Phenolic and Antioxidant Capacity Retention of Potato Peel Waste as a Function of Cultivar, Pretreatment and Drying Procedure

Abstract

Drying procedures employed for potato peels (both raw and boiled) may adversely affect the useful bioactive components present in them. This study envisaged the identification of a feasible drying procedure for handling bulk potato peel waste for maximising the retention of phytochemicals in the peel powder. The total phenols (TP), flavonoids (TF) and antioxidant capacity (TAC) were assessed in peels of three commercial and one newly developed anthocyanin rich Indian potato cultivars in response to boiling pretreatment and varying drying procedures. Microwave drying (600W) was best in terms of drying rate for both raw and boiled peels. It yielded the greatest amount of TP and TF in the dried raw peel, irrespective of cultivar. Dried raw peels of an thocyanin rich Kufri Neelkanth cultivar exhibited maximum TAC. Retention of TF, metal scavenging activity and reducing power followed almost a similar pattern as TP irrespective of cultivar, pretreatment and drying procedure. Our study shows that potato peel from Kufri Neelkanth (raw) and Kufri Frysona (both raw and boiled) are best source of phenolics and flavonoids and can serve as a suitable matrix for extraction of bioactive compounds which holds promise for use in the food industry.