Molecular Characterization Of Soluble Soybean Polysaccharide And Its Application In Acidic Milk Drinks

Soluble soybean polysaccharides (Soluble Soybean Polysaccharides, SSPS), is a new type of plant macromolecular polysaccharide with multiple superior function, and it is a kind of biomacromolecule with the commercial prospects which has not yet been developed completely. Although in Japan, South Korea and other countries, the application of SSPS were more widely and the researches were more deeply, but the relevant theoretical research still have many unknown fields which is worth exploring and researching, such as SSPS on the esterification degree, the rheological properties of SSPS solution and combination effect of SSPS and other polysaccharide on stability of acidified milk drinks, about which there has few research reports. Therefore, study on their characteristics as well as its function improvement still has great research value. The results can provide an important theoretical basis and guidance for the production and application of SSPS. This paper has carried on the related research around the molecular characterization of SSPS, esterification degree of SSPS and SSPS in the application of acidified milk drinks, the main research and conclusion are as bellow:1. Molecular characterization:Gel exclusion chromatography (GPC) is used to study the molecular weight, molecular weight distribution and molecular conformation in solution. The results show that the different extraction methods has great influence on molecular weight of SSPS, and SSPS is the coexistence of various molecular weight polysaccharides. The combination of Mark-Houwink equation [η]= 1.51×10-3 Mw0.42 (dl/g) speculates that the SSPS chains exhibited random coils with compact conformation in water.2. The characterization of rheological behavior:SSPS solution is a pseudo plastic fluid, it has obvious shear thinning rheological properties, and the higher concentration is, the more obvious shear thinned phenomenon is. In addition, high concentration SSPS solution shows obvious thixotropy.3. The DE of SSPS can be determined by a number of analytic techniques which include colorimetric method, titration, NMR and Infrared Spectroscopy. However, the complex sample preparation, multiple steps and time consuming are frequently encountered in other methods. Nuclear magnetic resonance (NMR) spectroscope is an attractive method for determination of DE because it’s an efficient, rapid and accurate method comparing with titration method.4. The preparation of different esterification degree of SSPS:The results combined with product function, product appearance, the production cost and other considerations, the optimal conditions of esterification reaction is in pH10, alkaline treatment under the condition of 100 ℃,90 min.5. Study on the stability of SSPS of acidified milk drinks:The different types of the esterification degree of value of SSPS samples were used in the determination of the stability of the acidified milk beverage. The lower esterification degree value of SSPS is, the better stability of acidified milk beverage is. The combination effect of SSPS and sodium carboxymethyl cellulose on stability of acidified milk drinks shows that the use of SSPS-CMC blend at the ratio of 1:1 and 3:2 showed worst stability of ASMDs while the ratio of 1:4 showed better stability of ASMDs compared with the two stabilizers were used individually or other in other ratios.