In this study, we analyzed the key genes of jasmonic acid synthesis and signal transduction pathway in tea plants, explored their expression patterns and investigated their effects on the formation of terpenoids during oolong tea processing. There are 11 key gene families in this pathway, including 133 candidate genes. The analysis of cis-acting elements shows that the promoter regions of the key genes of the pathway contained a large number of cis-acting elements, including jasmonic acid response, damage response and anaerobic induction response. qRT-PCR analysis shows that most of the genes of this pathway showed an upward trend during the withering process, reached the highest in the second shaking process, significantly decreased in the fourth shaking process, and slightly increased in the process before green removal, and the key genes of this pathway could respond to various stresses during oolong tea processing. HS-SPME-GC-MS detected 73 terpenoids, mainly including linalool, geraniol and α-farnesene and other substances with flower and fruit flavor. Correlation analysis shows that CsLOX11, CsLOX12, CsAOS2, CsAOC1, CsACX4, CsACX8, CsMYC2-4, CsMYC2_15, CsMYC2_21 and β-pinene, limonene and myrcene are positively correlated, and CsOPR2, CsTPL6 and CsLUG4 are positively correlated with trans nerolidol, α-farnesene and ionone, among which CsTPL6 was significantly positively correlated with 35 terpenoids. In summary, the key genes of jasmonic acid synthesis and signal transduction pathway of tea plants are involved in regulating the formation of terpenoids during oolong tea processing, and this study laid a foundation for exploring the molecular mechanism of aroma formation during oolong tea processing.

To investigate whether Fu brick tea (FBT) water extract can attenuate metabolic disorders in Type 2 Diabetes (T2DM) by regulating gut microbiota, a T2DM mouse model was established with streptozocin and 400 mg·kg^-1 FBT water extract administration. Diet, and water consumption, body weight, fasting glucose and glucose tolerance in mice were observed. Serum levels of insulin (INS), total bile acid (TBA), total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) were examined. Histopathological changes of ileum and pancreas were also observed. Furthermore, fecal samples were analyzed by 16 S rRNA gene sequencing. The results show that FBT reduced the serum lipid metabolism levels, blood glucose, and inflammatory cytokines. Simultaneously, FBT treatment significantly ameliorated pathological changes in the pancreas and ileum. Moreover, the diversity, structure and composition of T2DM-disrupted gut microbiota were restored by the supplementation of FBT. T2DM-induced increase in the relative abundance of Verrucomicrobia was remarkably restored by FBT. FBT increased the growth of many key beneficial bacteria, including Firmicutes, Bifidobacterium, Enterorhabdus, Prevotella_9, A2, Acetatifactor, Eubacterium_coprostanoligenes_group, Faecalibacterium, Coriobacteriaceae and Eggerthellaceae. Collectively, the study showed that FBT might alleviate dysbacteriosis and metabolic disorders in T2DM by increasing beneficial flora.

NUDIX hydrolase belongs to pyrophosphatase, which plays an important role in information transmission, plant growth coordination and responses to adversity stresses. In this study, 43 NUDIX family genes were identified based on the tea (Camellia sinensis) genome, and analyzed by bioinformatics and fluorescence quantitative PCR. The results show that the protein molecular weight of 43 CsNUDXs rang from 11.8~89.2 kDa, with 102 to 342 amino acids. The theoretical isoelectric point was from 4.49 to 9.26, and 18.6% of them were stable proteins. According to the evolutionary relationship, CsNUDXs is divided into six subfamilies. Cis-acting element analysis of promoter shows that CsNUDXs have many functional elements related to hormone response, adversity stress, growth and development. The expression patterns of CsNUDXs in different organs were analyzed. It was found that the expression levels of CsNUDX3 and CsNUDX7 were high in fruits, while the expression levels of CsNUDX22 and CsNUDX25 were extremely low in fruits, and the expression level of CsNUDX30 was extremely low in old leaves. In addition, the results of real-time fluorescence quantitative PCR show that the expression levels of CsNUDXs, such as CsNUDX1, CsNUDX2 and CsNUDX33 increased first, then decreased and then increased under the treatment of 1 mmol·L^-1 MeJA. However, under the treatment of 1 mmol·L^-1 SA, the expression levels of CsNUDX4, CsNUDX12 and CsNUDX22 decreased first, then increased and then decreased. While under the treatment of 300 mmol·L^-1 NaCl, the expression levels of CsNUDX2, CsNUDX4 and CsNUDX22 increased first and then decreased. In summary, the basic characteristics and functions of CsNUDXs were preliminarily analyzed by bioinformatics technology, and it was found that CsNUDXs could respond to high salt stress, MeJA and SA treatments.

