DNA methylation at 5-methylcytosine (5mC) sites serves as a key epigenetic regulator governing secondary metabolite biosynthesis in plants. However, how 5mC methylation modulates volatile compound biosynthesis in the single-petal jasmine cultivar “Bijian” remains unclear. By integrating metabolomic, transcriptomic, and methylomic analyses, we characterized the epigenetic regulation underlying terpenoid aroma biosynthesis in jasmine. The data showed a progressive accumulation of floral volatile metabolites during single-petal jasmine “Bijian” floral development, with volatile terpenoids being key contributors to its characteristic aroma. Fifteen volatile compounds, including α-farnesene, germacrene D, geraniol and (+)-delta-cadinene, were identified as key contributors to the aroma of “Bijian”. Furthermore, the overall density of 5mC methylation increased during flowering compared with the bud stage. Notably, CHH-type methylation in the genebody region showed a parallel increase with the expression of specific terpene synthase genes, and bisulfite sequencing PCR validated these methylation patterns. These findings indicate that DNA methylation acts as a potential regulator of floral scent formation in jasmine. This study provides new insights into the molecular mechanisms of floral scent biosynthesis during jasmine flowering from an epigenetic perspective.

Background: New-style tea beverages (NSTBs) are a fast-growing segment built on freshly extracted tea bases, made-to-order assembly, and decentralized franchise retail. Scale-up under these conditions has exposed persistent challenges in sensory reproducibility, physicochemical stability, food safety, and regulatory compliance. Scope and approach: This review examines how tea-base chemistry interacts with beverage matrix design in NSTBs. It traces how cultivar selection, processing history, blending strategies, and extraction parameters shape tea-base composition, and how these chemical signatures determine performance in dairy, plant-based milk, fruit, and hybrid systems. Health-oriented reformulation, including sugar reduction, lactose-free and clean-label design, and bioactive fortification, is evaluated against stability constraints and labeling requirements. The review also assesses the integration of digital supply-chain infrastructure, programmable brewing and dispensing platforms, and sensor-based quality monitoring in retail settings. Key findings and conclusions: Consistent NSTB quality requires matching tea-base composition to matrix conditions. Dilution, heat exposure, pH, mineral content, and colloidal structure govern flavor release, haze formation, sedimentation, and phase separation. Instability commonly arises from polyphenol-mediated complexation, pigment degradation, and poorly matched dispersion systems. Sugar reduction is most effective when tea-base adjustment is combined with aroma-taste interactions and texture design rather than sweetener substitution alone. Functional fortification introduces constraints related to microbial viability, ingredient compatibility, and regulatory compliance. Digital process control can reduce batch variability, but only when calibration and data handling are standardized across outlets. Bridging formulation design and reproducible retail execution is the central technical challenge for the sector.

Jasminum sambac is widely valued for its aroma, yet the monthly dynamics of volatile compounds and the proteomic basis associated with cultivar differences remain unclear. This study investigated monthly changes in volatile compounds in five jasmine cultivars using HS-SPME-GC–MS, and the total content of detected volatile compounds reached its highest level in August. Integrated volatile profiling and data-independent acquisition (DIA) proteomic analysis were subsequently applied to explore the proteomic basis associated with aroma differentiation. OAV analysis identified 17 potential key SDVs distinguishing jasmine cultivars, including methyl anthranilate, benzyl alcohol, and decyl aldehyde. Proteomic analysis revealed 23 proteins associated with terpenoid metabolism and 26 proteins associated with phenylpropanoid/benzenoid metabolism. Differences in protein abundance may contribute to aroma variation among jasmine cultivars. MYB8 and 4CL19 were identified as candidate proteins associated with benzaldehyde accumulation. These findings provide integrative insights into monthly volatile dynamics and the proteomic basis of aroma variation in jasmine.

This study explores the quality differences between purple-leaf black teas (FoShou, DaYeLong, ZiJuan) and green-leaf black tea (ZhuYeQi) through sensory evaluation, electronic sensory analysis, targeted metabolomics, dose-over-threshold (DOT) analysis, volatile metabolomics, odor activity value (OAV) analysis, and molecular docking. Purple-leaf black teas exhibit deeper orange infusions, complex floral-fruity aromas, and fresher, sweeter tastes, with ZiJuan scoring the highest overall. Targeted metabolomics identified 200 non-volatile metabolites (NVMs), DOT analysis highlighting key taste-related compounds such as glutamic acid, theaflavins, and flavonoid glycosides. GC-MS detected 169 volatile metabolites (VMs) were detected, with terpenoids, esters, and alkanes as dominant groups. OAV and correlation analysis identified β-ionone, linalool, and geraniol as major contributors to woody-floral aromas. Molecular docking implyed theaflavin's strong binding to umami receptors and δ-cadinene's affinity for olfactory receptors. These findings provide molecular insights into the quality attributes of purple-leaf black tea, with implications for future optimization and digital sensory evaluation.

