不同时期梨枣叶茶品质的差异性分析

目的:研究梨枣叶茶感官、滋味、色泽及营养品质随采收时期的变化规律。方法:采收五月至八月间五个时段的梨枣嫩叶,利用炒青工艺制茶,对枣叶茶进行感官评定,测定其水浸出物、可溶性糖、茶多酚、咖啡碱、氨基酸、矿质元素、总抗坏血酸以及叶绿素含量。结果:不同时期制成的枣叶茶水浸出物含量无显著差异(p>0.05),可溶性糖、游离氨基酸、茶多酚及抗坏血酸含量都表现出显著差异(p<0.05),由于咖啡碱含量极低,可视为未检出。此外梨枣叶茶具有高矿质元素Zn和Fe以及高VC含量的特点。最终五月份的梨枣叶茶条索紧细、色泽嫩绿,汤色明亮、滋味鲜醇,整体品质最好,水浸出物、游离氨基酸、茶多酚、可溶性糖和VC含量分别为41.82%、8.99%、5.64%、114.72mg/g和136.5mg/100g;六月份叶茶干茶色泽和茶汤滋味次之,七月和八月份叶茶干茶色泽和茶汤滋味最差。结论:五月份是梨枣叶茶收获制茶的的最佳时期,枣叶茶作为一种矿物质、维生素营养丰富,且无咖啡碱的新型茶叶极具开发潜力。

Difference analysis in quality of pear jujube leaf tea in different growth stages

Objective:The changing pattern of sensorial quality of flavor,color etc.,and nutritional quality character with the change of different growing stages. Methods:Tender leaves of pear jujube trees were selected in five growing stages from May to August,following by pan-firing to produce the tea,and the sensory evaluation,content of water extract,soluble sugar,tea polyphenol,caffeine,amino acids,mineral elements,ascorbic acid and chlorophyll were investigated. Results:No significant difference was found in the content of water extract(p>0.05),while the content of soluble sugar,amino acids,tea polyphenol and ascorbic acid significantly varied among stages(p<0.05). And the content of caffeine was in a rather low content which could be reported as not detected. Additionally,the pear jujube leaf tea contained high amount of Zn,Fe and Vitamin C. The tea in May possessed tight and thin strip,vivid green color,clear soup,fresh and pure taste with the best overall quality. The content of soluble sugar,amino acids,tea polyphenol,soluble sugar and ascorbic acid were 41.82%,8.99%,5.64%,114.72mg/g and 136.5mg/100g,respectively. The colour and taste of tea of June was in the second place,and the worst found in July and August. Conclusions:Leaves for tea making were best in May,and jujube leaf tea was with great potential of new tea development with rich content of minerals and Vitamins,and no content of caffeine.