Introdução: O café é a segunda bebida mais consumida do mundo. O grão de café é uma das mais importantes \"commodities\" alimentares, sendo o principal produto de exportação agrícola. A produção mundial de café na safra 2016-2017 alcançou 153,869 milhões de sacas de 60 quilos. A bebida de café é consumida sob diversos métodos e preparações e a adição de açúcar e/ou leite são as mais comuns. O crescente consumo de cápsula de café expresso vem ganhando os lares da população brasileira com aumento de 29 % de 2010 a 2015, com estimativa de crescimento na ordem de 18 % de 2015 até 2020. A busca por diferentes tipos de café está relacionada com os efeitos sensoriais que o café pode exercer para os humanos. Entretanto, o café é considerado uma bebida bioativa com efeito antioxidante que atua como anticancerígeno, anti-obesidade, antidiabético, anti-hipertensivo e hepatoprotetor. Deste modo faz-se necessário avaliar a atividade antioxidante das cápsulas de café expresso de acordo com sua intensidade (torra) e avaliar o efeito da adição de ingrediente sobre os compostos fenólicos, a atividade antioxidante e sua bioacessibilidade. Objetivo: Avaliar o efeito de diferentes intensidades de torra e da adição de ingrediente sobre os compostos fenólicos e a atividade antioxidante das cápsulas de café expresso e sua bioacessibilidade. Material e Métodos: O presente projeto foi dividido em dois ensaios. O primeiro ensaio contou com quatorze cápsulas comerciais de café expresso, sendo treze tradicionais e uma descafeinada. O segundo ensaio contou com três cápsulas, sendo duas tradicionais e uma descafeinada. Todas foram adquiridas em estabelecimentos comerciais da cidade de São Paulo. No primeiro ensaio as bebidas foram preparadas como descrito na embalagem usando uma cafeteira doméstica e água. No segundo ensaio, às bebidas (preparadas de acordo ao primeiro ensaio), foram adicionados 40 mL leite e/ou 5 g de açúcar. A atividade antioxidante foi investigada pelo ensaio de eliminação de radicais ABTS, pela capacidade de absorção de radicais peroxila de oxigênio pelo (ORAC) e a capacidade de eliminação de radicais DPPH. O teor total de fenólicos foi determinado pelo método de Folin-Ciocalteau, as melanoidinas foram avaliadas pela absorbância a 420 nm e a digestão in vitro foi realizada por hidrólise assistida por enzimas digestivas. O perfil fenólico foi avaliado por CLAE/DAD. A capacidade de inibição da peroxidação lipídica foi determinada pela medição de substâncias reativas ao ácido tiobarbitúrico (TBARS). Resultados: No primeiro ensaio, todas as bebidas de café em cápsula apresentaram atividade antioxidante de acordo os métodos ORAC, DPPH e ABTS, variando de acordo a intensidade (torra) de cada cápsula. O teor de fenólicos variou de 191,41 a 374,36 mg equivalentes de ácido clorogênico/dose de café e as melanoidinas variaram entre 0,197 nm e 0,372 nm. No segundo ensaio, os fenólicos totais variaram de 129,40 a 541,81 mg equivalentes de ácido clorogênico/dose nas bebidas digeridas e não digeridas, respectivamente. A atividade antioxidante foi maior nas bebidas com adição de leite. O teor total de fenólicos foi maior nas amostras não digeridas. O perfil fenólico encontrado nas amostras não digeridas e digeridas, foi cafeína, ácido clorogênico, ácido cafeico, ácido p-cumárico e ácido ferúlico. Após a digestão in vitro, os ácidos fenólicos e a cafeína estavam mais bioacessíveis nas bebidas de café com adição leite e com leite e açúcar em comparação com as bebidas de café puras. As bebidas não digeridas apresentaram menor produção de TBARS em relação àquelas digeridas. Conclusão: Todas bebidas de café expresso em cápsulas estudadas apresentaram atividade antioxidante. A maior intensidade da torra pode influenciar a quantidade de fenólicos totais e atividade antioxidante. O conteúdo de ácidos fenólicos e cafeína e a atividade antioxidante das bebidas dependem dos ingredientes adicionado à preparação. Os compostos são mais bioacessíveis em bebidas com leite com açúcar e com leite, em comparação com bebidas puras. Os resultados sugerem que existem interações entre ácidos fenólicos e componentes do leite por meio de interação hidrofóbicas e/ou hidrofílicas que afetam a biodisponibilidade de ambos. / Introduction: Coffee is the second most consumed drink in the world. Coffee beans are one of the most important food \"commodities\" being the main agricultural export product. World coffee production in the 2016-2017 harvest reached 153,869 million bags of 60 kilos. The coffee drink is consumed of several methods and preparations, the addition of sugar and / or milk is the most common. The increasing consumption of espresso capsules has been gaining the homes of the Brazilian population with a 29% increase from 2010 to 2015, with an estimated growth of around 18% from 2015 to 2020. The search for different types of coffee is related to the sensory effects that coffee can exert on humans. However, coffee is considered a bioactive beverage with antioxidant effect that acts as anticancer, anti-obesity, antidiabetic, antihypertensive and hepatoprotective Thus, it is necessary to evaluate the antioxidant activity of the espresso capsules according to their intensity (roast) and to evaluate the effect of the addition of the ingredient on the phenolic compounds, the antioxidant activity and its bioacessibilide. Objective: To evaluate the effect of different roast intensities and the addition of the ingredient on the phenolic compounds and the antioxidant activity of the espresso capsules and its bioaccessibility. Material and Methods: The present project was divided into two trials. The first trial included: Fourteen commercial espresso capsules, thirteen traditional and one decaffeinated. The second trial had three capsules, two traditional and one decaffeinated. Both were purchased at food stores in the city of São Paulo. In the first assay the beverages were prepared as described on the package using a domestic kettle and water. In the second assay, the beverages were prepared according to the first test, but 40 ml of milk and / or 5 g of sugar. The antioxidant activity was investigated by the ABTS radical scavenging assay, oxygen radical scavenging ability (ORAC) and the DPPH radical scavenging ability. The total phenolic content was determined by the Folin-Ciocalteau method, as melanoidins were evaluated for absorbance at 420 nm and an in vitro digestion was performed by digestive enzyme assisted hydrolysis. The phenolic profile was evaluated by HPLC / DAD. Lipid peroxidation was determined by the action of thiobarbituric acid reactive substances (TBARS). Results: In the first trial, all capsule coffee beverages presented antioxidant activity according to the ORAC, DPPH and ABTS methods, varying according to the intensity (roast) of each capsule. The phenolic range ranged from 191.41 to 374.36 mg of chlorogenic acid equivalent / mL of coffee and the melanoidins ranged from 0.197 nm to 0.372 nm. In the second assay, total phenolics ranged from 129.40 to 541.81 mg equivalents of chlorogenic acid / dose in the digested and undigested beverages, respectively. The antioxidant activity was higher in beverages with milk addition. The total phenolic content was higher in the undigested samples. The phenolic profile found in the undigested and digested samples was caffeine, chlorogenic acid, caffeic acid, p-coumaric acid and ferulic acid. After in vitro digestion, phenolic acids and caffeine were more bioaccessible in coffee drinks with added milk and with milk and sugar compared to pure coffee beverage. Undigested beverages presented lower TBARS production in relation to those digested. Conclusions: All espresso drinks in capsules studied have antioxidant activity. The intensity can influence the amount of total phenolics and antioxidant activity. The content of phenolic acids and caffeine and the antioxidant activity of the beverages depend on the ingredients added to the preparation. The compounds are more bioavailable in milk and sugar milk beverages compared to pure beverages. The results suggest that there are interactions between phenolic acids and milk components through hydrophobic and / or hydrophilic interaction that affects the bioavailability of both.

