Fruits and vegetables (F & V) afford protection against numerous chronic diseases such as cancer, cardio- and cerebrovascular and neurological diseases. The protective effect of F & V has generally been attributed to their antioxidant constituents such as vitamins A, C, E, folates, carotenoids and polyphenols. Dietary consumption of antioxidants is thought to guard humans against chronic illnesses through the mitigation of free radical damage to proteins, lipids and DNA.

 

Many methods are available for the estimation of total antioxidant activity (capacity) of F & V. One of the easiest methods is using commercially available free radical, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. This radical serves as the oxidising radical that would be reduced by an antioxidant (AH) and thus is a good indicator for the reaction.