Study On The Fermentation Technology Of Brown Rice Enzyme And Development Of Germinated Brown Rice Food Rich In GABA

Germinated brown rice leaven was a enzyme mixture fermented by germinated brown rice and germinated brown rice as main materials,adding honey and malt powder.Glutamic acid decarboxylase catalysis glutamate to synthesis GABA,kind of non-protein amino acid.As a kind of important inhibitory neutrotransmitters,it plays a very important role in life.This paper,one special starter for germinated brown rice leaven was select,and the optimum technological conditions were obtained through orthogonal optimization.Two kinds of germinated brown rice food enriched with GABA were developed.The main results are as follows:(1)This paper optimized the detection method of GABA in germinated brown rice.GABA had a good linear relationship in 0.02～0.6 mg/mL,related coefficient(r)was 0.9992.Mg was the highest trace element in brown rice sample,followed by Ca,far greater than Fe and Zn.Different brown rice samples of GABA content had significant differences(p<0.05).Germinated brown rice of 7 had the highest GABA content,almost 3 times of white rice of Num 5,and 6.Therefore,this paper selectd germinated brown rice as experiment materials.(2)Effect of Strains variety on GABA content and amylase activity was significantly different(P<0.05).Russian yogurt starter with 5 strains and high-sugar-tolerance active dry yeast of mauripan was the starter of lactic acid bacteria and yeast strains,respectively.However,GABA and amylase activity decreases,with the increase of proportion of yeast in mixed bacteria.Therefore,Russian yogurt starter with 5 strains was selectd as the special starter for germinated brown rice leaven.With GABA content as indexes,the optimum fermentation conditions was obtained through orthogonal test:fermentation temperature 35 ℃ fermentation time 6 h,inoculum 5%.GABA content was highest at 184.89 μg/mL and amylase activity was 3178.37 U/g.With amylase activity as indexes,the optimum fermentation conditions wasobtained through orthogonal test:fermentation temperature 35 ℃,fermentation time 6 h,inoculum 5%.The highest amylase activity was 3335.06 U/g,GABA content was 167.54μg/mL.The optimum fermentation medium was 150%of water,4%of honey,and 1%of malt powder.GABA content was 196.41 μg/mL and amylase activity was 3293.58 U/g。(3)The production technology of lactic acid beverage germinated brown rice was studied.With water ratio of 1:8,enzyme adding 0.7%,enzymolysis time of 20 min,enzymolysis temperature of 85 ℃ the DE value was the highest,51.29%.After measure the content of GABA in fermentation broth,milk:rice syrup=4:1,inoculation amount of lactobacillus 0.4%,fermentation temperature 50 ℃ and fermentation time 7 hours were the best parameter for fermentation.Under this circumstance,the GABA content in fermentation broth was 66.85 mg/100g.The sensory score was the highest as adding 50%fermentation broth,8%sucrose and 0.1%lactic acid.The centrifugal sedimentation rate was the lowest as adding 0.15%Sodium stearoyl lactylate(SSL),0.15%sodium alginate and 0.15%Amorophophallus Konjac gum.The lowest centrifugal sedimentation rate was 11.02%.After two times of homogeneous,the first was 20 MPa and the second was 20 MPa,the centrifugal sedimentation rate of the beverage was lowest with a good fluidity.When sterilizing at 85℃ for 1 min,the beverage could keep a white luster and a good stability with fewest GABA loss.(4)The best formula of producing germinated brown rice biscuit was optimized by the orthogonal test.The optimal formula of the product were found as follows:with the mixed powder quality of germinated brown rice flour and wheat flour as 100%,germinated brown rice flour 60%,wheat flour 40%,butter 22.5%,white granulated sugar 30%,egg wash 7%,water 12%,milk powder 5%,NaHCO3 loose agent 0.6%and flavour 0.08%.