Fungal enhancement of the antioxidant properties of grape waste

Abstract

The physico-chemical properties of grape waste were characterized to evaluate its potential to support the fungal growth of four Aspergillus and three Penicillium strains under solid-state fermentation (SSF) conditions for the production of phenolic antioxidants. In addition, the free radical-scavenging potential of DPPḢ and ABTS°+ radical solutions and lipid oxidation inhibition by linoleic acid peroxidation of extracts from fermented and unfermented grape waste were measured. Chemical profiling demonstrated that grape waste is a potentially good substrate for fungal SSF. The antiradical properties of grape waste were significantly enhanced (P< 0.05) after SSF with the Aspergillus niger GH1 strain, and those properties were well correlated with gallic acid content in the samples. Lipid oxidation inhibition was prevented using the extracts obtained from first 24 h of fermentation. We conclude that grape waste is a potential substrate source for the production of antioxidant compounds in a SSF system. © Springer-Verlag and the University of Milan 2011.