Leafhopper-pierced tea (LT), including green, yellow, white, and oolong, was compared with non-LT. Sensory evaluation showed LT had stronger floral and honey-like aromas, smoother texture, higher sweetness, and deeper infusion color. GC-MS identified 402 volatiles, 56 significantly upregulated. Linalool, geraniol, phenethyl alcohol, and damascenone all contributed to the honey aroma, with recombination-deficiency tests specifically confirming the key roles of phenethyl alcohol and damascenone. Non-targeted metabolomics found 31 upregulated non-volatiles. Correlation analysis indicated that 8-c-Ascorbylepigallocatechin 3-gallate, epiafzelechin 3-o-gallate-(4 beta -> 6)-epigallocatechin 3-o-gallate, and gallic acid moderated sourness and bitterness, while cyanidin 5-o-beta-D-glucoside enhanced sweetness, establishing the infusion's basic honey-like taste. Flavour assays, molecular docking, and E-tongue analysis demonstrated that phenethyl alcohol, damascenone, and geraniol enhanced aroma and taste through receptor interactions. These results underscore the dominant role of non-volatiles in honey flavour perception, with volatiles enhancing retronasal olfaction to define the unique honey flavour of LT.

While mechanical processing is known to influence tea aroma, the targeted regulation of key odorants by specific wrapping-twisting methods remains poorly understood. The headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) method was employed to analyze the characteristic aroma compounds of extruding-rolling tea (ERT) and wrapping-rolling tea (WRT). Integrated analysis of differential compounds, VIP values from the OPLS-DA model, and ROC curve analysis identified 16 key aroma compounds that effectively differentiated WRT from ERT. Combined OAV and ACI analyses revealed that seven key aroma compounds contributed to ERT, imparting floral, green, and sweet notes. The 11 aroma compounds, especially β-ionone, methyl salicylate, hexanal, and 2-pentylfuran, were conducive to the floral, green and fruity aroma characteristics of WRT. Molecular docking demonstrated that the four key WRT aroma compounds were stabilized by hydrophobic interactions with olfactory receptors, elucidating the molecular basis for their "Qingxiang" perception. These findings revealed that different wrapping-twisting methods regulated aroma formation through selective accumulation of compounds and combined activation of receptors, providing a theoretical basis for the targeted regulation of oolong tea aroma profiles.

Beiyuan Tribute Tea is produced mainly from the cultivar "Aijiaowulong" (AJWL), noted for its distinctive osmanthus-like aroma, yet its molecular basis remains unclear. We generated a chromosome-level AJWL genome (3.16 Gb; contig N50 130.03 Mb). Structural-variation analyses indicated AJWL is closer to Rougui (RG) and Tieguanyin (TGY) than to Shuchazao (SCZ), which shows clearer structural divergence. We integrated multiomics across the full processing workflow, along with sensory evaluation, aroma recombination and omission assays, and benchmarked against two osmanthus cultivars, identifying (Z)-β-ocimene, linalool, α-ionone, and dihydro-β-ionone as principal aroma contributors. Withering and shaking were dominated by enzymatic reactions, driving accumulation of (Z)-β-ocimene and linalool, whereas fixation and drying promoted heat-driven carotenoid cleavage, increasing α-ionone and dihydro-β-ionone. We further identified 29 structural genes in the MEP pathway, the MVA pathway and carotenoid-related pathways, mainly terpene synthase (TPS) and carotenoid cleavage dioxygenase (CCD), whose mechanically induced expression tightly tracked key volatile dynamics.

Global warming has increased outbreaks of the tea pest Ectropis grisescens. However, how water and nitrogen management modulates tea plant resistance against this pest through induced volatile organic compounds (VOCs) remains unclear. This study aimed to (1) characterize how water–nitrogen interactions alter the composition of VOCs in fresh leaves of Camellia sinensis cv. Rougui, and (2) identify key VOCs that mediate repellence against E. grisescens. Using gas chromatography–mass spectrometry (GC–MS) and olfactometry under three water and three nitrogen levels, we found that nitrogen effects on VOCs were contingent on water status. Four terpenoids—(+)-dihydrocarvone, myrcene, linalool, and β-ocimene—and one green-leaf volatile ((E)-3-hexenoic acid) significantly repelled E. grisescens, whereas hexanoic acid, 3-oxo-, ethyl ester acted as an attractant. Mechanistically, low-water–moderate-nitrogen and high-water–high-nitrogen treatments reduced repellent terpenoids and increased attractant VOCs, thereby elevating pest preference. These results demonstrate that water–nitrogen coupling shifts the balance between repellent and attractant volatiles, providing a physiological basis for manipulating tea plant resistance through agronomic management.

