Preparation And Functional Properties Of Potato Protein-sugar Covalent Complexes

Potato protein is high quality protein biological value an important source of this protein and polysaccharide through covalent binding of the complexes formed as a kind of natural food additives will have broad application prospects, the experiment of potato protein and maltose as the main raw material was modified by hydrothermal reaction, and ultrasonic assisted wet the modification on the optimum reaction conditions, the graft and the different preparation methods of the physicochemical properties and functions of system research, according to the functional properties of the outstanding design of a product.1 .Through the graft degree, degree of browning, emulsification, emulsion stability, bubble, single factor screening experiment of foam stability and thermal stability, and the response surface analysis of docking branch obtained in the reaction of pH 9.4, the protein concentration of 11.5 mg/mL, reaction time 4.45 h, reaction temperature is 82?, sugar / protein under the condition of 3 the highest grafting degree was 30.453%, the degree of browning was 0.416, emulsification was 0.324, the bubble was 98 %, Thermal stability of soluble proteinsme sured at 30??50??70??90? temperatures absorbance is(3.632,3.265,3.105,3.001).2.The use of ultrasonic assisted potato protein and saccharide graft reaction, grafting degree, degree of browning, emulsification, emulsion stability, bubble, foam stability and thermal stability of single factor tests and response surface analysis. The reaction of pH9.4, protein concentration of 12.42mg/mL reaction time 60 min, reaction temperature is 82?, sugar / protein 3, ultrasonic power 240 W, the grafting degree is 40.1874%, the degree of browning was 0.097, emulsification 0.384, emulsion stability is 63.4min, the bubble was 101 %, foam stability 7.9, thermal stability (3.823,3.601,3.462,3.388) were higher than that of the best results of single factor reaction. More than wet reaction without the use of ultrasound assisted reaction. 4.45 hours to reach 30.4%, shorten the reaction time, reduce the waste of energy. Shorten the reaction time to the browning degree decreases obviously, improve the graft of sensory color.3 .By changing the electrophoresis bands that contrast, wet reaction is to the covalent binding of protein and sugar together. By IR, found in the 1000cm-1-1300cm-1? 1340cm-1-1460cm-1 ?2800cm-1-3000cm-1 3200cm-1-3650cm-1 between the absorption peak appeared more obvious, determine the reaction group carbonyl, amino, sulfhydryl,reaction afer a large number of carboxyl and C-H the thermal differential scanning. By the comparison of structure and properties of graft reaction before and after, found after the protein denaturation temperature and glass transition temperature of wet modification increased,which give potato protein as food in the storage and transportation become more favorable.