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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-...

This work aimed to compare methods for the formation of complexes of bixin and curcumin with β-cyclodextrin (β-CD) and to evaluate the stability of the complexes formed by these methods and their food applications. The stoichiometric relationship between curcumin and β-CD was 1:2 and that between bixin and β-CD was 1:1. Curcumin-β-CD and bixin-β-CD complexes formed by kneading, coprecipitation, and simple mixing were evaluated by differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), or nuclear magnetic resonance (NMR-H). For both curcumin and bixin, the best method of complexation was coprecipitation. Complexation of colorants with β-CD promoted an intensification of color and increased water solubility; however, stabilization in the presence of light occurred only for bixin. Application of curcumin-β-CD in cheese and yogurt and bixin-β-CD in the curd did not alter the initial characteristics of the products, which were sensorialy well accepted. Therefore, the complexation of these natural colorants with β-CD favors their use in low-fat foods, broadening the field of industrial application.

O alto consumo de frutas tem sido associado à baixa incidência de doenças crônico-degenerativas, provavelmente devido à presença de compostos bioativos, como os antioxidantes, nestes alimentos. Os teores de compostos bioativos -ácido ascórbico, fenólicos totais, flavonóides e carotenóides totais -foram determinados em polpas obtidas a partir de 18 frutas tropicais adquiridas no Brasil. A atividade anti-radical livre foi avaliada pelo método ABTS. As frutas que apresentaram maior teor de compostos bioativos foram buriti, cajá-manga, canistel, murici, physalis, piquia e tucumã. Considerando a composição dos compostos bioativos analisados e as atividades anti-radical livre, as frutas foram divididas em 5 grupos, segundo Análise Hierárquica de Agrupamentos. Aplicando a Análise de Componentes Principais, a atividade anti-radical livre mostrou alta correlação com compostos fenólicos totais (r = 0,99) e flavonóides (r = 0,86); porém, a correlação encontrada foi muito pequena para ácido ascórbico (r = 0,02) e carotenóides totais (r = 0,08).High ingestion of fruits has been associated with low incidence of chronic-degenerative diseases, probably due to the presence of bioactive compounds in these foods, such as antioxidants. The levels of bioactive compounds -ascorbic acid, total phenolics, flavonoids and carotenoids -were determined in 18 pulps obtained from tropical fruits acquired in Brazil. The free radical scavenger activity was evaluated by the ABTS assay. The fruits that showed higher levels of bioactive compounds were buriti, otaheite apple, egg-fruit, golden spoon, physalis, piquia and star nut palm. Considering the composition of bioactive compounds and free radical scavenger capacities the fruits were divided into five groups, according to Hierarchical Cluster Analysis. Applying Principal Component Analysis, free radical scavenger showed high correlation with total phenolic compounds (r = 0.99) and flavonoids (r = 0.86); however, the correlation was found to be very poor with ascorbic acid (r = 0.02) and with total carotenoids levels (r = 0.08).Keywords: ascorbic acid, carotenoids, phenolic compounds, radical scavenger activity, Principal Component Analysis IntroductionBrazil stands out as the third largest world producer of fresh fruits due to a favorable climate and vast territorial land. Fruit growing agribusiness is a rapidly growing activity, present in all Brazilian states, accounting for 25% of the value of domestic agricultural production. In Brazil fruit growing has experienced a remarkable expansion of the harvested area in the latest years, including the native and exotic fruits. The commercialization directed almost exclusively to the internal market, has led to gains in foreign markets, which has been crucial to the improvement of production systems and of the fruit quality.¹ Despite the enormous fruit diversity, Brazil still needs to improve in this area, since the Brazilian participation in world exports of fresh fruit and fruit products amounted only to 5.7% in 2007.²The high ingestion of fruit...

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