Soybean isoflavones reduce citrinin production by Monascus aurantiacus Li AS3.4384 in liquid state fermentation using...

Monascus, a filamentous fungus, produces many bioactive substances. However, in the process of fermentation, Monascus also produces the mycotoxin citrinin. Owing to the presence of citrinin, the safety of Monascus products has been questioned and their wide application limited. Using soybean isoflavones (SI) as exogenous additives, alterations in citrinin production by Monascus aurantiacus Li AS3.4384 (MALA) in different media used for liquid state fermentation were investigated.

Results showed that the citrinin concentration was 95.98% lower than that of the control group after 16-days fermentation when 20.0 g L^-1 SI were added to rice powder and inorganic salt medium. Citrinin production was reduced by 97.24% after 12-days fermentation with 10.0 g L^-1 SI in starch inorganic salt medium; 82.52% after 20-days fermentation with 20.0 g L^-1 SI in starch peptone medium with high starch content; 45.07% after 14-days fermentation with 5.0 g L^-1 SI in starch peptone medium with low starch content; and 82.21% after 14-days fermentation with 20.0 g L^-1 SI in yeast extract sucrose medium.

The developed method of removing citrinin is simple, safe, and effective, and it can be applied to reduce the citrinin content of Monascus products. © 2019 Society of Chemical Industry.