Solid-state Fermentation Of Corn Read Rice And Extrection Of Monascus Red Pigments

Red rice contains red pigment,monacolin and other physiologically active substances.The functions are lowering cholesterol,blood sugar,blood pressure.It can be used as coloring agent,health food and pharmaceuticals.Monascus red pigment is natural and safe colorant and widely used in food,cosmetics and medicines.However,the raw material for red rice mainly was rice,the cost is very high.The extraction rate of Monascus red pigment,especially water-soluble Monascus red pigment is low.Paper studied the production of red rice using corn as raw materials to reduce the cost and the extraction process to increase the extraction rate of Monascus red pigment.Taking the color scale and tone as indexes and corn as raw material,five strains of Monascus spp.were screened.The strain M-3.438 was screened by solid-state fermentation and the red value and color tone of are 650 U/g and 0.959.Then taking cell growth as an index,the optimum medium of Monascus seed were determined as maize power of 5%,bean cake powder of 2%,MgSO4 7H2 O of 0.2%,K2HPO4 of 0.05%,pH value of 5.8 and the culture conditions were determined as medium volume 40 mL/250 mL,rotation speed 180 r/min,cultural temperature 30°C,cultural time 75 h.Taking corn as raw material,the soaking time of 18 h,the cooking time of 35 min,adding lactic acid during the soaking and the pH value of 5.5 were determined.The supplemented nutrient was optimized.During fermentation,3 mL nutrient broth containing glucose of 0.2%,yeast extract of 0.3%,ZnSO4 of 0.2% was supplemented every 8 hours.At these conditions,the red value and color tone were 1945 U/g and 1.27,and 199.23% and 32.24% higher than not optimized.The fermentation conditions were optimized.The optimum fermentation conditions of incolum amount 9%,cultural tempreture 30°C,cultural time 9 d were determined.At these conditions,the red value and color tone were 2528 U/g and 1.38,and 199.23% and 32.24% higher than not optimized.Corn red rice prepared by fermentation was accord with national standards.Taking extraction rate of as index,the conditions of extracting of corn Monascus red pigment using ethanol were determined as ethanol concentration of 60%,solid-liquid ratio of 17.5:1,extraction temperature of 60°C for 1.5 h.At these conditions,the extraction rate of Monascus red pigment reached 69.5%.On the basis of this study,the conditions of alcohol extraction by ultrasonic assisted were determined as supersonic wave frequency of 28 KHz,extraction temperature of 40? and extraction time of 30 min.At these conditions,the extraction rate of Monascus red pigment reached 95.4%,was 38.3% more than that not using ultrasound-assisted and extraction time was shorten 1 h..Taking extraction rate of water-soluble Monascus pigment as index,the conditions for extraction were determined as pH value of 5.5,liquid to solid ratio of 50:1,the temperature of 50°C,hydrolysis time of 2.5 h.At these conditions,the extraction rate reached 36.8%.Then water-soluble Monascus red pigment was extracted by ultrasonic assisted.The optimum conditions were determined as extraction temperature of 40°C,ultrasonic power of 300 W for 25 min.Under these conditions,extraction ratio of water-soluble Monascus red pigment reached 70.34%,and was 33.5% more than that of not using ultrasound-assisted extraction.