Recovery of polyphenols from red grape pomace and assessment of their antioxidant and anti-cholesterol activities

The present work aimed at the recovery and characterization of polyphenolic compounds extracted from red grape pomace (Vitis vinifera L.), a winemaking by-product. Polyphenolic compounds of wet (WP) and dried (DP) red pomace were recovered by enzymatic digestions and ethanol-based extractions. Fungamyl and Celluclast enzymes were found to be the most effective in enhancing polyphenol release from WP. WP samples showed the highest capacity of releasing polyphenols with 2. h control 24°C and 2. h 1% Celluclast resulting as the best treatments. A significantly lower amount of polyphenols was recovered from DP most probably as a consequence of the pomace drying. The best extracts contained high amounts of total polyphenols, flavonoids, tannins and anthocyanins and exerted antioxidant and cholesterol-lowering activities. The results support the possibility of exploiting the extracts coming from grape processing by-products as ingredients for functional and innovative products in the nutraceutical, pharmaceutical or cosmetic fields.