Sun Wei-wei, Yu Shu-juan, Yang Xiao-quan, Wang Jin-mei, Guo Jian, Guo Rui
College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2011 Dec;31(12):3307-10.
The mixed whey protein isolate (WPI)-dextran was treated by dry-heating to prepare Maillard reaction products (MRPs), which was characterized by the browning. The free amino groups content significantly decreased by 35.77% and 30.53% in glycated protein samples, as the molecular weight of dextran increased from 67 to 150 kD, respectively. This suggested that it was more difficult to be linked with WPI molecule when the chain length of dextran was increased. The characteristic of WPI-dextran conjugate was studied by fluorescence spectra in the paper. The maximum fluorescence intensity at 405 nm was obviously enhanced and G67 showed high fluorescence intensity than G150 over the wavelength range form 350 to 500 nm. This result revealed that the flourescent substance, a feature in Maillard reaction model system, was generated. As showed in the fluorescence spectra, the maximum fluorescence intensity at 470 nm was significantly decreased and the fluorescence intensity in each solution was in the order as follows: WPI>G150>G67. Moreover, the measurement of surface hydrophobicity index further showed that the hydrophobicity of WPI could be suppressed due to these two kinds of different molecular weight dextran.
将混合的乳清分离蛋白（WPI）-葡聚糖进行干热处理以制备美拉德反应产物（MRPs），其特征在于出现褐变。随着葡聚糖分子量从67 kD增加到150 kD，糖化蛋白样品中的游离氨基含量分别显著降低了35.77%和30.53%。这表明当葡聚糖链长增加时，其与WPI分子连接变得更加困难。本文通过荧光光谱研究了WPI-葡聚糖缀合物的特性。在350至500 nm波长范围内，405 nm处的最大荧光强度明显增强，且G67的荧光强度高于G150。该结果表明生成了美拉德反应模型体系中的荧光物质。如荧光光谱所示，470 nm处的最大荧光强度显著降低，且各溶液中的荧光强度顺序如下：WPI>G150>G67。此外，表面疏水性指数的测定进一步表明，这两种不同分子量的葡聚糖可抑制WPI的疏水性。
