds were examined to determine their content of carotenoids and antioxidant activity compared with those found in the whole seed. The organic and conventional residues exhibited higher levels of total carotenoids, provitamin A, and antioxidant activity by DPPH compared with the corresponding whole seeds. The conventional residue presented the highest antioxidant activity by TRAP and the highest levels of carotenoids in the antioxidant extract. The content of bioactive compounds and the oxidative stability of the oils obtained from the pressing of organic and conventional seeds “Bordô” and “Isabel” were also determined. No significant difference in the antioxidant activity by TRAP was observed between the samples, but the “Bordô” oils were more stable when heated and exhibited higher levels of lutein, α and β-carotene, and α-tocopherol. To investigate the quality, oxidative stability, and content of bioactive compounds in these oils, the organic “Bordô” oil was refined. The refined oil did not contain β-carotene and zeaxanthin, and the virgin oil of the same variety showed greater stability to heating. Thus, the results recommend the consumption of virgin oils due to their larger content of bioactive compounds. No significant difference was observed between the different modes of cultivation, suggesting that the preference for organic foods can be restricted to reasons such as the absence of pesticides and environmental appeal. The residues obtained from grape processing, including the residues obtained from the extraction of oil, exhibited high antioxidant activity and a high amount of carotenoids, suggesting their inclusion in foods as a natural source rich in bioactive compounds.
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Produção de cordeiros em pastagens tropicais e seus reflexos nos atributos qualitativos da carne / Production of lambs in tropical pastures abd its reflections on the qualitative attributes of meat

Hampel, Viviane da Silva January 2018 (has links)
A qualidade da carne produzida pelos ruminantes é um reflexo do alimento consumido pelos mesmos. Primeiramente realizamos uma abordagem metanalitica e verificamos que o tipo de sistema alimentar e o nível de tocoferol na dieta dos cordeiros enfluinciaram na qualidade da carne de cordeiro produzida. Assim, o objetivo foi avaliar a produção de forragem e composição química da dieta dos cordeiros alimentados com pastagens tropicais e seus reflexos sobre a qualidade da carne. Foram utilizamos 54 cordeiros, machos castrados, com idade e peso inicial de 3-4 meses e 20,4±3,97 kg, distribuídos aleatoriamente em três sistemas de terminação baseados em pastagens tropicais: 1) Capim aruana (Panicum maximum cv. IZ-5); 2) Feijão guandu (Cajanus cajan) e 3) Consórcio (Panicum máximo cv. IZ-5 e Cajanus cajan, sendo cada espécie semeada em metade da superfície do piquete. Para testar o efeito tanino, metade dos cordeiros de cada tratamento recebeu polietilenoglicol (PEG) duas vezes ao dia. A amostragem da pastagem foi realizada a cada 21 dias, totalizando 4 coletas. Foi reaizada simulação de pastejo para as amostragens para composição química da pastagem. Avaliou-se a produção de forragem, composição química, perfil de ácidos graxos e antioxidantes (tocoferol e taninos). Os cordeiros foram abatidos após 92 dias de experimento, com peso médio de 25,7±4,36 kg O perfil de ácidos graxos, concentração de tocoferóis, a coloração e a oxidação lipídica do músculo longissimus dos cordeiros foram avaliados. As pastagem apresentaram variação de masa de forragem, produção de colmos, produção de lâminas foliares e altura ao longo do tempo da avaliação. A inserção de leguminosas na dieta de cordeiros não altera a concentração de tocoferol, mas, ao longo dos períodos de avaliação, os níveis de tanino condensado e tanino total aumentam na dieta contendo leguminosas. A maioria dos acidos graxos estavam relacionados com o conteúdo de fibra em detergente neutro da dieta. A participação da leguminosa na dieta dos cordeiros aumenta o teor de omegas 3 e 6 disponíveis na dieta de cordeiros. A inclusão de PEG nas dietas dos cordeiros aumentou o valor do ângulo da tonalidade e diminuiu a intensidade de vermelho da gordura subcutânea. O sistema de pastagem exclusivamente de feijão guandu resultou em menor concentração de ácidos graxos saturados no musculo do que o sistema exclusivo de capim aruana. A carne de cordeiros terminados exclusivamente em Capim Aruana apresentou menor relação n-6: n-3 e menor oxidação lipídica após 6 dias de armazenamento do que animias mantidos em feijão guandu ou em pastagem consorciada. / The quality of the meat produced by ruminants is a reflection of the food consumed by those offered to them. First, we performed a meta-analytic approach and found that the type of food system and the level of tocopherol in the diet of lambs influenced the quality of the lamb meat produced. We used 54 male lambs with age and initial weight of 3-4 months and 20.4 ± 3.97 kg randomly distributed in three finishing systems based on tropical pastures: 1) Aruana grass (Panicum maximum cv. IZ-5); 2) Pigeon pea (Cajanus cajan) and 3) Consortium (Panicum maximum cv. IZ-5 and Cajanus cajan, each species being sown on half of the surface of the picket. To test the tannin effect, half of the lambs from each treatment received polyethylene glycol (PEG) twice daily. Pasture sampling was performed every 21 days, totaling 4 collections. Grazing simulation was performed for the chemical composition of the pasture. The forage production, chemical composition, profile of fatty acids and antioxidants (tocopherol and tannins) were evaluated.The lambs were slaughtered after 92 days of experiment, with weight of 25.7 ± 4.36 kg . The fatty acid profile, concentration of tocopherols, coloration and lipid oxidation of lamb longissimus muscle were evaluated The present variation pasture forage mass, stalk production, production of leaf blades and height throughout the evaluation time The insertion of legumes in the diet of lambs does not alter the concentration of tocopherol, but during the evaluation periods, , the levels of condensed tannin and total tannin increase in the diet containing legumes. Most of the fatty acids studied were related to the neutral detergent fiber content of the diet. The participation of the legume in the diet of lambs increases the content of omegas 3 and 6 available in the diet of lambs. The inclusion of PEG in lamb diets increased the value of the hue angle and decreased the red intensity of the subcutaneous fat. The grazing system exclusively of pigeon pea resulted in a lower concentration of saturated fatty acids in the muscle than the exclusive system of Aruana grass. Meat from lambs exclusively in Aruana grass presented lower n-6: n-3 ratio and lower lipid oxidation after 6 days of storage than those maintained on Pigeon pea or Mixed pasture.

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