Tea blending technology is based on finished tea. Blending fresh leaves during processing has not been proposed and investigated anywhere. This study investigates the impact of blending fresh leaves from different varieties on the flavor quality of black tea. The main taste components, including catechins, theaflavins, and free amino acids, were analyzed using HPLC, while the volatile components were analyzed using GC-MS. The results show that adding freshJinguanyinorJinxuanleaves toFudingdabaican regulate the ratio of esterified to non-esterified catechins, increase the content of theaflavins and amino acids, and positively impact the strength and freshness of the black tea. The sensory evaluation results show that the taste scores of FJG (black tea made from the blend of freshFudingdabaiandJinguanyintea leaves) (92.14 ± 0.41 b) and FJX (black tea made from the blend of freshFudingdabaiandJinxuantea leaves) (93.80 ± 0.19 a) are significantly higher than those ofFudingdabai(90.05 ± 0.31 d),Jinguanyin(86.10 ± 0.45 e), andJinxuan(91.03 ± 0.26 c). Furthermore, adding freshJinguanyinorJinxuanleaves toFudingdabaican also enhance the floral compounds in the black tea, specifically phenylacetaldehyde, linalool, benzyl alcohol, and oxidized linalool (linalool-type pyran), which make important contributions to the floral aroma of the black tea. Conclusions: Blending fresh leaves for processing can enhance the sensory quality of black tea. This work proposes new insights and methods to enhance black tea sensory quality via the blending of fresh tea leaves with different varieties during processing.
Withering time of fresh leaves is a key factor affecting the stability of flavor quality of Taiping Houkui tea (TPHK). It's effect and mechanism on the formation of flavor in TPHK remain unelucidated. Here, metabolomics and transcriptomics were combined to comprehensively investigate changes in the main flavor compounds and the expression patterns of related genes under different withering times. The results showed that withering had the greatest influence on the content of most amino acids and aroma volatiles. The relative content of most volatiles was observed to be highest at 6–8 h of withering time, which was consistent with the results from the sensory evaluation of aroma quality. Plant hormone signal transduction pathways played a key role in the variation of the flavor compound content under different withering times, especially ABA and JA signals. WGCNA demonstrated that ABA, JA, IAA, SA and different flavor substances were significantly associated with specific modules. JA may be involved in the metabolism of theanine during withering, while ABA may be involved in the accumulation of aromatic amino acids and main aroma components of TPHK. This research may serve as a reference for the optimization of the processing technology for TPHK.
危险品化学品经营许可证（带存储）