Bioactive compounds and antioxidant properties of selected fruits and vegetables available in the vaal region, south africa

This study was conducted to assess the level of phytochemicals and antioxidant properties in a selection of fruits and vegetables available in the Vaal Region, and examine the effect of cooking. A wide distribution and variation in quantities of phytochemicals among the different samples was noted. The antioxidant capacity (μmol Trolox-equivalent.100/g fresh-weight) ranged from 178.5 (green bean) to 1814.4 (apple), and total phenolics (mg gallic acid-equivalent.100/g fresh-weight) from 28.4 (apple) to 103.8 (carrot). Although significant levels of vitamin C (4.4-48.4mg.100/g fresh-weight) and Vitamin E (0.05-5.40mg.100/g fresh-weight) were recorded, polyphenols were the main provider of the antioxidant properties (r=0.778; P<0.001) followed by carotenoids, which showed significant correlation (r=0.472; P=0.020) with total antioxidant in vegetables. Cooking significantly affected (P<0.05) the levels of phytochemicals; however, the pattern varied among the different vegetables and phytochemicals. PRACTICAL APPLICATIONS: The variability in the composition and quantity of phytochemicals and antioxidant properties in the foods studied, as well as the variable effect of cooking, highlighted the importance to eat various foods to satisfy the needs for antioxidants. The results of this study will be used to develop a phytochemical constituent table that will be a useful tool for health professionals and consumers in choosing antioxidant- and phytochemical-rich foods, and to support future work in assessing the protective status of people from chronic degenerative disorders in the Vaal Region.