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

•Mix-culture fermentation (MF) of corn seeds is established to improve total phenolic content.•Adding strategy of S. cerevisiae and B. subtilis affects phenolic release in MF corn seeds.•FPase and α-amylase activities are related to phenolic mobilization of corn seeds in MF.•SEM and SDS-PAGE reveal the process of phenolic release in corn seeds during MF.•Phenolic fractions form MF exhibit high DPPH and ABTS+ radical scavenging activity.