莲藕中酚类化合物的化学氧化模拟试验

Simulation Experiment of Chemical Oxidation of Polyphenols in Lotus Root

为了解莲藕中酚类化合物的化学氧化,寻求控制莲藕褐变的有效方法,针对莲藕中的主要酚类化合物邻苯二酚、没食子酸及多巴进行了化学氧化模拟试验。结果表明,pH对化学氧化反应后褐变指数的影响最大,其次是酚类化合物的种类,反应温度的影响最小。酚类化合物在碱性条件下更易褐变;3种酚类化合物发生化学氧化反应的速率由快到慢依次是多巴、没食子酸、邻苯二酚。在莲藕加工过程中可以选择多巴及没食子酸含量较低的莲藕品种,并控制好pH,可以有效减缓莲藕中酚类化合物化学氧化反应的速率,达到防止莲藕褐变的目的。

The chemical oxidation of 3 kinds of polyphenols in lotus root, catechol, gallic acid and dopa, was simulated to find effective way to control the browning of lotus root. The results showed that pH had the biggest effect on browning of polyphenols, followed by kind of polyphenols, the temperature had less effect on browning. The browning degree was more serious under alkaline condition. The oxidation rate of the 3 polyphenols ranked from fast to slow was dopa, gallic acid, catechol. Choosing the lotus cultivar with lower content of dopa and gallic acid, and control the pH in storage and processing would effectively slow down the chemical oxidation of polyphenols thus help to control browning of lotus root.