Antioxidant activity and total phenolic content of some nuts commonly consumed in South-Western Nigeria

Abstract

Improved health associated with frequent eating of nuts as one of the most unexpected nutritional discovery of the 1990s formed the basis of this study. Hence, the evaluation of some selected nuts commonly consumed as snacks in the South West of Nigeria for antioxidant activity (AA) and total phenolic content (TPC) using ferric-ion reducing antioxidant potential (FRAP) assay and Folin-Coicalteau method. Results show that AA of nuts such as kola nuts (Cola acuminata; Cola nitida), coconut (Cocos nucifera), bitter kola (Garcina cola), African walnut (Plukenetia conophora), and cashew nut (Anacardium occidentale) ranged from 13.0 to 53.21 µmol Trolox Equivalent/100 g dry weight while the total phenolic content ranged from 204.95 to 1955.14 mg Gallic acid Equivalent/100 g of dry sample. Statistical analysis of the relationship between AA and TPC showed a random, nonlinear relationship between the two parameters, suggesting that the antioxidant activity of the nuts is not dependent on phenolics. The result also indicates that the nuts can be utilized as scavenger/mopping agents of free radicals, which are usually generated by essential metabolic processes in the body and environmental pollutions; thereby alleviating the symptoms of chronic and degenerative diseases such as cancer, diabetes, hypertension and any other age-related diseases reported to be on the increase in developing countries.