Antioxidant activity of custard apple (Annona squamosa) peel and seed extracts

Non-edible portions (seeds and peel) of custard apple (Annona squamosa) were extracted with solvents of varying polarity and evaluated for their antioxidant activity (AA) using 1,1-diphenyl-2-picryl hydrazyl (DPPH) and beta-carotene-linoleate model systems (P-CLAMS). The yields of methanol (MeOH) and ethyl acetate (EtOAc) extracts were higher from peel and seeds, respectively than other extracts. Various extracts responded differently to these model systems and exhibited varying degrees of AA. MeOH extract of the peel showed higher AA by beta-CLANIS (52.6% at 50 ppm) and DPPH method (90.6% at 25 ppm) than other extracts. However, in the case of seeds, acetone extract showed higher AA by beta-CLAMS (55.1% at 50 ppm) and DPPH method (83.3% at 25 ppm). Similar pattern of activity was also exhibited by the extracts using phosphomolybdenum method for the determination of antioxidant capacity (A-Cap).