Dissertationen zum Thema „Anthocyanin and antioxidant activity“
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Rosales, Soto Maria U. „Phenolics, anthocyanins and antioxidant activity in red raspberry muffins“. Pullman, Wash. : Washington State University, 2008. http://www.dissertations.wsu.edu/Thesis/Fall2008/M_Rosales_082708.pdf.
Der volle Inhalt der QuelleTitle from PDF title page (viewed on Dec. 31, 2008). "School of Food Science and Human Nutrition." Includes bibliographical references.
Al, Bittar Sheiraz. „3-Deoxyanthocyanins : Chemical synthesis, structural transformations, affinity for metal ions and serum albumin, antioxidant activity“. Thesis, Avignon, 2016. http://www.theses.fr/2016AVIG0264.
Der volle Inhalt der QuelleThis work deals with the chemical synthesis of simple analogs of anthocyanins, the main class of watersolublenatural pigments. Eleven flavylium ions with hydroxyl, methoxyl and beta-D-glucopyranosyloxylsubstituents at positions 4’, 5 and 7 have been prepared by straightforward chemical procedures.Moreover, the two main 3-deoxyanthocyanidins of red sorghum, apigeninidin (APN) and luteolinidin(LTN), have been synthesized in a one-step protocol. The physicochemical properties and antioxidantactivity are investigated for 3’,4’,7-trihydroxyflavylium chloride (P1), its 7-O-beta-D-glucoside (P2) and3’,4’,5,7-tetrahydroxyflavylium chloride (LTN). Owing to their catechol B-ring, they rapidly bind FeIII,AlIII and CuI, more weakly interact with FeII while promoting its autoxidation to FeIII. Following CuIIbinding, the pigments undergo oxidation. Aglycones P1 and LTN are moderate ligands of human serumalbumin (HSA) with chalcones having a higher affinity for HSA than the corresponding colored forms.The antioxidant activity of P1, P2 and LTN is investigated via two tests: reduction of the stable DPPHradical and inhibition of heme-induced lipid peroxidation (a model of postprandial oxidative stress inthe stomach). Aglycones P1 and LTN (especially in their colorless chalcone form) are more potent thanglucoside P2
Rosso, Veridiana Vera de. „Composição de carotenoides e antocianinas em acerola : estabilidade e atividade antioxidante em sistemas-modelo de extratos antocianicos de acerola e de açai“. [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256527.
Der volle Inhalt der QuelleTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Os pigmentos naturais, tais como antocianinas e carotenóides, proporcionam cor aos alimentos, contribuindo para o seu aspecto visual, atributo este de fundamental importância na aceitação e escolha de um alimento por seus consumidores. Concomitante, estes pigmentos possuem importantes funções e ações biológicas, podendo ser considerados promotores da saúde humana. Já é reconhecida a associação entre a ingestão de frutas e vegetais e a diminuição do risco de desenvolvimento de diversas desordens crônico-degenerativas, sendo os pigmentos um dos grupos de compostos bioativos aos quais são atribuídas tais ações. Acerola e açaí são frutas tropicais que contém elevados teores de compostos bioativos, como carotenóides e antocianinas. Os pigmentos, carotenóides e antocianinas, de duas variedades de acerola (Waldy Cati 30 e Olivier) obtidas em uma plantação brasileira durante as safras de verão de 2003 e 2004 foram analisados por cromatografia líquida de alta eficiência (CLAE). As duas variedades apresentaram ß-caroteno (265,5 ¿ 1669,4 µg/100g), luteína (37,6 ¿ 100,7 µg/100g), ß-criptoxantina (16,3 ¿ 56,5 µg/100g) e a-caroteno (7,8 ¿ 59,3 µg/100g) como carotenóides majoritários. Em ambas safras, os teores de ß-caroteno, ß-criptoxantina e a-caroteno foram significativamente maiores na variedade Olivier, entretanto o teor de luteína foi maior na variedade Waldy Cati 30. As duas variedades de acerola mostraram composição similar em termos de antocianinas e a cianidina-3-ramnosídeo foi a antocianina majoritária, seguida da pelargonidina-3-ramnosídeo, da cianidina-3,5-di-ramnosídeo e da peonidina-3-ramnosídeo. O teor de antocianinas totais da variedade Waldy variou de 6,5 a 7,6 mg/100g, enquanto para a variedade Olivier os teores variaram entre 7,9 e 8,4 mg/100g, para as safras de 2003 e 2004, respectivamente. Não foi verificada diferença significativa entre os teores de antocianinas totais das diferentes variedades e entre as duas safras. Dois lotes de polpa de açaí congelado apresentaram teores de antocianinas totais variando entre 282 e 303 mg/100g, apresentando a cianidina-3-glucosídeo e a cianidina-3-rutinosídeo nas proporções médias de 13,2% e 87,5%, respectivamente. A acerola é considerada uma das melhores fontes naturais de ácido ascórbico (AA) e, por esta razão, foi determinada a influência do AA na estabilidade do extrato de antocianinas de acerola utilizando como comparação o extrato de açaí, que não possui AA. Os experimentos demonstraram que o AA presente ao nível de 276 mg /100mL no extrato antociânico de acerola foi o principal responsável pela intensa degradação destas antocianinas, pois a adição de AA à solução de antocianinas de açaí na concentração de 276 mg/100mL provocou um aumento de 22 vezes na velocidade de degradação (kobs) quando comparada ao açaí não fortificado. Embora os sistemas-modelo antociânicos das duas frutas apresentassem a mesma concentração de AA (276 mg /100mL), o valor de kobs encontrado no sistema de acerola foi 3 vezes maior do que o kobs da solução de açaí. Essa diferença pode ter ocorrido devido à concentração 10 vezes maior de flavonóides no extrato antociânico de açaí, uma vez que os teores de polifenóis totais foram semelhantes nos dois extratos. A viabilidade do emprego dos extratos antociânicos de acerola e de açaí como ingrediente funcional foi avaliada em sistema simulador de bebidas isotônicas. Em todas as condições avaliadas, a degradação das antocianinas seguiu cinética de primeira ordem. A estabilidade das antocianinas em sistema simulador de bebida isotônica foi 1,3 e 1,7 vezes menor do que nos sistemas tampão citrato-fosfato para as antocianinas de acerola e de açaí, respectivamente, a pH 2,5, na presença de luz e de oxigênio. Em todos os sistemas, a perda gradual da cor vermelha e aumento da cor amarela foi observada através do incremento do parâmetro CIE L* (luminosidade) e diminuição dos valores de C* (intensidade de cor) que podem ser resultado da degradação do cátium flavilium e formação de chalconas, respectivamente. Utilizando os radicais estáveis ABTS¿+ e DPPH¿, a atividade anti-radical dos extratos de antocianinas de acerola e de açaí com diferentes graus de purificação foi avaliada, e comparada com padrões de antocianinas e de uma antocianidina. Os extratos bruto (EB), parcialmente purificado (EPP) e purificado (EP) de acerola apresentaram maior atividade antioxidante do que os respectivos extratos de açaí. A atividade anti-radical dos extratos brutos das duas frutas diminuiu à medida que o extrato bruto foi sendo purificado e, portanto, a presença de polifenóis, flavonóides e ácido ascórbico no extrato antociânico bruto influenciou na atividade anti-radical. Os resultados obtidos com padrões confirmaram que a atividade anti-radical aumenta com o número de grupos OH no anel B das antocianinas e que a atividade antioxidante diminui à medida que o número de açúcares ligados à molecula aumenta. Foram realizados estudos sobre a reatividade de antocianinas frente ao oxigênio singlete (O2(1?g)), através da avaliação do efeito protetor do EB, EPP e EP das antocianinas de acerola e de açaí sobre o actinômetro dimetil-antraceno, utilizando azul de metileno como sensitizador. A constante de desativação física (kq) foi determinada através dos métodos de foto-oxidação sensitizada e pela detecção da fosforescência do O2(1?g), e o nível de energia do estado triplete das antocianinas de açaí foi avaliado utilizando a técnica de time resolved photoacoustics (TRP). À medida que os extratos foram sendo purificados, a capacidade de desativação do O2(1?g) foi diminuindo. Dentre os padrões avaliados, malvidina, cianidina-3-rutinosídeo e cianidina-3-glucosídeo, a malvidina foi o melhor desativador de O2(1?g), independentemente do método utilizado para cálculo do kq. Os experimentos de TRP demonstraram que o estado triplete das antocianinas de açaí apresentam tempo de vida muito curto, indicando que a desativação do O2(1?g) não depende da formação do estado triplete das antocianinas
Abstract: Natural pigments, such as anthocyanins and carotenoids, are responsible for the colors found in foods, influencing its visual aspect, which is considered the main attribute for the acceptance and preference of a food product. At the same time, these pigments show important biological functions and actions, being considered human health promoters. The association between the intake of fruits and vegetables and the decreased risk of developing several chronic-degenerated disorders is already recognized, being the pigments one of the bioactive compounds responsible for such actions. Acerola and açaí are tropical fruits that contain high levels of bioactive compounds, such as carotenoids and anthocyanins. The pigments, carotenoids and anthocyanins, of two acerola varieties (Waldy Cati 30 and Olivier) harvested from a Brazilian plantation during the 2003 and 2004 summer harvests were analyzed by high performance liquid chromatography (HPLC). Both varieties presented ß-carotene (265.5 ¿ 1669.4 µg/100g), lutein (37.6 ¿ 100.7 µg/100g), ß-cryptoxanthin (16.3 ¿ 56.5 µg/100g) and a-carotene (7.8 ¿ 59.3 µg/100g) as the major carotenoids. In both harvests, the ß-carotene, ß-cryptoxanthin and a-carotene levels were significantly higher in the Olivier variety, whereas the lutein content was higher in the Waldy Cati variety. The two acerola varieties showed similar anthocyanin composition, being cyanidin-3-rhamnoside the major anthocyanin, followed by pelargonidin-3-rhamnoside, cyanidin-3,5-di-rhamnoside and peonidin-3-rhamnoside. The Waldy variety of acerola showed total anthocyanin content of 6.5 and 7.6 mg/100g, whilst 7.9 and 8.4 mg/100g were found in the Olivier variety, for the harvests 2003 and 2004, respectively. No statically differences for the total anthocyanin content were found between varieties and between harvests. Two brand of frozen pulp of açai presented 282 to 303 mg/100 g of total anthocyanin, with cyanidin-3-glucoside and cyanidin-3-rutinoside being found in average proportions of 13.2% and 87.5%, respectively. Acerola is considered one of the best natural source of ascorbic acid (AA) and due to this fact, the influence of AA on the stability of the acerola anthocyanin extract was evaluated using as comparison the açai anthocyanin extract which does not have AA. The experiments demonstrated that the 276 mg/100mL AA level present in the acerola anthocyanin extract is the major responsible for the intense anthocyanin degradation, since the degradation rate (kobs) of the anthocyanins in the açai extract fortified with 276mg/100mL AA, was 22 times higher than the kobs found in the natural açai extract. Although the anthocyanic model-systems from both fruits had the same AA concentration (276 mg /100mL), the kobs value observed in the acerola system was 3 times higher than that found for the açai solutions. This difference can be attributed to the 10 times higher flavonoid content found in the anthocyanin extract from açai, since the total polyphenol levels were similar in the systems from both fruits. The viability to employ the anthocyanin extracts of acerola and açai as functional ingredient was evaluated in isotonic soft drink model-systems. In all conditions studied, the anthocyanin degradation followed a first order kinetics rate. The anthocyanin stability in the isotonic soft drink system was 1.3 e 1.7 times lower compared to the citrate-phosphate buffer for the acerola and açai extracts, respectively, at pH 2.5, in the presence of light and oxygen. In all systems, the gradual fading of the red color was observed by the incresead L* values CIE parameter and decreased C* values, probably resulted respectively from the degradation of the flavillium cation and formation of chalcones. Using the stable radicals ABTS¿+ and DPPH¿, the radical scavenger activities of the acerola and açai anthocyanin extracts with different purification degrees were evaluated and compared to standards of anthocyanins and anthocyanidin. The crude (EB), partially purified (EPP) and purified (EP) extracts of acerola showed higher antioxidant activity than the respective extracts from açai. Since the radical scavenger activity of both crude extracts decreased with the purification process, the presence of polyphenols, flavonoids and AA in the anthocyanic crude extracts affected the antioxidant activity. The results obtained with the standards confirmed that the antioxidant activity increases with the increased number of OH groups in the B ring of the anthocyanins and that the activity decreases with the increased numbers of glycosilated sugars. Studies concerning the reactivity of anthocyanin extracts towards singlet oxygen (O2(1?g)) were carried out using the EB, EPP and EP anthocyanin extracts from acerola and açai, dimethyl-anthracene as actinometer and methylene blue as sensitizer. The physical quenching constant (kq) was determined by the sensitized photooxidation method and by the O2(1?g) phosphorescence detection. The energy level of the excited triplet state of açai anthocyanins was determined by the time resolved photoacoustics (TRP) technique. It was observed a correlation between the increased purification degree and a decrease in the O2(1?g) quenching. Among the standards evaluated, malvidin, cyanidin-3-rutinoside and cyanidin-3-glucoside, the malvidin was the best O2(1?g) quencher, independently of the method used for kq calculation. The experiments with TRP demonstrated that the açai anthocyanin triplet state had a very short life time, indicating that the O2(1?g) quenching does not occur via formation of the anthocyanin excited triplet state
Doutorado
Mestre em Ciência de Alimentos
Martinková, Patrícia. „Extrakce anthokyanových barviv z aroniových výlisků“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-376854.
