研究低聚壳聚糖与木糖的美拉德反应,考察了两种体系(低聚壳聚糖与木糖的质量比分别为1∶1和1∶3)反应过程中pH、吸光度及荧光值的变化,醇沉法提取4 h和8 h的低聚壳聚糖美拉德反应衍生物,分别为CX11-4、CX13-4、CX11-8和CX13-8.对衍生物进行红外表征和分子量测定,并研究其对羟基自由基·OH和DPPH的清除能力以及还原能力.结果显示:壳聚糖衍生物的抗氧化能力都明显优于低聚壳聚糖,抗氧化活性顺序为CX13-4＞CX11-4,CX11-8＞CX13-8.可见,壳聚糖美拉德衍生物的抗氧化活性不仅与反应物的比例有关,还与反应的时间有关.%Four kinds of the chitosan oligosaccharide derivatives were prepared though Maillard reaction by heating chitosan oligosaccharide and xylose with different times (4 h and 8 h) and different proportions ( the mass ratio of chitosan oligosaccharide and xylose was 1:1 and 1: 3),named CX11-4、CX13-4、CX11-8 and CX13-8,respectively. The pH,absorbance,and fluorescence were determined during the reaction. The chitosan oligosaccharide derivatives were characterized by FTTR and their molecular weight was determined by GPC. Their antioxidant activity was investigated by employing various established in vitro systems, such as hydroxy1/1, 1-dipheny1-2-picrylhydrazyl (DPPH) radicals scavenging and reducing power. The results showed all of the derivatives had strong antioxidant activity compared to chitosan oligosaccharide. The antioxidant activity was found to be CX13-4 ＞ CX11-4 and CX11-8 ＞ CX13-8,which indicated that the antioxidant activity of the chitosan oligosaccharide Maillard derivatives is not only related to the ratio of-NH2 and-C = 0 but also related to the reaction times.
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