【摘要】 本文通过模型体系的建立,研究了L-阿拉伯糖/半胱氨酸Maillard反应动力学。利用高效液相色谱-蒸发光散射检测器,分析了Maillard反应产物,比较了不同反应条件下阿拉伯糖/半胱氨酸模型体系中L-阿拉伯糖的残留情况的反应动力学特征。研究表明,pH5、120℃条件下,Maillard反应初期L-阿拉伯糖与氨基酸结合迅速,是一个动力学控制过程;随着反应时间的延长,反应速率趋于稳定,反应速率取决于Amadori化合物分解为产物的速率,是一个热力学控制过程。反应温度对Maillard反应速率的影响大于反应时间,高温可使Maillard反应速率迅速提高。初始pH对Maillard反应影响最大,酸性和弱酸性条件反应缓慢,中性和碱性条件下反应快速。pH5、反应温度120℃时,L-阿拉伯糖的残留率随反应时间的延长而下降,反应时间180 min时残留率为50.53%;pH5、反应时间1 h时,反应温度不同L-阿拉伯糖的残留率不同,在40~100℃范围内残留率变化(70.4%~76.78%)不大,在100~140℃范围内随反应温度的上升残留率迅速下降,140℃时残留率为27.79%;反应温度120℃、反应时间1 h时,酸性条件下不同初始pH,残留率变化不大。但中性及碱性条件下残留率迅速下降,pH9时残留率为15.1%。结论:反应时间对L-阿拉伯糖的残留率影响远不如反应温度和pH,其中pH的影响最为显著。更多还原

【Abstract】 The lossreactivity of L-arabinose in the Maillard reactionmodel system of containing arabinose/ and cysteine under different reaction conditions was analyzed and compared by method of high performance liquid chromatography(HPLC) associated with evaporative light-scattering detection(ELSD).In the initial stage of reaction of model system which was heated to 120 ℃ in an autoclave at pH5,Under the condition of pH5,120℃ the percentage of residual L-arabinose decreased with the increasing reaction time prolonging and after 180min reaction the percentage of residual L-arabinose was 50.53%;at pH5 after 1h reaction the ratio of residual L-arabinose changed a little(between 70.4%-76.78%) at the range of 40-100 ℃,but decreased rapidly at 100-140 ℃,and the ratio of residual L-arabinose reached 27.79% at 140 ℃;when reacting at 120 ℃ after for 1h reaction,the effect of pH on the ratio of residue of arabinose was weak when the initial pH of the system is lower than 7,but the effect became strong when the initial pH≥7 and the ratio of residual arabinose was 15.1%.L-arabinose combined with amino acid rapidly,and it was kinetics-controlled course.With the reaction continuing,the reaction rate was stable and determined by the decomposition rate of Amadori compounds.It was a thermodynamics-controlled course.Results showed that the effect of reaction time on the ratio of residual arabinosereaction rate is was weaker than those of temperature and pH,and initial pH of reaction mixture is was the most important factor.Under acidic or weak acidic condition the reaction was slower than that under neutral or alkaline condition.更多还原