L-抗坏血酸自降解过程的非酶褐变反应动态研究  

The process and dynamic research for the non-enzymatic browning reaction about the self-degradation of L-ascorbic acid

作　　者：李亚[1] 杨艳[1] 余爱农[1] 胡停伟 

机构地区：[1]湖北民族学院化学与环境工程学院,湖北恩施445000

出　　处：《食品工业科技》2016年第4期117-122,127,共7页Science and Technology of Food Industry

基　　金：国家自然科学基金项目(31360408);湖北省自然科学基金项目(2014CFC1126);国家民委科研项目(14HBZ012);湖北民族学院硕士学位论文培优基金(PY201502);湖北省高校优势特色学科群建设计划资助项目(鄂学位[2015]5号)

摘　　要：采用动力学方法,研究了L-抗坏血酸自降解过程中的非酶褐变行为。分别考察了反应时间、反应温度及溶液初始p H对L-抗坏血酸自降解过程中无色中间体(294 nm处特征峰)和褐变物质(420 nm处特征峰)的影响。研究了不同p H时,L-抗坏血酸的自降解过程中非酶褐变的反应动力学特征。结果表明:延长反应时间和提高反应温度均会加快L-抗坏血酸非酶褐变过程的降解,溶液的初始p H对L-抗坏血酸的非酶褐变过程也有较大影响,当p H为4.5时较宜生成无色中间体;而当p H为6.8时较适宜生成褐色物质。L-抗坏血酸的非酶褐变自降解过程符合零级反应动力学特征,在各条件下,生成无色中间体的活化能均小于生成褐色物质的活化能。The no-enzymatic self-degradation behavior of ascorbic acid was discussed by dynamics method.The influences of time,temperature and p H on uncolored-intermediate-products（UIPs） and brown-products（BPs） were separately investigated. The dynamics feature of UIPs and BPs was discussed in the degradation process of ascorbic acid based on the initiation different p H value. The results showed that the formation rate of UIPs and BPs would be speeded with the increasing temperature and prolonging reaction time and those rates would also be influenced by the initiation value of p H. The appropriate p H for formation UIPs was 4.5 and the appropriate p H value for BPs was 6. 8. The no- enzymatic self- degradation behavior of ascorbic acid for formation UIPs and BPs was characteristic of the zero-order kinetics,and the Eavalue for formation of brown precursor was much less than that of formation of BPs.

关 键 词：L-抗坏血酸 自降解 非酶褐变 动力学 

分 类 号：TS201.2[轻工技术与工程—食品科学]