No presente trabalho foi avaliada a capacidade antioxidante in vitro dos extratos do cotilédone da semente de girassol rajada, obtidos por extração seqüencial com solventes de diferentes polaridades, bem como avaliado o potencial antioxidante in vitro do extrato que apresentou maior capacidade in vitro. Todos os parâmetros in vitro (sistema β-caroteno/ácido Iinoléico, métodos FRAP, DPPH, ORAC e Rancimat) indicaram o extrato aquoso (EAq) como o de maior capacidade. Neste extrato, o ácido clorogênico (12,88%) foi identificado como o principal componente dos ácidos fenólicos. Na avaliação da capacidade antioxidante in vitro, ambas as determinações empregadas (TBARS e perfil de ácidos graxos) indicaram o EAq como capaz de exercer um efeito protetor sobre os ácidos graxos poliinsaturados dos tecidos adiposo, cerebral, hepático e plasmático de ratos Wistar machos recém-desmamados. / The aims of this work were to evaluate the in vitro antioxidant capacity of listed sunflower cotyledon extracts, obtained by a sequential extraction with solvents of different polarities, and to evaluate the in vitro antioxidant potential of the sample extract with highest in vitro capacity. Ali the in vitro parameters (β-carotene/linoleic acid system, FRAP, OPPH, ORAC and Rancimat methods) indicated the aqueous extract (EAq) as the extract with highest capacity. In this extract, the chlorogenic acid (12.88%) was identified as the principal fraction of phenolic acids. In the in vitro antioxidant capacity evaluation, both determinations used (TBARS and fatty acids profile) gave indication that the EAq was capable to exerce a protective effect on the polyunsaturated fatty acids of the adipose, cerebral, hepatic and plasm tissues of Wistar male rats just-weaned.

Orientador: Adriana Zerlotti Mercadante / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-18T21:40:04Z (GMT). No. of bitstreams: 1 Chiste_RenanCampos_D.pdf: 8233764 bytes, checksum: 20989b604d256eba3bcdcfda79445208 (MD5) Previous issue date: 2011 / Resumo: Os compostos bioativos presentes no reino vegetal 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, tais como câncer, inflamações, doenças cardiovasculares, catarata, degeneração macular e outras, sendo os carotenóides e compostos fenólicos alguns dos grupos de compostos bioativos aos quais são atribuídas tais ações. As sementes e os extratos de urucum (Bixa orellana L.) são utilizados como corantes nas indústrias alimentícias, farmacêutica e de cosméticos, devido à presença majoritária do carotenóide bixina. Até então, não havia sido relatada na literatura a composição de compostos fenólicos das sementes de urucum. Dessa forma, foi desenvolvido e validado um método por cromatografia líquida de alta eficiência acoplada aos detectores de arranjo de diodos e espectrômetro de massas (HPLC-DAD-MS/MS) para separar, identificar e quantificar bixina e os compostos fenólicos em semente de urucum. Adicionalmente, foi otimizado um procedimento de extração simultânea desses compostos através da metodologia de superfície de resposta. Além de bixina, conhecida por ser o principal carotenóide em sementes de urucum, a hipolaetina e um derivado de ácido caféico foram identificados, pela primeira vez, como os principais compostos fenólicos. O procedimento otimizado envolveu 15 extrações com acetona:metanol:água (50:40:10, v/v/v) como solvente, razão sólido-líquido de 1:9 (m/v) e 5 min para cada extração em ultrassom. O método cromatográfico proposto foi validado com sucesso para a análise simultânea de compostos fenólicos e bixina em sementes de urucum. Extratos líquidos de urucum com elevada capacidade antioxidante e potencial de cor foram obtidos a partir da extração de bixina e de compostos fenólicos de sementes de urucum utilizando solventes com diferentes polaridades (água, etanol:água, etanol, etanol:acetato de etila e acetato de etila). Os valores mais elevados de compostos fenólicos totais foram encontrados nos extratos obtidos com água, etanol:água e etanol (0,5 mg equivalentes de ácido gálico/mL), e o valor mais elevado de bixina foi encontrado no extrato obtido com etanol:acetato de etila (5,2 mg/mL), que foi caracterizado como o mais vermelho e o mais vívido (a* = 40,5, h°=46,1, C* = 58,4). O extrato obtido com etanol:acetato de etila também apresentou a maior atividade anti-radical livre (4,7 umol equivalente Trolox/mL) e a maior porcentagem de proteção ao triptofano contra o oxigênio singlete (63,6 %). Por outro lado, acetato de etila e a mistura etanol:água foram os solventes menos eficazes para a extração de compostos fenólicos e bixina, respectivamente. De acordo com a análise estatística multivariada, etanol:acetato de etila e acetato de etila foram os solventes mais promissores para obtenção de extratos de urucum com ambas as propriedades antioxidantes e de cor. A partir da extração com diferentes solventes (água, etanol:água, etanol, etanol:acetato de etila e acetato de etila), foram também obtidos extratos liofilizados de urucum, e a capacidade antioxidante na desativação de diferentes espécies reativas de oxigênio (ROS) e de nitrogênio (RNS) foi avaliada. Além disso, os teores de compostos fenólicos e de bixina dos extratos de urucum foram determinados por HPLC-DAD. Todos os extratos de urucum foram capazes de desativar todas as espécies reativas testadas (peróxido de hidrogênio, ácido hipocloroso, oxigênio singlete, radical óxido nítrico, ânion peroxinitrito e radical peroxila), em baixas concentrações na faixa de ?g/mL, com exceção do radical superóxido. O extratos de sementes de urucum obtidos com etanol:acetato de etila e acetato de etila, que apresentaram os maiores níveis de hipolaetina e bixina, respectivamente, foram os extratos com a maior capacidade antioxidante. Adicionalmente, o padrão de bixina apresentou os menores valores de IC50 na desativação de todas as ROS e RNS testadas. O piquiá (Caryocar villosum (Aubl.) Pers), fruta nativa da região Amazônica, pode ser considerado uma fonte inexplorada de compostos bioativos, uma vez que poucos estudos sobre seus constituintes químicos e fitoquímicos estão disponíveis. Dessa forma, a composição química e fitoquímica da polpa de piquiá foi determinada, incluindo a composição de carotenóides e de compostos fenólicos por HPLC-DAD-MS/MS. De acordo com a composição nutricional, água (52 %) e lipídios (25 %) foram os principais componentes encontrados na polpa e o valor energético total foi 291 kcal/100 g. Sobre os compostos bioativos, a polpa apresentou (base seca) maior teor de compostos fenólicos (236 mg equivalentes de ácido gálico/100 g), flavonóides totais (67 mg equivalentes de catequina/100 g) e taninos totais (60 mg equivalentes de ácido tânico/100 g) em relação ao teor de carotenóides totais (7 mg/100 g) e alfa-tocoferol (1 mg/100 g). Os principais compostos fenólicos identificados por HPLC-DAD-MS/MS, foram ácido gálico (182 ug/g polpa), seguido por ácido elágico ramnosídeo (107 ug/g polpa) e ácido elágico (104 ug/g polpa). Os principais carotenóides identificados foram all-trans-anteraxantina (3 ug/g), all-trans-zeaxantina (3 ug/g), all-trans-neoxantina (2 ug/g), all-trans-violaxantina (1 ug/g) e all-trans-?