Catechins are a kind of bioactive substances rich in tea, which have the functions of anti-oxidation, anti-tumor, anti-virus, anti-inflammatory and immune regulation. However, due to the high activity of phenolic hydroxyl groups, catechins are easy to lose in vitro and in vivo activities, resulting in lower bioavailability. The recent development of nanobiotechnologies is expected to solve the problem of low bioavailability of catechins through ligand design, accurate synthesis and intelligent regulation, which can expand its application in the field of life and health. In this review, a summary on the progress of catechin biomedical nanomaterials in recent years, including the anti-tumor, antibacterial, anti-inflammatory, drug delivery and anti-virus activities, was firstly made. Later, the construction and biological mechanism of catechin biomedical nanomaterials were discussed in detail. Finally, future perspectives on the design and application of novel catechin nanomaterials were provided.

This study investigated the effects and mechanisms of epigallocatechin gallate (EGCG) on high-fructose diet-induced metabolic disorders. Fifteen male SPF C57BL/6 mice were randomly divided into three groups: normal diet group (NCD), high-fructose diet group (HFD), and high-fructose diet supplemented with 1% EGCG group (HFE), with 5 mice in each group. After 8 weeks of feeding, the body weight, energy utilization rate, ALT and AST levels, as well as tissue morphology staining of the mice were measured. Furthermore, hepatic TNF-α, IL-1β, IL-6 and intestinal IL-6 inflammatory cytokine levels were detected by ELISA. The expressions of Srebp-1c, Tlr4, Myd88 in liver and Zo-1, Occludin, Tlr4 and Myd88 in intestine were measured by quantitative real-time PCR. Protein expressions of ZO-1 and Occludin were detected by IHC. The results show that dietary supplementation of EGCG could effectively reduce high-fructose diet-induced body weight gain, fat accumulation, hepatic and intestinal inflammatory responses, and could improve the intestinal barrier function by upregulating the expression of Zo-1 and the protein expressions of ZO-1 and Occludin. It also modulated lipid metabolism by reducing the expression level of Srebp-1c in liver, and downregulated the expression levels of inflammatory-related genes (Tlr4 and Myd88) in colon and liver. The results above suggest that dietary supplementation of EGCG has a preventive effect on high-fructose diet-induced metabolic disorders and inflammatory responses, and its mechanism may be related to the regulation of the gut-liver axis mediated by the TLR4/MyD88 signaling pathway.

It is reported that tea has many medical functions. However, consumers prefer decaffeinated tea and tea products due to caffeine’s negative disadvantageous. Decaffeination is realized by different methods, including the traditional methods such as water decaffeination, solvent extraction, adsorption separating and supercritical carbon dioxide extraction. The recent developmental microbial and enzymatic degradation and breeding low caffeine tea varieties are also developed for removal of caffeine. The investigation on tea decaffeination was reviewed, and the feasibility was discussed in this paper. The techniques of water decaffeination combined with adsorption separating, microbial and enzymatic degradation as well as low caffeine tea breeding were regarded as the main developmental direction of tea decaffeination by the authors.

In order to study the regulation mechanism of exogenous 5-aminolevulinic acid (5-ALA) on the chlorophyll synthesis and fluorescence characteristics of tea plants in response to drought stress, tea cultivar 'Shuchazao' was used as the experimental material in this study. Under PEG-6000 simulated drought stress environment and 5-ALA spraying pretreatment, the contents of chlorophyll a, chlorophyll b and total chlorophyll in tea seedling leaves were detected, and the chlorophyll fluorescence parameters and the expressions of key enzyme genes in tea leaves were further determined. The results show that exogenous 5-ALA significantly increased the contents of chlorophyll a, chlorophyll b and total chlorophyll in tea leaves under drought stress. Exogenous 5-ALA alleviated the decreases of maximum fluorescence (Fm), actual photochemical efficiency of PSⅡ [Y(Ⅱ)], maximum photochemical quantum yield of PSⅡ (Fv/Fm), photochemical quenching coefficient (qP), potential activity of PSⅡ(Fv/Fo), photosynthetic electron transfer rate (ETR) of PSⅡ reaction center, and the increases of initial fluorescence (Fo) and nonphotochemical quenching coefficient (qN). At the same time, exogenous 5-ALA induced the expressions of chlorophyll synthesis (CsHEMA1, CsHEME1, CsLIN2) and carbon assimilation-related enzymes (CsSBPase, CsTK) in tea plant under drought stress. The study demonstrates that spraying exogenous 5-ALA can effectively alleviate the degradation of chlorophyll and damage to PSⅡ reaction center of tea leaves under drought stress, maintain the higher photosynthetic activity, and improve the photoprotection ability of tea leaves.

