Effect Of Complex Enzyme Soaking Process On Soymilk Quality

Soybean soaking is a very important process in the preparation of soymilk,tofu,yuba and other soy products.Soaking can soften soybeans,facilitate the dissolution of nutrients during subsequent refining and reduce the loss of refining machinery.However,soaking takes a long time and discharges a large amount of soaking bean wastewater,which seriously affects the economic benefits of the soybean processing industry and limits the development of the industry.Aiming at the main components of soybean seed coat,this study proposes a new process of soaking with complex enzymes(cellulase and pectinase).The micro-degradation of soybean seedcoat allows water to quickly enter the inside of the seed,and meet the requirements of grinding in a short time.At the same time,the amount of soaking water is the saturated water absorption of soybeans,so as to achieve complete soaking of soybeans without soaking soybean wastewater.Therefore,the production time can be reduced,the waste of water resources can be reduced,and it is beneficial to the soybean product processing enterprises to reduce production costs and increase economic benefits.The main content sand conclusions of the research are as follows:(1)Taking the soybean water absorption rate index,the optimal conditions of cellulase and pectinase soaking method were determined by univariate experiments and quadrature experiments,respectively,and the optimal conditions for obtaining cellulase were 0.5% of enzyme addition,temperature 40 ℃,pH value 6;the optimal condition of pectinase was 0.5%,temperature 40 ℃,pH value 5,the effect of soaking time on water absorption under the optimal soaking conditions of cellulase and pectinase,and the effect of soaking time on water absorption rate was compared with the effect of soaking time on water absorption by traditional soaking method.Determine the enzymatic immersion time of 6h.(2)On the basis of a single enzyme,cellulase and pectinase were combined to study the effect of the complex enzyme on the water absorption rate of soybeans.The one-way test was carried out on the basis of soybean water absorption rate,soybean milk stability and color difference,and the response surface test was carried out on the basis of soybean water absorption rate on the basis of one factor,and the optimal parameters of the composite enzyme soaking method were optimized by the response surface test design: cellulase: pectinase = 1:1,soaking temperature 40 ℃,pH value of5.5,and the water absorption rate of soybean under this condition was 128.15%.The water absorption rate of the compound enzyme soaking method was further improved compared with the single enzyme soaking method in the same time.Finally,a new green soaking method was obtained that shortened the soaking time to 6h and did not discharge the soaked bean wastewater.(3)The soybean milk prepared by three different soaking methods of compound enzyme soaking method,traditional soaking method and non-soaking method was compared to explore its influence on the quality characteristics of soybean milk.The effects of different soaking methods on the internal structure of soybeans were studied by observation and scanning electron microscopy of soybean cotyledons after soaking,and the mechanism of rapid water absorption of soybeans in a short period of time by the compound enzyme soaking process was preliminarily investigated.The results show that the quality of soybean milk prepared by the non-soaking method is the worst,and there are significant differences in viscosity,stability,particle size,color difference,content of tannins and phytic acid,protein content,and content of total dietary fiber prepared by the complex enzyme soaking method and the traditional soaking method,and there are no significant differences in the content of tannin and phytic acid and total dietary fiber in the soybean milk prepared by the compound enzyme soaking method and the traditional soaking method.Therefore,the soybean milk prepared by the compound enzyme soaking method is equivalent to the traditional process of soaking for 12 h,which has the advantages of saving water,saving time and reducing pollution.