Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
Int J Biol Macromol. 2017 May;98:292-301. doi: 10.1016/j.ijbiomac.2017.01.127. Epub 2017 Feb 3.
The inferior thermal- stability of collagen hinders its extensive application in food industry, including edible packaging. To improve the thermal- stability and mechanical properties of collagen, we attempted to crosslink collagen with some proteins possessing excellent thermal stability (i. e., casein, keratin and soy protein isolate (SPI)). Observed from the SDS- PAGE and particle size distribution, some complexes with higher molecule weight and relative bigger size particle occurred in the protein mixture, especially after TGase crosslinking. Importantly, the crosslinking greatly improved the thermal- stable property of protein complex, especially that of the collagen- casein complex judged from differential scanning calorimetric (DSC). Moreover, the crosslinking enhanced the mechanical properties of the combined films in terms of tensile strength (TS) and elongation at break (EAB). Also, some obvious differences in morphology of proteins before and after TGase crosslinking were observed by scanning electron microscopy (SEM). These impacts of TGase crosslinking with heat- resistant proteins on collagen features were associated with the conformational changes of the protein complex analyzed by Fourier transform infrared spectroscopy (FTIR). In conclusion, TGase crosslinking with higher thermally stable proteins could be an effective method to contribute to collagen' application in food packaging field.
胶原的热稳定性较差,限制了其在食品工业中的广泛应用,包括可食用包装。为了提高胶原的热稳定性和机械性能,我们尝试用一些具有良好热稳定性的蛋白质(如酪蛋白、角蛋白和大豆分离蛋白(SPI))对其进行交联。从 SDS-PAGE 和粒径分布可以看出,在蛋白质混合物中,特别是在 TGase 交联后,出现了一些分子量更高、粒径相对更大的复合物。重要的是,交联大大提高了蛋白质复合物的热稳定性,尤其是从差示扫描量热法(DSC)判断的胶原-酪蛋白复合物的热稳定性。此外,交联增强了复合膜的力学性能,表现为拉伸强度(TS)和断裂伸长率(EAB)的提高。扫描电子显微镜(SEM)观察到 TGase 交联前后蛋白质形貌的一些明显差异。这些 TGase 与耐热蛋白交联对胶原特性的影响与傅里叶变换红外光谱(FTIR)分析的蛋白质复合物构象变化有关。总之,用热稳定性更高的蛋白质进行 TGase 交联可能是一种有效的方法,有助于胶原在食品包装领域的应用。