谷氨酰胺转氨酶对挤压糙米粉面团蛋白特性和面条品质的影响

将挤压糙米粉(EBR)与小麦粉以1∶1(m/m)的比例混合制成面条,研究了谷氨酰胺转氨酶(TG)添加量(0.5%、1.0%和1.5%)对面条性质的影响。结果表明,TG添加后,面条中游离巯基含量减少,SDS-PAGE条带显示面条中形成了大分子质量的聚集体。随着TG的添加,面条最佳蒸煮时间增加,干物质损失率降低,吸水率升高。添加量为1.0%时,面条最佳蒸煮时间和吸水率达到最大值,蒸煮损失率达到最小值。TG添加量为0.5%时,面条的硬度、耐咀性、回复性和剪切力最大。扫描电镜结果显示,TG的添加明显增强了面条内部结构的连接与聚合,面条内部变得更加紧实,连续性增强。TG添加量为0.5%~1.0%时,挤压糙米粉面条质构品质和蒸煮品质较好。

Effect of Transglutaminase on the protein properties of dough and quality of noodles prepared from extruded brown rice flour

The noodles were prepared from extruded brown rice flour and wheat flour (1:1, w/w), and the effect of addition amount of Transglutaminase (0.5%, 1.0%, 1.5%, w/w, dry basis) on the properties of noodles were studied. The results showed that the amount of free sulfhydryl group in noodles decreased with the Transglutaminase (TG) addition, and the bands from SDS-PAGE demonstrated that the aggregation with large molecular weight formed in the noodles. The cooking loss rate of dry materials in noodles decreased, but the water absorption of noodles increased. The water adsorption rate and the optimal cooking time of noodles reached maximal value, and the cooking loss of noodles reached minimal value when the addition amount of Transglutaminase was 1.0%. The hardness, chewiness, resistance and shear fore reached maximal value when the addition amount of Transglutaminase was 0.5%. The proteins were connected and the continuous structures formed in noodles with the addition of Transglutaminase. The texture and cooking quality of noodles prepared from extruded brown rice flour were better when the Transglutaminase content were 0.5%-1.0%.