Der volle Inhalt der QuelleDresch, Maria Terezinha Kreinecker. „Avaliação química e da potencial atividade antioxidante de extratos ricos em polifenóis, de espécies cultivadas em larga escala no Rio Grande do Sul, para utilização em formulações farmacêuticas“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/132768.
Der volle Inhalt der QuelleThe cultivation of plants from Vitis species (Vitaceae), popularly known as grapevine, is one of the most prominent economic activities in southern Brazil. The Vitis species is one of the plants that is most rich in polyphenolic compounds, responsible for numerous important pharmacological and biological activities, such as antioxidant activity. In this context, this study aimed to analyze qualitatively and quantitatively the principal groups encountered in grapevine extracts, the anthocyans and flavonoids, and to assay their antioxidant activities in vitro. For this purpose, two methods were developed and validated using high-performance liquid chromatography, employing a UV/VIS detector. The analysis of phenolic compounds included the utilization of two different columns: a column constituted by silica C18 and other RP18 column with bridged ethane-silicon hybrid particles. In both methods, a gradient system was used, with water and acetonitrile acidified with trifluoroacetic acid as a mobile phase. The methods developed were validated according to ICH evaluating parameters such as specificity, linearity, precision, sensibility, accuracy and robustness in the concentration range evaluated. The present study also analyzed the antioxidant activity in vitro of grapevine extracts employing the Total Reactive Antioxidant Potencial (TRAP) method, which was optimized and validated according to international patterns, using Trolox as a reference substance. This method also allowed evaluation of the total instantaneous reactivity (TAR). In all concentrations, the samples presented lower instantaneous reactivity than that of the reference compound. In contrast, the samples presented higher antioxidant activity than Trolox 200 nM.
Dalla, Nora Cleice. „Caracterização, atividade antioxidante "in vivo" e efeito do processamento na estabilidade de compostos bioativos de araçá vermelho e guabiju“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/60386.
Der volle Inhalt der QuelleThe fruit consumption is related to the low incidence of chronic diseases by a variety of compounds that have the interaction of these and their antioxidant potential. The processing from fresh food is necessary, both for preservation and to provide seasonal products all year round, however you must know what its implications. The red guava (Psidium cattleyanum SABINE) and guabiju (Myrcianthes pungens) are small native fruits southern Brazil. Its physical and chemical composition profile of anthocyanins, carotenoids and antioxidant activity, using two different methods (DPPH and ABTS), were investigated in fresh fruit, as well as the behavior of bioactive compounds and antioxidant activity in respect to air drying warm to 70 °C, freeze-drying and freezing. It was also carried out an experiment with rats to examine the antioxidant potential of fruit against the toxicity of antitumor cisplatin. The guabiju showed higher antioxidant activity, anthocyanins and carotenoids content than the red guava, but this fruit has high fiber content. In fresh guabiju β-carotene and malvidin 3- glucoside were predominant, with 40.4 % and approximately 60 % of total carotenoids and anthocyanins, respectively. In the fresh red guava predominant carotenoid and anthocyanin were β-cryptoxanthin, with 44.8 % and cyanidin 3-glucoside with hydrochloric 51.71 % of the total. Fruits dried at 70 °C and freeze- dried had higher antioxidant activity by DPPH method, while in the ABTS red guava dried at 70 °C and frozen after 90 days guabiju stood out. However, for bioactive compounds in the two fruits, hot air drying (70 °C) resulted in lower levels of anthocyanins and carotenoids. Freeze for 30 and 90 days increased the concentrations of carotenoids in red guava and guabiju, respectively. For anthocyanins, the highest levels were found in guabiju freeze dried and fresh red guava. Regarding the study of animals, fruits native acted protecting animals against the effects of cisplatin, reducing the levels of total cholestreol (TC), LDL and oxidized LDL (ox-LDL) levels of fat in the liver.
Hamalová, Veronika. „Stanovení vybraných chemických parametrů plodů šlechtěných odrůd bezu černého“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217082.
Der volle Inhalt der QuelleFaria-Machado, Adelia Ferreira de. „Identificação e determinação da atividade antioxidante de carotenoides e antocianinas de frutas“. [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256428.
Der volle Inhalt der QuelleTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Considerando a importancia de carotenoides e antocianinas, tanto como pigmentos naturais como pelas suas propriedades antioxidantes, este trabalho foi desenvolvido com o objetivo de avaliar, por meio de cromatografia liquida de alta eficiencia acoplada aos detectores arranjo de diodos e espectrometro de massas (HPLC-DAD-MS/MS), a composicao de carotenoides e antocianinas em nespera, jaca e jambolao, bem como estudar a atividade antioxidante apresentada por esses pigmentos em diferentes sistemas. Em funcao da coloracao desses frutos, apenas o jambolao foi submetido a analise de antocianinas. Cinco cultivares brasileiros de nespera foram avaliados: Centenaria, Mizauto, Mizuho, Mizumo e Nectar de Cristal. De vinte e cinco carotenoides separados, vinte e tres foram identificados, sendo que os principais foram all-trans-?-caroteno (19-55 %), alltrans-?-criptoxantina (18-28 %), 5,6:5¿,6¿-diepoxi-?-criptoxantina (9-18 %) e 5,6- epoxi-?-criptoxantina (7-10 %). Os conteudos de carotenoides totais variaram entre 196 ?g/100 g (cv. Nectar de Cristal) e 3020 ?g/100 g (cv. Mizumo). Os cultivares Mizauto, Mizuho, Mizumo e Centenaria apresentaram valores de provitamina A entre 89 e 162 ?g RAE/100 g e podem ser considerados uma boa fonte desta pro-vitamina. Nos tres lotes de jaca analisados, quatorze dos dezoito carotenoides identificados foram relatados pela primeira vez, sendo que os principais foram all-trans-luteina (24-44 %), all-trans-?-caroteno (24-30 %), alltrans-neoxantina (4-19 %), 9-cis-neoxantina (4-9 %) e 9-cis-violaxantina (4-10 %). O lote A apresentou o menor conteudo de carotenoides totais (34,1 ?g/100 g) e o menor valor de pro-vitamina A (0,8 ?g RAE/100 g), enquanto nos lotes B e C, os conteudos de carotenoides totais foram de 129,0 e 150,3 ?g/100 g e os valores de pro-vitamina A foram 3,3 e 4,3 ?g RAE/100 g, respectivamente. Os frutos de jambolao apresentaram dois carotenoides principais: all-trans-luteina (43,7 %) e all-trans-?-caroteno (25,4 %). A composicao de antocianinas foi marcada pela presenca de diglucosideos de cinco das seis agliconas comumente encontradas em alimentos, sendo que as principais antocianinas foram delfinidina 3,5- diglucosideo (45 %), petunidina 3,5-diglucosideo (32 %) e malvidina 3,5- diglucosideo (15 %). Esse padrao tambem foi observado para outros flavonoides, onde os principais compostos identificados foram diglucosideos de diidromirecetina, metil-diidromirecetina e dimetil-diidromirecetina, alem de mirecetina glucosideo e um ester de galoil-glucose. A atividade antirradical ABTS?+ (2,2¿-azinobis-(3-etilbenzotiazolina-6-acido sulfonico)) do extrato funcional rico em antocianinas, obtido de frutos de jambolao, foi dependente do pH do meio, com valores de TEAC (capacidade antioxidante equivalente a Trolox) entre 4,8 ?mol Trolox/g fruta (pH 1,0) e 12,7 ?mol Trolox/g fruta (pH 5,0). Esse extrato funcional apresentou cerca de 60 % de protecao ao dimetilantraceno frente a oxidacao por oxigenio singlete, em condicoes de pH 1,0 e 3,0, sendo essa atividade superior aquela apresentada por outras frutas vermelhas. Padrao de cianidina 3-glucosideo foi incorporado em lipossomas unilamelares grandes (LUV) preparados em duas condicoes diferentes de pH (3,1 e 7,4), sendo esses sistemas submetidos a oxidacao induzida por AAPH (diidrocloreto de ?,?¿-azodiisobutiramidina) a 37 °C. Observou-se que as formas de cianidina 3-glucosideo presentes no meio com pH 7,4 (hemiacetais e/ou chalconas e bases quinonoidais), com EC50 = 9,3 ???1,3 ?mol/L (concentracao de antioxidante necessaria para obter 50 % de protecao), apresentaram uma atividade 2,6 vezes maior que as formas presentes no meio com pH 3,1 (maior proporcao de cation flavilium e hemiacetais), cujo EC50 foi de 23,6 ???0,9 ?mol/L. Por fim, padroes de carotenoides, trolox e tocoferol foram microencapsulados com dois materiais de parede diferentes, goma arabica (GA) e maltodextrina (MD), por meio da tecnica de spray-drying. Quando comparada a MD, a parede de GA formou dominios hidrofobicos mais rigidos e compactos, melhorando a solubilizacao de moleculas apolares e reduzindo a acessibilidade de moleculas de oxigenio. Devido a efeitos de compartimentalizacao das moleculas de antioxidante nas microcapsulas (MC), as constantes de desativacao total (kQ) de oxigenio singlete (1O2) foram cerca de duas ordens de magnitude menores nas solucoes de MC, quando comparadas aos valores de kQ em meio homogeneo
Abstract: Considering the importance of carotenoids and anthocyanins, as both natural pigments and antioxidants, the present study was carried out to evaluate, by high-performance liquid chromatography connected to a photodiode array and a mass spectrometry detector (HPLC-DAD-MS/MS) the composition of carotenoids and anthocyanins from loquat, jackfruit and jambolao fruits, as well as to study the antioxidant activity showed by these pigments in different systems. Due to the colour of these fruits, only jambolao was submitted to anthocyanin analysis. Five loquat cultivars from Brazil were evaluated: Centenaria, Mizauto, Mizuho, Mizumo and Nectar de Cristal. Twenty five carotenoids were separated, and twenty three of them were identified. The main carotenoids were all-trans-?-carotene (19-55 %), all-trans-?-cryptoxanthin (18-28 %), 5,6:5¿,6¿-diepoxy-?-cryptoxanthin (9-18 %) and 5,6-epoxy-?-cryptoxanthin (7-10 %). The total carotenoid contents ranged from 196 ?g/100 g (cv. Nectar de Cristal) to 3020 ?g/100 g (cv. Mizumo). Cultivars Mizauto, Mizuho, Mizumo and Centenaria showed provitamin A values between 89 and 162 ?g RAE/100 g, and can be considered good source of this provitamin. In the three analyzed batches of jackfruit, fourteen of the eighteen identified carotenoids were reported for the first time in this fruit. The major carotenoids were all-trans-lutein (24-44 %), all-trans-?-carotene (24-30 %), all-trans-neoxanthin (4-19 %), 9-cisneoxanthin (4-9 %) and 9-cis-violaxanthin (4-10 %). Batch A showed the lowest total carotenoid content (34.1 ?g/100 g) and provitamin A value (0.8 ?g RAE/100 g), whereas for batches B and C, respectively, the total carotenoid contents were 129.0 and 150.3 ?g/100 g and the provitamin A values were 3.3 and 4.3 ?g RAE/100 g. The jambolao fruits showed two main carotenoids: all-trans-lutein (43.7 %) and all-trans-?