化学交联与酶法交联对鱼糜-明胶复合膜性质的影响

研究比较了戊二醛和谷氨酰胺转氨酶(TGase)对鱼糜-明胶复合膜的性质改良效果。当戊二醛的含量为蛋白质量的0.025%～0.1%时,膜的抗拉伸强度(TS)没有显著差异,但断裂延伸率(EAB)却随着戊二醛含量的增加而上升,当戊二醛含量增加到0.2%时,TS和EAB都出现了下降。然而,膜的TS和EAB都随着TGase的添加逐渐增加。虽然戊二醛和TGase都可以使蛋白发生交联,导致膜的固形物溶解率(FS)和蛋白溶解率(PS)下降,但是戊二醛的添加效果明显优于TGase。此外,戊二醛的添加会使膜的颜色变黄,而TGase不仅不会影响膜的色泽,还可以提高膜的透明性能。根据SDS-PAGE的结果,发现戊二醛和TGase都会使膜中蛋白分子发生交联形成高分子聚合物。FT-IR的分析结果表明,蛋白分子间的氢键作用随着TGase的添加逐渐减弱,随着戊二醛的添加出现先减弱后增强的趋势。

Effect of chemical and enzymatic cross-linking on the properties of surimi-gelatin composite films

The effects of cross-linking using glutaraldehyde(GLU) and transglutaminase(TGase) on the properties of surimi-gelatin composite films was evaluated in this study.When GLU concentration was adjusted to 0.025%～0.1% of protein,the tensile strength(TS) of films was not significantly influenced,while the elongation at break(EAB) increased gradually with adding GLU.When GLU concentration was further increased to 0.2%,both TS and EAB was decreased.Conversely,TS and EAB of films gradually increased with increasing TGase concentration.The addition of GLU and TGase in the composite films both could promote cross-linking within protein film network,resulting in decreased film solubility(FS) and protein solubility(PS) of films.However,the FS and PS of films modified by GLU decreased faster than those of TGase modified films.Furthermore,the yellowness of films containing GLU was increased,while the addition of TGase did not affect the color of films but improved the film transparency.Whether the films contained GLU or TGase,the polymerization of protein in surimi-gelatin composite films was found by SDS-PAGE.The FTIR data revealed that hydrogen bonds in the films were weakened by adding TGase,but they were strengthened following the initial gradual weakness when GLU was added.