Study On The Optimization Of Compound Enzyme Solution Pretreatment For Brown Rice Before Germination

The development of germinated brown rice has become a new way to improve the nutritive value of rice,during the process of brown rice germination,GABA,which has several physiological active functions,has a significant increase in its content,so the nutritive value of germinated brown rice is higher than that of brown rice,and far surpasses than that of rice.GABA is a kind of nonprotein amino acid,has the following function: Such as calm nerves,anti-anxiety,regulating cardiovascular function,regulate hormone secretion,immune regulation,healthy liver,kidney,blood pressure,anti-tumor,anti-cancer,anti-aging and so on.Sufficient absorption is the necessary condition for brown rice germination,the current manufacturing technique of brown rice germination requires that brown rice is soaked in water over 6h to achieve the required moisture content for germination,but in this technique,there are problems of long-time water absorption,low efficiency,and long-time immersion is not conducive to the germination of brown rice and leads to the loss of GABA.Although the germinated brown rice is a food material with high nutritive value,compared with rice,surface structure is still very close,within the same cooking time,because of the difficult thermoosmosis,the soakage of germinated brown rice is less than white rice's,and bran crude fiber content of germinated brown rice is still higher,so that germinated steamed brown rice has a poor taste,germinated brown rice has some limited constraints to be the main food,which restricts the development of germinated brown rice industry.Therefore,it's an urgent demand of a process for germinated brown rice,which not only can shorten immersion and water absorption,but improve the steaming and cooking edible quality of germinated brown rice.This study takes brown rice as raw material,applies biological enzyme method into the production process of germinated brown rice,targets the main component of brown rice's cortex,follows the selectivity principle of enzyme action,puts forward the new process of brown rice before sprout by using complex solution of cellulase and xylanase instead of distilled water for immersion.Conduct an experimental investigation of this technique,the main contents of this research are as follows:(1)Adopt the analysis method of single factor test,confirm the major parameters and the range of complex phosphoesterasum and treatment process before the sprout of germinated brown rice,study the effect law of enzyme treatment time,enzyme treatment temperature,concentration of compound enzymes solution,percentage of cellulase quality on the germinated brown rice yield.(2)Adopt secondary orthogonal rotation central composite experiment design method,study the effect law of complex enzyme's pretreatment parameters(enzyme treatment time,enzyme treatment temperature,concentration of compound enzymes solution,percentage of cellulase quality)on the germinated brown rice yield,and utilize Design Expert software to proceed parameter optimization of four factors,as to acquire optimum parameter combination region of complex enzyme's pretreatment process.(3)Base on the experimental optimization results,regard yield of germinated brown rice,GABA content as the index of evaluation,conduct contrast test on the traditional soaking process and pretreatment process of complex enzyme.And depend on the scanning electron microscope test and water absorption rate test of brown rice's grain,from two angles of cortex microstructure and water infiltration capacity,make the first exploration of the mechanism that complex enzymic method's pretreatment improves water absorption rate and germinated brown rice yield in the socking process of brown rice.(4)The effect on steaming and cooking edible quality of germinated brown rice caused by the pretreatment process of compound enzyme.The main research conclusions are as follows:(1)The test factors of enzymolysis time,enzymolysis temperature,complex enzyme concentration and enzyme matching have a significant effect on the germinated brown rice yield.Determine the parameter range of enzyme treatment time(60~180 min),enzyme treatment temperature(25~45 ?),concentration of compound enzymes solution(0.1~0.9 g/L),the mass percentage of cellulose(20 %~80 %).(2)Enzyme treatment time,enzyme treatment temperature,concentration of compound enzymes solution,percentage of cellulase quality have a significant effect on germinated brown rice yield.The pretreatment parameter combinations of complex enzyme are :mass ratio of cellulase and xylanase is 1.86:1 g/g,enzyme treatment time is 135 min,enzyme treatment temperature is 35 ?,the mass concentration of compound enzymes solution is 0.57 g/L.(3)Different samples' yield of germinated brown rice and GABA content have a significant difference(P<0.05).Compare pretreatment germination process of complex enzyme with traditional soaking process,the yield of germinated brown rice increases about 3.90%,GABA content increases about 3.86 mg/(100 g).(4)Compare with cooking characteristics of different kinds of rice,the germinated brown rice acquired by complex enzyme pretreatment technology has an improvement in cooking time,expansion rate,meal rate,gets higher sensory evaluation score,the edible quality is closer to high milled rice's.