-caroteno (0,7 ug/g). A capacidade anti-radical livre da polpa (3,7 mmol equivalente Trolox/100 g) indica que a polpa pode ser considerada um eficiente sequestrador do radical peroxila. Foram obtidos também extratos liofilizados de polpa de piquiá a partir da extração com diferentes solventes (água, etanol:água, etanol, etanol:acetato de etila e acetato de etila). Todos os extratos naturais foram caracterizados em relação ao teor de compostos bioativos (compostos fenólicos totais, flavonóides, taninos, carotenóides e tocoferóis). Além disso, a capacidade de desativação do radical peroxila, assim como a porcentagem de proteção contra o oxigênio singlete foi determinada para todos os extratos. Os extratos obtidos com água e a mistura etanol:água apresentaram os maiores teores (base seca) de compostos fenólicos totais (9,2 e 6,3 mg de equivalentes de ácido gálico/g, respectivamente), flavonóides totais (3,8 e 2,5 mg equivalente de catequina/g, respectivamente) e taninos totais (7,6 e 2,4 mg de ácido tânico/g, respectivamente). O extrato obtido com etanol:água também apresentou a maior capacidade de desativação do radical peroxila (ORAC) (0,3 mmol equivalente Trolox/g extrato). Por outro lado, o extrato obtido com etanol, que foi classificado como o de cor mais vívida e amarelo (C*ab = 13,7 e b* = 13,3), apresentou o maior teor de carotenóides totais (0,1 mg/g) e maior percentual de proteção contra o oxigênio singlete (10,6 %). Com base nos resultados deste estudo, etanol:água, água e etanol são os solventes mais promissores para obtenção de extratos de piquiá com alto teor de compostos bioativos, proteção contra o oxigênio singlete e capacidade sequestradora do radical peroxila. Portanto, tais informações são importantes para as indústrias alimentícia, cosmética e farmacêutica, sabendo que o piquiá e o urucum são fontes naturais acessíveis de compostos bioativos para serem usados como potencial matéria-prima para obtenção de extratos contra os danos oxidativos em alimentos ou sistemas biológicos / Abstract: The bioactive compounds found in the plant kingdom have important biological functions and actions and may be considered human health promoters. The association between the intake of fruits and vegetables and the decreased risk of developing several chronic-degenerative disorders is already recognized, being the carotenoids and phenolic compounds, groups of the bioactive compounds responsible for such actions. The annatto (Bixa orellana L.) seeds and extracts are used as colourant in the food, pharmaceutical and cosmetic industries, due to the presence of bixin. As far as we are concerned, no information about the composition of phenolic compounds present in the annatto seeds and extracts was reported. Thus, a method by high performance liquid chromatography coupled to diode array detector and mass spectrometer (HPLC-DAD-MS/MS) was developed and validated for separation, identification and quantification of phenolic compounds and bixin in annatto seeds. Furthermore, using response surface methodology, an optimized procedure for simultaneous extraction of both compound classes was established. In addition to bixin, known to be the main carotenoid in annatto seeds, hypolaetin and a caffeoyl acid derivative were identified as the main phenolic compounds. The optimized procedure involved 15 extractions using acetone:methanol:water (50:40:10, v/v/v) as solvent, a solid¿liquid ratio of 1:9 (w/v) and an extraction time of 5 min per extraction in a sonicator. Validation data indicated that the developed HPLC method is suitable for the simultaneous analysis of phenolic compounds and bixin in annatto seeds. Liquid annatto extracts with high antioxidant capacity and colour potential were obtained from annatto seeds by extraction of phenolic compounds and bixin using solvents with different polarities (water, ethanol:water, ethanol, ethanol:ethyl acetate and ethyl acetate). The highest levels of total phenolic compounds were found in the water, ethanol:water and ethanol extracts (0.5 mg gallic acid equivalent/mL), and the highest level of bixin was found in the ethanol:ethyl acetate extract (5.2 mg/mL), which was characterised as the reddest and the most vivid one (a* = 40.5, h° = 46.1, C* = 58.4). The ethanol:ethyl acetate extract also showed the highest antioxidant activity (4.7 umol Trolox equivalent/mL) and the highest percentage of tryptophan protection against singlet oxygen (63.6 %). On the other hand, ethyl acetate and ethanol:water were the least effective solvents for the extraction of phenolic compounds and bixin, respectively. According to the multivariate statistical analysis, ethanol:ethyl acetate and ethyl acetate were the most promising solvents to obtain annatto extracts with both antioxidant and colour properties. From the extraction with different solvents (water, ethanol:water, ethanol, ethanol:ethyl acetate and ethyl acetate), freeze-dried annatto extracts were also obtained, and the capacities to scavenge reactive oxygen (ROS) and reactive nitrogen (RNS) species were evaluated. In addition, the levels of phenolic compounds and bixin in the annatto extracts were determined by HPLC-DAD. All annatto extracts were able to scavenge all the tested reactive species (hydrogen peroxide, hypochlorous acid, singlet oxygen, nitric oxide radical, peroxynitrite anion and peroxyl radical) at low concentration in the ug/mL range, with the exception of superoxide radical. The ethanol:ethyl acetate and ethyl acetate extracts of annatto seeds, which presented the highest levels of hypolaetin and bixin, respectively, were the extracts with the highest antioxidant capacity, and the bixin standard presented the lowest IC50 values. Piquia (Caryocar villosum (Aubl.) Pers), a native fruit from Amazon region, can be considered an unexploited source of bioactive compounds, since few studies about chemical and phytochemical constituents are available. Thus, the chemical and phytochemical composition of piquia pulp was determinaed, including the composition of carotenoids and phenolic compounds by HPLC-DAD-MS/MS. According to the nutritional composition, water (52 %) and lipids (25 %) were the major components found in the pulp and the total energetic value was 291 Kcal/100 g. Regarding the bioactive compounds, the pulp presented (dry basis) higher content of phenolic compounds (236 mg gallic acid equivalent/100 g), total flavonoids (67 mg catechin equivalent/100 g) and total tannins (60 mg tannic acid equivalent/100 g) than total carotenoids (7 mg/100 g) and alfa-tochopherol (1 mg/100 g). The major phenolic compounds identified by HPLC-DAD-MS/MS were gallic acid (182 ug/g pulp), followed by ellagic acid rhamnoside (107 ug/g pulp) and ellagic acid (104 ug/g pulp). The main carotenoids identified were all-trans-antheraxanthin (3 ug/g), all-trans-zeaxanthin (3 ug/g), all-trans-neoxanthin (2 ug/g), all-trans-violaxanthin (1 ug/g) and all-trans-beta-carotene (0.7 ug/g). The antioxidant capacity of the pulp (3.7 mmol Trolox/100 g) indicates that the pulp can be considered a good peroxyl radical scavenger. Freeze-dried extracts of piquia using five solvents with different polarities (water, ethanol:water, ethanol, ethanol:ethyl acetate and ethyl acetate) were also obtained. All natural extracts were characterised in relation to the contents of bioactive compounds (total phenolic compounds, flavonoids, tannins, carotenoids and tocopherols). In addition, the scavenging capacity of all piquia extracts against peroxyl radical, as well as the quenching capacity against singlet oxygen were determined. All the data were used for classification of the piquia extracts applying multivariate statistical analysis. The water and ethanol:water extracts presented the highest levels of total phenolic compounds (9.2 and 6.3 mg gallic acid equivalent/g, respectively), total flavonoids (3.8 and 2.5 mg catechin equivalent/g, respectively) and total tannins (7.6 and 2.4 mg tannic acid/g, respectively). The ethanol:water extract also showed the highest scavenging capacity against peroxyl radical (ORAC) (0.3 mmol Trolox equivalent/g extract). On the other hand, the ethanol extract, which was classified as the most vivid and yellow one (C*ab = 13.7 and b* = 13.3), presented the highest level of total carotenoids (0.1 mg/g) and highest percentage of protection against singlet oxygen (10.6 %). Based on the results of this study, ethanol:water mixture, water and ethanol are the most promising solvents to obtain piquia extracts with high contents of bioactive compounds, protection against singlet oxygen and peroxyl radical scavenging capacity. Therefore, such informations are important for the food, cosmetic and pharmaceutical industries, since piquia and annatto are natural sources of bioactive compounds available for use as a potential raw material to obtain extracts against oxidative damage in foods or biological systems / Doutorado / Ciência de Alimentos / Doutor em Ciência de Alimentos

