Effect of plant maturity on the antioxidant profile of amaranthus cruentus and celosia argentea

ABSTRACT: Amaranthus cruentus L. and Celosia argentea L. were analyzed for antioxidant activities and antioxidant phenolic compounds at 3, 4, 5 and 6 weeks maturity. The results of the study showed that as A. cruentus matured from 3 weeks to 6 weeks after planting, antioxidant activities, total phenol and flavonoid concentrations increased. Antioxidant activities ranged from 40-74%, total phenol ranged between 2750-6330 mg/100 g while flavonoid was between 91-125 mg/100 g. Antioxidant activities, total phenol and flavonoid concentrations of C. argentea peaked at 5 weeks, after which there was reduction. Antioxidant activities was generally high in C. argentea (75-81%) while total phenol ranged between 9167 to 19344 mg/100 g. Antioxidant activities of C. argentea was higher than that of A. cruentus at 3 to 5 weeks of harvest but not significantly higher at 6 weeks. In terms of antioxidant profile, these vegetables are best consumed at 5-6 weeks of age.