Optimization of the hongqu starter preparation process for the manufacturing of red mold rice with high gamma‐aminobutyric acid production by solid‐state fermentation.

Red mold rice (RMR) generally contains gamma‐aminobutyric acid (GABA), which has several physiological functions. Monascus purpureus M162, with a high GABA production of 15.10 mg/g was generated by atmospheric and room temperature plasma mutation. Furthermore, we conducted a response surface methodology to produce a premium hongqu starter. The results revealed that under optimal conditions, that is, a substrate containing brown rice and bran in a brown rice: bran ratio of 9:1 (wt/wt), an inoculation size of 21.50 mL/100 g, a mixing frequency of one time/9 h, and a cultivation time of 7.20 days, the number of active spores, α‐amylase activity, and saccharification power activity was 4.15 × 107 spores/g, 155 U/g, and 3260 U/g in the high‐quality starter, respectively. These values were 224.32‐fold, 139.64%, and 141.74% higher than those obtained with M. purpureus M162 inoculated into steamed indica rice, respectively, and 153.70‐fold, 267.24%, and 151.63% higher than those obtained with the parent strain M. purpureus M1, respectively. The premium hongqu starter of M. purpureus M162 was inoculated into steamed indica rice to produce RMR with 15.93 mg/g of GABA. In conclusion, we proposed a novel strategy for functional RMR production with high GABA concentrations by solid‐state fermentation with Monascus spp. [ABSTRACT FROM AUTHOR]