Orange peel flour: A potential source of antioxidant and dietary fiber in pearl-millet biscuit

Orange peels, which consist of valuable bioactive compounds could play an important role in the management of degenerative diseases and yet remain underutilized. This study investigated the effect of orange peel powder (OP) at different level of substitution (5, 10, 15, and 20%) in the production of pearl millet (PM) biscuit on the proximate, antioxidant potentials, dietary fiber (DF), and consumer acceptance. The total phenol content of the biscuit was between 5.84 and 11.87 mg GAE/g, total flavonoid ranged from 1.20 to 8.12 mg QE/g, and ABTS radical content ranged from 1.17 to 2.19 mmol/TEAC/g. DF increased significantly (p < .05) with an increase in orange peel. The DF values ranged from 4.84 to 5.28%. The study shows significant increase in antioxidant properties and dietary fiber with increase in OP. Hence, OP could be used as a functional and nutraceutical ingredient in biscuit production. Practical applicationsOrange peels are agricultural waste generated during the production of orange juice and are valuable natural sources of antioxidants and dietary fiber. They have the potential to be an effective tool in managing chronic-degenerative diseases related to oxidative stress. The combination of pearl millet and orange peel was able to produce functional biscuit which is a promising snack, and has the potential of exposing consumers to new source of antioxidants and dietary fiber. It will also minimize waste and provide value addition to by-product considered as waste in agricultural processing.