综合了近年来国内外茶饮料加工技术的研究进展。围绕茶饮料加工中存在的茶汤浑浊、沉淀和香味闷熟、低下等主要问题,从茶叶浸提、过滤、品质保存、灭菌和包装等方面对各种技术方法和工艺技术参数进行了详细的论述。对一些新技术和新工艺进行了详细介绍,并根据现状提出今后茶饮料加工技术的发展方向。

Catechin is one of the most characteristic secondary metabolites in tea plants and the main component affecting tea quality and flavor. It possessesrich pharmacological effects, such as anti-oxidation, anti-virus, lipid lowering and weight loss, etc. In this study, the function of a catechin biosynthetic regulator CsTT2 was preliminarily identified using phylogenetic analysis, gene expression pattern analysis and molecular biology experiments. The results show that CsTT2 was a R2R3-MYB transcription factor that shares a branch withthe MYB transcription factor in Arabidopsis thaliana that regulates secondary metabolites. The expression levels of CsTT2 and catechin biosynthesis genes were relatively high in the apical bud tissue of tea plants with higher total catechin content. The results of subcellular localization, yeast assay and dual luciferase reporting system further reveal that CsTT2 was located into the nucleus and the protein it encodes possessed transcriptional activation capacity. CsTT2 could bind to the promoter of a key catechin biosynthetic gene ANR to activate its expression.

As a further extension of the deep processing technology of tea raw materials, tea aroma type distilled spirit combines the aroma of tea and wine, and has a unique flavor. In order to clarify the changes of flavor substances of tea aroma type distilled spirit under different processes, solid-phase microextraction/gas chromatography-mass spectrometry was used to analyze the flavor components. The odor specific magnitude estimation method and Odor activity value method in liquid-liquid extraction/gas chromatography-olfactometry-mass spectrometry were used to determine the characteristic flavor substances and their contribution to the overall flavor. The results show that 76 kinds of aroma substances were detected, including 32 esters, 14 alcohols, 10 aldehydes and ketones, 4 acids, 13 terpenes and 3 other substances. Gas chromatography-olfactometry mass spectrometry analysis results show that there were 21 aroma compounds that could be smelled, and 12 key aroma compounds were identified by OAV and OSME together, including linalool (rose flowers), anisole (herbal), ethyl caprate (fruit), ethyl caproate (wine aroma) and so on. The results show that different kinds of microorganisms, fermentation methods and distillation technology significantly affected the composition and contents of flavor substances in tea aroma type distilled spirit. The results of this study have important guiding significance for the characteristic aroma characterization and quality control of tea aroma type distilled spirit.

Grade is an important indicator for discerning the quality of green tea and other types of tea, and it is directly related to their selling prices. However, there is often a phenomenon of falsely labeling tea grades in the market, which seriously undermines consumer rights. At present, tea grade is mainly assessed by sensory evaluation. Sensory evaluation, after long-term development, has formed relatively unified standard, but it still has a certain subjectivity. To evaluate the tea grade more accurately and objectively, researchers have developed a series of quantitative evaluation methods for tea grade. Given the significant practical importance of evaluating tea grade, this article provided a comprehensive review of the recent research status in the qualitative and quantitative evaluation of tea grades, including bionic sensing intelligent sensory detection technology, specific chemical components detection and metabolomics techniques. Major problems and challenges on tea grade evaluation were discussed, and future development trend was also prospected in this study. It has positive guiding significance for objective, scientific and standardized evaluation and quality control of tea quality.

Dark tea is made from fresh leaves or mature shoots of tea plants (Camellia sinensis). Its manufacture process includes fixing, rolling, stacking and drying. The healthy benefits of dark tea attracted much attention. So far, a large number of in vitro experiments and animal model studies have revealed the potentially preventive effects of functional components in dark tea on some diseases, including hyperglycemia, hypertension, hyperlipidemia and many other diseases. During the past ten years, there had made a huge advance in research on functional components and healthy benefits of dark tea. These results not only provided a reliable theoretical basis for better understanding of health effects of dark tea, but also played an important role in promoting dark tea consumption. In this paper, the characteristics of dark tea and the progress of health effects of dark tea during the past five years were reviewed. The direction for future research was also proposed.

To explore the application prospects of berberine on the prevention and control of tea diseases, the antifungal activity of berberine against five different Colletotrichum species (C. fioriniae, C. karstii, C. chongqinggense, C. camelliae and C. gloeosporioides) were studied and the differences in antifungal activities were compared. The results show that berberine has the best inhibitory effect on both C. camelliae and C. chongqinggense, reaching 100% at the concentration of 12 mg·mL^-1, followed by C. gloeosporioides, C. karstii and C. fioriniae. The EC₅₀ (Concentration for 50% of maximal effect) of the five Colletotrichum species were 2.828, 3.288, 4.164, 4.778 mg·mL^-1 and 5.104 mg·mL^-1, respectively. The conidial and hyphal morphology of five Colletotrichum species under the treatment of berberine were examined, showing that berberine had a significant impact on the mycelial and conidial growth of five Colletotrichum species. With the increase of berberine concentration, part of hyphae expanded irregularly and the conidia grew abnormally. Results of the biological activity of Colletotrichum species show that the cell structure was damaged, the permeability of cell membrane was increased and the cell oxidative stress response was enhanced. Results of this study firstly confirm the antifungal activity and application prospects of berberine against Colletotrichum species, which provided a new approach and theoretical basis for the prevention and control of tea disease caused by Colletotrichum.

