The Critical Technology Of Enzymatic Succinylation Modification On Soybean Protein Isolated And The Application Research On The Chiffon Cake

Due to low price and low cholesterol level ,soybean protein isolated as a rich resource and a high nutritional value of vegetable proteins ,becomes an important source of nutrition for human and industrial raw materials .Soybean protein isolated has been widely used in the food industry ,to improved food processing performance and flavor with its unique function characteristics .However ,the functional characteristics of soybean protein isolated still has deficiencies ,that leads to the application in modern food processing by certain restrictions .This paper modifies soybean protein isolated with succinic anhydride and the laboratory-made complex of Aspergillus oryzae neutral protease ,Through single factor and design principle of the rotating combination optimizes the modification process. And products are used in the chiffon cake. The best replacement rate for eggs in the cake has been determined.1,Succinylation was used as modification reagents to modified soybean protein isolate. Functional properties of soybean protein isolate were measured before and after modified. The mathematical model of the relationship between protein solubility and modification is established. Using response surface method to find the suitable succinylation conditions: content of soybean protein isolated 7.0%, reaction temperature 54℃, amount of succinic anhydride 11%, reaction time 2h.2,Total RNA was successfully extracted from Aspergillus oryzae 41477,the neutral protease II gene were amplified by RT-PCR.The genes were insered into a expression vector pCal-n to get the recombinant plasmid pCal-n-NprⅡ.The recombinant plasmid transformed into E.coli BL21 and induce respectively by IPTG.ThroughSDS-PAGE method appraisal recombinant protein in the expression E.c oli BL21,the recombinant neutral protease's activity is 296.18U/mL by Folin method.3,Using recombinant neutral protease enzyme modified soy protein isolate ,this paper studies of the pH, temperature and enzyme hydrolysis on the functional properties of volume systematically. With the help of the combination of single-factor test and the test center , the optimal conditions for enzymatic modification is determined : value of pH 6.82, hydrolysis temperature 48℃, amount of enzyme 6627U/mL, hydrolysis time 120min.4,The influence to the quality of Chiffon cake is explored when non modified soybean protein isolated, amber acylation soybean protein isolated and enzymatic acylation soybean protein isolated is partly replaced eggs. Results shows, when the composite modified soybean protein isolated replacement rate is 10%, the production of quality Chiffon cake are most excellent. Summarily, composite modification has significantly improved the functional properties of soybean protein isolate. Replacing eggs in the cake Partly to improve the quality of the cake is feasible. This study can provide a theoretical basis for further improving the functional properties of soybean protein isolate.