The optimum ratio of EtOH:H2O (50:50 vv-1) was used as a medium for determination of extraction time affecting the phenolic antioxidant separation from the peel and seed of the Royal Project fruit samples. The optimum time of extraction was estimated from the IC50 value in which the lowest value was the highest antioxidant capacity. The time of 2 h was the optimum condition to extract antioxidants from Japanese pumpkin peels (JP), papaya seeds (PS), Japanese pumpkin seeds (JS), cantaloupe peels (CP), cantaloupe seeds (CS) and muskmelon seeds (MS), whereas optimum extraction time of 8 h
115Vol