四种氨基酸和单糖美拉德模式反应体系的颜色特征和自由基清除活性

美拉德反应(Maillard reaction, MR)可以产生具有特征颜色并具有自由基清除活性的物质。以木糖-甘氨酸、木糖-丙氨酸、木糖-天冬氨酸、葡萄糖-甘氨酸为四个反应体系，在30℃和60℃条件下研究比较其美拉德反应产物（Maillard reaction products, MRPs）的颜色、吸收光谱特征及自由基清除活性。结果表明，木糖-甘氨酸MRPs有特征性颜色出现，对大约570nm和630nm波长的可见光有较强吸收，并且这一特征在30℃加热条件下更为明显。而其他三组MRPs无此特征。四个反应体系的60℃ MRPs较30℃ MRPs有更强ABTS自由基清除活性，且在两个加热条件下，木糖-甘氨酸和木糖-丙氨酸MRPs均比另外两组体系的活性更强。

Color Characteristics and Radical Scavenging Activity of Four Model Systems of Maillard Reaction between Amino Acids and Monosaccharides

Color pigments with radical-scavenging activity can be formed via Maillard reaction (MR). In the present study, four MR systems of xylose-glycine, xylose-alanine, xylose-aspartic acid and glucose-glycine were heated at 30 ℃ and 60 ℃ and their color, absorption spectral characteristics and ABTS (2,2’-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)) radical scavenging activity were assessed and compared. Xylose-glycine MR product (MRP) showed characteristic color and strong absorbance at about 570 nm and 630 nm, which was more obvious at 30 ℃ than 60 ℃. Whereas no apparent peak was observed from xylose-alanine, xylose-aspartic acid and glucose-glycine MRPs. All the four MRPs heated at 60 ℃ had higher ABTS radical scavenging activity than those at 30 ℃. The xylose-glycine and xylose-alanine MPRs prepared at both 30 ℃ and 60 ℃ had higher ABTS radical scavenging activity than other two MPRs.