[Study on the production of citrinin by Monascus strains used in food industry]

Abstract

In order to screen strains with less or nearly no production of citrinin, thirty-five Monascus strains used in food industry were selected to investigate the effect of cultivation condition and the medium composition on citrinin production. The results from the study indicated that all strains produced citrinin on the rice with the levels ranging from 0.28 to 2458.80 mg/kg (201.60 mg/kg for the average and 61.99 mg/kg for the median, respectively), while 30 strains (85.71%) yielded this toxin on the submerged culture with the concentration between 0.09 and 55.65 mg/kg (11.99 mg/kg for the average and 3.51 mg/kg for the median, respectively). Therefore, citrinin production in rice in this study was higher than that in the liquid. In addition, the red pigment production in rice was 3-509 (average 93) times higher than that in the liquid. One strain with the highest color value (1134 U/g) but lower citrinin production in rice was obtained. These results suggested that it is necessary to make the safety evaluation of microorganisms for the production of foods and food ingredients, to investigate the ability of citrinin production by Monascus strains preserved by either the food manufacturer or the national culture collection units and, to survey the citrinin contamination in Monascus products countrywide. It is urgent for China to establish the tolerance limit of citrinin in foods fermented by Monascus species.