Wuyi Mingcong (WYMC) is a distinctive tea germplasm resource from Wuyi Mountain, known for its unique aroma and quality characteristics. However, the aroma quality of WYMC has been insufficiently studied. In this study, the aroma profiles of seven characteristic tea plant resources WYMC tea samples were characterized using sensory evaluation combined with headspace solid-phase microextraction and gas chromatography–mass spectrometry (HS-SPME-GC-MS). The results revealed that “floral,” “fruity,” “clean and refreshing,” “woody,” and “sweet” were the main aroma characteristics. A total of 37 volatile compounds were found to contribute significantly to the aroma profiles of the seven WYMC tea samples, with dihydrolinalool and (E)-β-ionone likely being the key contributors to their floral and fruity notes. Ten key volatile markers were identified as responsible for aroma differences between the Fujian Shuixian (SX) and seven WYMC tea samples. Phenylethyl alcohol, cis-3-hexenyl benzoate, δ-cadinene, nerol, and β-myrcene may be critical for the formation of WYMC’s characteristic aroma. cis-3-hexenyl benzoate and nerol may act as “broad-spectrum” aroma contributors, enhancing the overall intensity or layered nature of WYMC’s scent. The results of this study enrich the understanding of the aroma characteristics of WYMC and provide a theoretical foundation for the development and utilization of tea germplasm resources in the Wuyi Mountain.

The impact of seasonal variations on the quality of oolong tea products remains a subject of ongoing exploration. This study delves into the intricate relationships between seasonality, metabolites, and sensory characteristics in finished oolong tea products. Metabolomic data from 266 Tieguanyin oolong tea products harvested in both spring and autumn, along with corresponding sensory evaluations, were acquired. Using OPLS-DA and PLS-DA models with UPLC-QToF/MS data, our findings showed that seasonal effects were notably more pronounced in light-scented Tieguanyin products (lightly-roasted) compared to strong-scented products (moderately-roasted). Furthermore, over half of the identified key seasonal discriminant metabolites happened to be crucial for determining the sensory grade. The study marks the first-time recognition of triterpene saponins as critical factors in determining both the harvest season and the sensory grade of oolong tea. These insights deepen our understanding of the interplays between seasonal variations, metabolites, and sensory attributes in oolong tea products.

The tea green leafhopper (Empoasca onukii Matsuda) damages tea plants by piercing the leaves with its needle-like mouthparts to suck sap and secrete saliva, with the affected fresh leaves considered the best raw material for producing beauty tea. To investigate the role of leafhopper saliva in the formation of aroma quality in beauty tea, this study extracted leafhopper saliva and applied them to field-grown tea plants. The treated leaves were compared with fresh leaves from unaffected plants, as well as those with low and high leafhopper damage. The study analyzed the dynamic changes in aroma compounds during processing, as along with the major non-volatile quality components, aroma compounds, and sensory qualities of the resulting beauty tea. The results showed that alcohols, esters, and alkenes accounted for over 90 % of the compounds during the processing of beauty tea, with the proportion of alcohols such as (Z)-3-hexenol, benzyl alcohol, and linalool and its oxides increasing sharply after withering and remaining unchanged after panning. Beauty tea made from leaves treated with leafhopper saliva exhibited high levels of methyl salicylate, linalool, and dehydrolinalool, along with high free amino acid content and low tea polyphenol content, resulting in a tea infusion with floral, fruity, fresh, and sweet notes. The study found that applying aqueous leafhopper saliva to mechanically damaged leaves effectively simulates natural leafhopper feeding and produces high-quality beauty tea. These findings provide a theoretical basis for understanding tea plant-leafhopper interactions and producing high quality beauty tea.

