硫酸氨基葡萄糖非酶褐变的初步研究

将硫酸氨基葡萄糖样品分别在60、70、75、80℃下加热10h，测定加热过程中褐变指数、5- 羟甲基糠醛含量、硫酸氨基葡萄糖含量、pH 值的变化，用来表征非酶褐变进行的程度，将结果应用零级动力学方程拟合。结果表明，随着加热温度升高、时间延长，褐变指数、5- 羟甲基糠醛的含量逐渐增加，而pH 值和硫酸氨基葡萄糖的含量逐渐下降，硫酸氨基葡萄糖的非酶褐变反应符合零级动力学，褐变指数和5- 羟甲基糠醛含量变化的反应活化能分别为85.127、136.973kJ/mol，NaHSO3 对硫酸氨基葡萄糖的非酶褐变有一定的抑制作用。

Preliminary Study on Nonenzymatic Browning of Glucosamine Sulfate

Glucosamine sulfate samples were heated at 60, 70, 75 and 80 ℃ for 10 h, respectively. The changes in browning index (absorbance at 420 nm), contents of 5-hydroxymethyfurfural (5-HMF) and glucosamine sulfate and pH value were determined to estimate the extent of nonenzymatic browning during the heating process. Then zero-order kinetics was applied to describe the results. It was found that with the increase of heating temperature and time, 5-HMF content and browning index increase, while glucosamine sulfate content and pH value decrease. The nonenzymatic browning reactions of glucosamine sulfate accord with zero-order kinetics model, and the activation energies of changes of browning index and 5-HMF content are 85.127 kJ/mol and 136.973 kJ/mol, respectively. Moreover, NaHSO3 shows certain inhibitory effects against nonenzymatic browning of glucosamine sulfate.