Abstract:The harvest time significantly impacts the quality of Huangjinya green tea. This study, adopting sensory evaluation, physicochemical analysis, antioxidant capacity assays, and untargeted metabolomics methods, delves into the effects of the harvest time on the flavor compounds and sensory attributes of Huangjinya green tea. H-1, harvested on March 9th, stands out for its superior quality (a score of 87.71 points) and is characterized by a refreshing and floral aroma. H-2, harvested on March 15th, exhibits a unique floral and fruity fragrance. Conversely, H-3, harvested on April 6th, features pronounced astringency and a astringent and bitter aftertaste of astringency, and aftertaste of bitterness, which is attributable to its highrich contents of polyphenols (183.38 mg/g), flavonoids (181.51 mg/g), purine alkaloids (37.65 mg/g), and bitter amino acids (7 926.62 μg/g). In addition, H-3, alongside demonstratesing the strongest in vitro antioxidant capacity. Meanwhile, H-4, harvestedcollected on May 6th, boasts exceptional sweetness and freshness due to high levels of total free amino acids (53 274.52 μg/g), theanine (29 336.40 μg/g), and sweet amino acids (2 690.12 μg/g). Similar to H-3, H-4 possesses a complex flavor profile comprising refreshing, citric, fatty, and sweet attributes, sharing complex flavor characteristics like freshness, citrus, fat, and sweetness with H-3. Untargeted metabolomics analysis highlights that the lengthduration of the harvestpicking interval significantly influences the number of differential metabolites. Essentially, the precise timing of harvest intricately molds the unique flavor profile and sensory attributesquality of Huangjinya green tea by modulating its internal volatile and non-volatile compound contents. This groundbreaking research not only deepens our understanding of Huangjinya green tea but also lays a robust scientific foundation for its resource development, utilization, and optimal harvestpicking time management. The findings provide insight intoBy guiding production practices and enhancing tea quality improvement, it significantly contributes to the pursuit of excellence within the tea industry.