Made available in DSpace on 2014-08-20T13:42:09Z (GMT). No. of bitstreams: 1 Dissertacao_Roberta_Oliveira_Santos.pdf: 737750 bytes, checksum: 134e68dec2e207bf399a889e11168e51 (MD5) Previous issue date: 2011-02-16 / The maturation can be characterized as a sequence of changes that occur the last stages of development to the early stages of senescence, resulting in quality characteristics of the fruit. The best stage to harvest peaches depends mainly on the fate that will be given. The mature fruits are given to meet consumer demands, as those intended for storage should be firm to prevent physiological disorders and increase their potential for storage and longer shelf life. Thus the present study was aimed to detect changes that occur during the ripening fruits with emphasis on the synthesis and degradation of bioactive compounds. Were analyzed for this yellow-fleshed peaches of two cultivars: cv. Granada and cv. Diamante, harvested at three ripening stages: green, ripe and overripe. To determine the maturity stages of fruits were evaluated color parameters of skin, firmness, titratable acidity, total acidity and soluble solids. For the functional properties, were assessed the levels of carotenoids, levels of phenolic compounds and antioxidant activity in edible part of fruit. The results showed that peaches harvested at early stages of maturity had higher values of firmness and the greatest amount of phenolics compounds. The fruits harvested more mature showed reduction in the firmness and lower nutritional characteristics. / O amadurecimento, de modo geral, pode ser caracterizado como uma seqüência de mudanças fisiológicas que ocorrem dos últimos estádios de desenvolvimento até as etapas iniciais da senescência, resultando nas características de estética e qualidade do fruto. A escolha do melhor estádio para a colheita de pêssegos dependerá principalmente do destino que lhes será dado. Os frutos mais maduros são os indicados para satisfazer às exigências do consumidor, já os destinados ao armazenamento devem estar firmes para evitar distúrbios fisiológicos e aumentar seu potencial de armazenamento, bem como maior vida de prateleira. Deste modo, o presente trabalho teve por objetivo detectar as mudanças que ocorrem ao longo do amadurecimento das frutas enfatizando a síntese e degradação de compostos bioativos. Para isto foram analisados pêssegos de polpa amarela de duas cultivares: Granada e Diamante, colhidos em três estádios de maturação: verde, maduro e sobremaduro. Para determinação dos estádios de maturação das frutas foram avaliados os parâmetros de cor de casca, firmeza de polpa, acidez potenciometrica, acidez total titulável e sólidos solúveis. Foram avaliados também os teores de carotenóides totais, teores de compostos fenólicos totais e a atividade antioxidante na parte comestível do fruto. Os resultados mostraram que os pêssegos colhidos em estádios menos avançados de maturação apresentaram maiores valores de firmeza de polpa e maior quantidade de compostos fenólicos do que aqueles colhidos mais maduros.

Dans un contexte de réduction des intrants chimiques, l’utilisation des phytosanitaires naturels stimulant l’immunité végétale ouvre la porte vers une nouvelle approche de protection des plantes. Ces composés éliciteurs regroupés sous le terme de «Stimulateurs des Défenses naturelles des Plantes» (SDP) activent le système défensif de la plante la rendant plus résistante aux bio-agresseurs. Les SDP, de nature diverse, se présentent sous forme de composés uniques ou en mélange dans les extraits végétaux. Au cours de ma thèse, nous avons démontré l’activité SDP des extraits de marc de raisin. Les extraits issus de sous-produits de la vigne, marc de raisin rouge, marc de raisin blanc et pépins de raisin induisent diverses réactions de défense au sein de plantes modèles. Nous avons focalisé notre étude sur l’extrait de marc de raisin rouge (EMR) stimulant l’immunité chez le tabac. Infiltré sur feuilles, l’EMR induit la réponse de type HR caractérisée par l’apparition de lésions chlorotiques et accumulation de composés autofluorescents dans les tissus infiltrés. Ces réactions de défense locales ont été observées également chez l’arabette et la tomate. L’EMR déclenche les réponses LAR et SAR avec l’accumulation des transcrits des gènes de défense dans les feuilles de tabac et ce quelque soit son mode d’application (infiltration ou pulvérisation). Le mode d’action de l’EMR a été abordé sur cultures cellulaires de tabac BY-2. L’EMR induit une forte alcalinisation du milieu extracellulaire avec une mobilisation du calcium (Ca2+), l’expression des gènes de défense et la mort cellulaire. Une étude pharmacologique de la mort cellulaire suggère la mise en place de mort cellulaire programmée (PCD) dans les cellules de tabac. La caractérisation de la voie de signalisation activée par l’EMR a été étudiée avec le mutant NahG de tabac incapable d’accumuler l’acide salicylique (SA). Les réponses de défense (HR, LAR et SAR) sont faiblement induites par l’EMR chez le mutant nahG. L’EMR provoque une réponse de type HR fortement réduite avec une faible accumulation des composés autofluorescents et une diminution drastique de l’accumulation des transcrits des gènes PR suggérant l’intervention du SA dans l’induction des réactions de défense. Le degré de protection induit par l’EMR a été déterminé sur le pathosystème tabac/Phytophthora parasitica. Pulvérisé sur feuilles, l’EMR réduit de 45% les zones infectées par l’oomycète. Ce degré de protection semble être le résultat de l’activité antimicrobienne de l’EMR combinée à l’activité SDP. Aucune protection n’a été observée chez le mutant nahG confirmant l’implication de SA dans la résistance induite par l’EMR. Le fractionnement de l’EMR a permis de simplifier la formule active des extraits de raisin et d’identifier un mélange de molécules potentiellement capables d’induire l’activité SDP. Les composés actifs sont de nature polyphénolique et contiennent de la procyanidine B2 capable à elle seule d’induire la réponse de type HR et l’expression de l’antimicrobien PR1. Cependant, il semble que cette molécule agisse en association avec d’autres composés polyphénoliques pour stimuler le système défensif de la plante. / In order to reduce chemical inputs, the use of natural phytosanitary products stimulating plant immunity are emerging approaches in phytoprotection. These elicitor compounds known as "Plant Defense Inducers" (PDI) activate the plant defense system and improve their resistance to pests attack. PDI are single molecule or mixture of compounds extracted from plant. In my thesis, we demonstrated the PDI activity of different grape marc extracts. The winery byproducts, red grape marc extract, white grape marc extract and grape seed extract all induced various defense reactions in several plant models. We focused our study on the red grape marc extract (GME) which stimulates the immunity system in tobacco plants. When infiltrated into tobacco leaves, GME induced HR-like response characterized by the appearance of chlorotic lesions and accumulation of autofluorescent compounds in infiltrated tissues. Similar