Comparative study of red yeast rice with high monacolin K, low citrinin concentration and pigments in white rice and brown rice

Abstract

Growth pigments and metabolites of monacolin K and citrinin were compared for Monascus purpureus during 14-day solid-state fermentation on white rice and brown rice (Chai-Nart cultivar). Monascus purpureus IFRPD 4046 was selected as the target strain which produced the highest monacolin K content and the lowest citrinin content. Optimum fermentation conditions regarding moisture content, temperature and fermentation time were determined. A comparative study showed that monacolin K production in white rice was about twice higher than in brown rice. At the optimum conditions, concentrations of monacolin K dried at 55°C to constant weight were 132.98 and 66.48 mg/100 g in white rice and brown rice, respectively while citrinin was not detected. Results revealed that the IFRPD 4046 strain has a potential to produce red yeast rice with higher monacolin K in white rice than in brown rice with low citrinin content.