This study investigated the dynamic changes in jasmine tea during the scenting process and explored the differences in the aroma characteristics of jasmine tea scented with single-petal jasmine "Bijian" and traditional double-petal jasmine "Shuangban." Twenty-one key volatile compounds were identified from jasmine tea by headspace solid-phase microextraction-gas chromatography-mass spectrometry. Compared with the intensely floral and sweet fragrance characteristic of jasmine tea scented with double-petal jasmine "Shuangban," the tea scented with single-petal jasmine "Bijian" exhibited a fresher aroma, which can be attributed to the accumulation of methyl benzoate. Indole and eugenol were identified as the major contributors to the pronounced floral flavor. Furthermore, the large accumulation of alpha-farnesene, geraniol and alpha-ionone, helps jasmine tea to show a stronger freshness and fragrance aroma. These findings provide new insights into the aroma characteristics of jasmine tea scented with single-petal jasmine "Bijian" and support its application and promotion in tea production.

The quality differences between traditional black tea (NS) and shaken black tea (S), as well as the specific effects of shaking on quality-related metabolites and gene regulation in black tea, remain unclear. This study found that mechanical disruption during shaking facilitates the release of cellular contents, enhances polyphenol oxidase (PPO) gene expression levels, and modulates the synthesis of theanine, phenolic acids and proanthocyanidins as well as flavonoid metabolism, thereby promoting the accumulation of theanine (increased by 87.17 % in S vs NS), theaflavins (21.50 %), phenolic acids (19.14 %), proanthocyanidins (17.67 %), and flavonoid glycosides (13.52 %). This deepened infusion color and made its taste more smooth, thick, and mellow, thereby improving its taste and infusion color quality. Furthermore, shaking upregulates terpene synthase (TPS) gene expression and promotes volatile release through modulation of terpenoid, fatty acid, and amino acid metabolic pathways. However, the structural damage to tea leaves leads to a relatively low retention rate of volatile components in the finished tea. This phenomenon enhances the overall floral and sweet attributes of the tea, thereby improving its aroma quality. This study systematically elucidates the molecular mechanisms underlying the effects of shaking on black tea quality formation, filling the research gap regarding the relationship between mechanical disruption during shaking and quality-related metabolic regulation. Furthermore, it provides both theoretical foundations and technical guidance for the targeted and standardized processing of high-quality black tea.

To explore the dynamic changes in ‘Round leaf’ jasmine tea (RT) during the scenting process, targeted metabolomics and HS-SPME-GC–MS were used to identify the non-volatile and volatile compounds, and compare them with double-petal jasmine tea (DT). The analysis of taste activity values indicated that Asp, Thea, and Glu played significant roles in shaping the flavor profile of RT. The volatile compounds methyl anthranilate, benzyl acetate, linalool, indole, methyl benzoate and methyl salicylate were the key aroma compounds of jasmine tea. The volatiles (E)-3-hexenyl acetate, (E)-β-ocimene and benzeneacetaldehyde significantly contributed to the elegance and freshness of RT. Additionally, the aroma compounds in RT reached saturation during the fourth scenting process (S4). Notably, RT reached better quality in S4 while DT reached better quality in S5. It can provide a scientific basis for the optimization of RT quality and its application in production.

The dynamic changes of metabolites and their regulatory mechanisms during black tea processing are not yet fully clear. In this study, flavonoid glycosides, tea pigments, VTs, and FADVs were primarily influenced. The content of these components continuously increased during processing, reaching their maximum after fermentation, and then decreased after drying. Withering upregulated AM and GT genes, promoting the glycosylation of flavonoids; the upregulation of ANR and PPO genes facilitated the oxidative polymerization of catechins; and the upregulation of TPS, LOX, and HPL genes promoted terpenoid synthesis and fatty acid degradation. This led to an increase in the content of these components in withered leaves. The accumulation of these components during fermentation was mainly due to the disruption of cells during rolling, allowing enzymes and substrates to fully integrate and react during the prolonged fermentation process. The decline in compound during the drying was primarily attributed to thermal degradation.

Jasmine (Jasminum sambac) is globally renowned for its distinct fragrance and ornamental appeal, existing primarily in three floral morphologies: single-petal, double-petal and multi-petal. De novo sequencing and chromosome-level genome assembly were performed on two distinct jasmine varieties: 'Yuanye' double-petal and 'Bijian' multi-petal jasmines. These assemblies, along with three previously published genomes, were integrated to construct a pan-genome framework that comprehensively encompasses both the core and variable genomic components of jasmine. A substantial number of structural variations (SVs) and single nucleotide polymorphisms (SNPs) had been identified, of which 89.5% were insertions/deletions (size ≥ 50 bp), whereas gene families also exhibited significant contractions and expansions, revealing the high complexity and dynamics of the jasmine genomes. Comparative genomic approaches further revealed multiple transcription factor families associated with aromatic biosynthesis, floral organogenesis and environmental adaptability. Key genes involved in the formation of jasmine scent, with a particular focus on the variation in copy number and expression levels of critical enzyme genes responsible for the production of four major volatile terpenoids and benzyl acetate, thereby elucidating the genetic basis of jasmine aroma diversity. Additionally, within the MADS-box gene family, the PI and AP3 subfamilies are hypothesized to play crucial roles in the development of floral organs. Through the integration of these comprehensive data, a pan-genome website for jasmine was developed to facilitate data download and visualise genomic variations via a genome browser (https://www.pan-jasmine.cn/). In summary, this work provides valuable genomic resources for the genetic enhancement and marker-assisted breeding of jasmine.

