龙眼干贮藏过程的褐变研究

本文研究了龙眼干在不同的包装形式（抽真空，避光）和不同贮藏温度（4 ℃、25 ℃和37 ℃）下贮藏30 d内龙眼果肉的褐变情况，通过测定贮藏期间的色泽变化，研究了龙眼干的褐变动力学，探讨了不同影响因素对龙眼干贮藏效果的影响，利用通径分析的方法分析了龙眼干贮藏过程中褐变的主要原因。结果表明，对龙眼干色泽变化影响最大的因素为贮藏温度，其次是空气和光照：贮藏温度越高，龙眼干的褐变越快，空气和光照的存在均会不同程度地加速龙眼干褐变；本文推导了龙眼干储藏过程中的颜色变化符合零级动力学方程，定量地描述龙眼干在储藏中的褐变情况；通过分析龙眼干贮藏过程中Vc、总酚、5-羟甲基糠醛（5-HMF）含量的变化表明龙眼干在贮藏过程中色泽变化的主要原因是抗坏血酸降解和美拉德反应。
The browning processes of dried longan flesh stored for 30 d under different packaging conditions (vacuum and light-shielding) and at different temperatures (4 ℃, 25 ℃, and 37 ℃) were investigated in this study. Through analysis of the color changes during the storage period, the influence of these different factors on the storage performance of dried longan flesh was explored. The path analysis method was adopted to identify the main cause of browning during storage process, and the results showed that the factor with the most significant influence on color change was the storage temperature, followed by air and light. A higher storage temperature led to faster browning of dried longan flesh, and the presence of air and light could accelerate the color change to various degrees. The browning process of dried longan flesh during storage followed zero-order kinetics, which described the color change quantitatively. Analysis of the changes in content of vitamin C (Vc), total phenol, and 5-hydroxymethylfurfural (5-HMF) indicated that the main factors leading to the color change of dried longan flesh were the degradation of ascorbic acid and Maillard reaction.