Studies On Changes Of Active Substances And Antioxidant Activity During Processing Of Germinated Brown Rice

In this paper,germinated brown rice was taken as the research object,and the effects of four processing methods,puffing,cooking,baking,and lactic acid bacteria fermentation,on the content of γ-aminobutyric acid(GABA),phytic acid,oryzanol and antioxidative activity of physiological active substances in germinated brown rice were systematically studied.The four processing methods can maximize the retention of physiological active substances and antioxidant process parameters,and study the changes of polyphenols and flavonoids released from germinated brown rice prepared under four optimal conditions in simulated gastrointestinal digestion.Clearly maximizing preservation and improvement of the processing methods and methods for germinating physiological active substances and antioxidant activity of brown rice will provide a theoretical basis for future industrial production.The main conclusions are as follows:(1)The results of puffing on the physiological active substances and antioxidant activity of germinated brown rice showed that the puffing method for retaining the physiological active substances and antioxidant activity of germinated brown rice to the maximum was microwave puffing.The GABA content in the germinated brown rice after microwave puffing was reduced by 40.42%,the phytic acid degradation rate was 6.98%,and oryzanol content was 1.44 times that of the raw material.In terms of antioxidant activity,the DPPH radical scavenging rate,ABTS clearance rate,FRAP and ORAC values of the four antioxidant capacity indicators of microwave-expanded brown rice were declined.The declines in the values were 15.91%,12.14%,35.21%,and 22.27%,respectively.(2)The results of cooking on the physiological active substances andantioxidant activity of the germinated brown rice showed that the cooking time of the physiological active substance and the antioxidant activity of the germinated brown rice was kept as long as 20 min.The GABA under this condition increased by 66.31%;the phytic acid was degraded.The rate was 17.11%;oryzanol content was slightly decreased;in terms of antioxidant activity,the DPPH radical scavenging rate,ABTS clearance rate,FRAP value,and ORAC value of the four antioxidative capacity indicators of cooked brown rice after 20 min cooking were decreased by 6.82 %,13.12%,22.22% and 28.61%,respectively.(3)The results of baking on the physiological active substances and antioxidant activity of germinated brown rice showed that the conditions for keeping the physiological active substances and antioxidant activity of the germinated brown rice were as follows: baking temperature 150℃,baking time 15 min.,GABA loss in germinated brown rice prepared in this condition was 5.58%.The phytic acid degradation rate was 43.53%,and the content of oryzanol was increased by 21.54%.The DPPH radical scavenging rate,ABTS clearance rate,FRAP value,and ORAC value decreased by 14.77%,13.60%,9.10%,and 19.86%,respectively.(4)Through the comparison of three kinds of fermentation methods: single bacteria(Lactobacillus rhamnosus),double bacteria(Lactobacillus rhamnosus,Lactobacillus casei),and three bacteria(Lactobacillus casei,Lactobacillus acidophilus,Lactobacillus plantarum),it was determined that the fermentation method that retains the physiological active substances and antioxidant activity of germinated brown rice was single-bacterial fermentation,and the GABA content in the germinated brown rice milk that was fermented by the single bacteria increased by 111.45%;Phytic acid degradation rate was 19.51%;oryzanol content decreased not significantly,and the oryzanol content of single strain decreased less;in terms of antioxidant activity,the three antioxidant capacity indicators of single fermented germinated brown rice milk increased 24.39%,4.78%,14.76% and 62.62%.(5)In the simulation of gastrointestinal digestion,the release of polyphenols,flavonoids,and antioxidant activity of germinated brown rice after microwave puffing,cooking,baking,and lactic acid bacteria fermentation showed a significant increase(p<0.05),pepsin,pancreatic,enzymes and bile can promote the release of polyphenols and flavonoids,pH value has an impact on the release of flavonoids;gastric digestion at 3 h of microwave expansion,cooking,baking,lactobacillus fermentation germinated brown rice polyphenol release are 1.67,2.36,1.90,and2.99 times than at 0 h,the release of flavonoids were 1.55,1.59,2.14,and 2.01 times of gastric digestion,and the ORAC values were 2.90,3.57,2.89,and 4.77 times of 0 hours of gastric digestion.The rats were digested with microwave for 3hours.The amount of polyphenols released from cooked,roasted,and lactic acid bacteria-producing germinated brown rice was 1.38,1.10,1.30,and 1.07 times higher than that of the intestine digestion for 0 h,and the release of flavonoids was1.09,1.06,1.16,and 1.31 times that of 0 h of intestinal digestion.The ORAC value of intestinal digestion at 0 h was 1.65,1.75,1.50,1.68 times.