-carotene (25.4 %). The anthocyanin composition was marked by the presence of diglucosides of five among the six aglycones that are commonly found in foods. The major anthocyanins were delphinidin 3,5-diglucoside (45 %), petunidin 3,5-diglucoside (32 %) and malvidin 3,5-diglucoside (15 %). This pattern was also observed for other flavonoids, where the main identified compounds were diglucosides of dihydromyricetin, methyl-dihydromyricetin, and dimethyldihydromyricetin, in addition to myrecetin glucoside and a galoyl-glucose ester. The scavenging capacity of ABTS?+ (2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid)) showed by the anthocyanin-rich functional extract from jambolao fruits, was dependent on the medium pH, showing TEAC (Trolox equivalent antioxidant capacity) values between 4.8 ?mol Trolox/g fruit (pH 1.0) and 12.7 ?mol Trolox/g fruit (pH 5.0). This functional extract showed about 60 % of protection on dimethylantracene oxidation by singlet oxygen, in pH conditions of 1.0 and 3.0, being this activity higher than those showed by other red fruits. Cyanidin 3-glucoside standard was incorporated to large unilamelar liposomes (LUV) prepared at two different pH conditions (3.1 and 7.4). These systems were submitted to oxidation induced by AAPH (?,?¿-azodiisobutyramidine dihydrochloride) at 37 °C. The cyanidin 3-glucoside forms present in the medium at pH 7.4 (hemiacetals and/or chalcones and quinonoidal bases), with EC50 = 9.3 ???1.3 ?mol/L (antioxidant concentration required for 50 % protection), showed na activity 2.6 times higher than that showed by the forms present at pH 3.1 (higher proportion of flavylium cation and hemiacetals), whose EC50 was 23.6 ???0.9 ?mol/L. Finally, carotenoids, trolox and tocopherol standards were microencapsulated with two different wall materials, gum arabic (GA) and maltodextrin (MD), by the spraydrying technique. GA wall formed more rigid and compacted hydrophobic domains than those in the MD microcapsules, improving the solubilization of apolar molecules and reducing the accessibility of oxygen molecules. Due to compartmentalization effects of antioxidant molecules in the microcapsules (MC), the quenching rate constants (kQ) of singlet oxygen (1O2) were reduced almost twoorders of magnitude in MC solutions as compared with those observed in homogenous media. was also observed for other flavonoids, where the main identified compounds were diglucosides of dihydromyricetin, methyl-dihydromyricetin, and dimethyldihydromyricetin, in addition to myrecetin glucoside and a galoyl-glucose ester. The scavenging capacity of ABTS?+ (2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid)) showed by the anthocyanin-rich functional extract from jambolao fruits, was dependent on the medium pH, showing TEAC (Trolox equivalent antioxidant capacity) values between 4.8 ?mol Trolox/g fruit (pH 1.0) and 12.7 ?mol Trolox/g fruit (pH 5.0). This functional extract showed about 60 % of protection on dimethylantracene oxidation by singlet oxygen, in pH conditions of 1.0 and 3.0, being this activity higher than those showed by other red fruits. Cyanidin 3-glucoside standard was incorporated to large unilamelar liposomes (LUV) prepared at two different pH conditions (3.1 and 7.4). These systems were submitted to oxidation induced by AAPH (?,?¿-azodiisobutyramidine dihydrochloride) at 37 °C. The cyanidin 3-glucoside forms present in the medium at pH 7.4 (hemiacetals and/or chalcones and quinonoidal bases), with EC50 = 9.3 ???1.3 ?mol/L (antioxidant concentration required for 50 % protection), showed an activity 2.6 times higher than that showed by the forms present at pH 3.1 (higher proportion of flavylium cation and hemiacetals), whose EC50 was 23.6 ???0.9 ?mol/L. Finally, carotenoids, trolox and tocopherol standards were microencapsulated with two different wall materials, gum arabic (GA) and maltodextrin (MD), by the spraydrying technique. GA wall formed more rigid and compacted hydrophobic domains than those in the MD microcapsules, improving the solubilization of apolar molecules and reducing the accessibility of oxygen molecules. Due to compartmentalization effects of antioxidant molecules in the microcapsules (MC), the quenching rate constants (kQ) of singlet oxygen (1O2) were reduced almost twoorders of magnitude in MC solutions as compared with those observed in homogenous media
Doutorado
Doutor em Ciência de Alimentos
DE, LEONARDIS ANNA MARIA. „Study of responses to heat stress in durum wheat, and their relationship with nutraceutical quality“. Doctoral thesis, Università di Foggia, 2016. http://hdl.handle.net/11369/363199.
Der volle Inhalt der QuelleDurum wheat [Triticum turgidum (L.) subsp. turgidum (L.) convar. durum (Desf.)] is an important crop for human nutrition, especially in the Mediterranean area, where it is the main source of semolina for the production of pasta, traditional/typical bread, couscous, and burghul. Environmental stress can strongly limit the yield potential and affect qualitative characteristics of grain. The stress conditions that are commonly experienced by crops are extreme lack or excess of water (i.e., drought, flooding), presence of salt or contaminants (e.g., heavy metals), and temperature (i.e., cold, heat). In particular, environmental temperatures have increased since the beginning of the last century and they are predicted to further increase under the present conditions of climate change. Wheat is very sensitive to high temperatures during the reproductive phase, due to direct effects of temperature on grain numbers and dry weight. These phenotypic effects are due to molecular modifications at the different levels of gene expression, and to changes in metabolite accumulation levels. The aim of this study was to investigate the transcriptomic and metabolomic variations in response to heat stress in grains of two durum wheat genotypes, and their relationship with variation in grain composition that can affect the nutraceutical quality of the final product. The study was carried out on the durum wheat cv Primadur and T1303 (PI 352395 USDA code); the first is an elite cultivar with high grain yield and yellow index and the second one an anthocyanin-rich purple cultivar. Heat shock was imposed at 37°C from 5 up to 10 days after flowering (DAF). Immature seeds (14 DAF) and mature seeds (seeds at physiological maturity stage), collected from heat shocked and control plants (20°C), were analyzed. The response to stress was investigated with different approaches. Genome–wide gene expression analysis, carried out using Illumina HiSeq2000, showed that 1202 genes were differentially expressed in response to stress in the two genotypes. The number of up-regulated genes belonging to stress-related categories was higher in Primadur with respect to T1303, whereas the number of genes with nutrient reservoir activity was larger in T1303 compared to Primadur. These results were according to the higher sensitivity to stress of Primadur with respect to T1303, measured as grain weight loss. The profile of polar metabolites was investigated by gas chromatography-mass spectrometry (GC-MS). The effects of heat stress were genotype dependent. Although some metabolites (e.g., sucrose, glycerol) increased in response to heat stress in both genotypes, clear differences were observed. Following the heat stress, there was a general increase in most of the analyzed metabolites in Primadur, with a general decrease in T1303. Heat shock applied early during seed development produced changes that were observed in immature seeds, and also long-term effects 5 that changed the qualitative and quantitative parameters of the mature grain. The level of anthocyanins increased significantly in response to the heat stress whereas the levels of carotenoids were not affected. Only for T1303, the Trolox equivalent antioxidant capacity (TEAC) method assessed an increased antioxidant capacity of ground grains, in response to heat stress. Protein content increased only in T1303 that showed lower grain weight loss with respect to Primadur, in response to stress. Therefore, short heat-stress treatments can affect the nutritional and nutraceutical value of grain of different genotypes of durum-wheat in different ways. The present study increased the knowledge about the effect of mechanisms of adaptation to stress of wheat plants on nutritional and quality traits of grain and provides a global picture of the effects of the heat stress on metabolies and transcriptome of two different genotypes of durum wheat. Moreover, although the genetic backgrounds of two durum-wheat genotypes were different, it cannot be excluded that some of the differences observed in the responses to heat stress can be due to anthocyanin accumulation, which can be considered a trait of interest for future breeding activities for durum wheat.
Carvalho, Sarah Fiorelli de. „Produção, qualidade e conservação pós-colheita de frutas de diferentes cultivares de morangueiro nas condições edafoclimáticas de Pelotas-RS“. Universidade Federal de Pelotas, 2013. http://repositorio.ufpel.edu.br/handle/ri/1150.
Der volle Inhalt der QuelleStrawberry crop (Fragaria x ananassa Duchesne) is grown in all continents, and this fruit is very popular due of its color, scent and flavor. The aim of this work was to evaluate the adaptation, yield and quality of different strawberry cultivars under the climatic conditions of Pelotas, Rio Grande do Sul state. The experiments were conducted at Embrapa Temperate Climate, Pelotas-RS from 2011 to 2012. At first, we evaluated fruit, yield, number and average fruit size of the cultivars Albion, Aromas, Camarosa, Camino Real, Portola, Monterey, San Andreas, Strawberry Festival and Palomar. The second test was conducted at the Laboratory of Food Technology, and it evaluated physical and chemical characteristics (soluble solids contents, titratable acidity, soluble solids/titratable acidity, pH, and vitamin C) and quantified the bioactive compounds (phenolic compounds, anthocyanins and antioxidant activity) of the cultivars in three harvest dates: September, October and November. The cultivars showed significant differences for date and for comparison between cultivars in the physical and chemical characteristics. Phenolic compounds and antioxidant activity were higher in September, while anthocyanins was higherin November. The third test was conducted at the Laboratory of Postharvest Physiology. We observed the behavior of cultivars under the cold storage for up to eight days, using three replicates of five fruits in a factorial scheme 8x3 (eight cultivars x three dates). The variables studied were soluble solids content, titratable acidity, soluble solids/acidity, pH, color, luminosity, mass rot and decay incidence. During this period, the cultivars maintained the quality and there was no significant loss of mass, degradation of the compounds or symptoms of illness or unpleasant odor.
