Analysis of Flavor and Quality of High Quality Jianou Aijiao Oolong Tea

'Aijiao Olong' is a distinctive type of oolong tea from Fujian Province. To investigate the quality and flavor attributes of high-quality Aijiao Oolong tea, the Aijiao Oolong tea products from Jian'ou City were utilized as experimental materials, and classified samples with higher sensory quality scores into a high-quality group for analysis. The main taste and aroma compounds were analyzed using sensory evaluation, biochemical component analysis, and advanced technologies such as UPLC-QqQ-MS (Ultra-Performance Liquid Chromatography Triple Quadrupole Mass Spectrometry) and HS-SPME-GC-MS (Headspace Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry). The results demonstrated that the high-quality group of Aijiao Oolong tea had a distinct floral scent along with a rich, mellow, and fresh taste. Since the flavonoid content (1.50%±0.22%) was significantly lower than that of the ordinary group, the water extract (34.70%±1.36%), tea polyphenols (10.3%±0.69%), and caffeine (4.40%±0.32%) contents of high-quality Aijiao Oolong tea were all significantly higher than those of the ordinary group (P<0.05). The biochemical component results aligned with the tea soup's strong flavor and astringency trend in the high-quality group's sensory rating. Notably, 56.34% of the total amino acid content in the high-quality group was made up of umami amino acids. The fragrant arginine and the fresh, invigorating theanine were the primary distinguishing amino acid components, according to additional analysis using the OPLS-DA model. This could be the primary cause of the Jianou Aijiao Oolong tea soup's high freshness and sweet aftertaste. A total of 527 volatiles were identified in two group tea samples. Finally, 54 volatiles were screened as differential volatiles based on VIP≥1 and P<0.05. OAV and ACI analysis showed that mthyl salicylate, δ-decanolactone, geranyl acetate, and 2-ethyl-3-methylpyrazine were the main ingredients of the high-quality group, which mainly presented fruity and sweet flowery aroma, their content was significantly higher than that in the ordinary group. The findings can serve as a valuable foundation for investigating and determining the distinctive flavor and quality of high-quality Aijiao Oolong tea.