Dynamic changes of active substances of rice, Pueraria and yam fermentation by Monascus ruber
Y. Wang, Chao Gao, Pengcheng Long, Zhuoyu Hu, Lisha Zhu, Liling Wang, Yanchun Shao, Bin Wang, Yi He
Abstract
Monascus spp., a fungus of medicine food homology, produces various beneficial secondary metabolites such as monacolin K (MK) during fermentation. In this study, the mixed fermentation of Monascus with rice, Pueraria, and yam has been systematically investigated. Single-factor and response surface methodology (RSM) were carried out to maximize MK content, and the optimized fermentation results showed that the content of MK reached 1.40 ± 0.04 mg/g. The optimal fermentation process determined the ratio of 8: 1: 1 for rice, Pueraria, and yam, respectively, the inoculation amount was 106 spores/mL, fermentation time was 15 days. Further analysis of the content of active substance in the fermentation process revealed that the β-glycosidase activity increased, the amylase enzyme activity decreased, the dioscin content decreased by 19.5%, and the diosgenin content increased by 175%, suggesting that there was a dynamic equilibrium relationship among the changes of active substances. This study aims at provide a basis and reference for the research of Monascus fermented foods by medicine food homology raw materials.