O morangueiro (Fragaria x ananassa Duchesne) é cultivado em todos os continentes, e sua fruta, o morango, é muito popular devido sua coloração, aroma e sabor. Objetivou-se neste trabalho avaliar a adaptação, produção e qualidade de diferentes cultivares de morangueiro às condições edafoclimáticas de Pelotas-RS. Os ensaios foram realizados na Embrapa Clima Temperado, durante as safras de 2011/2012 e 2012/2013. No primeiro ensaio avaliou-se a produção, produtividade, número e tamanho médio de frutas das cultivares Albion, Aromas, Camarosa, Camino Real, Portola, Monterey, San Andreas, Strawberry Festival e Palomar. O delineamento experimental foi em blocos casualizados. As cvs. Strawberry Festival, Camarosa e Monterey proporcionaram a maior produtividade na safra 2011/2012, enquanto que a cultivar que se destacou na safra 2012/2013 foi Camarosa, sendo o pico de produção de todas as cultivares no mês de novembro. O segundo ensaio foi realizado no Laboratório de Tecnologia de Alimentos na safra 2012/2013. Avaliaram-se os atributos físicos e químicos (sólidos solúveis, acidez titulável, relação sólidos solúveis/acidez titulável, pH, teor de vitamina C) e quantificaram-se os compostos bioativos das cultivares (compostos fenólicos, antocianinas e atividade antioxidante) em três datas de colheita: setembro, outubro e novembro. As cultivares apresentaram diferenças significativas tanto para data, quanto para a comparação entre as cultivares nas características físicas e químicas. Os compostos fenólicos e a atividade antioxidante foram maiores no mês de setembro, enquanto que as antocianinas em novembro. O terceiro ensaio foi realizado no Laboratório de Fisiologia Pós-colheita. Utilizaram-se três repetições de cinco frutas, constituindo um esquema fatorial de 8x3 (oito cultivares x três datas). Observou-se o comportamento das cultivares diante do armazenamento em câmara fria por zero, quatro e oito dias, à temperatura de 1±0,5ºC e UR 90-95%. As variáveis estudadas foram sólidos solúveis, acidez titulável, relação sólidos solúveis/acidez, pH, coloração e luminosidade da epiderme, perda de massa e incidência de podridões. No período avaliado, as cultivares mantiveram a qualidade pois não houve perdas significativas de massa, degradação de compostos ou presença de sintomas de doenças ou odor desagradável.
Kapiton, Ulyana. „Srovnání vlastností aroniových pomazánek různého původu, složení a různé technologie výroby“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401850.
Der volle Inhalt der QuellePelikánová, Blanka. „Stanovení vybraných chemických parametrů v plodech nových odrůd rybízů“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217090.
Der volle Inhalt der QuelleBASTOS, Rafaella da Silva. „Estabilidade e potencial antioxidante de antocianinas do resíduo agroindustrial da uva Isabel cultivada no Vale do São Francisco“. Universidade Federal Rural de Pernambuco, 2015. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4886.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Large amounts of wine by-products are produced as a result of processing grapes in Brazil. Considering the presence of bioactive pigments in this material, the aim of this work was to investigate the antioxidant potential and stability of anthocyanins from the grape juice pomace. The grape residue (Vitis labrusca, cv. Isabella) was ceded by an industry producing of pure grape juice, located in the region São Francisco Valley, in the city of Petrolina-PE. The anthocyanin content was determined using pH-differential method. The isolated anthocyanin were identified and quantified by chromatography analysis using a RP-HPLC-DAD system. The antioxidant activity of the purified anthocyanins were evaluated for their ability to scavenge free radicals DPPH• (1,1-diphenyl-2-picrylhydrazyl) and ABTS•+ [2,2'-azino-bis (3-ethylbenzthiazoline-6sulfonic acid)], using gallic acid as standard. Purified anthocyanins were diluted in ethanol solution 95%: HCl 1.5N; 85:15 v/v (pH = 1.0) to evaluate the light stability, and distributed into test tubes, exposed and not exposed to light for a period of 840 hours (35 days) at 21°C ± 1°C, monitored by spectrophotometer readings. The effect of temperature on the stability of anthocyanins was evaluated using test tubes containing purified anthocyanins diluted into water, acidified with HCl (pH = 1.0), and subjected to temperatures of 50°C, 70°C and 90°C in thermostatic bath. Absorbance readings were made in the control sample (0h), and after 1, 3, 5 and 7 hours of heating. The absorbance data were used to calculate the rate constant (k) and half-life (t1/2) of anthocyanins through first-order kinetics equations. The average content of anthocyanins was 31.66 ± 0.63 mg. 100g-1 residue (expressed as malvidin-3-glucoside). A total of six majority different anthocyanins were identified: cyanidin-3-O-glucoside, delphinidin-3-O-glucoside, malvidin-3-O-glucoside, malvidin-3,5-O-diglucoside, pelargonidin-3-O-glucoside and peonidin-3-O-glucoside, with different concentrations. Malvidin 3-glucoside was the most abundant (61.66%) of the total observed, while malvidin-3,5-O-diglucoside (14.88%) was the second. The anthocyanin fraction showed high antioxidant potential against the radical DPPH• (EC50: 0.26 g. g DPPH•-1; TEC50: 1.37 minutes; AE: 2.79). After 5 minutes of reaction, at concentrations of 5-40 μg. mL-1, showed variations in the percentage scavenging between 48 and 94%, respectively, though there is a high correlation between anthocyanin content and antioxidant capacity (R = 0.93). Against the radical ABTS•+ anthocyanins exhibited significant action in capturing the radical with value of 199.35 uM Trolox. g-1. The half-life (t1/2) of the anthocyanin pigments, in the absence of light, was 3.320h (138 days) and in the presence of light was 505h (21 days), with the follows rate constants (k): 2.09 x 10-4 h-1 e 1.37 x 10-3 h-1, respectively, showing that presence of light contributed significantly to the instability of anthocyanins. In the study of heat stability, the rate constants (k) were: 1.84 x 10-2 h-1 (50°C); 7.82 x 10-2 h-1 (70°C); and 1.99 x 10-1 h-1 (90°C). The half-life of the samples occurred after 3.5h at 90°C and would occur after 8.9h and 37.7h for the samples at 70°C and 50°C, respectively, indicating the higher instability of anthocyanins to high temperatures. Anthocyanins from cv. Isabella grape juice residue are a promising source of natural dye which has antioxidant action with potential application in food products with an acidic pH, packaged in opaque packaging, and not subjected to severe heat treatment during processing.
Elevada quantidade de subprodutos vitivinícolas é produzida em decorrência do processamento de uvas no Brasil. Considerando a presença de pigmentos bioativos em sua composição, objetivou-se neste trabalho investigar o potencial antioxidante e a estabilidade das antocianinas do resíduo agroindustrial de suco de uva. O resíduo de uva (Vitis labrusca, cv. Isabel) foi cedido por uma indústria produtora de suco de uva integral, situada na região do Vale do São Francisco, Petrolina-PE. O teor de antocianinas totais foi determinado utilizando metodologia de pH diferencial. Para identificação e quantificação das antocianinas individuais, análises cromatográficas foram efetuadas por CLAE-DAD em fase reversa. A atividade antioxidante das antocianinas foi avaliada quanto à capacidade de sequestro dos radicais DPPH• (1,1-difenil-2-picrilhidrazil) e ABTS•+ (2,2’-azino-bis-3-etilbenzotiazolina-6-acido sulfônico), tendo o ácido gálico como composto de referência. Para avaliar a estabilidade à luz, as antocianinas foram diluídas em uma solução de etanol 95%: HCl 1,5N; 85:15 v/v (pH = 1,0) e distribuídas em tubos de ensaio, expostos à luz e ao abrigo da luz, a 21°C ± 1°C, durante um período de 840 horas (35 dias), monitorados por leituras em espectrofotômetro. O efeito da temperatura sobre a estabilidade das antocianinas foi avaliado utilizando tubos de ensaio contendo antocianinas diluídas em água acidificada com HCl (pH = 1,0) e submetidos a temperaturas de 50ºC, 70ºC e 90ºC, em banho termostatizado. Leituras de absorbância foram realizadas na amostra recém-preparada (0h) e após 1, 3, 5 e 7 horas de aquecimento. Os dados de absorbância foram utilizados para o cálculo da constante de velocidade (k) e do tempo de meia-vida (t1/2) das antocianinas por meio de equações cinéticas de 1ª ordem. O teor médio de antocianinas totais foi de 31,66 mg. 100g–1 de resíduo (expresso em malvidina-3-glicosídeo). Seis antocianinas majoritárias foram identificadas: cianidina-3-O-glicosídeo; delfinidina-3-O-glicosídeo; malvidina-3-O-glicosídeo; malvidina-3,5-O-glicosídeo; pelargonidina-3-O-glicosídeo; e peonidina-3-O-glicosídeo, em diferentes concentrações. Malvidina-3-O-glicosídeo foi a mais abundante (61,66%) seguida da malvidina-3,5-O-diglicosídeo (14,88%). A fração antociânica demonstrou elevado potencial antioxidante frente ao radical DPPH• (EC50: 0,26 g. g DPPH•-1; TEC50: 1,37 minutos; EA: 2,79). Aos 5 minutos de reação, nas concentrações de 5 a 40 μg. mL–1, apresentou variações no percentual de sequestro entre 48 e 94%, respectivamente, constatando uma alta correlação entre o teor de antocianinas e a capacidade antioxidante (R = 0,93). Frente ao radical ABTS•+ as antocianinas exibiram significativa ação na captura do radical com valor de 199,35 μM Trolox. g-1. Na ausência de luz, o tempo de meia vida dos pigmentos antociânicos foi de 3.320h (138 dias), e na presença de luz foi de 505h (21 dias), apresentando constantes de velocidade de 2,09 x 10-4 h-1 e 1,37 x 10-3 h-1, respectivamente, demonstrando que a luminosidade contribuiu para a instabilidade das antocianinas. No estudo de estabilidade ao calor, as constantes de velocidade foram: 1,84 x 10-2 h-1 (50°C); 7,82 x 10-2 h-1 (70°C); e 1,99 x 10-1 h-1 (90°C). O tempo de meia-vida ocorreu após 3,5h a temperatura de 90°C, e ocorreria após 8,9h e 37,7h, a 70°C e 50°C, respectivamente, constatando a maior instabilidade das antocianinas à altas temperaturas. As antocianinas do resíduo de suco de uva cv. Isabel são uma fonte promissora de corante natural que possui ação antioxidante, com potencial aplicação em produtos alimentícios que tenham pH ácido, sejam acondicionados em embalagens opacas, e não sejam submetidos à tratamentos térmicos severos durante o seu processamento.
Bochi, Vivian Caetano 1982. „Chemical characterization and biological activity of the Ceylon gooseberry (Dovyalis hebecarpa) in different ripening stages = Caracterização química e atividade biológica da groselha do ceilão (Ddovyalis hebecarpa) em diferentes estadios de maturação“. [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254314.
