远红外变温提香技术对工夫红茶风味品质的影响

提香是有效提升茶叶风味品质的重要加工工艺。本实验采用L27(36)正交试验并结合感官审评和风味品质成分分析，研究远红外变温提香技术对工夫红茶风味品质的影响。结果表明，远红外变温提香条件因素对茶叶感官总分影响的主次顺序依次为第三阶段温度＞第一阶段温度＞第一阶段时间＞第二阶段时间＞第二阶段温度＞第三阶段时间，优选远红外变温提香工艺A1B1C1D3E1F2（即第一阶段70 ℃、时间30 min，第二阶段100 ℃、时间30 min，第三阶段115 ℃、时间10 min）能明显提升毛茶的香气品质和滋味品质（分别提高了4.66 分和5.00 分）。风味品质成分分析结果表明，采用优选组合工艺所得产品的茶黄素相对含量（（0.81±0.02）%）较未提香茶样（（0.70±0.01）%）显著增加（P＜0.05），而茶红素相对含量（（6.81±0.07）%）、总茶多酚相对含量（（14.79±0.03）%）等显著降低（P＜0.05）。在5 个工夫红茶中共鉴定出40 种香气成分，其中醇类化合物的种类（10 种）和相对含量最高（占香气成分的47.60%～51.07%）。与未提香茶样相比，采用优选组合工艺所得产品的醇类、醛类及其他类香气物质相对含量有所降低，而烯烃类、酮类、酯类相对含量有所增加；芳樟醇及其氧化物（24.60%）、香叶醇（13.16%）、水杨酸甲酯（9.13%）、苯乙醛（7.11%）、苯乙醇（5.98%）等为其主要香气成分。远红外变温提香工艺能有效提高红茶的风味品质，可为工夫红茶加工技术的提升提供一定的技术参考。

Effect of Far-Infrared Variable-Temperature Aroma Enhancement Technology on the Flavor Quality of Congou Black Tea

Aroma enhancement is an important process to develop the flavor quality of tea. In this study, an L27 (36) orthogonal array design was employed to investigate the effect of far-infrared variable-temperature aroma enhancement technology on the flavor quality of Congou black tea as determined by sensory evaluation and analysis of flavor components. Results showed that the temperature in the third step, the temperature in the first step, the duration of the first step, the duration of the second step, the temperature in the second step, and the duration of the third step affected the overall sensory score of tea, ranked in decreasing order of importance. Under the optimized conditions: the first step lasted at 70 ℃ for 30 min, the second step lasted at 100 ℃ for 30 min, and the third step lasted at 115 ℃ for 10 min, the aroma and taste quality of raw tea were significantly improved (an increase in sensory scores by 4.66 and 5.00 points, respectively). The content of theaflavin was significantly increased from (0.70 ± 0.01)% to (0.81 ± 0.02)% (P < 0.05), whereas the contents of thearubigin and total polyphenols were significantly decreased to (6.81 ± 0.07)% and (14.79 ± 0.03)% (P < 0.05), respectively. A total of 40 aroma components in five black tea samples was detected, with alcohols being the most predominant, including 10 alcohol compounds (together accounting for 47.60% to 51.07% of the total aroma compounds). Compared to the sample without aroma enhancement, the contents of some aroma substances such as alcohols and aldehydes in Congou black tea were decreased after variable-temperature aroma enhancement, while the contents of olefines, ketones and esters were increased. Furthermore, linalool and its oxide (24.60%), geranol (13.16%), methyl salicylate (9.13%), phenylacetaldehyde (7.11%) and benzene ethanol (5.98%) were the major aroma components. Far-infrared variable-temperature aroma enhancement technology could greatly improve the flavor quality of black tea, which will provide a technical reference for improving the processing technology for Congou black tea.