The quality of tea is the embodiment of the shape and inner quality of tea, and evaluating the quality of tea quickly and accurately is essential for tea trade and processing. Sensory evaluation, composition analysis and detection, and emerging technologies are the main tea quality evaluation techniques at present. This article summarized the research progress of three major evaluation technologies in recent years, and focused on the development trend of emerging technologies. Sensory evaluation is greatly influenced by subjective factors, but combined with quantitative description and analysis can reduce the influence of subjectivity. Component analysis detection has high threshold, difficult operation, time-consuming and labor-consuming, and the results obtained are relatively accurate. Emerging technologies are simple, fast, and non-destructive, but at present they cannot achieve satisfactory accuracy. In the tea product diversification today, only multi-dimensional comprehensive utilization of multiple methods can quickly and efficiently detect the quality of tea, and provide assistance for the healthy and efficient development of the tea industry.

In order to obtain the characteristics of the mitochondrial genome (mitogenome) and explore phylogenetic relationship, the mitogenome sequence of Stephanitis chinensis collected from Ankang city, Shaanxi Province was determined by Illumina and Sanger sequencing methods. The result shows that the mitogenome of S. chinensis is 18 085 bp in length, including 37 coding genes [13 protein-coding genes (PCGs), 22 tRNAs, and 2 rRNAs], and one control region of 3 678 bp. The gene organization of S. chinensis is the same as the ancestral gene order of insect mitogenome. The AT content of whole mitogenome is 78.10%. Among the 13 PCGs, six start with the typical ATG, seven start with ATT or ATA, and ten end with the typical TAA or TAG. Only cox2, atp6 and cox3 terminate with T. The highly occurred codons in the PCGs are UUA, AUU, UUU and AUA, and the top 4 amino acids are Leu, Ile, Phe and Ser. There are 23 mismatches of GU, UU, GA and AA in 22 tRNAs. All the tRNAs could form the common clover-leaf secondary structures, except trnS1(GCU), which lacks the DHU arm. The control region contains 3 type of non-tandem repeats and 4 (TTAG)_n in the front-end region (FER) and one tandem repeat in the back-end region (BER), and several stem-loop structures. Phylogenetic analysis shows that Stephanitis mendica has the closest relationship with S. chinensis. All the insects from Tingidae were clustered together, and placed at the base part of the phylogenetic tree.

Aroma is one of the key indicators to evaluate tea quality, and aroma quality is formed by the complex interactions between different volatile compounds. Premium roasted green teas generally have characteristics of excellent flavor quality, and are the most typical and representative Chinese green tea. In recent years, studies on their volatile compounds had increased gradually and made good progress. However, there were very few systematic explanations on the composition characteristics in aroma compounds of diverse high-quality roasted green teas. Therefore, the present study summarized the research progression in volatile compounds of premium roasted green teas in recent twenty years, enumerated the aroma compounds, illuminated the common compounds, and further discussed the key aroma compounds. These results will provide scientific evidence for the flavor evaluation and aroma quality control for the premium roasted green tea.

The volatile compositions of 17 kinds of Fenghuang Dancong Tea with different aromatics were analyzed using a combination of simultaneous distillation extraction and gas chromatography-mass spectrometry (SDE-GC/MS), then compared with their ancestor, narcissus series tea, and the non-narcissus series tea. The results showed that according to the aroma pattern similar to or higher than the rate of 95% , they are classified into seven aroma patterns: Huangzhi aroma(gardenia Magnolia fragrance), Xingren aroma(almond fragrance), Milan aroma (honey-orchid fragrance), Zhilan aroma(iris orchid fragrance), Yulan aroma(magnolia fragrance), Juduozai whose aroma pattern was not identified and Gong aroma. The similarity are different not only between each aromatics and varieties, but also between each aromatics and their original variety. By analyzing the difference in the aroma components of different Fenghuang Dancong tea with same aroma pattern, it showed that Dancong tea with different aroma pattern has content differences on the common components, and each also has its characteristic components. For example, the isoeugenol in the Dancong tea with Zhilan aroma, α-cadinol in the Huangzhi aroma, torreyol, β-ionone and caryophyllene in the Milan aroma and the 4-terpenol in the Juduozai Dancong tea, and methyl anthranilate of the Gong aroma. These components may be the characteristic aroma composition in the respective Fenghuang Dancong tea, and can be used as one of the important basis in the aroma pattern classification in the Fenghuang Dancong tea.

Fresh leaves are processed into black tea by a series of enzymatic oxidation and other reactions. There are some distinctions in the flavor and functional chemicals between black tea and other tea. The black tea is endued with numerous health care functions by its chemical components, which play roles in the physiological regulation and illness prevention in gastrointestinal tract. The functional components in black tea can keep the intestinal flora balance by inhibiting the growth of harmful bacteria and promoting the growth of beneficial bacteria, protect the gastrointestinal mucosa by preventing oxidation of tissues, repairing oxidative damages and interaction with gastric mucus, glutathione and other substances. It can also adjust digestion and absorption by interaction with the enzyme digestion and promoting gastrointestinal peristasis, prevent gastrointestinal disease by interaction with the immune system regulatory factors, related transcription factors and enzymes. This paper reviews the recent advance in physiological regulation and disease prevention by black tea.

