Utilization of grape pomace extract as a source of natural antioxidant in biscuits

Abstract

In the present study, grape pomace extract (GPE) was employed as a source of natural antioxidants to reduce lipid oxidation in the food matrix. The total phenolic of GPE was investigated by three various solvents (methanol, ethanol, and acetone). Individual phenolic compounds by HPLC and antioxidant capability, including 1,1- diphenyl-2-picryhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) tests, were also evaluated. The obtained results showed that GPE owned good antioxidant activity, which gives DPPH of 86.89% and FRAP of 73.93%. Peroxide values (PV), free fatty acids (FFA), and thiobarbituric acid (TBA) were applied as measures to assess the antioxidant efficacy of GPE (0.5%, 1%, 2% and 3%) in biscuits. At the end of 6 months storage period of biscuits, it was observed that increasing the GPE concentration enhanced the capability of inhibiting lipid oxidation. The findings from this work demonstrate that GPE at various levels exhibited very powerful antioxidant ability. Therefore, grape pomace extract in fatty food products could be utilized as a natural antioxidant to reduce lipid oxidation, which can be useful for future food applications