枣果实发育过程中游离单糖含量动态研究

采用HPLC方法和碘量法对冬枣和金丝小枣果实中游离单糖的动态变化进行了测定。结果表明:枣中的游离单糖有葡萄糖、果糖、半乳糖、鼠李糖和阿拉伯糖。在枣果发育的各个阶段均以果糖所占比例最大,其次是葡萄糖和半乳糖,鼠李糖和阿拉伯糖含量很低;果糖、葡萄糖和半乳糖含量在枣果发育前期逐渐增加,临近白熟期达最高值,随果实着色成熟又有所下降;枣果游离单糖中的酮糖只有果糖,醛糖主要为葡萄糖和半乳糖,各约占50%,另有少量的鼠李糖和阿拉伯糖。

Variations of the contents of dissoluble monosaccharides during fruit development of Ziziphus jujuba Mill

The contents of dissoluble monosaccharides of Chinese jujube(Ziziphus jujuba Mill.cv Dongzao and Z.jujuba Mill.cv Jinsixiaozao) during fruit development were measured by both HPLC and iodine methods.The dissoluble monosaccharide consists of glucose,fructose,galactose,rhamnose and arabinose.During the whole period of fruit development the contents of fructose remained the highest among the monosaccharides,and the contents of rhamnose and arabinose were the lowest.The contents of glucose,fructose and galactose increased with fruit development but decreased during fruit maturation.The ketose of Chinese jujube includes only fructose,and the aldose is mainly composed of glucose and galactose(about 50%,respectively),with small amount of rhamnose and arabinose.The traditional representation of glucose by using aldose is improper,while that of fructose by ketose is reasonable.