RESUMO -Características físico-químicas (cor, pH, acidez total titulável, sólidos solúveis totais, conteúdo de lipídios e umidade) e níveis de compostos bioativos (ácido ascórbico, fenólicos totais) foram determinados em quinze amostras de polpas de frutos procedentes da região Amazônica (abiu, acerola, açaí, araçá-boi, bacaba, bacuri, buriti, cajá, cajarana, caju, cupuaçu, graviola, murici, noni e tamarindo). A atividade de radicais livres foi avaliada pelo método de ABTS. Algumas polpas apresentaram alta potencialidade antioxidante, associada com a atividade antirradicais livres obtida e os conteúdos dos componentes bioativos como compostos fenólicos e ácido ascórbico, destacando-se acerola e acaí. O conteúdo total de compostos fenólicos foi correlacionado à capacidade antioxidante das polpas. Termos para indexação: ácido ascórbico, compostos fenólicos, TEAC, Análise de Componentes Principais. PHYSICAL AND CHEMICAL CHARACTERIZATION OF FRUIT PULPS FROM AMAZONIA AND THEIR CORRELATION TO FREE RADICAL SCAVENGER ACTIVITYABSTRACT -Physical and chemical characteristics (color, pH, titratable acidity, total soluble solids, lipid content, moisture) and levels of bioactive compounds (ascorbic acid, total phenolics) were determined in fifteen samples of fruit pulps from Amazonia (abiu, acerola, açaí, araça-boi, bacaba, bacuri, buriti, cajá, cajarana, caju, cupuaçu, graviola, murici, noni e tamarindo). The free radical scavenger activity was evaluated by the ABTS assay. Some pulps presented high antioxidant potential, associated with the free radical scavenger activity measured and the content of bioactive components, such as phenolic compounds and ascorbic acid, especially in acerola and açaí. The total phenolic content was correlated to antioxidant capacity of pulps. Index terms: ascorbic acid, phenolic compounds, TEAC, Principal Component Analysis. INTRODUÇÃOO Brasil é o terceiro maior produtor de frutos (6 % da produção mundial) (ANDRIGUETO et al., 2010), mas a fruticultura Amazônica representa menos do que 0,2 % desse total (ROMERO, 2009). A agricultura tradicional da região é composta basicamente por hortaliças, raízes nativas, plantas medicinais e frutos exóticos (CLAY et al., 1999), que são utilizadas tanto para consumo in natura quanto para elaboração de produtos processados (ANDRIGUETO et al., 2010; SOUSA et al., 2001). Nos últimos anos, houve um incremento da exploração econômica de produtos e subprodutos de algumas frutíferas específicas, atribuído à crescente preocupação do consumidor com a relação entre dieta e saúde (YAHIA, 2010). A caracterização física e química das frutos e a quantificação de componentes bioativos são importantes para o conhecimento do valor nutricional, e do ponto de vista comercial, para agregar valor e qualidade ao produto final. Dentre os compostos com propriedades funcionais em alimentos, substâncias com atividade antioxidante têm recebido grande atenção, pois auxiliam a proteger o organismo humano contra o estresse oxidativo, evitando e prevenindo uma série de distúrbios crônico-...

Orange juice is considered an excellent dietary source of several bioactive compounds with beneficial properties for human health. Citrus sinensis Osbeck cv. 'Cara Cara' is a bud mutation originated from 'Washington' navel orange, also known as 'Bahia' navel orange. The ascorbic acid, flavonoid, and carotenoid contents in pasteurized and nonpasteurized Bahia and Cara Cara juices using two LC-MS/MS platforms were investigated. Higher ascorbic acid content was observed in Bahia compared to Cara Cara in both pasteurized and nonpasteurized juices. Total flavanones content as well as hesperidin levels were higher in Cara Cara with respect to Bahia pasteurized juice. Cara Cara was also characterized by a significantly higher and diversified carotenoid content compared to Bahia juice with a mixture of (Z)-isomers of lycopene, all-E-β-carotene, phytoene, and phytofluene isomers accounting for the highest carotenoid proportion. The exceptionally high carotenoid content of Cara Cara may be particularly interesting for nutritional or functional studies of uncommon carotenes in a citrus food matrix.

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Carotenoids, widely distributed fat-soluble pigments, are responsible for the attractive colorations of several fruits and vegetables commonly present in our daily diet. They are particularly abundant in yellow-orange fruits (carrots, tomatoes, pumpkins, peppers, among others) and, although masked by chlorophylls, in dark green leafy vegetables. Several health benefits have been attributed to carotenoids or to foods rich in these pigments, by means of different mechanisms-of-action, including the role as provitamin A of almost 50 different carotenoids and the antioxidant activity that protects cells and tissues from damage of free radicals and singlet oxygen, providing enhancement of the immune function, protection from sunburn reactions and delaying the onset of certain types of cancer. Common food sources and the efficiency of the absorption of carotenoids, analytical approaches used for measurement of their antioxidant effect and an overview of some epidemiological studies that have been performed to assess the beneficial impact of carotenoids in human health are outlined in this chapter.

Addition of lutein to dairy products is an alternative that widens the range of foods which could be lutein source. However, bioaccessibility is an essential aspect to be considered during the development of products with added bioactive substances. We evaluated the in vitro bioaccessibility of lutein esters added to milk and yogurt with different fat contents, and determined the efficiency of enzymatic hydrolysis of the esters during digestion. Bioaccessibility of lutein and efficiency of hydrolysis were significantly lower in skimmed products than semi-skimmed and whole products, indicating thata minimal amount of fat is required to allow micellization and hydrolysis. The efficiency of ester hydrolysis ranged between 12-35%, which was attributed to pancreatic lipase. Whole and semi-skimmed samples were shown to be good vehicles for the addition of lutein, since presented bioaccessibility indices (38.3-47.5%) similar to those found in natural food sources of xanthophylls.

Xanthophyll esters are significant contributors to the carotenoid profile in the colostrum, while mature milk does not contain these compounds. Therefore, fatty acid acylation to xanthophylls is activated during the accumulation of carotenoids in the human mammary gland. The sharp decline in the amount of xanthophyll esters in mature milk indicates that the lipophilic components are those recently incorporated in the mammary epithelium.

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