Der volle Inhalt der QuelleTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: A groselha do Ceilão (Dovyalis hebecarpa) é uma fruta exótica de coloração roxa quando madura. Não foram encontrados trabalhos que identifiquem os principais compostos fenólicos na espécie, ação antioxidante e efeitos biológicos. Sendo assim, além da otimização da extração, esse trabalho avaliou os principais compostos fenólicos na casca e polpa de D. hebecarpa por cromatografia líquida acoplada a espectrômetro de massas (CLAE-DAD-EM), o potencial antioxidante in vitro e o efeito sobre a resposta imunológica em camundongos. Com exceção da razão entre amostra e solvente, avaliada univariadamente, a otimização das variáveis de extração foi realizada utilizando planejamento experimental multivariado. O processo otimizado foi realizado em menor tempo (20 minutos), com menos solvente orgânico (20% de acetona) e com maior rendimento (aumento de 10% no teor total de compostos fenólicos e de 26% no teor total de antocianinas monoméricas) do que a metodologia inicial. A caracterização do perfil de antocianinas revelou que D. hebecarpa é fonte de compostos não acilados, sendo delfinidina-3-O-rutinosídeo e cianidina-3-O-rutinosídeo os majoritários. Casca e polpa possuem composição similar, no entanto, maiores concentrações são encontradas na parte externa do fruto. Amostras de dois anos consecutivos e em duas datas de amostragem foram recolhidas para avaliação de variações entre estações do ano. Considerando que a ação antioxidante se dá por diversos mecanismos, metodologias de FRAP, ABTS e ORAC foram empregadas. Os maiores resultados de atividade antioxidante foram obtidos com a metodologia de ORAC, indicando marcada atividade sequestradora de radicais peroxil dos compostos extraídos. De forma diferenciada para polpa e casca dos frutos, efeitos significativos sob os teores de antocianinas, de compostos fenólicos e capacidade antioxidante, foram observados devido à variação climática entre as datas. Adicionalmente foram avaliados parâmetros biométricos e composição nutricional. Alterações no peso e tamanho dos frutos (p<0,05), assim como, na composição nutricional (p<0,05) foram observadas. Esses resultados, possivelmente, devem-se as diferenças de disponibilidade de água e incidência solar entre as datas de amostragem. Os valores médios dos teores de compostos fenólicos e antocianinas encontradas são similares aos relatados para outras frutas vermelhas. Nos testes in vivo, camundongos C57Black6 foram divididos em 4 grupos que receberam por 5 dias uma dose diária de extrato bruto em alta, média e baixa dosagem (32µg, 16µg e 8µg equivalentes de cianidina-3-O-glucosídeo/animal, respectivamente). Para o grupo controle foi utilizada solução salina. Após 24 horas do fim do tratamento, os animais foram imunizados com OVA (ovalbumina), conforme metodologia padrão. No 14° dia, os animais foram sacrificados e os tecidos recolhidos para análise. Foram monitoradas a proliferação celular em baço e linfonodos, assim como, sua diferenciação em linfócitos T CD4+/CD8+ por citometria de fluxo. Os grupos tratados com CGCE apresentaram redução na proliferação celular em linfonodos, assim como na razão CD4+/CD8+. Sendo assim, os resultados indicam um possível efeito anti-inflamatório do extrato aquoso bruto de groselha do Ceilão, porém pesquisas adicionais de caracterização de citocinas e tratamentos prolongados são necessárias para confirmação dos resultados encontrados
Abstract: D. hebecarpa is a dark purple/red berry produced in Brazil as an exotic fruit with potential for large scale production and commercialization. Fruits are believed to contain high phenolic and anthocyanin concentration that provide color and defense to the plant. Moreover, these compounds have been extensively studied for their antioxidant activity and potential human health benefits. Thus, this work has optimized extraction prior to the skin and pulp anthocyanin profile characterization by HPLC-PDA-MS aiming to obtain the simplest and mildest conditions with maximum phenolic yield. Moreover, it was evaluated in vitro antioxidant capacity and the effect of water-based crude extract on immune system of mice. Solid-liquid ratio was determined in a linear experiment using ANOVA and Tukey (p<0.05). Acetone, ethanol and water were the extraction solvents evaluated by Simplex Lattice design. Time and acid concentration were evaluated using response surface methodology (RSM) to determine variables effect and their interactions. The optimized conditions achieved were: solid-liquid ratio of 1:120, acetone 20% with 0.35% formic acid, 20min, and no re-extraction. However, satisfactory results were obtained using just water as solvent. The optimized extraction used less organic solvent than the other conditions tested and showed higher yields than the initial ones (an increase of 10% and 26% of total phenolic compounds and total monomeric anthocyanins, respectively). The analytical HPLC chromatogram showed five major anthocyanins (Delphinidin-3-glucoside, Delphinidin-3-rutinoside, Cyanidin-3-glucoside, Cyanidin-3-rutinoside, and Petunidin-3-rutinoside) in addition to two minor pigments (Peonidin-3-rutinoside and Malvidin-3-rutinoside). Samples from two consecutive years were used for quantification purposes and antioxidant measurements. High concentration of phenolics and anthocyanins were detected in skin samples with the same anthocyanin profile of pulp part. FRAP, ABTS, and ORAC methodologies were used to evaluate antioxidant mechanisms. A strong peroxyl scavenger capacity was detected for D.hebecarpa samples by ORAC methodology which could indicate possibly health effects of fruit consumption. Significant variations of anthocyanin, total phenolic content, and antioxidant capacity were observed in pulp and skim possibly as a result of weather conditions. Concomitantly, biometric parameters and nutritional composition seems to be affected as well (p<0.05). C57Black6 mice were used for in vivo evaluation of immuno-modulatory effect of water-based Ceylon gooseberry crude extract (CGCE). Animals were treated with high, medium, and low dosages of CGCE (32µg, 16µg, and 8µg cyanidin-3-O-glucose/animal/day, respectively) during 5 days. Saline solution was used as a control group. Animals were challenged after 24 hours from the last dose using a standardized immunization protocol with OVA and CFA. After euthanasia, blood, spleen, and lymph nodes were collected and analyzed. Cell proliferation using MTT and lymphocyte profile by flown citometry was determined in spleen and lymph nodes, as well as IgG levels in blood samples. Results indicate a possible anti-inflammatory effect. Since, there was an decrease in lymph node cell proliferation response as well as in CD4+/CD8+ ratio. In summary, D. hebecarpa is a rich source of anthocyanins with concentration levels as high as reported for other berry fruits. The strong antioxidant activity and some evidences of in vivo anti-inflammatory effects suggest this fruit as source for future scientific works aiming to evaluate possible health effects
Doutorado
Ciência de Alimentos
Doutora em Ciência de Alimentos
Burdějová, Lenka. „Charakterizace plodů aronie (Aronia melanocarpa) a muchovníku (Amelanchier alnifolia)“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217029.
Der volle Inhalt der QuelleKasparavičienė, Giedrė. „Antioksidacinio poveikio preparatų su juodųjų serbentų (Ribes nigrum L.) uogų ekstraktu tyrimas ir vertinimas“. Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060126_123333-20838.
Der volle Inhalt der QuelleRezende, Diana Figueiredo de. „Estudo comparativo de características físico-químicas e nutricionais da soja preta e amarela“. Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-08032013-151843/.
Der volle Inhalt der QuelleBrazil is the second largest producer of soybean (Glycine max, L.), accounting for almost 30% of the world\'s production. Over 80% of the total production is destined to oil extraction and protein for human consumption. Soybean and soy-product consumption has been rising as an alternative to animal protein and due to its potential health benefits. Most of the scientific literature refers to yellow soybeans, while studies on black soybeans are still scarce. This project aimed to study and compare black and yellow soybeans, cultivated in Brazil in similar climatic and environmental conditions, as to their physical characteristics and chemical composition, including phenolic compounds and antioxidant activity. The effect of cooking on phenolic compounds and antioxidant activity was also investigated. No significant difference was observed between black and yellow soybeans as to nutrient content, fatty acid composition and physical characteristics, such as seed-weight, hydration capacity and cooking time. However, black soybeans had a much higher content of total phenolic compounds (TPC) and flavonoids than yellow soybeans. TPC and flavonoid contents in black soybeans were 4.78 mg gallic acid equivalents/g and 1.75 mg (+)-catechin equivalents/g, respectively. Yellow soybeans had on average 40% less TPC and approximately 60% less flavonoids. Unlike yellow soybeans which lack anthocyanins, black soybeans were found to have an average content of 0.92 mg cyanidin-3-O-glucoside equivalents/g. High performance liquid chromatography coupled to photodiode array and mass spectrometry detectors (HPLCDADMS/MS) was used to identify two anthocyanins, namely cyanidin-3-Oglucoside and peonidin-3-O-glucoside, and cyanidin. Black soybeans also showed a 70% higher DPPH-free radical scavenging activity than yellow soybeans, and a 50% higher ORAC value. Cooking reduced at least 40% of phenolic compounds and antioxidant capacity in all soybean samples, both black and yellow. High correlations between phenolic compositions and antioxidant activities were observed, before and after cooking. These results suggest that black soybean consumption or new processed food products from these crops may offer consumers an opportunity to diversify their diet with food nutritionally equivalent to yellow soybeans, but possibly with greater health benefits. The possibility of expanding black soybean cultivation, including small-scale production, may create a new market niche for a value-added food product.
OLIVEIRA, Karlla Karinne Gomes de. „Resíduo da indústria de polpa congelada de uva (cultivar Isabel) como fonte de antocianinas“. Universidade Federal Rural de Pernambuco, 2015. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4883.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The agribusiness processing of tropical fruits have generated waste that may have great potential, as well as having nutritional constituents, still have significant levels of bioactive compounds. Thus, this research aimed to use frozen pulp residue of grape extract and purify anthocyanins, evaluate its antioxidant capacity as well as its stability to light and heat.The residue was transferred by a processing unit (Recife - PE), whose grapes cultivar Isabel (Vitis labrusca L.) came from the city of São Vincente Ferrer - PE. The anthocyanin content was determined by differential pH method and its purification using C18 cartridges promoted the removal of sugars, acids and not anthocyanin phenolic compounds.The antioxidant activity of purified anthocyanins was evaluated by the ability to scavenge the radicals DPPH• (1,1-diphenyl-2-picrylhydrazyl) and ABTS•+ (2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid), with gallic acid as reference compound.To evaluate light fastness, anthocyanins were diluted in 95% ethanol solution: 1.5N HCl; 85:15 v/v (pH 1.0) and exposed to light and no light.To assess the effect of heat, anthocyanins were diluted in water, acidified with HCl (pH = 1.0) and subjected to temperatures of 50°C, 70°C and 90°C in thermostated bath. Absorbance readings were taken after 1, 3, 5 and 7 hours of heating. The data obtained from reading the absorbance of diluted anthocyanins were used for the calculation of the rate constant (k) and half-life (t1/2) using 1st order kinetics equations.The total anthocyanin content in grape residue was 15.56 ± 0.33 mg. 100g-1 residue. Anthocyanins purified showed good efficiency against the radical DPPH• (EC50 of 0.14 ± 0.01 g. g DPPH-1 and TEC50 < 5 minutes) and strong ability to sequester (> 80%). Against the radical ABTS•+ anthocyanins showed sequestration capacity of 241.36 ± 3.74 μmol TEAC.g-1 sample. The results showed that in the presence of light, time of half-life (t1/2) of the anthocyanin pigments was 656.87h and in the absence of light was 6.525.42h, demonstrating that the absence of light contributed significantly to the increase the stability of anthocyanins. Anthocyanins subjected to heat at temperatures of 50°C, 70°C and 90°C showed a half-life (t1/2) 159.31h; 8.77h and 3.05h, respectively, demonstrating that these pigments are degraded with increasing temperature. The results show the agroindustrial residue grape frozen pulp is a promising source of anthocyanins, which showed significant antioxidant properties, being efficient at capturing the DPPH• and ABTS•+ and can be used in foods that have acidic pH, put in opaque packaging, and are not subjected to severe heat treatment during processing.
