Plantain peel - a potential source of antioxidant dietary fibre for developing functional cookies

Abstract

Plantain cultivar Nendran is popular as a staple food in many parts of India and deep fried chips made from raw matured Nendran are one of the popular snack items in India. This study aims to utilize peel from Nendran varietythe main byproduct of banana chips industry- to develop high fibre cookies with enhanced bioactive content. Proximate analysis indicated that peels are rich in total dietary fibre (64.33 g/100 g), vitamins (Folic acid- 33.12 mg/100 g) and minerals (Potassium- 35.61 mg/100 g). Nendran Peel Flour (NPF) was extracted with hexane, ethyl acetate and methanol. Phenolic and flavonoid content was high for ethyl acetate extract (15.21 and 9.39 mg QE/g dry weight). Methanol extract was more potent in reducing Copper ion (2.36 μM TR/g dry weight) and scavenging NO (IC50-381.71 μg/mL). Ethyl acetate extract was capable of scavenging DPPH and hydroxyl radical. HPLC profiling showed presence of gallic acid, protocatechuic acid, rutin hydrate and quercetin in ethyl acetate extract and gallic acid, chlorogenic acid and vanillic acid in methanol extract. Cookies prepared with NPF possess higher total dietary fibre content. There was a decrease in spread ratio, breaking strength and browning index of cookies as the percentage of NPF increased. NPF incorporation gradually increased the phenolic content from 4.36 to 5.28 mg GAE, compared to control cookie (3.21 mg GAE). DPPH scavenging activity also increased with increase in NPF. Hence NPF is a very good source of antioxidant dietary fibre and acceptable cookies can be produced by replacing wheat flour with 10 % NPF