Dept. of Sustainable Biomaterials, 230 Cheatham Hall, Blacksburg, VA 24061, U.S.A.
Dept. of Food Science and Technology, 402A HABB1, Blacksburg, VA 24061, U.S.A.
J Food Sci. 2018 Apr;83(4):946-955. doi: 10.1111/1750-3841.14018. Epub 2018 Mar 25.
The effects of transglutaminase on soy protein isolate (SPI) film forming solution and films were investigated by rheological behavior and physicochemical properties based on different manufacturing conditions (enzyme treatments, enzyme incubation times, and protein denaturation temperatures). Enzymatic crosslinking reaction and changes in molecular weight distribution were confirmed by viscosity measurement and SDS-PAGE, respectively, compared to 2 controls: the nonenzyme treated and the deactivated enzyme treated. Films treated with both the enzyme and the deactivated enzyme showed significant increase in tensile strength (TS), percent elongation (%E), and initial contact angle of films compared to the nonenzyme control film due to the bulk stabilizers in the commercial enzyme. Water absorption property, protein solubility, Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopy revealed that enzyme treated SPI film matrix in the molecular structure level, resulted in the changes in physicochemical properties. Based on our observation, the enzymatic treatment at appropriate conditions is a practical and feasible way to control the physical properties of protein based biopolymeric film for many different scientific and industrial areas.
Enzymes can make bridges selectively among different amino acids in the structure of protein matrix. Therefore, protein network is changed after enzyme treatment. The behavior of biopolymeric materials is dependent on the network structure to be suitable in different applications such as bioplastics applied in food and pharmaceutical products. In the current research, transglutaminase, as an enzyme, applied in soy protein matrix in different types of forms, activated and deactivated, and different preparation conditions to investigate its effects on different properties of the new bioplastic film.
基于不同的制造条件（酶处理、酶孵育时间和蛋白质变性温度），通过流变行为和理化性质研究了转谷氨酰胺酶对大豆分离蛋白（SPI）成膜溶液和膜的影响。与 2 个对照（未经酶处理和失活酶处理）相比，通过粘度测量和 SDS-PAGE 分别确认了酶交联反应和分子量分布的变化。与未经酶处理的对照膜相比，用酶和失活酶处理的膜的拉伸强度（TS）、伸长率（%E）和初始接触角显著增加，这是由于商业酶中的大量稳定剂。吸水率、蛋白质溶解度、傅里叶变换红外（FTIR）和 X 射线衍射（XRD）光谱表明，酶处理的 SPI 膜基质在分子结构水平上发生了变化，导致了理化性质的变化。根据我们的观察，在适当的条件下进行酶处理是控制蛋白质基生物聚合物膜物理性质的一种实用且可行的方法，适用于许多不同的科学和工业领域。
酶可以在蛋白质基质的结构中选择性地在不同的氨基酸之间架桥。因此，酶处理后蛋白质网络发生变化。生物高分子材料的行为取决于网络结构，以适应不同的应用，如应用于食品和制药产品的生物塑料。在当前的研究中，转谷氨酰胺酶作为一种酶，以不同的形式（激活和失活）应用于大豆蛋白基质，并在不同的制备条件下，研究其对新型生物塑料膜的不同性质的影响。