local defense reactions have been observed in Arabidopsis thaliana and tomato. GME also triggered LAR and SAR responses and induced defense gene transcript accumulation in tobacco leaves after infiltration or spraying. The GME mode of action was studied using the suspension-cultured cells of tobacco BY-2. GME induced rapid alkalinization of extracellular medium with calcium mobilization, expression of defense genes and cell death. A pharmacological approach of this defensive phenomenon suggests the establishment of programmed cell death (PCD) in tobacco cells. The characterization of the signaling pathway activated by GME was studied using tobacco nahG mutant unable to accumulate salicylic acid (SA). Defense responses (HR, LAR and SAR) induced by GME were impaired in the nahG mutant. GME drastically reduced HR-like response symptoms and PR transcript accumulation. These data suggest the implication of SA in the GME-induced plant defense reactions. The GME-induced protection was evaluated in the model pathosystem of compatible interaction between Nicotiana tabacum and Phytophthora parasitica var. nicotianae (Ppn). GME could reduce by 45% the infected areas induced by the oomycete on tobacco leaves. This level of protection was the result of the combined antimicrobial and PDI actions of GME. GME had no protecting effect against Ppn on NahG leaves evidencing the involvement of SA in the GME-induced resistance. GME fractionation led to identification of a bioactive molecule mixture capable of inducing the PDI activity. The active compounds are polyphenolics and involve procyanidin B2 which is by itself able to induce the HR-like response and PR1 transcript accumulation. This compound should act in combination with other polyphenolic molecules to stimulate the full plant defense reactions.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Rosmarinus officinalis L., popularly known as rosemary, is a medicinal and aromatic species used in the cosmetics and food processing industries, with interest for the herbal industry. This study aimed to determine the biomass production and volatile oil during the growth of rosemary plants cultivated under different salinity (nutritious solution concentrations) and different nitrogen (N) concentrations, and to evaluate the effect of the extracts and volatile oil of the species on the Allium cepa L. cell cycle and genetic material, as well as knowing the phenolic compounds present in the extracts and the chemical composition of volatile oil. The work was divided into two stages: the first aimed evaluating the production of biomass and volatile oil during the rosemary plants growth cultivated under different nutritious solution concentrations, as well as the effect of oil and extracts on the A. cepa cell cycle and genetic material, besides determining the chemical composition of the oil and the phenolic compounds present in the extracts; the second stage aimed evaluating biomass and volatile oil production during the rosemary plants growth cultivated under different N concentrations, as well as the effect of oil and the extracts on the A. cepa cell cycle and genetic material, and determining the chemical composition of the oil and the phenolic compounds present in the extracts as well. The rosemary leaves were collected and analyzed for dry matter, volatile oil extraction and preparation of aqueous extracts by infusion at 5, 20, and 50 g.L-1 concentrations for plants cultivated under different salinities, and 5 and 50 g.L-1 concentrations for plants cultivated at different N concentrations. The volatile oil was analyzed by Gas Chromatography to knowledge of its constitution, and the aqueous extracts were analyzed by High Performance Liquid Chromatography for phenolic compounds determination. The oil and extracts effect was evaluated on the A. cepa cell cycle and genetic material. The completely randomized design was used, and the biomass production and volatile oil yield data were subjected to analysis of variance with polynomial regression and the remaining data were compared by the Scott-Knott test at the 5% level of probability. The nutritious solution concentration, the N concentration and the plant age interfere into the biomass production, and consequently into the rosemary volatile oil yield. However, do not alter the oil and extracts effect on the A. cepa cell cycle and genetic material. The volatile oil and extracts inhibited cell division in all concentrations, and this effect is dose-dependent. In addition, extracts did not show genotoxicity, in spite of oil concentration of 10% being genotoxic. The majority compounds camphor, 1.8 cineole, α-pinene, β-myrcene and verbenone, beyond of β-pinene compounds only controlling the oil crop plants in the concentrations of 8:05, 13:05 and 15:55 mmol.L-1. The phenolic compounds present in the extracts were rosmarinic acid, chlorogenic acid, caffeic acid, carnosic acid, kaempferol, quercetin and rutin. / Rosmarinus officinalis L., popularmente conhecida como alecrim, é uma espécie medicinal e aromática utilizada na indústria de cosméticos e agroalimentícia, com interesse para a indústria de fitoterápicos. Objetivou-se determinar a produção de fitomassa, óleo volátil, composição química do óleo e compostos fenólicos presentes nos extratos, durante o crescimento de plantas de alecrim cultivadas com diferentes salinidades (concentrações de solução nutritiva) e diferentes doses de nitrogênio (N), além de avaliar o efeito dos extratos e óleo volátil da espécie sobre o ciclo celular e material genético de Allium cepa L.. Foram coletadas as folhas de alecrim para determinação da fitomassa, extração de óleo volátil e preparo de extratos aquosos por infusão. Avaliou-se a produção de fitomassa e óleo volátil durante o crescimento de plantas de alecrim cultivadas com diferentes salinidades (1.0, 2.0, 3.0, 4.0 e 5.0 dS.m-1) e em diferentes doses de N (5.55, 8.05, 10.55, 13.05 e 15.55 mmol.L-1), além de avaliar o efeito do óleo (3 e 10%) e dos extratos (nas concentrações de 5, 20, e 50 g L-1 para as plantas cultivadas em diferentes salinidades e nas concentrações de 5 e 50 g L-1 a partir das plantas cultivadas em diferentes doses de N), sobre o ciclo celular e material genético de A. cepa. O óleo volátil foi submetido à análise por Cromatografia Gasosa para conhecimento de sua constituição, e os extratos aquosos à análise por Cromatografia Líquida de Alta Eficiência para a determinação dos compostos fenólicos. As plantas cultivadas em diferentes salinidades foram coletadas aos 100 e aos 160 dias após o plantio (DAP) e as cultivadas em diferentes doses de N aos 90, 180, 270 e 365 DAP. Foi utilizado o delineamento experimental inteiramente casualizado, os dados de produção de fitomassa e rendimento de óleo volátil foram submetidos à análise de variância com regressão polinomial e os demais dados foram comparados pelo teste Scott-Knott (p<0,05). A salinidade, a dose de N e a idade fisiológica da planta interferem na produção de fitomassa e consequentemente no rendimento de óleo volátil de alecrim e não alteram o efeito do óleo e dos extratos sobre o ciclo celular e material genético de A. cepa. O óleo volátil e os extratos inibiram a divisão celular em todas as concentrações estudadas e esse efeito é dose dependente, mas sem apresentar genotoxicidade, exceto na concentração de 10% quando o óleo foi genotóxico. Os compostos majoritários do óleo foram cânfora, 1.8 cienol, α-pineno, β-myrceno e verbenona, além dos compostos β-pineno majoritários apenas no óleo de plantas cultivadas nas concentrações de 8.05, 13.05 e 15.55 mmol.L-1. Os compostos fenólicos presentes nos extratos foram ácido rosmarínico, ácido clorogênico, ácido cafeico, ácido carnósico, canferol, quercetina e rutina.