In the Chinese tea cultural system, the etiquette, customs, ceremonies and literatures of tea are interactive and complementary, which build up the major part of Chinese tea culture and become important media of its spiritual core as well. In this paper, the etiquette, customs, ceremonies and literatures of Chinese tea, as an example, are disserted in the aspects of its historical formation and forms. On the basis of previous research, the spirit of Chinese tea culture is investigated, of which the core is concluded as Harmony, Respect, Rectitude, Beauty and Reality, realizing the sublimation from the physical to the spiritual level. The inheritance, promotion and development of Chinese tea culture and its spiritual core are of critically important era value for guiding the construction of socialist core value, firming the confidence in national culture and building a harmonious society.

By describing the theory and method of tea classification in China and foreign countries, and the special manufacturing technology and the quality characteristic of dark tea, it was regarded that whatever the semi-finished or the finished tea of Liupu tea, both of them were under the process of pilling up and color changing and according with the theory of tea classification, and the related standard and regulation, so could be called as dark tea, according to the investigation on the method of piling up and color changing in the various manufacturing stages of processing process of Liupu tea, the major factors influencing the piling up and color changing and the sensory quality characteristics of semi-finished tea and finished tea. However, the finished tea have received two times of piling up and color changing processes in comparing with the semi-finished tea.

Aroma, as an important character of black tea, influences the intuitive judgment of tea drinkers. Black tea got various scents by the volatile compounds from glycosides hydrolyzation, carotenoids and lipids degradation, Maillard reaction pathway, and caramelization reaction. This paper reviewed the influencing factors involved in aroma formation during black tea processing from fresh tea leaves, withering, rolling, fermentation, to drying. The prospects for future research trends of black tea aroma were also suggested.

Sensory quality evaluation of the primary dark tea under traditional, 45℃, 50℃ controlled pile-fermentation was performed. Meanwhile, volatile components were compared and analyzed by headspace solid phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with principal component analysis (PCA) and partial least-squares discrimination analysis (PLS-DA). The results show that compared with traditional and 50℃-controlled pile-fermentation, the primary dark tea under 45℃-controlled pile-fermentation presented better aroma pleasure, purity and concentration. Furthermore, it appeared less impurity odor. A total of 24 key different volatile components were obtained from traditional and temperature-controlled pile-fermentation. The relative contents of α-cedrene, neophytadiene, olivetol, δ-cadinol, carvacrol, 2,6-di-tert-butyl-p-cresol, (Z)-7-hexadecenal, trans-β-ionone were significantly higher under the temperature-controlled pile-fermentation than those under traditional pile-fermentation. The research results could provide basis and reference for improving aroma quality of primary dark tea.

Tea polyphenols (TP) have various biological activities including anti-oxidation, anti-tumor, anti-cancer, anti-virus and the enhancement of non-specific immunity of human body. After combining with various polysaccharides such as cyclodextrin, black fungus polysaccharide or chitosan, some biological activities of TP can be strengthened. However, the mechanism of the interaction between TP and polysaccharides still remains unclear. Therefore, it is of great importance to explore the structure and interaction between TP and polysaccharides. Recently, an increasing number of researches were reported on the interaction between TP and polysaccharides. Generally, this review introduced the classification and structure of TP and polysaccharides, then summarized the types, influencing factors, research methods and function of interactions between TP and polysaccharides, which provided a reference for the subsequent study of the interaction between TP and polysaccharides with other active substances and changes in functional properties.

In this study, the simultaneous distillation and extraction method and gas chromatography mass spectrometry (GC-MS) were used to determine the aroma components of eight different jasmine teas in Fuzhou. At the same time, the internal standard method was used to determine the relative content of each aroma, and the results were compared and analyzed. The results show that there were more than 47-55 kinds of volatile components with 26 common volatile components, including alcohols, aldehydes, esters, acids, ketones, phenyl, heterocyclic compounds, hydrocarbons and a small amount of other compounds. The range of terpene index was 0.937-0.970. The range of JTF index was 2.752-5.632. According to the comprehensive assessment, the grades of eight jasmine teas were evaluated. As a whole, jasmine Longya, jasmine Zhenwang and ecological scented tea had the highest quality, followed by jasmine Yinhao, jasmine Longhao, and jasmine Dabaihao, while the qualities of jasmine Bailongzhu and premium scented tea were the lowest. The results of this study provided a theoretical basis for distinguishing jasmine tea quality in Fuzhou effectively.

