转谷氨酰胺酶对乳清浓缩蛋白-纳米微晶纤维素复合膜性能的影响

张涛; 宋尧; 姜淑娟; 钱方; 妥彦峰; 吴晓萌; 牟光庆

doi:10.13386/j.issn1002-0306.2019.22.039

转谷氨酰胺酶对乳清浓缩蛋白-纳米微晶纤维素复合膜性能的影响

Effect of TGase on Performance of Whey Protein Concentrate-nanocrystalline Cellulose Composite Film

摘要

摘要: 为了研究转谷氨酰胺酶(TG)对乳清浓缩蛋白(WPC)-纳米微晶纤维素(NCC)复合膜性能和结构的影响,本研究以WPC和NCC为原料,利用TG酶处理对WPC-NCC复合膜的机械性能和屏障性能进行优化,并探究TG酶的交联作用对乳清蛋白分子二级结构和复合膜成膜微观结构的作用情况。结果表明,在TG酶的添加量达到12 U/g_蛋白时,WPC-NCC复合膜的抗拉强度达到2.25 MPa,断裂伸长率达到86.75%,水蒸气透过率为4.40×10^-12 gmPa^-1s^-1m^-2,有效改善了WPC-NCC复合膜的机械性能性和水蒸气屏障性能。经过TG酶的处理,乳清蛋白结构向稳定有序的方向转变,减少了复合膜的孔洞数量和孔径,使成膜表面结构更加致密,促进了复合膜的机械性能和水蒸气屏障性能的提升。

Abstract: To investigate the effect of transglutaminase(TGase)on the performance and microstructure of whey protein concentrate(WPC)-nanocrystalline cellulose(NCC)composite film,WPC and NCC were used as raw materials,mechanical properties and barrier properties of WPC-NCC composite films with TGase treatment were optimized and the effect of cross-linking of TGase on the secondary structure of protein molecule and the microstructure of the composite film were investigated in our study. The results showed that tensile strength of WPC-NCC composite film reached to 2.25 MPa,elongation at break reached to 86.75%,and water vapor permeability decreased to 4.40×10^-12 g mPa^-1s^-1m^-2 when the amount of TGase added at 12 U/g protein. TGase effectively improved the mechanical properties and water vapor barrier properties of WPC-NCC composite film. TGase promoted protein structure to change in a stable and orderly direction,reduced the number of pores and pore size in the composite film,and made the microstructure of film denser. It also showed that the improvement of mechanical properties and water vapor barrier property were closely related to the microstructure.