用碘量法测糯玉米、水果玉米中游离单糖的含量

Determination of the Content of Free Monosaccharides in Waxy Corn and Fruit Corn by Iodine

用碘量法测定糯玉米和水果玉米中的游离单糖,结果表明:糯玉米和水果玉米中的单糖含量有差别,水果玉米含糖量是糯玉米的五倍,糯玉米的含糖量0.9%,水果玉米中的含糖量4.5%。实验中发现:1两者运用碘量法测定糖的含量时,各个滴定终点的颜色有很大的差异。2在滴定前的避光放置10~15min后,会有明显褪色,其中可能含有某种不稳定的色素。本文将介绍实验具体的操作方法和实验过程中出现的一些现象,并分析其原因。

Determination of free monosaccharides, waxy corn and fruits in corn by iodometric method showed that different monosaccharide content of waxy corn and fruit corn, corn fruit sugar content is five times of waxy corn, sugar containing 0.9% waxy corn, sugar containing 4.5% fruit in maize. The results showed that: when the content of sugar was determined by the method of iodine, the color of each titration endpoint was very different. Before the 10 ~ 15 min of the light before titration, there will be obvious fading, which may contain some kind of unstable pigment. In this paper, we will introduce some experimental methods and some phenomena in the experiment, and analyze the reasons.