The timing of spring bud flush (TBF) is an important agronomic trait of tea plants, which has great effects on the flavor quality and economic benefits of tea. In this study, to discover key candidate genes regulating TBF, a F₁ population of ‘Longjing 43’× ‘Baihaozao’ comprising 327 offspring was used and a two years’ investigation of TBF were performed in the tea garden. Based on the high-density genetic map constructed from the F₁ population, QTL mapping for the sprouting index (SPI) of tea plants was performed using MapQTL 6.0 and GACD 1.2 software. The phenotypes of SPI in 2022 and 2023 show significant trait segregation and exhibit obvious quantitative trait characteristics in the progeny population. MapQTL 6.0 was identified as a primary QTL (qSPI-5-1), which explained 18.30% (2022) and 7.60% (2023) of phenotypic variations, respectively. GACD1.2 software identified two stable QTLs (qSPI-1, qSPI-5-2), which explained 2.75%-18.40% of phenotypic variations. While qSPI-5-2 and qSPI-5-1 were largely overlapped. The confidence intervals of the above QTLs were compared to the reference genome of tea plants, and 23 candidate genes related to the TBF were found by function annotation analysis. These results provided theoretical references for further investigation on the regulatory genes and molecular mechanisms of spring bud flushing in tea plants.

In order to explore the relationship and the current situation between the geological background of tea garden and the content of heavy metal elements in tea, the rocks, soil and tea in Mengku tea garden and Jingmai tea garden in Yunnan Province were selected as the research objects. The contents of 10 heavy metal elements (Cd, Co, Cr, Cu, Hg, Ni, Pb, Zn, Mn, As) were determined. Multivariate statistical analysis and spatial analysis were used to summarize the characteristics and risk assessment of heavy metals in tea gardens. The results show that: (1) compared with the abundance of elements in the crust, the rocks in Mengku and Jingmai tea gardens were rich in As. While the rocks of Mengku tea garden were poor in Hg and the rocks of Jingmai tea garden were poor in Mn. (2) The soil of Mengku tea garden was mainly polluted by As and Cr. The soil of Jingmai tea garden was mainly polluted by Cr and Cu. They were all lightly polluted and had good soil quality. (3) The average contents of heavy metal elements in tea followed the order of Mn>Zn>Cu>Ni>Cr. The accumulation ability followed the order of Mn>Zn>Hg>Cu>Ni. Only a few tea samples from Mengku tea garden had As content exceeding the standard. And the heavy metal contents in tea were generally at the safe level. (4) For tea samples from Mengku and Jingmai tea gardens, Mn had the highest non-carcinogenic risk. As in Mengku tea had the highest carcinogenic risk. Cr in Jingmai tea had the highest carcinogenic risk. And other heavy metal elements were within the safe range.

In this paper, the anti-aging effects of tea in model organisms such as Caenorhabditis elegans, Drosophila flies and mice were reviewed. The main functional components (tea polyphenols, theanine and caffeine) were especially emphasized. The beneficial functions of tea in preventing age-related diseases were summarized. Furthermore, the latest research on its mechanism of regulating the nutrient-sensing signaling networks was expounded. Finally, the future research direction was briefly discussed.

In recent years, the novel-tea beverage industry has developed rapidly, becoming the third largest form of tea consumption after traditional loose-leaf tea and fast-moving bottled tea. The rapid expansion has intensified competition within the industry, making it crucial to increase customers’ purchase intention and frequency for the long-term healthy development of the industry. This study constructed an analytical model for enhancing the purchase intention of young consumers of novel-tea beverage from the perspective of customer perceived value. Though empirical research based on 1 900 consumer survey data points, the study examined the impact of product innovation, scene experience and brand exposure on customers’ purchase intention. The findings are as follows: (1) Product innovation, scene experience and brand exposure all positively influence customers’ purchase intention. (2) Functional value, experiential value and emotional value enhance the effects of product innovation, scene experience and brand exposure on purchase intention. (3) Product innovation, scene experience and brand exposure all positively affect purchase frequency, though there is some discerpancy between purchase intention and actual purchase behavior. Notably, product innovation plays a significant role in translating purchase intention into actual purchase behavior. Based on these conclusions, it is suggested that novel-tea beverage companies should highlight the uniqueness of product innovation, build interesting scene experiences, and link brand exposure emotions in their operations.

