Comparative analysis of the in vitro antioxidant activity of white and black pepper

As a result of normal metabolic processes, the human body produces reactive oxygen species capable of oxidizing biomolecules that can damage DNA, cells, and contribute to chronic disease. This process can be attenuated or perhaps reversed by diets containing spices that have the ability to scavenge reactive oxygen species. The present study measured the concentration of polyphenols in peppercorn (black and white) using the Folin-Ciocalteu method and investigated the radical scavenging activities of hydrolyzed and nonhydrolyzed pepper extracts using 1,1-diphenyl-2-picrythydrazyl, the superoxide radical, and the hydroxyl radical as substrates. The hydrolyzed and nonhydrolyzed extracts of black pepper contained significantly (P < .001) more polyphenols compared with those of white pepper. For either of these peppercorns, the hydrolyzed extract contained significantly (P < .001) more polyphenols compared with the nonhydrolyzed extract. A dose-dependent effect was observed in the free radical and reactive oxygen species scavenging activities of all the extracts, with the black pepper extracts being the most effective. Peppercorns especially black pepper, which constitutes an important component in the diet of many sub-Saharan and oriental countries, can therefore be promoted for their nutritional importance as antioxidants and radical scavengers. (c) 2006 Published by Elsevier Inc.