谷氨酰胺转氨酶对荞麦面条品质的影响

Effects of transglutaminase on qualities of buckwheat noodles

为了改善荞麦面条的品质,采用谷氨酰胺转氨酶(TG酶)对其进行处理,研究谷氨酰胺转氨酶对荞麦面条品质特性(面条吸水率、蒸煮损失及质构特性)和微观结构的影响,采用十二烷基硫酸钠—聚丙烯酰胺凝胶电泳(SDS—PAGE)和体积排阻高效液相色谱(SE—HPLC)对面条中蛋白质交联聚合特性进行研究,探讨其作用机制。结果表明,添加TG酶能显著降低荞麦面条的吸水率和蒸煮损失,提高其硬度和拉断力,当添加0.01%的TG酶时,荞麦面条的蒸煮损失达到最小值。RVA分析表明,随着TG酶添加量的增加,荞麦面粉的峰值黏度、终值黏度和回生值增加,崩解值降低。电泳图中低分子量亚基条带变浅,SDS蛋白可萃取率降低,说明添加TG酶诱导面条中的蛋白质发生了交联聚合行为,并经微观结构观察,这种交联形成了致密而连续的蛋白网络结构,使得淀粉很好地镶嵌在其中,从而影响了荞麦面条的品质。

Addition of transglutaminase （TG） was used to improve the quality of buckwheat noodles. The effect of TG on the water absorp tion, cooking loss, texture properties and microstructure of buck- wheat noodles was investigated, as well as protein polymerization and the mechanism impacting on the quality of noodles by SDS--PAGE and SE--HPLC. The results indicated that addition of TG signifi- cantly （P 〈 0.05） decreased the water absorption and cooking loss of noodles, increased the hardness and tensile force. When adding 0.01% TG, the lowest cooking loss of buckwheat noodles was ob- tained. In addition, with the increase of TG, RVA viscosity proper ties of buckwheat noodle flour increased except for breakdown. Furthermore, an obvious decrease in the intensity of the protein bands with lower molecular weight was observed in SDS PAGE patterns and the SDS extractable protein decreased, which demonstrated that TG promoted the protein cross linking in the buckwheat noodles. And a tight and continuous protein network was observed by CLSM, which made the starch granules be well embedded in it and thus im- pacted the quality of buckwheat noodles.