为了探讨谷氨酰胺转氨酶(TG)对植物蛋白美拉德反应改性的作用，本文利用米渣蛋白(RDP)分别与葡萄糖、核糖、麦芽糊精1:1进行干法糖基化反应，研究TG的添加(10 μ/g的RDP)对反应产物结构和流变学特性的影响。结果表明：随着反应的进行，核糖与RDP糖基化反应的接枝度最大，TG酶能够提高糖基化反应接枝度；内源荧光λmax红移且强度降低，红外光谱显示不同产物的结构变化显著，但TG对产物的结构影响不大；糖基化反应可降低表面疏水性，而TG促其增大；糖基化反应主要是Lys和Arg含量减少，组氨酸含量增加，且核糖更利于与自由氨基的反应，TG对产物氨基酸组成无影响；糖基化产物溶液都是假塑性流体，核糖接枝产物表观粘度最大，TG促使表观粘度增高；三种糖基化产物动态模量随剪切频率增大而变化较大，其中核糖反应产物表现出类似凝胶特性，G′>G″且较RDP均增加，TG提高核糖、葡萄糖反应产物的G′与G″。

In order to investigate the role of transglutaminase (TG) on the modification of vegetable proteins using Maillard reaction, rice dreg protein (RDP) was used in the present study for glycosylation reactions in a dry state with glucose, ribose, and maltodextrin separately in a mass ratio of 1:1, and the effect of adding TG (10 u/g RDP) on the structure and rheological properties of RDP-sugar conjugates was studied. The results showed that the Maillard reaction products (MRPs) of RDP with ribose exhibited the highest degree of substitution (DS) and TG could enhance the DS. The λmax of the intrinsic fluorescence was redshifted and their intensity decreased. Additionally, FTIR spectra showed significant changes in the structure of different products, while TG had little effect on the structure of the products. Glycosylation reaction could reduce the surface hydrophobicity, while TG could increase it. During the Maillard reaction, lysine (Lys) and arginine (Arg) contents were reduced and the histidine (His) content was increased. Additionally, ribose was conducive for the reaction with free amino groups, while TG had no impact on the amino acid composition. Rheology measurement indicated that all MRP solutions were pseudoplastic fluid. The maximum apparent viscosity was detected in ribose-grafted products and TG promoted the increase in apparent viscosity. Mechanical spectra showed that the dynamic shear moduli of the three kinds of MRPs displayed significant changes with increasing frequency. The MRPs of RDP-ribose exhibited gel-like characteristics with G' > G" and both values were higher than that of RDP. TG increased G' and G" values of MRPs from ribose or glucose glycosylated and cross-linked RDP.

国家“863”计划基金(2013AA102203-5)；江西省自然科学基金 (20142BAB213006)；科技支撑计划(20151BBF60041)；教育厅青年基金(GJJ13020)