Effects of blanching and drying treatment on the phtyochemical properties of annona squamosa peel

Abstract

Processing of Annona squamosa (custard apple) generates considerable amount of wastes in the form of peels and seeds rich in phytochemicals which can be exploited to investigate its neutraceutical properties, and used as an alternative to synthetic food additives. The present study was designed to probe into the effects of blanching and drying treatment of the Annona squamosa peel. Results demonstrated that blanching and drying had considerable effects on colour and phytochemical properties of the powdered peel. The colour values revealed that the blanched-dried sample exhibited greater L∗ value (74.590) at 7 min than the unblanched sample (63.033) dried at 55°C. An increasing trend of lightness (L∗) followed with the increase in blanching time and drying temperature. Antioxidant activity for unblanched sample dried at 50°C and sample blanched for 5min and dried at 50°C exhibited better IC50 values of 104.712 ìg/ml and 148.23 ìg/ml respectively. The unblanched-dried (50°C) and blanched-dried (50°C-5min) sample similarly exhibited better retention of total polyphenols, 20.06 ± 0.6mg/mL and 37.9 ± 1.0mg/mL, respectively. Thus, this study suggests that combination of drying temperature of 50°C and blanching time of 5 min are the optimum processing conditions for good retention of antioxidant property of Annona squamosa peel.