The fermentation of rice for anka pigment production

Optimal physical parameters of the solid state fermentation of rice to produce anka pigments and their influences on pigment production were studied. Anka pigment production, especially that of two orange anka pigments (rubropunctatin and monascorubrin), was highly sensitive to the moisture content of the rice substrate. Optimal initial moisture content of rice substrate was 24%. Pigment formation was retarded when extra water was added to the inoculated substrate during cultivation. High filling amount of rice substrate in a flask was unfavorable for pigment production. Loosening of the inoculated substrate once a day enhanced pigment production. With a high carbon dioxide level in the incubator, no orange pigments were detected. Freeze drying the fermented material produced a superior yield of anka pigments, while oven drying at 50°C for 24 h was a reasonable alternative. Journal of Industrial Microbiology & Biotechnology (2000) 25, 141–146.