A study on the production of citrinin by Monascus spp.

The mycotoxin citrinin was detected by TLC and by HPLC in Monascus cultured on "red rice", collected from various manufacturers. Most,,red rice" sampl es (n = 32) contained citrinin in a range from 0.2 mg/kg to 140 mg/kg, whil e citrinin was not detected in three,,red rice" samples. Monascus strains w ere isolated from these samples of "red rice", and some strains (Monascus a nka and Monascus ruber) were identified as potential citrinin producers whe n cultivated in YES medium. Cultivation of one strain in solid and submerge d cultures (synthetic medium) was carried out to aim at citrinin-free produ ction of Monascus pigment. When monosodium glutamate or histidine were used as the sole nitrogen source to cultivate Monascus ruber strain JH-2 (a pot ential citrinin producer in liquid culture), no citrinin was detected in th e fermented broth, while fermentation on rice or wheat resulted in high tox in concentrations. Finally, aspects of citrinin determination methods (TLC, HPLC) for high color value "red rice" samples are discussed in this paper.