变温干燥处理对秋季绿茶品质的影响

Effect of variable temperature drying on the quality of autumn green tea

中文关键词:  秋季绿茶  变温干燥  感官品质  呈味物质  香气物质

英文关键词:autumn green tea  variable temperature drying  sensory quality  taste compounds  aroma substances

中文摘要:

      目的 探究变温干燥处理对秋季绿茶品质的影响。方法 以茶树品种碧香早秋季一芽二叶为原料, 在传统绿茶90℃烘二青、75℃烘至足干的干燥工艺基础上, 提高烘二青温度至85~95℃ 2~4 min, 烘三青温度至85~95℃ 2~3 min, 从感官品质、呈味物质及香气物质3方面探讨变温干燥及其组合处理对绿茶品质的影响。结果 与传统绿茶干燥工艺相比, 90℃二青干燥17 min后升温至100℃干燥3 min、75℃三青10 min后, 升温至95℃干燥3 min、最后回温至75℃烘至足干的变温干燥处理加工出的绿茶栗香高长、滋味醇厚且综合感官品质最佳, 其茶多酚、咖啡碱、酯型儿茶素等苦涩滋味物质含量显著下降(P<0.05), 醇类、酯类、杂环化合物等香气物质的相对含量分别增加了26.14%、38.95%、81.34% (P<0.05), 其中苯甲醇、芳樟醇、水杨酸甲酯、2-正戊基呋喃等栗香特征性香气成分增幅较大, 且新增加了植烯、金合欢醇、丁位癸内酯等甜香、花果香香气成分。结论 在秋季绿茶干燥过程中, 烘二青、烘三青组合变温处理有利于提高秋季绿茶品质。

英文摘要:

      Objective To investigate the effect of variable temperature drying treatment on the quality of autumn green tea. Methods Flushes of two leaves and a bud of tea variety Bixiangzao picked in autumn were as raw material, based on the traditional green tea drying processes of 90℃ for the initial drying process and 75℃ for the re-drying process, the temperature of the initial drying process was increased to 85?95℃ for 2?4 min, and the temperature of the re-drying process was increased to 85-95℃ for 2-3 min, the effects of variable temperature drying and its combination treatment on the quality of green tea were investigated in terms of sensory quality, taste compounds and aroma substances. Results Compared with the traditional drying technology, the green tea produced by the drying process of the initial drying at 90℃ for 17 min, then to 100℃ for 3 min, and the re-drying at 75℃ for 10 min, then to the 95℃ for 3 min, and then 75℃ backing to enough dry had the best overall sensory quality with high long chestnut aroma and mellow taste, while the content of bitter taste substances such as tea polyphenols, caffeine and ester catechin was significantly reduced (P<0.05), the relative content of tea-scented substances such as alcohols, esters and heterocyclic compounds increased by 26.14%, 38.95% and 81.34% respectively (P<0.05), among them, the characteristic aroma composition of chestnut aromas such as benzoyl alcohol, aromatic camphor, salicylic acid, 2-positive ternary furans increased significantly. Furthermore, the sweet, flower and fruit aroma components including phytene, (2E,6E)-farnesol, δ-decalactone were freshly added. Conclusion During the drying process of autumn green tea, the combination of proper temperature treatment in initial drying and re-drying process is conductive to improve the quality of autumn green tea.