As agroindústrias processadoras de frutas tropicais têm gerado resíduos que podem apresentar grande potencial, pois além de possuir constituintes nutritivos, ainda apresentam significantes teores de compostos bioativos. Assim, esta pesquisa teve como objetivo utilizar resíduo de polpa congelada de uva para extrair e purificar antocianinas, avaliar sua capacidade antioxidante assim como, sua estabilidade frente à luz e ao calor. O resíduo foi cedido por uma unidade processadora (Recife – PE), cujas uvas da cultivar Isabel (Vitis labrusca L.) foram provenientes da cidade de São Vicente Férrer – PE. O teor de antocianinas foi quantificado pelo método de pH diferencial e sua purificação, utilizando cartuchos C18,promoveu a remoção de açúcares, ácidos e compostos fenólicos não antociânicos. A atividade antioxidante das antocianinas purificadas foi avaliada pela capacidade de sequestrar os radicais DPPH• (1,1-difenil-2-picrilhidrazil) e ABTS•+ (2,2’-azino-bis-3-etilbenzotiazolina-6-acido sulfônico), tendo o ácido gálico como composto de referência. Para avaliar a estabilidade à luz, antocianinas foram diluídas em solução de etanol 95%:HCl 1,5N; 85:15 v/v (pH=1,0) e expostas à luz e à ausência de luz. Para avaliar o efeito do calor, antocianinas foram diluídas em água, acidificada com HCl (pH=1,0) e submetidas a temperaturas de 50ºC, 70ºC e 90ºC, em banho termostatizado. Leituras da absorbância foram efetuadas após 1, 3, 5 e 7 horas de aquecimento. Os dados obtidos na leitura da absorbância das antocianinas diluídas foram utilizados para o cálculo da constante de velocidade (k) e do tempo de meia vida (t1/2) utilizando equações cinéticas de 1ª ordem. O teor de antocianinas totais no resíduo de uva foi de 15,56 ± 0,33mg. 100g-1 de resíduo. As antocianinas purificadas apresentaram boa eficiência frente ao radical DPPH• (EC50 de 0,14 ± 0,01 g.g DPPH-1 e TEC50 < 5 minutos) e forte capacidade de sequestrar (> 80%). Frente ao radical ABTS•+ as antocianinas apresentaram capacidade de sequestro de 241,36 ± 3,74 μmol TEAC.g-1 de amostra. Os resultados obtidos evidenciaram que em presença de luz, o tempo de meia vida (t1/2) dos pigmentos antociânicos foi de 656,87h e na ausência de luz foi de 6.525,42h, demonstrando que a ausência de luz contribuiu significativamente para o aumento da estabilidade das antocianinas.As antocianinas submetidas ao calor, às temperaturas de 50ºC, 70ºC e 90ºC apresentaram de tempo de meia vida (t1/2) de 159,31h; 8,77h e 3,05h, respectivamente, demonstrando que estes pigmentos sofrem degradação com aumento da temperatura. Os resultados evidenciam o resíduo agroindustrial de polpa congelada de uva é uma fonte promissora de antocianinas, que apresentaram significativa propriedade antioxidante, mostrando-se eficientes em capturar os radicais DPPH• e ABTS•+, podendo ser utilizadas em alimentos que possuam pH ácido, acondicionados em embalagens opacas, e que não sejam submetidos à tratamentos térmicos severos durante seu processamento.
Pannitteri, Claudia Rita. „Study of agronomical and postharvest factors influencing qualitative and nutraceutical traits on blood orange and pomegranate fruits“. Doctoral thesis, Università di Catania, 2017. http://hdl.handle.net/10761/3988.
Der volle Inhalt der QuelleM'be, Cho. „Procédés de production et influence des propriétés fonctionnelles des poudres de calices d’Hibiscus sabdariffa et de leurs fractions sur la formulation de boisson“. Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0274.
Der volle Inhalt der QuelleHibiscus sabdariffa (hibiscus) is a plant with edible calyxes containing polyphenol and anthocyanin molecules that are both antioxidant compounds and responsible for their attractive red color for consumers. These particularities constitute a good health potential that meets the current market demands, and an economic potential for industries. However, this tropical and seasonal plant whose water-rich calyxes are highly perishable, sensitive to humidity and heat, and whose the interesting molecules (anthocyanins) are heat-sensitive and unstable in aqueous medium. In this context, the calyx transformation into powder allows, besides optimizing the transport cost and storage space, to stabilize the calyxes by ensuring a long product shelf-life, and to improve the biomolecule accessibility. This allows to benefit to its health assets provided that the process is controlled. One of the best ways to preserve the calyx original nutritional properties (anthocyanin content, antioxidant activity) is to obtain minimally processed products by combining controlled oven-drying, grinding and fractionation by sieving. This process was studied in this work and the powder physicochemical properties (particle size and shape, structure, porosity, fiber proportion, anthocyanin content, antioxidant activity) and functional properties (flowability, reconstitution, biomolecule extractability) were systematically evaluated for drink formulation. The interest of such a process is the ease of its implementation applicable to all plants, the powder ease of use, the improvement of the biomolecule availability and accessibility. This work allows identifying the impact of sun-drying and grinding on the powder physicochemical properties, the latter impacting the functional properties. The substitution of sun-drying by controlled oven-drying and an additional fractionation by sieving preceded by grinding allowed improving the powder functional properties. These powder functional properties were singular and allowed to distinguish specific applications for each powder type (fine or coarse powders)
Baliūtytė, Eglė, und Eglė Krivickienė. „MĖLYNIŲ UOGŲ PREPARATŲ TYRIMAS IR VERTINIMAS“. Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140618_215826-24426.
Der volle Inhalt der QuellePurpose of the work: To make the comparable ingredients and technology analysis of selected blueberry preparations registered in Lithuania, evaluate quantitatively and determine the antioxidant activity. Tasks: to investigate the supply of blueberry preparations registered in Lithuania. To make the comparable ingredients analysis of preparations mentioned above. Determine the phenolic compounds and anthocyanins quantity using the spectrophotometry method. Measure the antioxidant activity of selected preparation using DPPH method. Research objects and methodology: Preparations with blueberry extract and blueberry powder. Spectrophotometric methods were used for analysis: total phenolic content according calibration curve of galic acid; total anthocyanins - pH differential method; antioxidant activity - DPPH free radical inhibition. Results and conclusions: Until June, 2013 y. Lithuania set 47 record Blueberry fruit preparations. There was noticed that in 97 percent composition of the preparation, blueberry raw material shape - extract. 91 percent of explored preparations are multicomponent and just 9 percent - one-component. Determined by spectrophotometry, that the highest levels of the phenolic compounds are in ”Mėlynių ekstraktas“, capsules of (“Vitaforce”, United Kingdom) and the lowest – “Visioblue strong’’, capsules of (”Hankintatukku Oy’’, Finland). The quantity of Anthocyanins per recommended daily dose in the preparation was studied by spectrophotometry method. The... [to full text]
Javorská, Kateřina. „Stanovení vybraných chemických parametrů plodů moderních odrůd angreštů“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217081.
Der volle Inhalt der QuelleAzevedo, Miriane Lucas. „Perfil fitoquímico, atividades antioxidante e antimicrobiana de amora-preta (Rubus fruticosus) cv. Tupy em diferentes estádios de maturação cultivada em clima temperado“. Universidade Federal de Pelotas, 2010. http://repositorio.ufpel.edu.br/handle/ri/1326.
Der volle Inhalt der QuelleBlackberry (Rubus fruticosus) is considered a fruit rich in the phytochemical compounds, mainly phenolic acids and anthocyanins, which have a high potential for antioxidant and are also present L-ascorbic acid, carotenoids and tocopherols. Based on the concentration changes that these compounds undergo during the fruit ripening stages, this work aims to study the changes in the phytochemical profile of blackberry cv. Tupy, grown in temperate climates, in Pelotas, and effects on antioxidant and antimicrobial activity. Were determined five stages of ripening from green to mature through the external color of the fruit, and to confirm the differences between them, each stage was measured physical-chemical, determining total acidity (TA), total soluble solids (SS),ripening index (SS/TA) and instrumental analysis of color (hue angle). With regard to the phytochemical profile were analyzed phenolic compounds, L-ascorbic acid, carotenoids and tocopherols. It can be stated that according to the results of the different ripening stages did not affect significantly (p≤0.05) the total phenolic compounds, catechin and L-ascorbic acid. For the individual phenolic compounds during the fruit development, the derivatives of benzoic acid increased, the same behavior occurs with epicatechin, that among these is composed of higher concentration, the levels of cinnamic acid derivatives showed a different behavior, there fall of these levels. Anthocyanins increased during the fruit ripening, detaching the cyanidin-3-glucoside. The carotenoids and tocopherols decreased during ripening. One can conclude that it is possible to mount a phytochemical profile of blackberry cv. Tupy, grown in temperate climates, to differentiate their ripening stages, but it is necessary to carry out several determinations, since it is not possible to say which assessment contributed most to the differentiation of stages along the ripening. Another observation concerns the antioxidant activity increased during ripening, in vitro and in vivo, but noted that it is not possible to determine which compound has a higher antioxidant capacity in isolation, but found that there was a synergism between the phytochemical compounds present in fruit, which vary over the course of its development. Likewise, we can not say if there was an increase in antimicrobial activity over the course of ripening, and even if there was a specific secondary compound responsible for this antimicrobial activity, but that it exists, since the bacterium Salmonella enteritidis showed sensitivity to the extracts but with different answers.
Amora-preta (Rubus fruticosus) é considerada um fruto rico em compostos fitoquímicos, principalmente ácidos fenólicos e antocianinas, que possuem um elevado potencial antioxidante e também estão presentes ácido L-ascórbico, carotenóides e tocoferóis. Com base nas mudanças de concentração que esses compostos sofrem ao longo dos estádios de amadurecimento do fruto, este trabalho tem por objetivo estudar as alterações no perfil fitoquímico da amora-preta cv. Tupy, cultivada em clima temperado, na região de Pelotas, e os efeitos na capacidade antioxidante e antimicrobiana. Foram determinados cinco pontos de maturação do verde ao mais maduro, através da coloração externa do fruto, e para confirmar as diferenças entre estes, cada estádio foi avaliado físico-químicamente, determinandose acidez total titulável (AT), sólidos solúveis totais (SS), índice de maturação (SS/AT) e análise instrumental da cor (ângulo hue). Com relação ao perfil fitoquímico foram analisados os compostos fenólicos, ácido L-ascórbico, carotenóides e tocoferóis. Pode-se afirmar que de acordo com os resultados os diferentes estádios de maturação não afetaram significativamente (p≤0,05) os compostos fenólicos totais, a catequina e o ácido L-ascórbico. Para os compostos fenólicos individuais ao longo do desenvolvimento dos frutos, os derivados do ácido benzóico aumentaram, o mesmo comportamento ocorre com a epicatequina, que dentre todos é o composto de maior concentração, os teores dos derivados do ácido cinâmico apresentaram um comportamento diferenciado, houve queda destes teores. As antocianinas aumentaram ao longo da maturação do fruto, destacando a cianidina-3-glicosídeo. Os carotenóides e os tocoferóis decresceram no decorrer da maturação. Pode-se concluir que é possível montar um perfil fitoquímico da amora-preta cv. Tupy, cultivada em clima temperado, para diferenciar seus estádios de maturação, porém é necessária a realização de diversas determinações, uma vez que não é possível afirmar qual avaliação contribuiu em maior parte para a diferenciação dos estádios ao longo da maturação. Outra observação, diz respeito à atividade antioxidante que aumentou ao longo da maturação, tanto in vitro quanto in vivo, contudo foi observado que não é possível determinar qual composto tem maior capacidade antioxidante isoladamente, mas sim foi verificado que há um sinergismo entre os compostos fitoquímicos presentes no fruto, que variam ao decorrer do seu desenvolvimento. Da mesma maneira, não podemos afirmar se houve um aumento na atividade antimicrobiana ao decorrer da maturação, e nem se houve um composto secundário específico responsável por esta atividade antimicrobiana, mas sim que esta existe, uma vez que a bactéria Salmonella Enteritidis mostrou sensibilidade aos extratos, porém com diferentes respostas.