To improve the flavor of green tea juice processed from summer tea leaves, the enzyme-assisted dynamic extraction method was applied. The chemical components and taste of fresh green tea juice prepared under different extraction conditions with enzyme treatment (EM: tannase or its combination with protease/cellulase/pectinase) were investigated. The results showed that EM could reduce the bitterness and astringency of the tea juice by up to 40 % and 39 %, and enhance the sweet aftertaste to 132 %. These improvements resulted from a significant decrease in ester catechins and an increase in non-ester catechins and gallic acid. In addition, it was also found that the tea juice extracted with EM had less sediment (73 %) and better stability. Therefore, combined dynamic extraction with EM for the extraction of green tea leaves could effectively improve the taste, and increase the extraction rate of tea juice, promoting the utilization rate of abandon-plucked tea leaves in summer.

Volatile organic compounds (VOCs) are produced by plants responding to biotic and abiotic stresses. According to their biosynthetic sources, induced VOCs are divided into three major classes: terpenoids, phenylpropanoid/benzenoid, and fatty acid derivatives. These compounds with specific aroma characteristics importantly contribute to the aroma quality of oolong tea. Shaking and rocking is the crucial procedure for the aroma formation of oolong tea by exerting mechanical damage to fresh tea leaves. Abundant studies have been carried out to investigate the formation mechanisms of VOCs during oolong tea processing in recent years. This review systematically introduces the biosynthesis of VOCs in plants, and the volatile changes due to biotic and abiotic stresses are summarized and expatiated, using oolong tea as an example.

The color and taste of tea infusion play crucial roles in assessing tea quality. While color can be easily quantified, taste perception is subjective in nature. Can the color of tea infusion directly reflect its taste? In this study, spectroscopy and metabolomics techniques combined with machine learning algorithms, were used to identify the key compounds that responsible for both color and taste in Qingxiang Tieguanyin (QXTGY) tea infusion. The results showed strong correlations between almost all of 46 differential compounds and the taste profile of the tea infusion. Notably, quercetin 3-O-glucosyl O-glucosyl rutinoside, rutin, and quercetin 3-O-glucoside O-glucoside were found to establish a connection between the color and taste of QXTGY tea infusion. Specifically, within a certain range, these compounds promoted a darker color (deepening the yellowness) in the tea infusion while simultaneously reducing its umami and brisk taste. This indicates that the color of tea infusion can reflect its taste to some extent. Furthermore, quercetin 3-O-glucosyl O-glucosyl rutinoside had the most significant impact on the color of the tea infusion. The findings of this study offer an alternative objective approach to evaluate the taste of tea infusion by objectively determining its color.

To investigate the aroma quality characteristics of Anxi Huang Jingui Oolong tea under various rolling methods,this study used headspace solid-phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS)in conjunction with sensory evaluation to analyze aroma components.Sensory evaluation results revealed that Anxi Huang Jingui exposed to the wrapping-rolling method had a unique fruity perfume,but the tea that processed using the extruding-rolling method had a pronounced honey scent.Using HS-SPME-GC-MS,605 tea aroma components in total were detected,and 49 primary differential aroma compounds were screened using the VIP＞1 and P＜0.05 criteria.Odor activity value(OAV)and aroma character impact value(ACI)analysis revealed that Anxi Huang Jingui with extruding-rolling method produced higher levels of phenylacetaldehyde and β-ocimene,resulting in a honey aroma.While wrapping-rolling Anxi Huang Jingui produced higher levels of nerol,phyllobutyrate,geranyl isobutyrate,and indole,contributing to the unique fruit formation.The findings of this study would contribute to elucidating the aroma quality characteristics of Anxi Huangjingui Oolong tea and provide a scientific basis for the production of Anxi Huangjingui and the protection of its geographical indication products.