Antioxidant and prebiotic effects of a beverage composed by tropical fruits and yacon in alloxan-induced diabetic rats

The aim of this study was to evaluate the antioxidant and prebiotic effect of a beverage composed by tropical fruits and yacon in alloxan-induced diabetic rats. To obtain the beverage, a Response Surface Methodology was used, with concentration of yacon extract (x1) and the sweetener (x2) added to a mixture of tropical fruits as independent variables, and the sensorial acceptance as response. The optimized beverage showed higher values for antioxidant capacity, measured by ABTS, FRAP and DPPH assays. Thus, the fructooligosaccharides content (2.32 +/- 0.65 g FOS/100 g), total phenolic (126.83 +/- 9.48 mg gallic acid equivalent/100 g) and ascorbic add (171.64 +/- 7.31 mg/100 g) shows that the beverage contains high levels of these bioactive compounds. In addition, the beverage was tested in vivo, using male Wistar rats, divided into five groups (control, non-treated diabetic, and diabetic treated with 100, 200 or 400 mg of lyophilized beverage/kg/day). The results showed a promotion of the growth of lactobacilli in cecal material and an increase in catalase activity in the liver, in a dose-dependent manner, showing the prebiotic and antioxidant effects of the beverage in the diabetic model.