Study On The Exploition Of Monascus And The Separation Technology Of Monascus Pigments

Monascus is a probiotic,and the monascus red pigments,the secondary metabolite of Monascus,has been widely used in the food industry.Meanwhile,monascus products are rich in functional substances such as monacolin K,which has the effect of lowering blood lipid.In this paper,Monascus was used as the strain to ferment the rice to produce the monascus rice.The security of monascus rice,determination of monacolin K,conditions of solid fermentation culture and extraction conditions of monacolin K were explored and optimized.At the same time,the monascus red pigments were separated and purified to obtain the single component.The methods for the determination of monacoline K and total arsenic in monascus rice were established.The content of monacolin K in monascus rice was determined by HPLC.This method could accurately determine the content of monacolin K in monascus rice,and the relative standard deviation was 0.04%,the recovery was 98.26%,and there is a good linear relationship between 5-100 ug/mL.The equation is y=15071.74x-312,R~2=0.99829.The total arsenic content in monascus rice was determined by hydride atomic fluorescence method.There is a good linear relationship between 0-25 ng/mL,and the linear equation is y=0.0019 x+0.0045,R~2=0.9914.The effect of each factor on Monacolin K production by monascus was investigated by single factor test.Placket-t Burman was used to screen out the significant factors.Response surface optimization test was used to determine the optimal conditions for Monacolin K solid fermentation to obtain the maximum yield of Monacolin K.The results showed that the best solid fermentation medium was 37.7%rice with grain size of 14 mesh,5.4%bran,52.9%water,2.5%glucose and 1.5%peptone.Adjusting pH to 5 and the loading volume was 60.43 g/500 mL.The optimum fermentation conditions were that the Monascus was cultivated at 30?for 36 h,and the obtained Monascus was transfered into the solid fermentation medium and cultivated initially at 30?for 3 days and then cultivatesd at 26?for 15 days.The yield of Monacolin K under these optimum conditions was 14.53 mg/g.Ultrasound-assisted method was adopted to extract the monacolin K in monascus rice.The effects of four single factors,extraction solvent,material-liquid ratio,extraction temperature,extraction time,on the yield of monacolin K were studied.On the basis of single factor test,the response surface test was used to optimize the extraction condition of monacolin K by taking the yield of monacolin K as the response value.The optimal extraction condition of monacoline K:the solvent was methanol,the solid-liquid ratio was 1:41.79,the extracting temperature was 61.57?and the extraction time was 41.18 min.Under these conditions,the maximum yield of monacolin K was 1.39%.Monascus pigments were extracted from monascus rice by ultrasound-assisted method.And the monascus pigments were purified in order to obtain the single monascus pigment with the highest alcohol solubility.The alcohol soluble monascus pigments were separated and obtained by silica gel column chromatography.Then the variety of the obtained alcohol soluble monascus pigments was detected by silica gel thin layer chromatography.Using the prepared silica gel plate to purify the alcohol soluble monascus pigments,and the single monascus pigment with the highest alcohol solubility was collected.Finally,and the purity of the single monascus pigment was determined by HPLC.