Evaluation of Cellulolytic Enzyme-Assisted Microwave Extraction of Punica granatum Peel Phenolics and Antioxidant Activity.

Abstract

Conventional techniques for phenolics extraction from pomegranate (Punica granatum) peel (PP) have several insufficiencies like longer time duration, bioactive degradation, excess use of harmful chemicals and solvents. In the present study, we established the synergistic use of two non-conventional extraction strategies i.e., enzyme-assisted extraction (EAE) using a cellulolytic enzyme preparation (Viscozyme) followed by microwave-assisted extraction (MAE) for efficient recovery of phenolics from PP. This optimized method was individually compared with EAE, MAE, and conventional solvent extraction (CSE) methods for recovering PP phenolics with maximum antioxidant activity (AOA). Extracts were analyzed for AOA using ferric reducing antioxidant power (FRAP) and cupric reducing AOA (CUPRAC) methods. Response surface methodology (RSM), was used as an optimization tool to achieve maximum yield of phenolics and with highest AOA at power 443.5W, time 131.0min, and solvent-to-solid ratio 23.6:1. The predicted values for maximum phenolics and AOA obtained through RSM were 305mg GAE/g, 1788μmol TE/g (FRAP) and 2641μmol TE/g (CUPRAC), respectively. Phenolic contents of only 94.6, 165.46, and 197.6mg GAE/g were achieved through CSE, EAE and MAE, respectively. Here we substantiate the auxiliary role of Viscozyme and microwave treatment in achieving high phenolic content and AOA from PPs. Phenolic rich extracts are known to act as multi-target ligands that inhibit various enzymes involved in diseases like Alzheimer's, Parkinson's, and diabetes mellitus. The extract can be commercially exploited for the development of functional foods, supplements, and natural preservatives.