Arts, Mariken J. T. J. „Assessing antioxidant activity“. [Maastricht : Maastricht : Universiteit Maastricht] ; University Library, Universiteit Maastricht [host], 2007. http://arno.unimaas.nl/show.cgi?fid=8676.
Der volle Inhalt der QuelleLošková, Tereza. „Extrakce anthokyanových barviv z bezinkových výlisků“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-376808.
Der volle Inhalt der QuelleGaiz, AlMottesembellah A. „Anthocyanin as an Antiplatelet Therapy in Diabetes: Immunopathological Assessment“. Thesis, Griffith University, 2021. http://hdl.handle.net/10072/403246.
Der volle Inhalt der QuelleThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Medical Science
Griffith Health
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O'Reilly, James Daniel. „Antioxidant activity of dietary flavonoids“. Thesis, King's College London (University of London), 1999. https://kclpure.kcl.ac.uk/portal/en/theses/antioxidant-activity-of-dietary-flavonoids(10c771a4-169d-405b-a1cd-354e86ebd109).html.
Der volle Inhalt der QuelleJames, Leanne. „Manganese complexes with biomimetic antioxidant activity“. Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/7073.
Der volle Inhalt der QuelleWang, Xiaoxi. „Evaluation of Antioxidant Properties of Native Utah Berries and Their Potential for Use in Meats“. DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7331.
Der volle Inhalt der QuelleWilliamson, E. „The antioxidant activity of #DELTA#'5-avenasterol“. Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233864.
Der volle Inhalt der QuelleBranco, Diana Patrícia Rodrigues. „Metallothionein functions: metal chelation and antioxidant activity“. Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/7317.
Der volle Inhalt der QuelleIt is generally accepted that the principal roles of metallothioneins (MTs) lie in the detoxification of toxic metals and regulation of the metabolism of essential trace metals. However, there is increasing evidence that it can act as a free radical scavenger. Although the great number of studies on the antioxidant activity of MTs, the effective physiological role of this protein is still unclear. In order to understand the role of MTs in the protection against metal contamination and oxidative stress, the bivalve Cerastoderma edule was used to evaluate the response of MTs in both situations. Cadmium, a widely reported MT inducer, was used to simulate metal contamination whereas H2O2, an oxidizing compound, was used to simulate oxidative stress. In the first approach, cockles were exposed to a range of Cd and H2O2 concentrations and MTs and TBARS were quantified. Results showed that both treatments induced MT synthesis, confirming the involvement of MTs in metal contamination and oxidative stress. Indeed, the use of MTs as biomarkers for metal pollution was questioned due to the similar synthesis of MT in the two highest concentration used. At last, one concentration of Cd (10 μM) and of H2O2 (20 μM) were selected and cockles were exposed again. TBARS concentration and the intracellular amount of H2O2 were determined. Metal-MT complexes in the two conditions and control were isolated by size exclusion chromatography, and the binding of Zn and Cd to MTs and other cytosolic proteins was evaluated. Furthermore, MTs were quantified and their content in each treatment and control was compared to the amount of Zn associated to them. Results showed that the >H2O2 treatment induced high levels of oxidative stress, demonstrated by the high lipid peroxidation and intracellular concentration of H2O2. Data also indicated that Cd was mainly associated with MTs pool in the Cd treatment, confirming that the protective role of MTs in metal contamination in this bivalve species was due to the binding of MTs to Cd ions. Additionally, the percentage of Zn bound to MTs decreased in the H2O2 treatment, indicating Zn release in oxidative stress. Also, MTs molecules were not as metalated as in the control, confirming Zn release from MTs in oxidative stress and indicating that MTs were needed for demands other than Zn distribution. Further studies on the redox status of MTs are needed to determine the redox status of MTs in the oxidative stress, and understand if, in this bivalve, MTs are acting as ROS scavengers.
Os papéis geralmente associados às metalotioninas (MTs) resumem-se á desintoxicação de metais tóxicos e à regulação do metabolismo dos metais essenciais. No entanto, existem evidências cada vez mais acentuadas de que as MTs atuam na proteção contra o stresse oxidativo. Apesar do grande número de estudos que se focam na actividade antioxidante das MTs, o papel fisiológico efetivo destas proteínas não foi ainda clarificado. A fim de compreender o papel das MTs no stress oxidativo e na proteção contra o efeito dos metais, o bivalve Cerastoderma edule foi selecionado neste estudo para avaliar a resposta das MTs em ambas as situações. O cádmio, um forte indutor das MTs foi usado para causar contaminação metálica enquanto o H2O2, sendo um composto oxidante, foi usado para provocar stresse oxidativo. Numa primeira abordagem, os berbigões foram expostos a uma gama de concentrações de Cd e H2O2 e as MTs e os TBARS foram quantificados. Os resultados mostraram que apenas o H2O2 provocou peroxidação lipídica no berbigão e que ambos os tratamentos induziram a síntese de MTs, confirmando o envolvimento destas na contaminação metálica e no stresse oxidativo. De facto, a utilização das MTs como biomarcadores de poluição metálica foi neste estudo questionada devido á síntese de quantidades semelhantes de MTs nas duas concentrações mais elevadas de Cd e H2O2. Numa segunda abordagem, os berbigões foram novamente expostos a uma concentração selecionada para cada tratamento (10 μM de Cd e 20 μM de H2O2). A concentração dos TBARS e a quantidade intracelular de H2O2 foram determinados. Os complexos metal-MT em ambas as condições e no controlo foram isolados por cromatografia de exclusão molecular e a ligação entre os iões de Zn e Cd e as MTs e outras proteínas citosólicas foi avaliada. Para além disso, As MTs foram quantificadas em cada tratamento e no controlo, sendo o seu conteúdo comparado com a quantidade de Zn ligado. Os dados indicaram que o tratamento com H2O2 induziu elevados níveis de stresse oxidativo, demonstrado pela elevada peroxidação lipídica e pela grande concentração intracelular de H2O2. Relativamente aos resultados da cromatografia, os iões de Cd estavam principalmente ligados às MTs no tratamento com Cd, confirmando o efeito protector das MTs na contaminação metálica nesta espécie de bivalve. Adicionalmente, a percentagem de Zn ligado às MTs diminuiu no tratamento com H2O2, indicando que o stresse oxidativo impõe a libertação de Zn por parte das MTs. Em jeito de confirmação, as MTs estavam menos metaladas no tratamento com H2O2 do que no controlo. Seriam necessários estudos complementares para perceber se neste bivalve as MTs actuam como eliminadoras de ROS.
Tegazzini, Diana. „Design, synthesis and activity evaluation of antioxidant peptides“. Thesis, Queen's University Belfast, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603073.
Der volle Inhalt der QuelleKeceli, Turkan. „Antioxidant and antimicrobial activity of olive oil phenolics“. Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325073.
Der volle Inhalt der QuelleQuartley, Benjamin J. P. „The antioxidant activity of green tea in vivo“. Thesis, University of Surrey, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308646.
Der volle Inhalt der QuelleMohamed, Amal. „Antioxidant activity of flaxseed proteins and their hydrolysates“. Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119689.
Der volle Inhalt der QuelleCertaines composantes des graines de lin sont reconnues pour avoir des effets antioxydants. L'objectif du projet de recherche ci-présent est d'étudier les effets antioxydants des protéines des graines de lin et de leurs hydrolysâtes. Les protéines et leurs hydrolysâtes ont été préparé à partir de graines de lin dégraissées ou natures et démucilaginées, avec et sans dialyse. Leurs effets antioxydants ont été examinés avec le test de scannage DPPH, le test du pouvoir de réduction, et le test des ions métalliques chélates. Le degré d'hydrolyse (DH) des protéines était plus élevé avec l'utilisation d'une protéase bactériale qu'avec l'utilisation de trypsine. En utilisant la protéase bactériale, un DH plus élevé a été observé avec les graines démucilaginées et dégraissées avec dialyse/protéine (DDFPD, 30% DH), les graines dégraissées avec dialyse/protéine (DFPD, 28% DH), et les graines nature avec dialyse/protéines (14% DH), comparé aux graines protéine/sans dialyse qui ont eu comme résultat DDFPND 28%, DFPND 25% DH, et NDFPND avec 12% DH. Les protéines et leurs hydrolysâtes du traitement avec dialyse ont montré qu'il y avait bel et bien un effet antioxydant. Les hydrolysâtes, du test DDFPD et de l'utilisation du protéase bactériale, ont montré un niveau d'activité de radicaux libres plus élevé (DPPH 73.23%) ainsi qu'un pouvoir de réduction de (0.15) à une concentration de 2.5 mg/ml, de même qu'une habilité au Fe2+ de 75% à la concentration de 1mg/ml. Les résultats de SDS-PAGE et PAGE-original des échantillons non hydrolysés montrent qu'il n'y a aucun changement dans le comportement électrophorétique résultant du traitement: une bande majeure qui correspond au MW 48 KDa et trois bandes mineures avec un MW de 16, 23, et 34 KDa. Dans les échantillons d'hydrolysâtes SDS-PAGE du DDFPNDH et les hydrolysâtes du NDFPNDH obtenus en utilisant la trypsine ont montré une bande résistante.
Johnson, Michelle E., W. Andrew Clark, S. E. Dahlman, W. D. Elrod und C. M. Stanage. „Betalain in Beets Enhance Antioxidant Activity in Hummus“. Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etsu-works/2515.
Der volle Inhalt der QuelleLiu, Zheng-Xian. „Antioxidant activity of Mn-salophen complex and its effects on antioxidant enzymes in Escherichia coli“. Diss., Virginia Tech, 1994. http://hdl.handle.net/10919/40046.
Der volle Inhalt der QuellePh. D.
Niero, Giovanni. „Development of analytical methods for phenotypic characterization of antioxidant compounds and antioxidant activity of milk“. Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3427152.
Der volle Inhalt der QuelleI radicali liberi sono molecole reattive e instabili, con uno o più elettroni spaiati nell'orbitale esterno, con possibili effetti negative a livello di cellule vegetali e animali. In particolare, i radicali liberi sono responsabili della perossidazione dei lipidi, dell'ossidazione delle proteine e del danneggiamento del DNS, che causa un aumento del rischio di mutazioni. Gli antiossidanti rappresentano un'importante difesa contro questi danni. Gli alimenti di origine vegetale sono noti come risorse primarie di antiossidanti, come i fenoli, gli antociani, i tocoferoli, i carotenoidi, i precursori del retinolo e l'ascorbato. In questo contesto, gli scopi della presente tesi di dottorato sono: i) lo sviluppo e la validazione di metodi analitici per la quantificazione dei tocoferoli, dei tioli e della capacità antiossidante totale nel latte; ii) la descrizione della variazione fenotipica dei tioli in vacche da latte e a duplice attitudine; iii) la descrizione della variabilità della capacità antiossidante totale (TAA) nel latte di vacca, di bufala, pecora e capra; iv) la valutazione della capacità del medio infrarosso nella predizione della TAA del latte vaccino; v) la valutazione dell'effetto della scrematura e del trattamento al calore sulla concentrazione in tocoferoli e sulla TAA.
Singh, Prabhjot. „Antioxidant activity of food proteins and food protein hydrolysates“. Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104895.