Algal infestation in water bodies causes the release of soluble organic compounds that impact negatively on the taste and odour of the water. With increasing pollution in water bodies and increasing nutrient loading from agricultural activities, most water reservoirs in South Africa and around the world have become affected by this problem. In this study, an advanced oxidation process (AOP), namely, photocatalysis was evaluated for its potential to degrade aromatic compounds; and taste and odour causing bi-cyclic compounds originating from algae. Semiconductor photocatalysis is an environmentally friendly technology requiring no chemical inputs which is capable of completely mineralising organic pollutants to CO2 and H2O thereby eliminating production of unwanted by-products. Although processes involved in the photo-degradation have been reported for a wide range of pollutants, the degradative pathway in this process has not been fully established. In this study, compounds including phenol, 2-chlorophenol, 4-chlorophenol and nitrophenol were successfully eliminated from simulated wastewater. Degradation of geosmin at an environmentally significant initial concentration of 220 ng/L to levels below the lowest detectable concentration was achieved with an optimum catalyst concentration of 60 mg/L at a rate of 14.78 ng/L/min. Higher catalysts loading above 60 mg/L resulted in a decrease in degradation rates. An increase in initial geosmin concentration resulted in a decrease in rates. Ionic species commonly found in surface waters (HCO3 -, and SO4 2-) significantly reduced the efficiency of geosmin degradation. Degradation of geosmin produced acyclic intermediates from ring fission tentatively identified as 3,5-dimethylhex-1-ene, 2,4-dimethylpentan-3-one, 2-methylethylpropanoate and 2-heptanal. The results obtained indicate that the degradation of organic pollutants in aqueous solution is as a result of synergic action from hydroxyl radicals, positive holes and direct photolysis by UV radiation, though the predominant pathway of degradation is via hydroxyl radicals in solution. Major aromatic intermediates of phenol degradation include catechol, resorcinol and hydroquinone produced in the order catechol > resorcinol > hydroquinone. All three are produced within 2 minutes of photocatalytic reaction of phenol and remain in solution until all phenol is degraded in aerated systems. Production of resorcinol in non-aerated systems is transient, further supporting the hydroxyl radical dominant reaction pathway. / Thesis (PhD)--University of Pretoria, 2014. / gm2014 / Chemical Engineering / unrestricted

Photo-initiated reactions involve the use of ultraviolet (UV) or visible light radiation to effect chemical transformations. Some of the advantages of photo-initiated reactions over thermal or high pressure reactions include mild reaction conditions like ambient temperature and pressure, good control over the reaction by the simple switching on/off the light source, and faster reaction kinetics. Usually, semiconductor photocatalysts or oxidizing agents are used to enhance the rate of photo reactions. “Photocatalysis” involves the generation of valence band holes and conduction band electrons by the band gap excitation of a semiconductor photocatalyst. These charge carriers produce reactive hydroxyl and superoxide radicals, which mediate oxidation and reduction reactions. However, the oxidizing agents are decomposed by the incident radiation to generate reactive radicals, which accelerate the photo reaction. Today, photocatalysis and photo-oxidative reactions are widely being practiced for environmental pollution abatement, synthesis of fine chemicals, synthesis of polymers, generation of hydrogen as a clean energy carrier, and in anti-fogging and self-cleaning surface treatments. The present investigation focuses on elucidating the mechanism and kinetics of environmentally and synthetically relevant photo-initiated reactions for a better understanding of the fundamental aspects of the photo processes. The different photo-initiated reactions studied in this dissertation can be grouped under the broad categories of (i) photocatalytic degradation of organic compounds like dyes and phenols, and reduction of metal ions, (ii) photocatalytic degradation of polymers, (iii) selective photocatalytic oxidation of cyclohexane, (iv) sonophotocatalytic degradation of dyes, (v) photopolymerization, and (vi) sonophotooxidative degradation of polymers. Nano-sized TiO2, synthesized by solution combustion technique (henceforth denoted as CS TiO2), was used as the photocatalyst for most of the above reactions, except for the last two polymer reactions, where organic initiators were used. Invariably, the photocatalytic activity of CS TiO2 was compared with the commercially available Degussa P-25 TiO2 (DP25). Based on the experimental results, detailed mechanisms were proposed for the different reactions, kinetic models were derived, and the rate coefficients signifying the importance of the underlying reaction steps were evaluated. Pd2+ substituted and Pd0 impregnated TiO2 were synthesized by solution combustion and reduction techniques, respectively, and characterized by powder XRD, XPS, TEM, BET surface area, UV/visible, TGA, FT-IR and photoluminescence measurements. While the above catalysts are known to be more active compared to CS TiO2 for the gas phase NO reduction and NO decomposition reactions, it was found in this study, that these catalysts exhibit lower activity for the degradation of organic compounds like dyes, phenol and 4-chlorophenol, in the aqueous phase. The decrease in activity was correlated with a reduction in surface area and photoluminescence intensity of these catalysts, compared to CS TiO2. Ag+ substituted (Ag sub) and Ag0 impregnated (Ag imp) nano-TiO2 were synthesized by solution combustion and reduction techniques, respectively, and characterized by the above standard measurements. These catalysts were used for the photodegradation of dyes, and the selective photooxidation of cyclohexane to cyclohexanone. For the photocatalytic degradation of dyes, unsubstituted CS TiO2 exhibited the highest activity, followed by 1% Ag imp and 1% Ag sub. However, for the photooxidation of cyclohexane, the total conversion of cyclohexane and the selectivity of cyclohexanone followed the order: 1% Ag sub > DP-25 > CS TiO2 > 1% Ag imp. The kinetics of photodegradation of the dyes and the photooxidation of cyclohexane was modeled using Langmuir-Hinshelwood rate equation, and a free radical mechanism, respectively. This study proves that the photoactivity of a catalyst is not solely determined by a single physical property, but rather by a number of variables including the surface area, band gap, surface hydroxyl content, oxide ion vacancy and surface charge of the catalyst. The photocatalytic degradation of five anionic, eight cationic and three solvent dyes, containing different functional groups, was evaluated. The degradation of the dyes was quantified using the initial rate of decolorization and overall percent mineralization. The decolorization of the anionic dyes with CS TiO2 followed the order: Indigo Carmine > Eosin Y > Amido Black 10B > Alizarin Cyanine Green > Orange G. The decolorization of the cationic dyes with DP-25 followed the order: Malachite Green > Pyronin Y > Rhodamine 6G > Azure B > Nile Blue Sulfate > Auramine O ≈ Acriflavine ≈ Safranin O. CS TiO2 exhibited higher rates of decolorization and mineralization for all the anionic dyes, while DP-25 was better in terms of decolorization for most of the cationic dyes. The solvent dyes exhibited adsorption dependent decolorization. The observed results were rationalized based on the molecular structure and degradation pathway of the dyes. The simultaneous photocatalytic degradation of phenolic compounds like phenol and 4-nitrophenol, and the reduction of metal ions like copper (Cu2+) and chromium (Cr6+) were studied. It was found that the presence of phenol accelerated the reduction of Cu2+ to Cu+, and the presence of phenol and 4-nitrophenol accelerated the adsorption of Cr6+ onto CS TiO2. A detailed dual-cycle, multi-step reaction mechanism was proposed for the simultaneous degradation and reduction, and a model was developed using the network reduction technique. The kinetic rate constants in the model were evaluated for the systems studied. The simultaneous UV and ultrasound (US) degradation of anionic dyes was carried out in presence of CS TiO2. The rates of degradation and mineralization of the dyes were higher for the sonophotocatalytic process compared to the individual photo-and sonocatalytic processes. The effect of dissolved gases and US intensity on the sonophotocatalytic degradation of the dyes was evaluated. A dual-pathway network mechanism of sonophotocatalytic degradation was proposed for the first time, and the rate equations were modeled using the network reduction technique. The kinetic rate coefficients of the individual steps were evaluated for all the systems by fitting the model with the experimental data. Eosin Y and Fluorescein dye sensitized visible light degradation of phenol, 4chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol was studied. A detailed mechanism of sensitized degradation was proposed, and