Production of citrinin by Monascus strains used in food industry

Thirty-five Monascus strains used in food processing were selected to conduct the effect of cultivation conditions and the medium composition on citrinin production with the aim of screening for the strains with less or nearly non-citrinin production. The results indicated that all strains produced citrinin on solid-state culture (rice) with the levels ranged from 0.28 to 2460 mg/kg (average 202 mg/kg and median 62 mg/kg), while 30 strains (86 %) in submerged fermentation medium produced citrinin between 0.09 and 56 mg/kg (average 12 mg/kg and median 3.5 mg/kg). In addition, the red pigment production on rice was found to be 3-510 (average 93) times higher than that in the liquid. One strain with the highest red pigment yields (color value, 1130 U/g) but lower citrinin production was obtained. These results suggest that it is necessary to make the safety evaluation of microorganisms used for the production of foods and food ingredients, to investigate the ability of citrinin production by Monascus strains preserved by either the food manufacturers or the national culture collection units, and to survey for the citrinin contamination in Monascus products countrywide. It is urgent for China to establish the tolerance limit for citrinin in Monascus products.