不同嫩度和加工工艺龙团凤饼茶风味品质差异分析

Differences in Flavor Quality of Loong and Phoenix Tea Cake with Different Tenderness and Processing Technologies

摘要:

该实验基于感官审评技术和非靶向代谢组学，分析了不同嫩度和工艺龙团凤饼茶风味品质的差异。感官审评结果表明，以单芽、一芽二三叶通过传统洗、蒸、榨、研、造、焙工艺制成的SX-B和SX-L，单芽省略“榨茶”工艺制得的SX-B-BZ，以及单芽通过烤箱干燥的样品SX-B-KX，前三者滋味和香气得分较高，且点茶审评总分均高于第四个样品。香叶酸甲酯具有花香，其含量在SX-B、SX-B-BZ、SX-B-L中无显著差异，且皆显著高于SX-KX。(Z)-3-己烯醇、异丁酸庚酯具有青香和花果香，在SX-L中有较高的ROAV值。茴香脑和胡椒酮在SX-B、SX-B-BZ、SX-B-KX中的贡献作用较大，凸显香料香的品质特征。因此，龙团凤饼茶原料可拓展至一芽二三叶，SX-B-BZ与SX-B无显著差异，可省略“榨茶”工艺，烤箱干燥具有火味，故不建议采取此方式。此外，黄酮醇或黄酮糖苷类等物质在龙团凤饼茶代谢物中占比较大，可能是构成茶汤醇厚滋味的重要物质，茶皂素类含量较高，推测与沫饽品质的形成有关。本试验结果可为创新龙团凤饼茶的加工工艺提供一定的理论依据。

Abstract:

In this experiment, Loong and Phoenix Tea Cakes, prepared from tea leaves with varying tenderness (i.e., harvested at the one-bud or one-bud and two-to-three-leaf stage) and subjected to different processing methods, were characterized by sensory evaluation and non-targeted metabolomics analysis to clarify their differences in flavor quality. The results of the sensory evaluation showed that SX-B (one-bud) and SX-L (one-bud and two-to-three-leaf) were prepared through a complete traditional process. SX-B-BZ (one-bud) was prepared through a modified traditional process (without pressing), whereas SX-B-KX (one-bud) was prepared through a modified process (roasting in an oven instead of in a wok). The results of the sensory evaluation showed that SX-B, SX-L, and SX-B-BZ scored higher than SX-B-KX in terms of taste, aroma, and overall score of whisked tea. SX-B, SX-B-BZ, and SX-B-L did not differ significantly in the content of methyl geranate (with a floral aroma), whereas their methyl geranate contents far exceeded that of SX-KX. SX-B, SX-B-BZ, and SXB-L did not differ significantly in the content of methyl geranate (with a floral aroma), whereas their methyl geranate contents far exceeded that of SX-KX. SX-L had a high relative odor activity value for (Z)-3-hexenol and heptyl isobutyrate (with grassy, floral, and fruity aromas). Anethole and piperitone contribute more in SX-B, SX-B-BZ, and SX-B-KX, highlighting a spicy aroma. Therefore, the raw materials of Loong and Phoenix Tea Cakes can be extended to include tea leaves harvested in the one-bud and two-to-three-leaf stages. SX-B-BZ and SX-B had similar qualities, which allowed the pressing process to be omitted. However, oven roasting introduces an over-fired taste, which is not ideal. Flavonoids or flavonoid glycosides constitute a significant proportion of the flavor metabolites of Loong and Phoenix Tea Cakes, likely contributing to the mellow taste of the steeped tea. Additionally, the abundance of tea saponins may influence froth quality. These findings can serve as a theoretical guide for developing new processes for Loong and Phoenix Tea Cakes.