Study On The Preparation Conditions Of Fermented Soybean Milk With Antioxidant Capacity

With the improvement of living standards,the health awareness of people has gradually increased,and the pursuit of food and beverage nutrition has become higher.Soy is not only rich in nutrients needed by the human body,but also contains a variety of special active ingredients.In this paper,soybeans are used as raw materials to study the soymilk enzymatic hydrolysis technology and fermentation conditions,and the storage characteristics and antioxidant properties of fermented enzymatic soymilk are studied,which provides a reference for the further development of new fermented soymilk.The main findings are as follows:1.Research on the enzymolysis conditions of soybean milk.After washing the soybeans,add purified water at a ratio of 1:10,add 0.03 g edible citric acid per 1L of water,boil for 5 minutes,filter,and discard the filtrate.The pretreated soybeans were added with purified water with a material-to-liquid ratio of 1:6 and soaked at 37? for 4 hours to prepare soybean milk.Taking the degree of hydrolysis as the evaluation index,single factor test and response surface test were used to optimize the enzymatic hydrolysis conditions of soybean milk.The results showed that the best protease is Novozym 11039 neutral protease,the addition amount is 0.2%,the enzymolysis temperature is 50?,and the enzymolysis time is 4 h.The resulting enzymolysis soymilk has a good flavor,with a sensory score of 90.6 and a degree of protein hydrolysis of 12.43%.2.Research on fermentation conditions of enzymatic hydrolysis of soybean milk.Using sensory scores,antioxidant capacity and the number of viable lactic acid bacteria as indicators,single factor test and response surface test were used to optimize the fermentation conditions of soy milk to obtain the best fermentation conditions:the ratio of soy milk to cow's milk was 1:1(v/v),xylo-oligosaccharides are added at 5%,4%Lactobacillus fermentum grx08 and 1.5%Lactobacillus starter(Streptococcus thermophilus and Lactobacillus bulgaricus)are added,fermented at 39? for 4 h,and the fermentation enzyme is prepared Soymilk has uniform color,unique luster of soymilk,fine tissue,uniform texture,moderate viscosity,rich milk flavor,sweet and sour taste,sensory score reaches 90.2 points,antioxidant ability is 2.22 mM,and the number of viable lactic acid bacteria is 8.89 log CFU/mL.3.Evaluation of the antioxidant capacity of fermented enzyme hydrolyzed soybean milk The total antioxidant capacity(T-AOC)kit was used to compare the total antioxidant capacity of soymilk,fermented soymilk,and fermented soymilk samples.The results showed that fermented soymilk had better iron-reducing power than soymilk and fermented soymilk.With a certain increase,the antioxidant ability reached 2.23 mM.4.Study on the storage characteristics of fermented soymilk.According to the number of viable bacteria,antioxidant capacity,pH value,acidity,viscosity and other indicators of fermented milk,the storage characteristics of fermented soymilk were studied to determine the best storage time.The results showed that the best storage time of fermented soymilk at 4? was the 7th day,the sensory evaluation at this time was 92.33 points,the antioxidant value was 2.85 mM,the number of viable bacteria was 9.32 log CFU/mL,and the acidity was 83.01 °T,pH is 4.6,viscosity is 1243 cP.5.Preliminary establishment of the quality index of fermented soymilk.Based on the results of three batches of product quality analysis,considering the antioxidant capacity,sensory,physical and chemical,microbiological,and viable number of lactic acid bacteria,combined with national mandatory standard indicators,a product quality standard for fermented soymilk was established.