a mechanistic model for the rate of degradation of the phenolic compound was derived by using the pyramidal network reduction technique to evaluate the rate coefficients. An important conclusion of this study indicates that at low initial dye concentrations, the rate of degradation of the phenolic compound is first order in the concentration of the dye, while at high initial dye concentrations, the rate is first order in the concentration of the phenolic compound. The different phenolic and dye intermediates that were formed during degradation were identified by mass spectrometry, and a most probable pathway of degradation was proposed. The solution photopolymerization of methyl-, ethyl-, butyl-and hexylmethacrylates in presence of benzoyl peroxide as the initiator was studied. The effect of initiator and monomer concentrations on the time evolution of polymer concentration, number average molecular weight (Mn) and polydispersity (PDI) was examined. The reversible chain addition and β-scission, and primary radical termination steps were included in the mechanism along with the classical initiation, propagation and termination steps. The rate equations were derived using continuous distribution kinetics and solved numerically to fit the experimental data. The model predicted the instantaneous increase of Mn and PDI of the polymers to steady state values. The rate coefficients exhibited a linear increase with the size of the alkyl chain of the alkyl methacrylates. Poly(acrylamide-co-acrylic acid) copolymers of different compositions were synthesized and characterized. The copolymers were statistical with a relatively high percentage of acrylamide units, as determined by 13C-NMR. The aqueous phase photolytic and photocatalytic degradation of the copolymers and the homopolymers was conducted. The degradation was modeled using continuous distribution kinetics. The degradation followed a two step mechanism, wherein the rapid first step comprised of the scission of weak acrylic acid units along the chain, which was followed by the breakage of the relatively strong acrylamide units. The rate constants for the weak and strong links followed a linear trend with the percentage of acrylic acid and acrylamide in the copolymer, respectively. The photocatalytic degradation of the copolymers of methyl methacrylate with butyl methacrylate (MMA-BMA), ethyl acrylate (MMA-EA) and methacrylic acid (MMA-MAA) was carried out in toluene. The copolymers and the corresponding homopolymers degraded randomly along the chain. The degradation rate coefficient was determined using continuous distribution kinetics. The time evolution of the hydroxyl and hydroperoxide stretching vibration in the FT-IR spectra of the copolymers indicated that the degradation rate follows the order: MMA-MAA > MMA-EA > MMA-BMA. The photodegradation rate coefficients were compared with the activation energy of pyrolytic degradation. The observed contrast in the order of thermal stability compared to the photostability of these copolymers was attributed to the two different mechanisms governing the scission of the polymers and the evolution of the products. The mechano-chemical degradation of poly(methyl methacrylate), poly(ethyl methacrylate) and poly(n-butyl methacrylate) using US and UV radiation, in presence of benzoin as the photoinitiator, was carried out. A degradation mechanism that included the decomposition of the initiator, generation of polymer radicals by hydrogen abstraction of the initiator radicals, and reversible chain transfer between the stable polymer and the polymer radicals, was proposed. The mechanism assumed mid-point chain scission due to US and random chain scission due to UV radiation. The steady state evolution of PDI was successfully predicted by the continuous distribution kinetics model. The rate coefficients of polymer scission due to US and UV radiation exhibited a linear increase and decrease with the size of the alkyl group of the poly(alkyl methacrylate)s, respectively.

Les nématodes parasites du tube digestif demeurent une contrainte majeure pesant sur la santé, le bien être et les productions des petits ruminants élevés à l’herbe. Le mode usuel de maîtrise de ce parasitisme repose sur l’emploi répété de molécules chimiques anthelminthiques. Toutefois, le développement et la diffusion généralisée de résistances à ces molécules dans les populations de vers imposent désormais d’utiliser ces traitements avec discernement et de trouver des solutions complémentaires ou alternatives. L’incorporation dans la conduite d’élevage (ration des moutons ou des chèvres) de légumineuses fourragères riches en tannins condensés dotées de propriétés anthelminthiques s’est avérée une option prometteuse pour réduire le recours aux molécules chimiques. Toutefois, une des difficultés d’application de ces plantes tient à la variabilité des résultats observés. En prenant le sainfoin comme modèle de légumineuse contenant des tannins et en s’appuyant essentiellement sur des méthodes in vitro basées sur les larves 3 infestantes, l’objectif général de cette thèse est d’analyser le rôle respectif de facteurs liés à l’environnement, aux variétés génétiques ou aux modes de préservation technologiques sur les propriétés anthelminthiques. Quelque soit le critère envisagé, une forte variabilité a été observée. Les principales variations liées à l’environnement dépendaient de l’année et du cycle de coupe, ainsi que du site d’exploitation. Parmi les 38 variétés testées, 9 se sont avérées à forte activité AH, alors que 22 étaient à très faible activité. Enfin, les résultats ont aussi surtout souligné une plus forte activité antiparasitaire dans des formes séchées ou ensilées par comparaison à des échantillons frais. La comparaison des profils biochimiques liés à cette variabilité a permis une exploration des composés phénoliques expliquant l’activité anthelminthique. L’existence d’une relation dose-réponse a été précisée. Le rôle des tannins condensés a été confirmé, notamment ceux à faible degré de polymérisation et à faible poids moléculaire. L’importance des prodelphinidines qui seraient plus actives que les procyanidines reste à confirmer. De plus, il a été montré que d’autres flavonoides peuvent jouer un rôle, notamment les flavan-3-ols et les flavonols. La différence d’activité entre les échantillons de sainfoin ensilés ou fanés par comparaison aux échantillons frais s‟expliquerait en partie par la présence de formes non glycosidés de flavonols. Ces résultats devraient conduire à développer des méthodes de dosage pour identifier les échantillons de sainfoin, et plus généralement de légumineuses riches en tannins, dotés de propriétés anthelminthiques significatives. / Gastrointestinal nematodes remain a major constraint on the health, welfare and production of small ruminants. Over the past decades, the usual mode of control of this parasitism has mainly relied on the repeated use of chemical anthelmintics. However these treatments are nowadaysfacing some limits among which the most important is the development and widespread diffusion of resistance to these chemical molecules within worm populations. Consequently, the need to find complementary or alternative solutions is becoming urgent. The possible exploitation of forage legumes, rich in condensed tannins, with anthelmintic properties, by incorporation in the diet of sheep or goats, seems a promising option to reduce the reliance on chemical molecules. However, one of the main difficulties to use these plants as nutraceuticals relates to the variations in results. By using sainfoin (Onobrychis viciifoliae) as a model of tannin-containing legume and based on in vitro methods on the infective third stage larvae, the main objectives of this PhD were i) to examine the influence of environmental, genetic (40 different varieties) and technological (mode of preservation) factors on the anthelmintic properties of sainfoin and ii) to analyse whether differences in phenolic compounds might explain the variations. Whatever the factor considered, a high variability in results was observed. The main variations due to the environmental factors depended on the year and the cycle of cutting, as well as on the site of cultivation. Among the 38 varieties tested, only 9 have shown AH activity over 50 %. Last, a higher antiparasitic activity was found in the dried or ensiled forms compared to the fresh samples. A comparison of the biochemical profiles associated with these variations indicated a role of proanthocyanidins plus other phenolic compounds in the anthelmintic properties. The dose-response relationship between the AH activity and the ability to form complex with proteins was defined. The role of condensed tannins was confirmed, particularly those with a low degree of polymerization. The respective importance of prodelphinidins vs procyanidins remains to be further investigated. Moreover, the possible role of other flavonoids, in particular of flavan-3-ols and flavonols was also confirmed. The difference in activity between dried or ensiled forms compared to fresh sainfoin samples was partly explained by the presence of flavonol aglycosides. These results should favour the development of measurements in order to identify sainfoin samples with higher anthelmintic properties.

