Total reducing capacity of fresh sweet peppers and five different Italian pepper recipes

Processing and preparation methods are generally believed to result in a depletion of naturally occurring antioxidants in food. To evaluate the antioxidant properties of fresh sweet peppers (Capsicum annuum) and five different Italian recipes based on sweet peppers (pickled; “peperonata”; grilled; in sour–sweet condiment; salted), water- and lipid-soluble extracts from fresh and processed peppers were analysed using high-performance liquid chromatography coupled with an electrochemical detector. Total reducing capacity (TRC) and contributions of hydrophilic reducing capacity (HRC) and lipophilic reducing capacity (LRC) to the TRC were determined in all the samples. Three important antioxidant compounds were measured: ascorbic acid, β-carotene and lycopene. The contribution of these individual compounds to TRC was estimated.