Effects of onion peel extract on bioactive components, textural and sensory characteristics of chickpea-based fried snack

Onion peel waste is generated in huge amount during processing. This waste is a huge source of antioxidants specially quercetin. Therefore, it can be utilized to increase the phenolic and flavonoid content of food products. The present study proposed the use of different onion peel extracts (OPE) in a South Asian snack called “sew.” Sew is a cold-extruded rod-shaped snack made from chickpea flour and spices. After extrusion, it is deep fried till appearance of golden-brown color. The polyphenols from onion peels were extracted in (a) EWE (ethanol and water-based) medium, (b) EAAE (ethanol and acetic acid-based) medium, and (c) WE (water extract). These three OPEs were separately sprayed over chickpea grits before making flours, which were then used for making sew. Antioxidant activity of EWE, EAAE, and WE extracts were found to be 59.06%, 36.85%, and 28.07%, respectively, and both gram-positive and gram-negative bacteria were inhibited by these three extracts. Addition of OPE led to a significant increase in antioxidant activity of snack (sew), and panelists were unable to perceive any statistical difference in control and extract added snacks in terms of sensory attributes. Interestingly, marked improvement was observed in textural characteristics (measured objectively) of snacks containing extracts and the percent decline in hardness as observed in EAAE, EWE, and WE containing fried snacks were found to be 56.83%, 37.95%, and 34.55%, respectively, after 60 day's storage, whereas 71.28% decline was recorded for control snack. Thus, incorporation of OPE proved to be an innovative method to improve the nutraceutical profile of chickpea-based fried snack.