Orientador: Helena Teixeira Godoy / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T06:47:07Z (GMT). No. of bitstreams: 1 Ballus_CristianoAugusto_D.pdf: 2840544 bytes, checksum: cd74911d057ffa04ee6e1e5b54ebc8e9 (MD5) Previous issue date: 2014 / Resumo: O consumo de azeite de oliva extravirgem (EVOO) é altamente recomendado por seus benefícios à saúde humana. No Brasil, a ingestão de EVOO, o qual é importado de outros países, vem aumentando anualmente. Nos últimos anos, o Brasil começou a produzir EVOO, porém de maneira experimental. No capítulo 1 foi apresentada uma revisão bibliográfica destacando os estudos mais relevantes acerca do composição química e dos benefícios à saúde do azeite de oliva extravirgem. No capítulo 2, o objetivo foi determinar o teor de fenólicos totais (TFT) e a capacidade antioxidante (CA), bem como a correlação entre o TFT e cada um dos quatro métodos de CA, de 15 marcas de EVOO, cada qual em três lotes, resultando em 45 amostras. O TFT foi avaliado pelo método do reagente de Folin-Ciocalteu, enquanto a CA foi determinada pelos ensaios de FRAP, ABTS, DPPH¿ e ORAC. O TFT variou de 70 a 297 mg EAG kg-1, FRAP de 114 a 1557 µmol ET kg-1, ABTS de 0,5 a 1,9 mmol ET kg-1, DPPH¿ de 72 a 1129 µmol ET kg-1, e ORAC de 1,1 a 12,9 µmol ET g-1. Houve elevada e significativa correlação entre o TFT e cada um dos métodos de CA (FRAP, r2 = 0,8904; p < 0,001; ABTS, r2 = 0,7837; p < 0,001; DPPH¿, r2 = 0,7908; p < 0,001; ORAC, r2 = 0,7431; p < 0,001). Portanto, a maioria das marcas de EVOO apresentaram considerável TFT e elevados valores de CA. No capítulo 3, o objetivo foi otimizar a separação de 17 compostos fenólicos previamente detectados em EVOO. Foi utilizado um planejamento experimental Doehlert, avaliando-se o pH e a concentração do eletrólito. Resolução, tempo de corrida e coeficientes de variação dos tempos de migração foram as respostas. A função de desejabilidade de Derringer foi utilizada para otimizar simultaneamente as 37 respostas. Os 17 picos dos compostos foram separados em 19 minutos em capilar de sílica fundida (50 µm diâmetro interno, 72 cm comprimento efetivo) com bulbo estendido e eletrólito ácido bórico 101,3 mmol L-1 (pH 9,15, 30 kV). O método foi validado e aplicado em 15 amostras comerciais de EVOO. No capítulo 4, o objetivo foi determinar o teor de compostos fenólicos, tocoferóis e ácidos graxos de 17 EVOO monovarietais produzidos em Minas Gerais, durante duas colheitas. Foram quantificados os ácidos palmítico (6-12,6%), palmitoleico (0,2-2,5%), esteárico (1,6-2,2%), oleico (70,8-84,3%), linoleico (3,2-11,7%), a-linolênico (0,6-1,4), araquídico (0,4-0,8%), 9-eicosenoico (0,4-0,9%) e os compostos tirosol (NQ-155,21 mg kg-1), (+)-pinoresinol (2,89-22,64 mg kg-1), hidroxitirosol (ND-37,74 mg kg-1), luteolina (ND-2,23 mg kg-1), a-tocoferol (28,92-232,93 mg kg-1), ß-tocoferol (ND-9,56 mg kg-1) e ?-tocoferol (ND-18,75 mg kg-1). Em geral, os resultados foram similares aos descritos na literatura. O objetivo do capítulo 5 foi determinar o teor de compostos fenólicos em EVOO brasileiros por cromatografia líquida de rápida resolução acoplada à espectrometria de massas por tempo de voo com ionização por electrospray (RRLC-ESI-TOF-MS). Foram analisadas 25 amostras de EVOO do Rio Grande do Sul, Santa Catarina e Minas Gerais e duas colheitas. Foram identificados e quantificados 20 compostos fenólicos das classes dos alcoóis fenólicos, secoiridoides, lignanas e flavonoides. Os teores de compostos fenólicos totais nos EVOOs destacaram-se nas variedades Coratina (364 mg kg-1), Arbosana (255 mg kg-1) e Grappolo (228 mg kg-1). Desta forma, os EVOOs brasileiros são promissores no que se refere ao teor de compostos fenólicos totais, visto que os valores são comparáveis àqueles dos EVOOs de elevada qualidade produzidos em outros países / Abstract: Consumption of extra-virgin olive oil (EVOO) is highly recommended for its benefits to human health. In Brazil, consumption of EVOO, which is imported from other countries, is increasing annually. In the last years, Brazil started to produce EVOO,although in an experimental way. In chapter 1, a literature review highlighting the most relevant studies on the chemical composition and the health benefits of the extra-virgin olive oil is presented. In chapter 2, the aim was to determine the total phenolic content (TPC) and the antioxidant capacity (AC), as well as the correlation between TPC and each one of the four AC methods, of 15 EVOO brands, each one in three batches, resulting in 45 samples. TPC was evaluated by Folin-Ciocalteu reagent method, while the AC was assessed using FRAP, ABTS, DPPH¿ and ORAC assays. The TPC varied from 70 to 297 mg GAE kg-1, FRAP from 114 to 1557 µmol TE kg-1, ABTS from 0.5 to 1.9 mmol TE kg-1, DPPH¿ from 72 to 1129 µmol TE kg-1, and ORAC from 1.1 to 12.9 µmol TE g-1. High and significant correlation was found between the TPC and each one of the AC methods evaluated in this study (FRAP, r2 = 0.8904; p < 0.001; ABTS, r2 = 0.7837; p < 0.001; DPPH¿, r2 = 0.7908; p < 0.001; ORAC, r2 = 0.7431; p < 0.001). Therefore, most of the EVOO brands presented a considerable TPC and high AC values. In chapter 3, the aim was to optimize the separation of 17 phenolic compounds already detected in EVOO. A Doehlert matrix experimental design was used, evaluating the effects of pH and electrolyte concentration. Resolution, runtime and migration time relative standard deviation values were used as responses. Derringer¿s desirability function was used to simultaneously optimize all 37 responses. The 17 peaks were separated in 19 minutes using a fused-silica capillary (50 mm internal diameter, 72 cm of effective length) with an extended light path and 101.3 mmol.L-1 of boric acid electrolyte (pH 9.15, 30 kV). The method was validated and applied to 15 EVOO samples found in Brazilian supermarkets. In chapter 4, the aim was to determine the phenolic compounds, tocopherols and fatty acids contents of 17 monovarietal EVOOs produced in Minas Gerais state, during two crop years. Compounds identified comprised palmitic acid (6-12.6%), palmitoleic acid (0.2-2.5%), stearic acid (1.6-2.2%), oleic acid (70.8-84.3%), linoleic acid (3.2-11.7%), a-linolenic acid (0.6-1.4), arachidic acid (0.4-0.8%), 9-eicosenoic acid (0.4-0.9%), tyrosol (NQ-155.21 mg kg-1), (+)-pinoresinol (2.89-22.64 mg kg-1), hydroxytyrosol (ND-37.74 mg kg-1), luteolin (ND-2.23 mg kg-1), a-tocopherol (28.92-232.93 mg kg-1), ß-tocopherol (ND-9.56 mg kg-1), ?-tocopherol (ND-18.75 mg kg-1). Some of these monovarietal EVOOs presented results similar to those described in the literature. The aim of chapter 5 was to determine the phenolic compound contents of Brazilian EVOO, using rapid-resolution liquid chromatography coupled to electrospray ionization time-of-flight mass spectrometry (RRLC-ESI-TOF-MS). A total of 25 EVOO samples from Rio Grande do Sul, Santa Catarina and Minas Gerais states and two crops, were analyzed. It was possible to identify and quantify 20 phenolic compounds, belonging to the phenolic alcohol, secoiridoid, lignan and flavonoid classes. EVOOs from Coratina (364 mg kg-1), Arbosana (255 mg kg-1) and Grappolo (228 mg kg-1) varieties presented the highest total phenolic contents. The results showed that Brazilian EVOOs are promising concerning the total phenolic contents, since the values were comparable to those from high-quality EVOOs produced in other countries / Doutorado / Ciência de Alimentos / Doutor em Ciência de Alimentos