Fractionation of hydro-ethanolic extracts from grape pomace through membrane processing: the effect of membrane and extracting media on process performance

Abstract

Grape pomace are generated as waste in juice and winemaking industry in huge quantities. Studies have shown that nutrient extracts from these particular plant matrices garner myriad of benefits in health and nutraceuticals sector. Moreover, the newer recognition of monomeric and oligomeric phenolic compounds as bioactive molecules of commercial value such as gallic acid, catechin, epicatechin, quercetin and resveratrol gives scope for its extensive study and extraction from the pomace. The need for optimizing the biocompatible solvent extraction of ethanolic-water composition is realized and the kinetics of extraction time is demonstrated. The work focusses on novel use of membrane technology for separation and fractionation of lower flavan-3-ols from the crude extract. Four different membranes of varied pore size, chemical nature and material were chosen. Of these, Duramem 900, a class of Organic Solvent Nanofiltration membrane showed lower rejections of monomeric and oligomeric phenolic compounds. This membrane was then subjected to the comparative study of nanofiltration and diananofiltration.