不同采摘季节工夫红茶品质的研究

The effects of different plucking seasons of fresh tea leaves on congou black tea quality

以不同季节(春、夏、秋)采摘的茶树鲜叶为实验材料,按照工夫红茶常规制造工艺(萎凋、揉捻、发酵和干燥)制成红茶,分析了茶多酚、游离氨基酸、茶红素(TR)、茶黄素(TF)、茶褐素(TB)含量,采用顶空固相微萃取方法结合气质联用技术鉴定了不同采摘季节工夫红茶中香气物质种类,并进行了感官审评。结果表明,不同季节的工夫红茶中,春季红茶茶多酚含量最高(19.19%~22.49%),游离氨基酸含量最高(2.73%~2.91%),茶褐素含量最低(6.73%);夏季和秋季红茶各项指标接近,茶多酚含量低于春季,为16.77%~18.67%,游离氨基酸也低于春季,含量为2.28%~2.46%;而夏季的茶黄素和茶红素都高于秋季和春季,含量为7.97%。不同季节工夫红茶香气物质都主要包含醇类、醛类、酯类、酮类、烯类和烷烃类等。其中,醇类物质是工夫红茶的主要香气物质,占香气总量的44.86%~60.79%。香叶醇、水杨酸甲酯、β-芳樟醇、苯乙醇、苯甲醛和苯乙醛是不同季节工夫红茶的主要呈香物质组分。香叶醇含量在春季占绝对优势,其中春季香叶醇含量最高,能达到40%以上,而夏季、秋季呈明显降低趋势;水杨酸甲酯和芳樟醇类春季含量较低,从夏季开始则有增加趋势。感官审评结果表明,春季工夫红茶评分最高(92.0分),秋茶居中(89.4分),夏茶次之(86.3分)。

Black tea made from fresh tea leaves picked in different seasons（spring, summer and autumn） were served as material, which were prepared by the orthodox method. Polyphenols, free amino acids and tea pigments（thearubigins, theaflavins, theabrownins） were analyzed, aroma constituents were analyzed by adopting headspace solid-phase micro-extraction and gas chromatography-mass spectrometry, and sensory evaluation were also carried on. The result showed that the contents of polyphenols（19.19%~22.49%） and free amino acids（2.73%~2.91%） of spring tea were both highest, the content of theabrownins was lowest（6.73）. The content of polyphenols of summer tea ranged from 16.77% to 18.67%, and free amino acids ranged from 2.283% to 2.46%, the content of theabrownins was 7.97%. Alcohols, aldehydes, esters, ketones, terpenes, hydrocarbon alkyls and etc. were common primary components among different plucking seasons, especially, alcohols were the most main constitutes, accounting for 44.86%~60.79% of the total. Geraniol was the most predominant aroma compounds in both spring, representing over 40% of the total aroma. However, methyl salicylate, linalool and linalool oxides contents increased significantly from summer. In the meanwhile, the ratio of geraniol to ？-linalool and its oxides was variable with the change of plucking month. Sensory evaluation score ranking for spring（92.0）, autumn（89.4）, summer（86.3）.