The Study Of Soybean Peptides' Preparation,Seperated And Property

The soybean peptides are a group of active peptides gotten from soybean proteins by controlled hydrolysis and refinement. The preparation techniques of soybean peptides through hydrolyzing soybean isolated proteins by Alcalase and flavourzyme and the quality and application of productions were studied. Through statistics and analyzes, the effects of pretreatments, temperature, concentrations of substratum, proportions of enzyme to substratum and time on enzymic hydrolysis were studied. Through uniform designs and statistical analyzes, a mathematical model was set up as follow:Based on this model, the optimum monoenzyme hydrolysis conditions: 60℃, pH8.0, substratum concentration 8.38%, proportion of Alcalase to substratum 4.5%, proportion of enzyme to substratum 4.5%, hydrolysis time 2h; the optimum dienzyme hydrolysis conditions: 55℃, pH7.5, substratum concentration of dienzyme hydrolysis 8%, proportion of Alcalase to substratum 4.5%, proportion of flavourzyme to substratum 5%, hydrolysis time 4h. The mixed peptides of dienzyme hydrolysis had comparatively little molecular weights and tasted well. According to this technique, the best hydrolysis effects were gotten and a large number of mixed peptides were prepared.The dienzymic and monoenzymic mixed peptides were isolated by molecular sieves and ultrafiltrations, and 11 kinds of peptide products with different molecular weights were gotten.Through measuring the physical and chemical and physiological characters, it was testified that the levels of the soluble stability, thermal stability and viscosity were higher than those of soybean proteins and had the physiological activities of resisting oxidation and improving fermentation.The optimum techniques of desiccations by vacuum freezing, spraying and fluid beds were respectively studied to get different peptide products according to different applied areas. The vacuum freezing desiccations had the least effects on product characters and were fit for preparing analytic samples; spraying desiccations can get comparatively abundant fined soybean peptide powders and applied to healthy protecting products and fine chemical industry; fluid bed desiccations had the highest efficiency, but which needed amylum and whose products were comparatively rough, so which were fit for food productions.