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.