Research On Quality Variation And Regulation Of Normal Temperature Preservation Of Soymilk

Soymilk is rich in nutrients,and contains biological active ingredients such as soya saponins and isoflavones,which can effectively reduce the concentration of cholesterol in the blood and prevent the occurrence of various cardiovascular and cerebrovascular diseases and other chronic diseases.Therefor,soymilk is increasingly welcomed by consumers.Maintaining nutritional quality of soymilk requires a more rigorous processing and storage environment.However,due to improper processing or storage conditions,the problems such as browning of finished products,serious smell of soybean,decrease of nutrient substance and decrease of stability have restricted the promotion and development of soymilk.With selected non-genetically soybean as raw material,based on the optimization of the key process parameters of soybean milk,this topic dynamically monitors the changing rules of the sensory quality and nutritional quality of soybean milk during storage.By adopting the combination of physical and chemical methods of regulation,the quality of the product is guaranteed and the shelf life is confirmed.The research results are as follows:1.The optimization parameters of soybean milk processing were as follows:milling temperature 60 ?,ratio of bean to water 1:8,cooked pulp temperature 95 ?,8min.In the conditions,the sensory score of soybean milk produced was the highest,94.5,and the production quality was the best.Among them,the cooked pulp temperature had the greatest influence on the sensory quality of soybean milk,and the grinding temperature had the smallest effect on the quality.2.Taking plain soybean milk as an example,the initial shelf life of soybean milk stored at room temperature was explored.When stored for 60 days,the total number of colonies in soybean milk was 10 cfu/mL,which was significantly lower than the national standard of 100 cfu/mL,and no deterioration of quality occurred.However,at the time of storage to 80 days,the microorganisms in the original flavor of soymilk had been severely exceeded and the value of food was lost.3.The quality change law of soybean milk during storage at room temperature(22-25?)was investigated.Sensory quality:During the entire storage period,the sensory qualities of plain soymilk,sweet soymilk and black soybean milk all showed a downward trend.After 60 days of storage,the sensory score of the sweet soymilk was the highest,85.2,and the plain soymilk was the lowest,82.8,indicating that the sweetness of the sweet soymilk had the best sensory quality and was the least affected by the storage period.Nutritional quality:At the beginning of storage,the protein content of black soybean milk was the highest at 3.27g/100g,followed by sweet soymilk at 2.78g/100g.With the extension of the storage period,the protein content of the three flavors of soymilk did not change significantly;In terms of fat content,the fat content of the three types of soymilk decreased with the increase of storage period.During the entire storage period,the fat content of the sweet soymilk had the smallest decrease of 5.30%,and the plain soymilk had the largest decrease,which was 8.06%.The change pattern of the soluble solids was similar to that of the fat content.In the aspect of flavor substances,the content of hexanal in the three kinds of soybean milk and bean odor substances was the highest,and the rest were 2-ethylfuran,n-hexanol,2-pentylfuran and benzaldehyde.In addition,the content of hexanal in plain soymilk increased by 24.7%during the whole storage period,which was the largest increase.4.The optimum preservation conditions of soybean milk were determined.Through physical and chemical comprehensive regulation tests on soymilk,it was found that the combination of low temperature(4?)and 0.10g/kg s-polylysine + 0.l0g/kg nisin can significantly inhibit the growth and reproduction of microorganisms in soymilk.The shelf life of soybean milk was extended to 130 days,delaying the speed of deterioration of soybean milk quality,maintaining product stability,and preventing the loss of nutrients.This has very important practical significance for the production of soybean milk.