Der volle Inhalt der QuelleLe but principal de cette recherche constituait l'analyse du potentiel antioxydant, à diverses concentrations, d'hydrolysats de protéine de soya (HPS) et d'hydrolysats de protéine de pois chiche (HPP). Les hydrolysats de protéine ont été isolés à l'aide de l'enzyme protéolytique trypsine. Les HPS et HPP démontraient respectivement un potentiel antioxydant de 16.5 à 32% et 3.4 à 26.8 % lorsque présents à des concentrations de 2.5 à 10 mg/mL. L'utilisation d'une colonne C18 a permis de séparer, par CLHP-PI, les HPS et HPP en quatre fractions (F I, F II, F III, et F IV) qui furent dosées avec du DPPH (1,1-diphényl-2-picrylhydrazyle) afin de comparer leur pouvoir de scavenging sur les radicaux. Pour les HPS, le potentiel antioxydant de F III (47.7 %) était supérieur à celui des autres échantillons alors que pour les HPP, 27.9 % (F II) était le seuil maximal. Dans les deux cas, les hydrolysats étaient concentrés à 1mg/mL. L'hydrolyse des échantillons de protéine a été confirmée par SDS-page. La deuxième partie de l'étude visait à mesurer l'impact de la pascalisation sur le degré d'hydrolyse et le potentiel antioxydant des protéines. Des isolats de protéine de soya (IPS) et de protéine de pois chiche (IPP) ont été traités à haute pression (400 MPa et 600 MPa) pendant 5 et 10 min. Le degré d'hydrolyse des IPS et IPP soumis à la pascalisation et à la trypsin ont démontré une augmentation constante allant de 12.4 à 24.9 % pour les isolats de protéine de soya et de 13.6 à 26.2 % pour les isolats de protéine de pois chiche. L'analyse au DPPH du pouvoir d'épuration des radicaux a montré que le potentiel antioxydant des hydrolysats a plus que doublé, passant de 32 à 67 % pour les HPS et de 26.8 à 56.6 % pour les HPP, lorsqu'ils étaient traités par hautes pressions. Cela démontre que la pascalisation améliore le degré d'hydrolyse et le potentiel antioxydant des hydrolysats de protéines.
Juan-Badaturuge, Malindra. „Antioxidant activity and phytochemical evaluations of selected medicinal plants“. Thesis, University of Greenwich, 2010. http://gala.gre.ac.uk/8098/.
Der volle Inhalt der QuelleTsang, Catherine. „Antioxidant activity, protective effects and absorption of polyphenolic compounds“. Thesis, University of Glasgow, 2004. http://theses.gla.ac.uk/1560/.
Der volle Inhalt der QuelleKasase, Chitundu. „Antihypertensive and antioxidant activity of peptides derived from fish“. Thesis, University of Surrey, 2009. http://epubs.surrey.ac.uk/844585/.
Der volle Inhalt der QuelleCHIH, TSAI CHIA, und 蔡嘉芝. „The stability and antioxidant activity of purple napiergrass anthocyanin“. Thesis, 2004. http://ndltd.ncl.edu.tw/handle/86814606679204020825.
Der volle Inhalt der Quelle國立屏東科技大學
食品科學系
92
The purple variety of napiergrass (Pennisetum purpureum), with the common name of “medicine sugarcane”, possesses higher antioxidant capacity, which was accredited to its anthocyanin contents. At present, there are no related researches available in Taiwan regarding purple Napiergrass. This research was aimed to study the characteristics and processing stability of this anthocyanin. Since sucrose and vitamin C were reasoned to affect the stability of this pigment, a model system was used to investigate the changes of color quality, patterns of anthocyanin and antioxidant capacity as being heated under different sucrose or vitamin C concentration. The results showed that there were five kinds of anthocyanin with possible acyl groups in the purple napiergrass. Preservation at 5℃ revealed that pH 1 and 2 were the most stable environments for the pigment, whereas pH 2 exhibited the best heat stability after being heat treated at 90℃ for 12 hours. Heating the pH 3 model system at 90℃ showed that appropriate concentrations of sucrose and vitamin C facilitated the hyperchromic effects, which could favor the heat stability of pigment. The best pigment retention was found with vitamin C of 4 mg/100 ml which prolonged for 12 hours. The conservation durations of anthocyanin were shortened with increasing amounts of sucrose addition. 20% of sucrose accompanied with by 4 mg/100 ml of vitamin C would reinforce the anthocyanin retention. Monomeric ACN increased before heating but polymeric ACN enhanced after heating, with the presence of sucrose or vitamin C. Monomeric ACN was found being highest for concurrent additions of 20% sucrose and 4 mg/100 ml of vitamin C, yet the addition of either one would promote the formation of monomeric ACN. Correlation analysis revealed a significantly negative correlation (-0.99) between the degradation index (DI) and monomeric ACN, which implied the preservation ability of pigment by monomeric ACN. As to the antioxidant capacity of the anthocyanins extract of purple napiergrass, the DPPH scavenging ability before heating presented no significant differences regardless of treatments, yet both the FRAP reducing power and TEAC total antioxidant capacity rapidly increased after heating with sucrose additions. FRAP reducing power augmented by two folds with sucrose alone or accompanied by vitamin C after being heated for 24 hours. Vitamin C alone in contrast reduced the antioxidant capacity during heating. The correlation coefficient between FRAP reducing power and monomeric ACN was determined to be 0.95 before heating. Heating the solutions with the presence of sucrose resulted in the large enhancement of FRAP yet decreasing monomeric ACN. It was hypothesized as the effect of sucrose browning reaction. The proof of existence for ascorbic acid-anthocyanin complex could not be deduced. The intensification of maximum absorption peaks for anthocyanin with various metal ions could be attributed to the copigmentation effects. The formation and the optimum environments for sustaining the complex would need to be investigated further.
Turner, Martha Kathleen. „Anthocyanins increase antioxidant enzyme activity in HT-29 adenocarcinoma cells“. 2009. http://purl.galileo.usg.edu/uga%5Fetd/turner%5Fmartha%5Fk%5F200908%5Fms.
Der volle Inhalt der QuellePiakong, Nur Azidah Binti, und Nur Azidah Binti Piakong. „Effects of Processing and Storage on Color, Total Phenolics, Total Anthocyanin, Total Carotenoid and Antioxidant Activity of Some Tropical Fruit Jams“. Thesis, 2016. http://ndltd.ncl.edu.tw/handle/g46c8s.
Der volle Inhalt der Quelle國立宜蘭大學
園藝學系碩士班
104
Recently, there has been an increased interest in plant pigment and phenolic compounds of fruits, due to their antioxidant capacity. Other than that, as consumers are more wary of the usage of synthetic colour additives in food products, researchers are looking into the potential use of natural pigments such as anthocyanin, and also the methods to better retain this beneficial pigments. Thermal processing is the main method used in jam making, therefore the impact of this process on the bioactive compounds is important in order to assess the antioxidant capacity and colour quality changes over processing and storage of food product. The first part of this study aimed to determine the effect of processing and storage on colour, total phenolics, anthocyanin, carotenoid and antioxidant capacity of various fruit jams viz. passion fruit, kumquat, pineapple and dried roselle. While the second part of this study is to evaluate the effect of processing and storage of mix pineapple and roselle jams on their color, total phenolics, anthocyanin, carotenoid and antioxidant capacities. Roselle was added into pineapple pulp as a natural acidifier in order to meet the gelatinization requirement of pectin and increase antioxidative effect. The results of present study showed that jam processing caused significant changes in bioactive compounds of fruits, as well as their antioxidant capacity and colour properties. Long term storage of kumquat and roselle jam caused significant changes in total phenolics, total anthocyanin, total carotenoid and DPPH radical scavenging activity. While only significant reduction of total anthocyanin was found in passion fruit jam after storage. In addition, total phenolics, total anthocyanins and antioxidant capacity of pineapple showed significant reduction after 5 months of storage at room temperature. The addition of roselle pulp into pineapple jam increased the total anthocyanin compounds, when compared to only single pineapple jam. Total anthocyanins reduced significantly in all mix jam samples. In comparison of bioactive compound retention in different jam pH, pH 3.0 of pineapple and roselle mix jam was able to retain the highest percentage of total anthocyanin, total carotenoid and antioxidant capacity. It can also be observed that after storage in room temperature for 5 months, the presence of brown pigments increased as a result of anthocyanin degradation. Fruit jams also lost their bright colour. Despite the reduction in valuable bioactive compounds, jam processing is able to retain them during storage.
Liu, Wei-Ting, und 劉威廷. „Antioxidant activity and rat C6 nerve cell cytoprotection ability of anthocyanins from mulberry juice“. Thesis, 2010. http://ndltd.ncl.edu.tw/handle/58713513576655118252.
Der volle Inhalt der Quelle臺灣大學
食品科技研究所
98
This study investigated the cytoprotection effect of mulberry juice (MJ) anthothyanin on neuronal glial cell. The results showed that freeze dried mulberry juice powder (MJP) contained 19 mg /g anthocyanin. After purified with solid phase extraction device, anthocyanin content in freeze dried anthocyanin extract from mulberry juice (AEMJ) increased to 243 mg/g. The HPLC analysis revealed that cyanindin-3-glucoside and cyanidin-3-rutinoside are the major anthocyanin in AEMJ. The results of in vitro antioxidant test revealed that the DPPH free radical scavenging ability of MJP achieved to 81% at a concentration of 4 mg/ml. The DPPH free radical scavenging ability of 1 mg/ml AEMJ achieved to 90%, higher than that of catechin at the same concentration. The reducing power of MJP increased with the treated concentration. The absorption value was about 1.58 with the treated concentration of 2 mg/ml. The reducing power of AEMJ, similar to catechin, achieved to 2 at a concentration of 0.25 mg/ml. The rat glial tumor C6 cell was used for investigating the cytoprotection ability of MJP or AEMJ under hypoxia condition induced with Na2S2O4. The cell viability was 60.98 % for hypoxia rat glial tumor C6 cell control group at Na2S2O4 concentration of 5 mM. The cell viability of hypoxia C6 cells was 89.74% when pre-incubated with MJP contains 25 μg /ml anthocyanin. The cell viability of hypoxia C6 cells was 92.21% when pre-incubated with AEMJ contains 50 μg /ml anthocyanin. The intercellular antioxidant glutathione of hypoxia C6 cells increased, however, the superoxide dismutase activity of hypoxia C6 cells decreased, when pre-cultured with AEMJ. The results indicated that both MJP and AEMJ possess cytoprotection ability on hypoxia rat C6 glial cells.
Nehybová, Monika. „Antioxidační aktivita plodů různých kultivarů Sambucus nigra L“. Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-340542.
Der volle Inhalt der QuelleHambira, Chipo. „Proanthocyanidins, anthocyanins and phenolic acids in food barleys of diverse origin“. 2010. http://hdl.handle.net/1993/3841.
Der volle Inhalt der QuelleYu, Lilei. „Identification and Antioxidant Properties of Phenolic Compounds during Production of Bread from Purple Wheat Grains and Investigation of Bread Extracts after Simulated Gastrointestinal Digestion“. 2014. http://hdl.handle.net/1993/24316.
Der volle Inhalt der QuelleSrivastava, Anita. „Effect of storage conditions on phenolic compounds and antioxidant activity of blueberry extract and the effect of anthocyanins from selected cultivars of Georgia-grown blueberries on apoptosis and phase-ii enzymes“. 2006. http://purl.galileo.usg.edu/uga%5Fetd/srivastava%5Fanita%5F200612%5Fms.
Der volle Inhalt der Quelle