Separation And Applications Of Soybean Peptides

Soybean peptides have many distinct physical-chemical properties and biochemical activities, and also possess merits respectively in widespread source of raw materials, low price, great safety, no side effects, easy for industrial production. This article respectively studied the physical-chemical properties, methods for separation, purification and applications in some aspects, with two kinds of soybean peptides as the investigate objects, offered experimental foundation for further research of soybean peptides product.Common compositions, physical-chemical properties of the two kinds of sample peptides were determined and analyzed, the results showed that: the two kinds of peptides generally owned the same amino acids compositions, but were quite different in protein content; soybean separation protein peptides kept better dissolved state in wide pH condition. Viscosity of the two kinds of sample peptides augmented with the concentration increasing, soybean separation protein peptides kept good fluidity when concentration overtopping 60%, but crude soybean peptides not; soybean separation protein peptides showed more powerful abilities both in deoxidation and antioxidation, but less in emulsibility and its stability.Gel filtration chromatography (GFC) was used to elute and separate the soybean separation protein peptides with Sephadex G-25 as the loading material, the optimum elution requirements were: the ratio of diameter to height of the chromatographic column was 1:35; addition volume of sample was 3mL; sample concentration was 0.01 g/mL; elution flow rate was 16mL/h; elutriant was distilled water. The analysis result of HPGPC showed that : each elution composition was single component, molecular weights respectively were: component 1: 1860 Da; component 2: 1426Da; component 3: 853Da; component 4: 376Da. Infrared chromatographic analysis showed that: the peak forms of the four components were fundamentally coincident with each other, and showed typical amides absorption peaks between 3049-3406cm^-1 and 1690-1630cm^-1.DA201-Câ…¡macroporous adsorptive resins was used as the packing material to elute and separate crude soybean peptides, diameter to height of the column was 1:30, the pH of sample peptides solution was 3.0, the concentration was 45mg/mL, the amount of the active peptides solution was 40mL, the adsorption flow rate was 0.5mL/min, the resolution flow rate was 1.0mL/min, resolution volume of water was 2BV, 4 compositions was attained through gradient alcohol eluting; after being further eluted by gel chromatography Sephadex G-25, 6 compositions were attained, and the molecule weights determined by HPGPC were respectly: aâ… : 1845Da, 209Da; bâ… : 288Da; bâ…¡: 4019Da, 402Da, 207Da; câ… : 2314Da, 197aD; dâ… : 1318Da, 180Da; dâ…¡: 2719Da, 209Da. Response surface method (RSM) was used to was used to optimize the technology and conditions of soybean peptides chelating Calcium, the optimum process parameters were: the ratio of soybean peptides to CaCl₂ was 4.2:1 (w/w), water bath time was 22.3 min, the times of absolute alcohol volume to mixed liquor was 6, under which, the yield of soybean peptides-Calcium was 65.48%, and the content of calcium was up to 7.74g per 100g soybean peptides-Calcium. The result of infrared chromatographic analysis showed that: both the amino group and carboxyl group participated in the chelating reaction.The experiment analyzed the effect of the two sample peptides to the growth of S. thermophilus by using methods of count plate and optical density, the result showed that: both the two sample peptides promoted the growth of S. Thermophilu, with the addition amounts increasing in the nutrient mediums, the growth promotion action made by crude soybean peptides tapered while soybean separation protein peptides enhanced. Optical density method was used to analyze the effect of the two sample peptides to the growth of B. infantis, the result showed that: smaller addition amount of crude soybean peptides made a obvious growth promotion action but tapered with the addition amount increasing, while the growth promotion action made by soybean separation protein peptides enhanced with the addition amount increasing.