Journal of Tea Science Research, 2024, Vol.14, No.6, 322-334 http://hortherbpublisher.com/index.php/jtsr 323 The accumulation of aroma compounds in tea is the result of a complex interaction between genetic and environmental factors, including pre-harvest stress, post-harvest processing, and epigenetic modifications (Zeng et al., 2019; Yang et al., 2021; Wu et al., 2023; Qiao et al., 2024). Genotype determines the potential for aroma synthesis, while environmental signals—such as mechanical damage, light, temperature, and biotic stress—regulate gene expression and metabolic pathways through mechanisms such as DNA methylation and chromatin remodeling (Zeng et al., 2020; Yue et al., 2025). This dynamic gene-environment interaction leads to the diversity and complexity of aroma lineages in different tea varieties and production areas. This study explores the biosynthesis and regulatory mechanisms of key aroma substances in a variety of tea varieties, attempting to identify key genes, allelic variations, and their regulatory networks related to aroma diversity and quality. This study hopes to provide theoretical support for tea breeding projects, help cultivate new tea varieties with specific aromas, meet evolving consumer preferences and market trends, and promote the sustainable development of the tea industry. 2 Overview of Key Aroma Compounds in Tea Varieties 2.1 Major categories of tea aroma compounds The aroma of tea is determined by a variety of volatile compounds, including terpenes (e.g., linalool, geraniol, β-ionone), alcohols (such as phenylethanol, 1-octen-3-ol), aldehydes (like phenylacetaldehyde, hexanal), ketones (such as 6-methyl-5-heptene-2-one) and esters (Chen et al., 2020; Feng et al., 2022; Xiao et al., 2022; Yu et al., 2023). These compounds give tea different floral, fruity, grassy, sweet and baked aromas, and are the main source of the aroma characteristics of various types of tea (Wang et al., 2020; Yu et al., 2023). Secondary metabolites, like terpenoids and carotenoid degradation products, also play a key role in aroma formation. During the growth and processing of tea leaves, they generate important odor-active substances through biosynthesis and enzymatic reactions, thus shaping the unique sensory flavor of tea leaves (Feng et al., 2022; Zheng et al., 2022; Liang et al., 2024). 2.2 Distribution of aroma compounds in various tea cultivars Different tea varieties have characteristic aroma spectra. For example, Longjing green tea is rich in geraniol, linalool and β-ionone, and has a distinct floral and sweet aroma (Wang et al., 2020). Varieties such as Fuding Dabaicha and Jinxuan also show unique volatile component compositions, among which the differences in the content of key compounds such as methyl salicylate, phenylacetaldehyde and β-geranyl constitute their unique sensory attributes (Xiao et al., 2022; Wang et al., 2025). White teas such as Baihaoyinzhen and Baimudan are mainly composed of alcohols and aldehydes, showing a fresh and grassy scent (Chen et al., 2020). The aroma spectrum of tea is not only affected by genetic background, but also regulated by environmental factors such as geographical origin, processing methods and post-harvest treatment. For example, the baking process of oolong tea can enhance its roasted and cinnamon aroma, while tea that has not been deeply processed is more likely to retain the aroma of fresh leaves (Yang et al., 2021; Chen et al., 2024; Liang et al., 2024). This interaction between genotype and environment leads to large differences in the content and composition of aroma components between different varieties and production areas. 2.3 Detection and metabolomics analysis of aroma compounds Gas chromatography-mass spectrometry (GC-MS), often used in conjunction with olfactory detection (GC-O) and solid phase microextraction (SPME), is currently a conventional method for identification and quantitative analysis of tea aroma components (Xiao et al., 2022; Yu et al., 2023; Wang et al., 2025). Non-targeted metabolomics methods can be used to conduct a comprehensive spectrum analysis of volatile components of different tea types and grades (Lin et al., 2023; Chen et al., 2024). The identification of key aroma components is usually based on the test results of GC-MS and GC-O, and the calculation of odor activity values (OAVs) to evaluate the sensory contribution of each component in the overall aroma (Wang et al., 2020; Feng et al., 2022). Multivariate statistical analysis methods, such as principal
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