Optimization of solid state fermentation preparation for yam fermented by monascus

ObjectiveSolid state fermentation preparation for yam fermented by monascus was optimized to provide technical support for yam resources development and utilization. MethodUsing yam as raw materials, on the basis of single factor test, fermentation time, substrate quantity, inoculation rate and initial moisture content of medium as investigation factors and color value as evaluation index, the optimum solid state fermentation condition for yam fermented by monascus was determined by orthogonal test. According to QB/T2847-2007 Functional Monascus Rice(Powder) and GB/T5009. 124-2003 Measure ment of Amino Acid in Food, functional components of yam fermented by monascus was analyzed.ResultThe order of factors affecting solid state fermentation preparation for yam fermented by monascus was as follows:substrate quantity>initial moisture content of medium>fermentation time>inoculation rate. In addition, the optimal fermen-tation conditions were: fermentation time 13 d, substrate quantity 45 g(placed in 250 mL triangular flask), inoculation rate 0.4% and initial moisture content of medium 60%. In this condition, the average color value of yam fermented by monascus reached 1205.42 u/g. The content of functional components for blood lipid reduction Monakelin K was 80.00 mg/100 g, which was 10.00 times of monascus before fermentation. The content of functional components for blood pressure declineγ-aminobutyric acid was 31.74 mg/100 g, which was 10.58 times of monascus before fermentation. ConclusionUsing yam as substrate quantity instead of indica rice for monascus, the obtained monascus yam contains high functional compo-nents. This study could open up a new way to make full use of yam resources.