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(p0.05),while the content of soluble sugar,amino acids,tea polyphenol and ascorbic acid significantly varied among stages(p0.05). 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.