Fruits, vegetables, and commercial frozen pulps (FP) consumed in the Brazilian diet were analyzed for antioxidant activities using two different methods, one that determines the inhibition of copper-induced peroxidation of liposome and another based on the inhibition of the co-oxidation of linoleic acid and beta-carotene. The anthocyanin-rich samples showed the highest, concentration-dependent, antioxidant activities in both systems. In the liposome system, at both 10 and 50 microM gallic acid equivalent (GAE) addition levels, the neutral and acidic flavonoids of red cabbage, red lettuce, black bean, mulberry, Gala apple peel, jambolao, acai FP, mulberry FP, and the acidic flavonoids of acerola FP showed the highest antioxidant activities (>85% inhibition). In the beta-carotene bleaching system, the samples cited above plus red guava gave inhibition values >70%. On the other hand, some samples showed pro-oxidant activity in the liposome system coincident with a low antioxidant activity in the beta-carotene system. There was no relationship between total phenolics content, vitamin C, and antioxidant activity, suggesting that the antioxidant activity is a result of a combination of different compounds having synergic and antagonistic effects.

*A quem a correspondência deve ser enviada Physico-chemical characterization and bioactive compounds of blackberry fruits (Rubus sp.) grown in BrazilCaracterização físico-química e de compostos bioativos em amora-preta (Rubus sp.) cultivada no BrasilNeuza Mariko Aymoto HASSIMOTTO 1 , Renata Vieira da MOTA 2 , Beatriz Rosana CORDENUNSI 1 *, Franco Maria LAJOLO 1 IntroductionFruit and vegetable intake has proven to reduce the development of a considerable number of chronic diseases, such as cancer and cardiovascular diseases. The protective effect evidenced in laboratory and epidemiological studies has been associated with a variety of nutrient and non-nutrient constituents, being many of them characterized by their antioxidant properties (PIETTA, 2000). Among the compounds with high antioxidant capacity are ascorbic acid, tocopherols, β-carotene and phenolic compounds, especially flavonoids (DREWNOWSKI; GOMEZ-CARNERO, 2000).Anthocyanins, the glycoside form of the anthocyanidins, belong to a class of flavonoids which present water-soluble pigments responsible for the orange, red and blue colors of many fruits, vegetables, leaves, flowers and roots. Anthocyanidins vary with different hydroxyl or methoxyl substitutions in their basic structure, flavylium (2-phenylbenzopyrillium). Only six of the 16 anthocyanidins identified in natural products occur frequently and in many different vegetables and fruits: cyanidin, pelargonidin, delphinidin, peonidin, petunidin and malvidin (WU; PRIOR, 2005a;. Anthocyanins are highly studied compounds because of their effects on human health as antioxidant compounds, as shown in a number of in vitro and in vivo studies HEINONEN, 2003), for their anti-inflammatory effect modulating ciclooxygenase 1 and 2 enzymes (TALL et al., 2004) and their inhibitory effect on the development of some cancer cells (HAGIWARA; YOSHINO; ICHIBARA, 2002).Among the small fruits group, including strawberry, raspberry, blueberry and blackberry crops, blackberry appears as the richest source of anthocyanins, with cyanidin content ranging from 93 to 280 mg.100 g -1 fresh weight depending on the cultivar (CONNOR et al., 2002), followed by black raspberry (up to 197 mg), blackberry (153 mg) and strawberry (32 mg) (WANG; LIN, 2000). Blackberry plants were introduced in Brazil by the Estação Experimental de Pelotas (RS), renamed ResumoCinco cultivares de amora-preta (Rubus sp.) foram avaliadas quanto a sua capacidade antioxidante, perfil de compostos bioativos e composição físico-química. Os níveis de ácido ascórbico total, presentes na forma de ácido desidroascórbico, variaram entre 9,8 a 21,4 mg.100 g -1 (b.u.). Os principais flavonóides presentes nas cinco cultivares foram: a antocianina cianidina (66 a 80% do total de flavonóides); o flavan-3-ol epicatequina; e os flavonóis quercetina e traços de caenferol. As cinco cultivares apresentaram alta capacidade antioxidante quando avaliadas pelo sistema de co-oxidação β-caroteno/ácido linoléico, similar ao antioxidante sintético BHT, na concentração de 50 µM. A cu...

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