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...