(1) The Monascus erythraea is inoculated into the fermentation broth at a fermentation temperature of 32 to 34 ° C, a pH of 6 to 8, and a fermentation time of 60 to 90 hours.

In the above fermentation process, the pH value changes, the fermentation starts to adjust the pH at 7.3-7.8, the best 7.5; after the fermentation for 22-26 hours, the pH drops to 6.8-7.2, the best 7; to the fermentation 46-50h, pH It is 6 to 6.5, preferably 6.5; the pH is maintained until the end of the fermentation.

(2) filtering the fermentation broth (1), pickling the monascus pigment cake containing the hyphae and the insoluble water, and then dissolving the filter cake in an organic solvent, and simultaneously adding an appropriate amount of glutamic acid to the solvent to adjust The pH was 9 to 11, stirred, filtered, and the filtrate was passed through an ion exchange resin capable of removing residual glutamic acid, followed by removal of metal impurities therein, followed by filtration to obtain a scarlet red water containing red soluble red pigment.

(3) The filtrate (2) was spray-dried to obtain a purple-black modified red yeast red powder.