干银鱼的褐变反应底物研究

Research on the Maillard discoloration substrates of dried whitebait

银鱼是我国重要的经济鱼类,然而其干制品在加工和贮藏过程中极易发生褐变,影响产品的价值。研究采用85℃加热的方式加速干银鱼的褐变进程,对褐变反应的关键底物如葡萄糖、核糖、抗坏血酸及氨基酸等进行了测定。研究未检测到抗坏血酸和葡萄糖,核糖未随褐变发生明显变化,总氨基酸和游离氨基酸均呈下降趋势,褐变产物的荧光强度呈现上升趋势。因此可以判断氨基酸参与的美拉德反应是干银鱼褐变的重要原因,而葡萄糖、核糖和抗坏血酸并不是褐变的直接底物。

Whitebait is an important fish species with high economic value. However, dried whitebait is prone to browning during drying and storage, thus would impair its commercial value. In this study, dried whitebait was heated at 85 ℃ to accelerate browning. Glucose, ribose, ascorbic acid and amino acids in dried whitebait that could participate in Maillard reaction were determined. The results showed that the ascorbic acid were not detected, the ribose remained stable, the total and free amino acids in dried whitebait showed a decreasing tendency, the fluorescence intensity showed an increasing tendency with discoloration. Therefore, the amino acid that involved in the Maillard reaction were substrates for browning of dried whitebait, while glucose, ribose and ascorbic acid were not directly involved in the browning of whitebait by heating.