摘要
为研究反应时间对低聚壳聚糖衍生物抗氧化性能的影响,通过低聚壳聚糖与木糖的美拉德反应(低聚壳聚糖的氨基与木糖的羰基的物质量比为1∶1),考察了反应过程中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CX4和CX8。对两种衍生物进行红外表征和相对分子质量测定,并研究其对超氧阳离子O2-、羟基自由基OH和DPPH的清除能力以及还原能力。结果显示:UV-Vis光谱在278 nm波长处吸收峰于反应前期有明显增强,但4 h后增长非常缓慢;在343 nm的激发波长和435 nm发射波长下的荧光强度于反应前期快速增加,但2 h后呈下降趋势;两种衍生物对O2-、OH及DPPH的清除能力以及还原能力均得到显著提高,且CX8的抗氧化性明显优于CX4,即随着反应的进行壳聚糖衍生物的抗氧化性能不断提升。
In order to investigate the influence of reaction time on the antioxidant activities of the chitosan oligosaccharide(COS) derivatives,two kinds of COS derivatives were prepared through Maillard reaction by heating COS and xylose with 4 h and 8 h separately(the ratio of-NH2 and C=O was 1∶1),named CX4 and CX8.The absorbance and fluorescence were determined during the reaction.The chitosan oligosaccharide derivatives were characterized by FTIR and their molecular weight was determined by GPC.Their antioxidant activity was investigated by employing various established in vitro systems,such as superoxide/hydroxyl/1,1-diphenyl-2-picrylhydrazyl(DPPH) radicals scavenging and reducing power.The results as flowers:the UV-Vis absorbance at 278 nm had a sharply increase within the first 2 h,which attribute to the Maillard intermediate products;The fluorescence intensity(Ex 343 and Em 435 nm) sharply increased within the first 2 h with a subsequent decrease when heating time increased.Though the Maiilard intermediate products and fluorescence prouducts had not accumulated after 4 h,the derivatives of 8 h showed stronger antioxidant activity compared to the derivatives of 4 h.The antioxidant activity was found to be in the order of CX8>CX4>COS,which indicated that the derivatives had the better antioxidant activity as the reaction processed.
出处
《食品与生物技术学报》
CAS
CSCD
北大核心
2012年第11期1198-1202,共5页
Journal of Food Science and Biotechnology
基金
上海市生物医药和农业科技领域重点科技项目(08391911500)
2009年上海市优秀学科带头人计划项目(09XD1402000)
上海市教委重点学科建设项目(J50704)
关键词
低聚壳聚糖
木糖
美拉德反应
抗氧化活性
chitosan oligosaccharide,xylose,Maillard reaction,antioxidant activity
