枇杷叶伸长期主要成分变化及制茶适性研究

为探明枇杷叶新芽伸长生长过程中主要成分含量变化规律以及对制茶适性的影响。以春、夏新发枇杷叶为材料，在伸长生长过程定期进行主要成分测定，并对以不同长度夏梢新叶的加工适性进行比较分析。结果表明：在伸长生长过程中，枇杷夏梢和春梢新叶的黄酮、总酚和三萜酸的含量都呈逐渐下降趋势，而可溶性总糖含量先升高后下降；其中夏梢枇杷新叶主要成分含量总体高于春梢。不同长度夏梢新叶加工的叶茶中，其黄酮、总酚、三萜酸、酚类单体成分和抗氧化性能及水浸出物中VC和游离氨基酸含量均随叶长的增加呈显著下降趋势，可溶性总糖呈先上升后下降趋势。结果表明，枇杷新叶可用于叶茶的加工利用，以长度2～13 cm之间叶片所制叶茶品质最优。

Changes in Major Components and Tea Making Suitability of Loquat Leaves during Growth

In order to find out the pattern of changes in the contents of the major components during the growth of loquat sprouts and its influence on the tea making suitability of loquat leaves, the major components of loquat leaves were determined regularly during two growing seasons: spring and summer, and the tea processing suitability of new leaves of different lengths collected in summer was analyzed comparatively. The results showed that the contents of flavonoids, total phenols and triterpenoid acids in new leaves decreased gradually during both growing seasons, while the content of total soluble sugar increased first and then decreased. In general, the contents of the main components in summer leaves were higher than in spring leaves. The contents of flavonoids, total phenols, triterpenoid acids, phenolic monomers and antioxidant activities of loquat leaves decreased significantly with the increase in leaf length, and so did the contents of vitamin C and free amino acids in the water extract of leaves, whereas the content of soluble total sugar increased first and then decreased. The results showed that loquat leaves can be processed into tea, and the quality of tea made from leaves between 2 and 13 cm long is the best.