α-聚赖氨酸提高谷朊蛋白酶促交联及其膜材料性能的研究
发布时间：2018-07-17 20:49
【摘要】：谷朊蛋白是生产小麦淀粉的副产品,来源广泛,具有独特的粘弹性,良好的生物相容性及生物可降解性,是制备蛋白膜的理想原料。谷氨酰胺转氨酶(TGase)可催化蛋白间发生ε-(γ-谷氨酰基)赖氨酸共价转移,进而发生交联反应。谷朊蛋白可被TGase催化改性。本课题以谷朊蛋白为原料,利用TGase的催化作用,引入含有多个伯胺基的α-聚赖氨酸,通过增加谷朊蛋白的作用位点,提高谷朊蛋白的反应性能,并与丝素蛋白交联改性制备蛋白复合膜,以克服单一谷朊蛋白膜机械性能较差,水溶失率较大的缺点。主要探讨了谷朊蛋白膜的制备方法以及酶促反应的工艺条件,考察了α-聚赖氨酸对酶促谷朊蛋白的增效作用;研究了酶促改性对蛋白膜的水稳定性性、疏水性、热稳定性及微观形态的影响,并考察蛋白膜在食品保鲜中的应用。研究结果表明:当蛋白含量为5%(g/mL),甘油浓度为1%(g/mL)时,蛋白溶液具有较好的成膜性能。TGase用量为20 U/g谷朊蛋白,蛋白反应液pH值为7.0,反应温度为40℃,反应时间为3 h时,对谷朊蛋白进行改性后制得的谷朊蛋白膜的拉伸性能较好,为4.36 MPa。α-聚赖氨酸使TGase催化单一谷朊蛋白及谷朊/丝素蛋白共混体系中氨气的释放量有所提高;十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)结果显示,引入α-聚赖氨酸的蛋白酶促反应体系中,蛋白大分子生成量明显增加;谷朊/丝素蛋白混合体系中含有α-聚赖氨酸时,TGase酶促反应后谷朊蛋白中所含丝素的特征氨基酸含量上升。谷朊/丝素蛋白复合膜较单一谷朊蛋白膜机械性能有所提高,当α-聚赖氨酸存在时,谷朊/丝素蛋白经TGase酶促改性后所得到的复合膜的机械性能增加至5.21MPa,同时,蛋白膜的疏水性和热稳定性提高,水溶失率降低,且对小番茄贮藏效果较好。扫描电镜(SEM)显示TGase及α-聚赖氨酸的作用使单一谷朊蛋白膜及谷朊/丝素蛋白膜材料的表面变得粗糙,截面结构更加紧密。
[Abstract]:Glutenin, a by-product of wheat starch production, is an ideal raw material for the preparation of protein film, because of its unique viscoelasticity, good biocompatibility and biodegradability. Glutamine aminotransferase (TGase) can catalyze 蔚-(纬 -glutamyl) lysine covalent transfer between proteins, which leads to cross-linking reaction. Glutenin can be modified by TGase. Using glutenin as raw material and using TGase as catalyst, 伪 -Poly (lysine) containing several primary amino groups was introduced to improve the reactivity of glutenin by increasing the interaction sites of glutenin. Protein composite membrane was prepared by crosslinking with silk fibroin to overcome the disadvantages of poor mechanical properties and high water solubility of single glutenin membrane. The preparation method of glutenin membrane and the conditions of enzymatic reaction were discussed, the synergistic effect of 伪 -polylysine on enzymatic glutenin was investigated, and the water stability and hydrophobicity of enzyme modified glutenin membrane were studied. The effects of thermal stability and micromorphology, and the application of protein film in food preservation were investigated. The results showed that when the content of protein was 5% (g / mL) and the concentration of glycerol was 1% (g / mL), the dosage of TGase was 20 渭 g glutenin, the pH value of protein reaction solution was 7.0, the reaction temperature was 40 鈩，
本文编号：2130894
[Abstract]:Glutenin, a by-product of wheat starch production, is an ideal raw material for the preparation of protein film, because of its unique viscoelasticity, good biocompatibility and biodegradability. Glutamine aminotransferase (TGase) can catalyze 蔚-(纬 -glutamyl) lysine covalent transfer between proteins, which leads to cross-linking reaction. Glutenin can be modified by TGase. Using glutenin as raw material and using TGase as catalyst, 伪 -Poly (lysine) containing several primary amino groups was introduced to improve the reactivity of glutenin by increasing the interaction sites of glutenin. Protein composite membrane was prepared by crosslinking with silk fibroin to overcome the disadvantages of poor mechanical properties and high water solubility of single glutenin membrane. The preparation method of glutenin membrane and the conditions of enzymatic reaction were discussed, the synergistic effect of 伪 -polylysine on enzymatic glutenin was investigated, and the water stability and hydrophobicity of enzyme modified glutenin membrane were studied. The effects of thermal stability and micromorphology, and the application of protein film in food preservation were investigated. The results showed that when the content of protein was 5% (g / mL) and the concentration of glycerol was 1% (g / mL), the dosage of TGase was 20 渭 g glutenin, the pH value of protein reaction solution was 7.0, the reaction temperature was 40 鈩，
本文编号：2130894
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