COMPARATIVE STUDY ON PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY OF FEUTRELL'S EARLY AND KINNOW PEEL EXTRACTS

Phenolic compounds and antioxidant activities of 70% ethanol extracts of the peels from two Pakistani citrus mandarin cultivars, namely, Feutrell's Early and Kinnow, were investigated. Results were compared with synthetic antioxidants and also with Chinese Ponkan mandarin peel to see the varietal and geographical effects. The cultivars showed the significant differences in total polyphenols, flavonoids and phenolic acids. Ferulic acid ranging from 1193.84 to 1640.87 mu g/g dry weight was the dominant phenolic acid in all cultivars. The antioxidant activity of extracts as determined by beta-carotene bleaching assay ranged from 28.40 to 43.78% and was in the following order: Kinnow < Feutrell's Early < Ponkan. A strong positive correlation was observed among the analyzed phenolic compounds and the antioxidant capacities. Results reveal that citrus peels under study might be used as an economical source of natural antioxidants, and both cultivars and geographical factors affect the bioactive composition in citrus mandarin peel.