Optimization Of Solid-state Fermentation And Extraction Methods For High-yield Orange Pigment Red Yeast Rice

Monascus is a traditional medicinal and edible fungus that can produce a range of beneficial secondary metabolites such as Monascus pigment through solid-state or liquid fermentation.Monascus pigment has physiological multiple functions such as lipid-lowering,anti-inflammatory,anti-cancer,antibacterial,antioxidant and so on.In this experiment,the solid-state fermentation of Monascus CS9,CS8 and MPs-8 preserved in the laboratory were used to study the effects of different fermentation substrates,different seed liquids,different fermentation methods and fermentation period on the yield of orange pigment in Monascus fermentation products.The flavor of the solid-state fermentation products were determined.And the extraction methods of orange pigment were optimized,the result are as follows:Using Monascus CS9 for solid-state fermentation adding okara and soybean meal to the fermentation substrate can promote the production of secondary metabolites to a certain extent adding zinc sulfate to the fermentation substrate can greatly improve the color value of Monascus CS9 fermentation products.Compared with the blank rice matrix the color value was increased by 267 times.The effects of different zinc sulfate concentrations,different seed liquors and fermentation methods on the yield of orange pigments in solid-state fermentation of Monascus CS9 were studied.The optimal solid-state fermentation conditions of Monascus CS9 are:rice with 1 mmol/100g zinc sulfate,seed liquid medium is glucose 6%,peptone2%,KH₂PO₄1%,Mg SO₄.7H₂O 0.5%,tissue culture flask,fermentation for 12 days.The content of orange pigment O1 was as high as 198.79 mg/g,the content of O2 was as high as 223.87 mg/g,and the content of citrinin was 10.11μg/g under these conditions.The effects of different seed liquid media on the solid-state fermentation of Monascus MPs-8were studied,and the trend was similar to that of Monascus CS9.The volatile flavor compounds of Monascus CS9 blank rice group and rice added1 mmol/100g zinc sulfate group were determined by GC-MS.The results showed that the blank rice group was rich in esters,up to 34 kinds,and had a strong wine flavor.The volatile flavor substances are alcohols and esters,the main volatile flavor substances in1 mmol/100g zinc sulfate group are ketones,alcohols and olefins.The extraction method of monascus orange pigment was optimized,the results showed that the use of petroleum ether:dichloromethane=2:1（v/v）,petroleum ether:ethyl acetate=2:1（v/v）had the best extraction effect on monascus orange pigment,and could reduce the red pigment The interference of components is beneficial to the quantitative analysis of orange pigment.By optimizing the solid-state fermentation conditions of Monascus,a fermentation sample with high yield of orange pigment and low yield of citrinin was obtained.At the same time,optimizing the extraction method of monascus orange pigment.It can provide a reliable technical platform for the development of new products of natural monascus orange pigment,and provide a certain reference value for the industrial production of monascus orange pigment.