Tea is one of the important cash crop in China. Its growth and development will be affected by different adversity, leading to the decline of tea quality and yield. Light-harvesting chlorophyll-protein complex mainly affects the photosynthetic efficiency of plants, and also plays important roles in adaptation to environmental stresses. In order to study the characteristics of the light-harvesting chlorophyll-protein complex in tea plants, the gene CsLhcb2 encoding the light-harvesting protein complex was cloned from tea cultivar ‘Longjing 43’, and the sequence characteristics, phylogenetic tree, physical and chemical properties, subcellular localization, secondary structure, tertiary structure and its expression profiles under low temperature treatment were analyzed. The results show that the open reading frame of CsLhcb2 gene is 798 bp, encoding 265 amino acids. This gene contains a typical of Chloroa-b-bind conservation domain. The similarity of CsLHCB2 amino acid sequence with 15 plant species was 91.32%. Phylogenetic tree analysis shows that the CsLHCB2 protein of tea plant was closely related to Datura stramonium, Sedum alfredii and Vitis vinifera, and far from Dendrocalamus latiflorus and Phyllostachys edulis. The relative molecular weight of CsLHCB2 protein is 28 662.77 and the theoretical isoelectric point is 5.69, which belongs to hydrophilic protein. Subcellular localization prediction results show that CsLHCB2 protein is mainly located in chloroplasts. Quantitative RT-PCR results show that CsLhcb2 gene may participate in the process of low temperature stress in tea plants. Under normal temperature treatment, the relative expression level of CsLhcb2 gene showed a trend of increasing first and then decreasing within a photoperiod (24 h). ‘Longjing 43’ and ‘Shuchazao’ reached their peak value at 1 h after light treatment, and 'Baiyeyihao' reached their peak value at 6 h after light treatment. Under low temperature of 4 ℃ treatment, the expression of Lhcb2 of the three tea cultivars all reached the peak at 12 h of light treatment, among which the expression level of CsLhcb2 in ‘Shuchazao’ was the highest, which was 1.18 and 1.98 times higher than that of ‘Longjing 43’ and ‘Baiyeyihao’, respectively. The results provided a reference for further research on the role of light-harvesting chlorophyll-protein complex response to low temperature in tea plants.

As the unique kind of tea, Chinese dark tea characterize with the tasty and stale aroma which refers to the pile fermentation. This review summarized the recent progress in flavor chemistry research of Chinese dark tea. Analyzed with the chemistry property of the aroma components, derivatives of methoxyl benzene and allylaldehyde were clarified as the characteristic components of the flavor of Chinese dark tea. Subsequently, as well as microorganism, the effect of the processing procedure, such as pile fermentation, drying, storage and et al, on the aroma quality were declared. Also, the affection of the raw material and the extraction method of flavor were indicated. Therefore, separation and characterization of the characteristic flavor compounds, the transformation mechanism of the functional group on the skeleton of aroma molecular and the participation of microorganism in the formation of the flavor of Chinese dark tea will be the research topic in future.

Tea biochemistry is a subject of life science on Camellia Sinensis. It mainly focus on characteristic secondary metabolites of tea plants, especially those in the fresh tea shoots using biochemical and molecular techniques as research tools. Those metabolites include catechins, caffeine, theanine and volatile terpenes, which contribute greatly to tea quality and healthy effects. The major research fields of tea biochemistry involve the biosynthesis of secondary metabolites in tea plants, their transformation during tea processing and their effects on final tea quality and healthy function. Recently, there have several breakthroughs in the metabolites biosynthesis pathway, tea genome, specific tea germplasm metabolome, the processing metabolome, as well as the chemistry of tea quality. Since tea biochemistry is the fundamental in tea science, its achievements provide the theoretical basis and method approaches to tea cultivation and breeding, tea primary and further processing, tea trading and tea culture. With the development of tea industry and life science & technology, it is believed that the advancement of tea biochemistry will push forward tea industry to a high level at the sustainable development.

China is rich in tea resources. Under the background that the production of traditional tea is greater than the sales, the utilization rate of middle or low grade tea, summer and autumn tea resources are low, which affects the benefit level of tea industry. Comprehensive processing of tea is an important way to improve the utilization rate of tea resources and the scale and efficiency of tea industry. This paper systematically expounds the general situation of the international tea comprehensive processing industry, the development process and current situation of China′s tea comprehensive processing industry and technology, and analyzes the development trend of China′s tea comprehensive processing technology and products.

Based on the recent literatures, the dissolving, releasing and transformation patterns of tea internal compounds and exogenous contaminants were summarized and discussed in this study. Physicochemical properties of chemicals and tea brewing methods are the internal and external cause affecting extraction rates of chemicals during tea brewing. Internal cause plays a crucial role in extraction rates, while external cause is more prominent for the leaching of tea internal substances. Water solubility of chemicals is positively correlated with extraction rates, while octanol-water partition is negatively correlated with extraction rates. Increasing water temperature is helpful for increasing extraction rates of chemicals and their concentrations in tea infusion. Brewing time is negatively correlated with extraction rates in a period of time, while the concentrations of chemicals in tea infusion increase with the brewing time. Compared with other pesticides, most of neonicotine pesticides and carbamate pesticides have higher extraction rates over 60%. The results of extraction rates of metal elements in tea infusion are quite different, and extraction rates of fluorine, nickel and cobalt have high extraction rates over 50%, while extraction rates of lead range from 20% to 50%. Metabonomic analysis based-high resolution mass spectrometry technique is a promising and powerful method for profiling extracting pattern of chemicals during tea brewing. Meanwhile, extracting behavior of toxic compounds during tea brewing will be deeply understood by using thermodynamic theory and kinetic model of mass extraction.

