用大豆蛋白膜改善预油炸春卷微波加热后的脆性

针对预油炸春卷经冷冻、微波加热后因水分外迁造成产品品质下降的问题，研究了涂布大豆蛋白膜对保持春卷皮脆性的影响。通过对大豆蛋白膜的成型条件及机理的研究，由单因素与正交实验得出大豆蛋白膜的最佳配方为大豆分离蛋白40 g/L、甘油15 g/L、谷氨酰胺转胺酶1.5 g/L；应用此涂膜后，电镜观察显示春卷皮层较未涂膜前致密而平整，经微波加热后能保持良好的脆性。进一步对涂膜春卷的微波升温特性进行考察，发现大豆蛋白膜的应用提高了春卷皮对微波的感受能力，缩小了春卷表皮和馅心之间的温度梯度，进而可缩短微波复热时间，对保持微波复热后的脆性有帮助。

Technology to increase the crispness of pre-fried spring-roll by microwave reheating using soy protein isolate film

The mechanism and molding condition of soy protein isolate film were investigated in order to improve the crispness of pre-fried spring-roll after freezing and reheated with microwave, which was strongly affected by the moisture immigration outward. The parameters of soy protein film-forming were studied with single-factor and orthogonal experiments, and the optimized results were soy protein isolate 40 g/L, glycerol 15 g/L and transglutaminase(TG) 1.5 g/L. Observed by Scan Electron Microscopy(SEM), the spring-roll coated with the protein film was revealed to be more smooth, tighter and less interspace compared with its counterpart without film, as well as be more able to resistant against moisture immigration. Furthermore, the temperature profile of film-coated spring-roll in microwave reheating was studied. It show that the film-applying of soy protein isolate can distinctly increase the capacity of microwave-absorbing and shorten the temperature difference between the outer and fillet, which can also save heating time by microwave and lead to good crispness of reheated spring-roll.