Regulation of phenolic release in corn seeds (Zea mays L.) for improving their antioxidant activity by mix-culture fermentation with Monascus anka, Saccharomyces cerevisiae and Bacillus subtilis

In this study, mix-culture fermentation (MF) with M. anka, S. cerevisiae and B. subtilis to regulate phenolic release in corn seeds was investigated. Results showed the adding strategy of S. cerevisiae and B. subtilis significantly (p < 0.05) influenced the total phenolic content (TPC) of corn seeds, and the highest TPC in MF was 22.56-fold rise than that of unfermented control. Moreover, the phenolic compounds in corn seeds were shifted after MF. SDS-PAGE revealed some enzymes produced by microorganisms were regulated, and the α-amylase and FPase activities were changed to improvement in MF. SEM micrographs of corn seeds in MF varied markedly with the cell walls structure destroyed, so as to release of the phenolic fractions in corn seeds. Based on the phenolic mobilization, DPPH and ABTS⁺ radical scavenging abilities of phenolic fractions from corn seeds were improved in MF. This paper provides a prospect fermentation process for improving the phenolic release in corn cereals.

Keywords: Antioxidant activity; Corn cereals; Mix-culture fermentation; Phenolic release.