The signing of RCEP had facilitated intra-regional trade liberalization. It is of great practical significance to investigate the impact of RCEP on China's tea import and export trade. Based on the tea trade data of China and other RCEP members from 2011 to 2020, combining the analysis of the current situation of intra-regional import and export trade, this study calculated several indicators such as revealed comparative advantage index (RCA), export similarity index (ESI), trade complementarity index (TCI), trade intensity index (TI) and intra-industry trade index (GL) to measure the competitiveness and complementarity of bilateral tea trade. The results indicate that the tea export competitions between China, Vietnam and Indonesia were more prominent. China's tea export had long-term comparative advantages, and the comparative advantages of green tea export were obvious, while the comparative advantages of China's export of large packaged black tea lag behind Indonesia and Vietnam. China's tea export was highly similar to Japan, Thailand, Singapore and South Korea, and had strong competitiveness in export structure. In addition, the tea trade between China and New Zealand, Brunei, Australia was highly complementary. China's tea trade with Indonesia, New Zealand and Vietnam was mainly intra-industry trade in some years, while with Australia and Myanmar was mainly inter-industry trade. Finally, under the framework of RCEP agreement, strategies including expanding potential markets, dealing with technical barriers to trade and optimizing export structure were proposed.

Metabolic syndrome (MS) is an abnormal multi-metabolic disease that comprises a combination of various diseases such as hypertension, abnormal blood sugar, dyslipidemia and obesity. Tea polyphenols (TPs) are the characteristics secondary metabolites in tea leaves. The latest studies show that TPs can improve the disorder of gut flora (GF) and modulate the co-metabolism of Host-GF by the intervention & treatment to achieve the goal of improving MS. This paper systematically summarized the absorption and metabolism of TPs and the effects of TPs on GF in in vitro fermentation models, animal experiments, and clinical trials. The underlying mechanism among TPs-GF-Host was described, which would facilitate further exploring the effects of TPs on human health based on the theory of intestinal flora and developing functional products of TPs. In addition, it also provided theoretical foundation for developing functional products associating with TPs.

Producing good quality lipid-soluble tea polyphenols (LTP) was the research focus at home and abroad. Tea polyphenols’ modification by solvent, emulsion and molecular modification were reviewed in this paper. The advantages and disadvantages among these three methods were compared. The antioxidant properties of liphophilic tea polyphenols and its mechanism were introduced. Its antioxidant properties in different antioxidant systems were compared. And the application of LTP as antioxidants was forecasted. At the same time, the developing direction of LTP production was proposed.

Liupao tea is a kind of distinctive dark tea products in Guangxi Zhuang Autonomous Region with a long history of production and marketing. It has unique flavor quality characteristics and health-care effects, which has attracted much attention in recent years. In this paper, the research progress on chemical composition and biological activity of Liupao tea over the last 20 years was reviewed, and the future research interests of Liupao tea were also discussed preliminarily.

Metabolomics, an important branch of systems biology, mainly study the changes of small molecule metabolites affected by the internal and external environments (gene or environmental changes). Metabolomics has been widely applied in the field of natural medicine development, botany, microbiology and food safety researches. The application of metabolomics in tea science has also been developed rapidly in recent years. In this article, the application of metabolomics in three major aspects of tea researches (growth and development, the quality formation during processing and the evaluation of tea function) was reviewed and discussed. We believed that metabolomics would play an irreplaceable role in the analysis of gene function, the regulation of metabolic network, the cultivation and the quality improvement in tea.

In order to investigate the aroma characteristics of Zhenghe white tea with different storage years, quantitative descriptive analysis (QDA) combined with headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the aroma characteristics and volatile components of Zhenghe white peony tea stored for 0, 5, 10 and 15 years. The results show that the aroma characteristics of Zhenghe white peony tea varied significantly among different storage years. The aroma characteristics of BMD0 were mainly pekoe, fresh, sweet and floral. With the extension of storage time, the pekoe, fresh, sweet and floral weakened, while the stale flavour and woody increased. A total of 66 volatile components were detected in Zhenghe white peony tea with different storage years, mainly alcohols, esters and acids, with the highest alcohol content in BMD0 and BMD5, and the highest ester content in BMD10 and BMD15. With the extension of storage time, the total volatile components decreased significantly, and the composition and proportion of relative contents changed significantly. The Orthogonal partial least-squares discrimination analysis (OPLS-DA) model could effectively discriminate Zhenghe white peony tea with different storage years. A total of 14 volatile components were screened based on relative odor activity value (rOAV)>1, while 30 volatile components were screened based on variable importance for the projection (VIP)>1. Based on rOAV value>1 and VIP value>1, 6 major volatile components were screened, including β-ionone, α-ionone, nerolidol, benzyl alcohol, benzeneacetaldehyde, linolenic acid. This study provided a theoretical reference and basis for the scientific storage of white tea and the flavour analysis of aged white tea.