干燥方式对脱酰胺小麦面筋蛋白特性的影响

Effects of Drying Methods on Characteristics of Deamidated Wheat Gluten

采用喷雾干燥和冷冻干燥两种方法制得了脱酰胺小麦面筋蛋白,通过红外光谱分析、拉曼光谱分析及轴对称型分析法表征了所制得的面筋蛋白的结构及界面性质的变化,并对其乳化和起泡性进行了分析.结果表明:冷冻干燥法能更好地保持蛋白形态;脱酰胺后蛋白基团强度发生变化;冷冻干燥法所得蛋白的结构展开程度较高;喷雾干燥法所得蛋白的起泡性及乳化性均高于冷冻干燥法所得蛋白,但起泡稳定性及乳化稳定性降低;脱酰胺面筋蛋白能较好地降低界面张力,其中喷雾干燥法所得蛋白降低界面张力的能力更高,但界面膜弹性低于冷冻干燥法所得蛋白,可能是由于喷雾干燥中形成了不利于界面膜稳定性的不溶性组分.

Deamidated wheat gluten was prepared via spray drying and freeze drying, and the structure as well as the interfacial properties of the product was characterized by means of FT-IR, Raman spectroscopy and axisymmetric drop shape analysis. Then, the emulsifying and foaming properties of the gluten were analyzed. The results show that （1） freeze drying helps to maintain the protein structure well; （2） the molecular vibration intensity changes after deamidation; （3） freeze drying may result in greater structure unfolding of protein; （4） the samples obtained by spray drying possess higher foaming and emulsifying ability but lower stability; and （5） deamidation helps to reduce the surface intension of gluten, and the samples obtained by spray drying are more effective in reducing the surface tension but is of lower interracial film elasticity, as compared with the samples obtained by freeze drying, which might be caused by the formation of insoluble protein that lowers the stability of the interfacial film.