Liberation and recovery of phenolic antioxidants and lipids in chokeberry (Aronia melanocarpa) pomace by solid-state bioprocessing using Aspergillus niger and Rhizopus oligosporus strains

•Solid-state fermentation (SSF) of chokeberry pomace with A. niger and R. oligosporus.•Polyphenolic amounts and antioxidant potentials increased significantly by SSF.•A longer fermentation time resulted in greater loss of total anthocyanins.•SSF resulted in lipids with better nutritional-quality characteristics.

The present study focused on the changes in polyphenols, antioxidant activities and lipid compositions from chokeberry pomace during solid-state fermentation (SSF) with Aspergillus niger and Rhizopus oligosporus. The extractable phenolics increased more than 1.7- fold during both fermentation processes. A similar trend was observed for total flavonoids. The obtained results also indicated that a longer fermentation period resulted in a greater loss of anthocyanins. The free radical scavenging ability of phenolic extracts, evaluated by DPPH and TEAC assays, were significantly enhanced during the SSFs. HPLC-MS analysis of phenolic compounds showed that the amounts of flavonols and cinnamic acids increased while the concentrations of glycosylated anthocyanins decreased substantially. The SSF of chokeberry pomace also resulted in a significant increase in lipids with high linoleic acid content (57-61% of the total fatty acids). The present investigation demonstrated that SSF enriched the chokeberry pomace with phenolic antioxidants and lipids with better nutritional-quality characteristics.