Study On Enrichment Of γ-Aminobutyric Acid By Fermentting Rice Bran

Rice bran is a by-product in the rice processes. A rice bran resource is rich in China. To improve the utilization ratio of rice bran, this article studied the production of the γ-Aminobutyric acid (GABA) by liquid and solid state fermentation methods, which used the rice bran as the raw material and fungus as the Aspergillus oryzae.The basic elements of the main raw material rice bran were analyzed.The effects of fermentation conditions, including the temperature, relative humidity, cultivating time, inoculation quantity and the rotation speed on the cultivation (RSC) were studied. The result showed that the optimum conditions of the solid state fermentation for producing the γ-Aminobutyric acid were at 32℃,3 days cultivation,10% of inoculation quantity and 90% of relative humidity;And the optimum conditions of the liquid state fermentation method for producing the γ-Aminobutyric acid were:at 28℃,2 days cultivation,10% of inoculation quantity and 130 r/min of RSC. Based on the results of single factor test, the optimum project of glutamic acid (Glu), calcium chloride and Tween-80 of medium components to enrichment of γ-aminobutyric acid by Rice Bran by L9(33) orthogonal experiment. The optimal conditions of enrichment technology were obtained through orthogonal experiment:Glu 5g, CaCl2 4g, Tween-80 4ml.Under these conditions, the content of GABA was 142.04 mg/100 g dry weight solid by solid state fermentation;And Glu 5g, CaCl2 5 g, Tween-80 4ml.Under these conditions, the content of GABA was 92.80mg/100 g dry weight solid by liquid state fermentation.The experimentations were carried out about the effect of the optimal fermentation products on the protein, polysaccharide and the ability to remove DPPH ·. The optimal liquid fermentation product of the highest protein content to 17%. And the optimal solid fermentation product and rice bran were 14.5% and 13.1%, respectively. And the rice bran polysaccharide content is the highest, about 19.5%, after fermentation has trace loss,15.4% of solid fermentation and 16.6% of the liquid fermentation. Fermentation extract on DPPH · have clear effect, but free radical clearance rate is lower than Vc. After fermentation sample extracts clearance rate is higher than rice bran extract, And the free radical clearance rate of solid fermentation is 83.09, So the fermentation products have certain antioxidative ability.Through analyzing the experimental data, solid state fermentation equipment was successfully designed. It is suggested that dynamic fermentation was better than static fermentation in the aspect of the strains with a beneficial effect on metabolism. To some extent, the solution of fermentation uneven had been resolved and the efficiency of fermentation had been improved.