Study on Red Pigment and Citrinin Present in Red Yeast Rice Prepared from Thai Rice

Red yeast rice was prepared using Monascus purpureus CMU001 by fermentation on various kindsof Thai rice, especially, the most well known varieties of white glutinous rice such as Kor Kho 6 (RD6)and Sanpathong 1 (SPT1), purple glutinous rice (Kam), and non-glutinous rice (Mali105). In order to studythe effect of nutrient variation, soybean milk was also added during cultivation as amino acids source. Thered yeast rice products obtained were studied for the intensity of red pigment. The results indicated thatthe most intense red pigment was present in RD6 at 3 weeks of cultivation without soybean milk. On theother hands, the highest intensity was achieved when RD6 used was only at 2 weeks of cultivation withsoybean milk. For the analysis of citrinin content, the results suggested higher amount when glutinous ricewas used. The highest amount was found in SPT1 red yeast rice fermented for 2 weeks. The best resultwith the lowest amount was found, among glutinous rice, in RD6 fermented for 3 weeks in the presence ofsoybean milk. Keywords : Citrinin / HPLC / Monascus purpureus / Red Pigment / Red Yeast Rice