Study On The Key Techniques Of Soymilk Produced From Soybean Meal

Soybean meal is the by-product of oil processing industry and the completely plantprotein, which contains more than48%protein and eight kinds of essential amino acids.Soybean meal is mainly used to produce animal’s feed and soybean protein at present,some used as the fermentation of raw materials for food and industrial. Using soybeanmeal as the main raw material to produce soy milk can not only takes full advantage ofby-product of oil processing industry, but also reduces the cost of production of soymilk. The high-protein and low-fat characteristics of soymilk made by soybean mealmake it more suitable for some special populations to drink. This topic used soybeanmeal as the main raw material to prepare soy milk, mainly studied the key techniques ofsoybean meal milk processing: optimal conditions for soybean meal protein dissolutionand the factors that affect the stability of soybean meal milk and how to control thesefactors. We had not seen the research in this area currently.The topic mainly studies subjects aspects as follows:(1) Dissolute water-soluble protein in the soybean meal using physical andchemical dissolution to improve the dissolution rate of soybean meal protein.Theoptimal conditions for soybean meal protein dissolution is determined by studying theproperties of soybean meal protein and exploring the dissolution conditions.In this study, water extraction experiments of shaker oscillation and magnetismstirring were carried firstly, five factors were chosen to carry single-factor experiments:the solid-liquid ratio, pH of dissolution, time, temperature and rotational speed. Itdetermined that the magnetic stirring method is the best option of direct dissolution ofsoybean meal protein by comparison. Orthogonal experiment was carried based onsingle-factor experiments. On this basis, enzymatic hydrolysis experiments werecarried.During the single-factor experiments, these four factors were chosen: enzyme/protein, enzymatic hydrolysis pH, enzymatic hydrolysis time, enzymatic hydrolysistemperature. And orthogonal test was designed on the basis of single-factor experimentsto determine the best dissolution conditions for enzymatic solubilization. Experimentsshowed that the best protein dissolution conditions were promote soluble by enzymesolution using magnetism stirring as pre-treatment:solid-liquid ratio1:10, waterextraction pH8, temperature40℃, time10min, stirring speed1200r/min; enzymedosage1200u/g, enzymatic hydrolysis pH8, enzymatic hydrolysis temperature55℃, enzymatic hydrolysis time1.5hours. Under this condition, the dissolution rate of thesoybean meal protein can reach the value of79.6%, compared with43.8%stationarydissolved and65.7%of the magnetic stirring, it has a substantial increase.(2) The topic mainly explored the effects of different factors on the stability ofsoybean meal milk, and propose the best solution to improve its stability. This canprovide the oretical basis for producing soybean meal milk in industry.The stability of soybean meal milk is influenced by many factors, such as processparameters of homogeneous conditions, pH, boiled pulp, stable effects of stabilizer andsalt, sterilizing condition.etc. By studying the impact of these factors on the stability ofsoybean meal milk, identify methods to improve the stability of soybean meal milk.Bymeasuring the absorbance of soybean meal milk before and after centrifugation in thisexperiment, the stability can be quickly determined. The experiment proved theoptimum conditions to improve the stability of the soybean meal milk were: dispersedhomogeneous twice and high pressure homogenization once(25MPa,70℃), pH8,boiling syrup(100℃,5min), STP0.06%,stabilizer (carrageenan0.12%＆xanthan0.04%＆pectin0.10%),high temperature sterilizing(121℃,10min)and cooling quickly aftersterilization. These conditions above can significantly improve the stability of soybeanmeal milk.(3) Compared the nutrition characters of soybean meal milk and traditionalsoymilk by experiments, the results showed that: the protein content of soybean mealmilk was2.70g/100mL, fat content0.35g/100mL, solids content4.25g/100mL, exceptthat fat content was lower than traditional soy milk, protein and solids content have notsignificant differences to the traditional soymilk.