转谷氨酰胺酶交联时间对玉米胚芽蛋白 功能性质的影响Effect of transglutaminase cross-linking time on functional properties of corn germ protein

为解决玉米胚芽蛋白溶解性低的问题，提高其在食品工业领域的实际应用，以玉米胚芽蛋白为原料,通过酶解、转谷氨酰胺酶(TGase)交联，制备了不同交联时间的玉米胚芽蛋白，利用红外光谱仪和粒度分析仪分析玉米胚芽蛋白结构和表面性质的变化，并检测其溶解性、乳化性、起泡性等功能性质。结果表明：随着交联时间的延长，玉米胚芽蛋白的溶解性、起泡能力、持水性、乳化活性逐渐增强，乳化稳定性变化趋势与之相反，泡沫稳定性先升后降，持油性先降后升；与原样相比，交联3 h的玉米胚芽蛋白的乳化活性提高了16.7倍，持水性和持油性分别增加了9.16%和8.71%；TGase交联反应改变了玉米胚芽蛋白的二级结构，酰胺Ⅰ带的伸缩振动增强， β-转角增多，蛋白质粒径和Zeta电位发生改变，蛋白质结构和表面性质的改变造成其功能性质的变化。综合来看，交联3 h的玉米胚芽蛋白的功能性质表现最佳。 In order to solve the problem of low solubility of corn germ protein and improve its application in the field of food industry, the corn germ protein was used as raw material, and different corn germ proteins were prepared by enzymatic hydrolysis and cross-linking with transglutaminase (TGase) at different cross-linking time, and the changes of structure and surface properties of corn germ protein were analyzed by infrared spectroscopy and particle size analyzer, and the functional properties such as solubility, emulsification and foaming were examined. The results showed that with the increase of cross-linking time, the solubility, foaming ability, water-holding capacity and emulsifying activity of corn germ protein gradually increased, the change of emulsifying stability was opposite, foam stability first increased and then decreased, and oil-holding capacity first decreased and then increased. Compared with the original sample, the emulsifying activity of the corn germ protein prepared by cross-linking for 3 h increased by 16.7 times, and the water-holding capacity and oil-holding capacity increased by 9.16% and 8.71%, respectively. The TGase cross-linking reaction changed the secondary structure of corn germ protein, the stretching vibration of the amide I band was enhanced, the β-turn angle increased, the protein particle size and Zeta potential were changed, and the changes of the protein in structure and surface properties resulted in changes of their functional properties. In conclusion, the 3 h cross-linked corn germ protein shows the best functional properties.