Studies On γ-Aminobutyric Acid Enrichment Technology In Rice Bran And Development Healthy Soft Drink

The changes of GABA content in rice bran during accumulation in different buffer system were investigated.The effects of culture solution components and culture condition on GABA content in rice bran were observed.The GABA-rich rice bran solution was used as main submerged fermentation substrate for Ganoderma lucidum cultivation.The broth was used as the main raw material of rice bran beverage for further research and development.1.Compare the effects of PBS with CBS and ABS on GABA accumulation in rice bran.Results showed that the maximum GABA content reached 258.0 mg/100 g in PBS. The maximum GABA content in PBS was 1.6 times and 3.2 times as in CBS and ABS, respectively.The cultivate system was PBS,80 mmol/L,time 6 h,the ratio of solution to solid 15.The contents of cultivate solution components,sodium glutamate(MSG),calcium chloride(CaCl₂),vitamin B₆(VB₆) on GABA accumulation in rice bran were optimized by Box-Behnken design.Results showed the maximum GABA content up to 602.82 mg/100 g was 1.37 times as the control when MSG 52.9 mmol/L,CaCl₂ 1.44 mmol/L,VB₆ 0.62 mmol/L.2.The condition parameters of GABA accumulation in rice bran were optimized by response surface design.The optimization condition parameters for GABA accumulation in rice bran were temperature 41.3℃,pH 5.2,time 6.1 h.Under those conditions,the GABA content reached 679.2 mg/100 g,which was 1.14 times as the control.3.GABA-enriched rice bran solution was used as main submerged fermentation substrate for Ganoderma lucidum cultivation.The indexes of fermentation process were investigated during fermentation.Total sugar,reducing sugar,soluble solid content in the fermentation process showed a downward trend;pH,crude polysaccharide content,free amino acid content at first declined then rebound,while GABA levels remained unchanged.4.The rice bran healthy soft drink was developed using Ganoderma lucidum fermentation broth as main raw material.The rice bran drink consist of Ganoderma lucidum fermentation broth 20%,defatted milk powder 2%,Jujube juice 16%, Acesulfame-K 0.005%.The composite stabilizer of beverage consist of A(edible gelâ… ) 0.25%,B(edible gelâ…¡) 0.06%,C(edible gelâ…¢) 0.15%,D(Duality improver)0.06%.The fuzzy comprehensive evaluation methodology was carried out for rice bran drink evaluation; results showed the drink was acceptable by comsumers.