| As the major grain-producing and oil-producing country in the world, china also produce large amounts of soybean meal by-product of grain and oil processing annually, make use of soybean meal by enzymolysis is a great help to improve resource utilization, improve animal product quality, reduce environmental pollution。 It’s harmful to use chemically synthesized what is commonly used to treat hypertension, antihypertensive peptides derived from soybean meal is safe, without any side effects, and there is no antihypertensive effect for people whose blood pressure is normal, its suitable applies to the base material as oral agents or functional foods. Soybean meal is taken as raw materials in this paper to get antihypertensive peptides whit blood pressure lowering effect, main results are as follows:Degree of hydrolysis (DH) and the ACE inhibitory rate (IP) were taken as the assessment of indicators, choose alkaline protease from all five kinds of proteases, study the effect of temperature, initial pH, substrate concentration, enzyme dosage and time on the enzymatic hydrolysis,and find out that the best enzymatic hydrolysis time is180min. Orthogonal experiment was designed on the basis to determine the optimum conditions:temperature of65℃, enzyme dosage8000U/g,3%of the substrate concentration, pH7.5, time180min. ACE inhibition was57.1%. Analysis of variance was that temperature factors significant at the5%level significantly affected the enzyme concentration, substrate concentration, initial pH was not significant. Study the effect of heating pretreatment of raw materials and ultrasonic pretreatment on the enzymatic hydrolysis,150W for the optimal pretreatment ultrasonic power, time for180s;100℃is the optimum temperature of the heating pretreatment time of30s.Ultrafiltration enzymatic hydrolyzate of soybean by ultrafiltration membrane with MWCO10,6,3ku, component of the ACE inhibitory rate reached67.8%which is less than3ku. Ultrafiltration membranes isolated soy antihypertensive peptides from a single factor and orthogonal experiments, the best experimental conditions are as follows:temperature35℃, operating pressure of0.20MPa, pH8, ACE inhibition rate of75.7%. Orthogonal test results of analysis of variance, and the pH factor in the5%significance level significantly affected the temperature and operating pressure of the two factors was not significant. MWCO3ku following components gel column for further separation and purification, select the Sephadex G-25gel column, eluent ultrapure water sample volume of1ml of conditions on the concentration of25mg/ml, elutionflow rate of30ml/h, the isolated five-eluting peaks, of which the second component of the ACE inhibitory rate of85.7%.The solubility of soybean peptide is relatively stable, but when the solubility at pH4is slightly reduced because the soybean peptide isoelectric point of pH4.5. Emulsifying activity of soy peptide with the pH values increase continuously enhance the highest stability at pH4, soy peptide hydrolyzate under acidic conditions better foaming properties, especially near the isoelectric point, but the foam stability at pH <6under the conditions of poor, after the foam stability increases with the increase of the pH value. Soybean peptide has good stability even at high temperatures in the room temperature or low temperature, in the actual production to meet the ordinary storage needs. The light of a small inhibition of Na+, of Fe2+to ACE inhibition rate, Zn2+, of Ca2+then the emergence of a slight increase, several common food additives are to some extent, reduce the soybean peptide ACE the inhibition rate of soybean peptide good stability in both acid and alkaline environment, conducive to the further processing. Antihypertensive effect in vivo simulation experiments show that will remain relatively stable through the gastrointestinal tract enzymes to digest ACE inhibitory activity。... |
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