荔枝果皮褐变过程中花色素苷含量的变化及测定

Change of Anthocyanin Content and It's Determination During Lychee Pericarp Browning

对荔枝果皮花色素苷含量与果皮褐变的关系进行了研究 ,详细比较了荔枝上两种花色素苷的测定方法 ,结果表明 :随着采后荔枝果皮褐变指数的升高 ,果皮花色素苷含量显著下降 ,两者呈现很好的负相关 .盐酸甲醇法测定褐变荔枝果皮的花色素苷含量时存在较大的干扰 ,主要原因是盐酸甲醇将不溶于水的褐色物质也提取了出来 ,褐色物质的盐酸甲醇溶液在 5 30nm处有较强烈的光吸收 。

Lychee pericarp browning index increased while the content of anthocyanins decreased with storage time, and there was a good correlation between pericarp anthocyanin content and browning index when the pH-differential method was used as the analytic method. However, there was no obvious change in the content of anthocyanins while the fruit browned when the acidific methanol method was used. To confirm the correlationship between pericarp browning and anthocyanins content, these two methods was compared. Besides anthocyanins, acid methanol also extracted the brown compounds, which were insoluble in water and interfered with the determination. According to the solubility of anthocyanins in water, φ =1% HCl was used as the extract solution in the pH-differential method, which would not extract the brown compounds. Additionally pH differential method could eliminate the interference of other compounds with the determination.