Use of grape pomace for the production of hydrolytic enzymes by solid-state fermentation and recovery of its bioactive compounds.

A cocktail of biomass hydrolytic enzymes was produced by solid-state fermentation (SSF) by the mutant strain Aspergillus niger 3T5B8, using as substrate a mixture of grape pomace and wheat bran, and compared to the production when wheat bran was used as the sole substrate. The two enzymatic cocktails were subsequently used for the extraction of bioactive compounds from grape pomace and the relationship between the activities of the cocktail and the release of phenolic compounds was evaluated. Although the wheat bran SSF process was more effective for enzyme production, the enzymatic cocktail produced by the grape pomace - wheat bran mixture was more effective for the extraction of compounds with higher proanthocyanidins content and higher antioxidant potential (p < 0.05). A significant correlation between the bioactive compounds and enzyme activity was observed.