Chinese Tea Research Articles

Dynamic change of oligopeptides and free amino acids composition in five types of tea with different fermentation degree processed from the same batch of fresh tea (Camelilia Sinensis. L.) leaves

Our previous studies have confirmed oligopeptides could be meaningful to tea taste and biofunction. As the total content of oligopeptide among different tea types were varied. It is a natural speculation that certain tea processing step could be vital for oligopeptides enrichment. In current study, five types of traditional Chinese tea were produced from the same batch of fresh leaves. Step processing samples were acquired through which to profile the oligopeptides and free amio acids composition change during tea processed. As a result, firstly, withering was the vital step for oligopeptide enrichment, followed by fermentation, yellowing and drying. Secondly, as the enrichment of oligopeptides was often accompanied by the increase of protein amino acids, suggesting certain proteins degradation in fresh leaves could be the main source of oligopeptides. Thirdly, a total of 166 abundant oligopeptides were screened out, through which 14 high degradation protein were also located by protomic approaching.

Rapid varietal authentication of oolong tea products by microfluidic-based SNP genotyping

Oolong tea is one of the most popular Chinese teas, and its quality is significantly affected by the variety of tea plant. The growing demands lead to the adulteration of premium oolong tea products, e.g., Tieguanyin oolong tea. In this study, microfluidic technology and single-nucleotide polymorphism (SNP) biomarkers were used to authenticate the varieties of oolong tea products. Forty-eight pairs of primers were screened, and they can be used to authenticate Tieguanyin oolong tea via high-throughput microfluidic SNP chips. Through the combination of the NJ tree and PCoA plot methods, the study found that the most frequent adulterant of Tieguanyin oolong tea on the market is Benshan. For the first time, the commercial behavior of using Fuyun6 and Jinguanyin as adulterants or contamination in the production of Tieguanyin oolong tea was reported. This research has proposed rapid authentication technology for oolong tea to provide food quality supervision and promote consumer trust.

‘Goed voor alle gebreecken’

When Chinese tea was first introduced in Europe in the seventeenth century, it quickly became popular both as a hot drink and as medicine. In the Netherlands, the interest in Chinese goods and tea in particular reached its apogee in the last decades of the century. Such products were avidly consumed, but they were also discussed in numerous book publications. These publications largely focused on how tea could have a beneficial effect on health and wellbeing. However, tea consumption was also mocked in satirical culture. Even before tea truly became a mass-consumer good, the anonymous publishers of the Oost-Indische thee post (1687) and the Darmstadse thee courant (1687) took up the growing tea mania for their satirical genre parody. They confirmed tea’s continued association with health and medicine, but also testified to the first stirrings of debates on the participation of women and the ‘lower classes’ in the tea ritual. This article looks at the complex ways in which tea was represented in Dutch culture at the turn of the eighteenth century.

A clinical study to observe the efficacy and safety of Besunyen Detox Tea for constipation.

Introduction:Functional constipation (FC) is a common functional gastrointestinal disease and is one of the most common outpatient diseases. The purpose of this study was to investigate the efficacy and safety of the traditional Chinese medicine Besunyen Detox Tea (BDT) for FC and to compare the effect of BDT between constipation patients with and non-dryness-heat syndrome.Methods and analysis:This multicenter, prospective, observational registry study included 1000 participants diagnosed with FC. This study will collaborate with 3 comprehensive hospitals and 15 community hospitals and recruit patients into the registry between July 2022 and July 2023. After enrollment, we will collect the individual characteristics of each patient, anthropometric data and general condition, bowel movement, patient assessment of constipation symptoms, patient assessment of constipation quality of life, TCM syndrome scale, and time to take the laxative product again after treatment. We will also record adverse events and economic indicators at each visit.Discussion:This is the first registry-based study to collect real-world data of participants diagnosed with FC receiving BDT treatment. The results of this registry may also reflect these characteristics and provide direct clinical evidence to verify the importance of syndrome differentiation and treatment for the use of TCM health care products.

NIR Spectrometric Approach for Geographical Origin Identification and Taste Related Compounds Content Prediction of Lushan Yunwu Tea.

Lushan Yunwu Tea is one of a unique Chinese tea series, and total polyphenols (TP), free amino acids (FAA), and polyphenols-to-amino acids ratio models (TP/FAA) represent its most important taste-related indicators. In this work, a feasibility study was proposed to simultaneously predict the authenticity identification and taste-related indicators of Lushan Yunwu tea, using near-infrared spectroscopy combined with multivariate analysis. Different waveband selections and spectral pre-processing methods were compared during the discriminant analysis (DA) and partial least squares (PLS) model-building process. The DA model achieved optimal performance in distinguishing Lushan Yunwu tea from other non-Lushan Yunwu teas, with a correct classification rate of up to 100%. The synergy interval partial least squares (siPLS) and backward interval partial least squares (biPLS) algorithms showed considerable advantages in improving the prediction performance of TP, FAA, and TP/FAA. The siPLS algorithms achieved the best prediction results for TP (RP = 0.9407, RPD = 3.00), FAA (RP = 0.9110, RPD = 2.21) and TP/FAA (RP = 0.9377, RPD = 2.90). These results indicated that NIR spectroscopy was a useful and low-cost tool by which to offer definitive quantitative and qualitative analysis for Lushan Yunwu tea.

Trilobatin alleviates non-alcoholic fatty liver disease in high-fat diet plus streptozotocin-induced diabetic mice by suppressing NLRP3 inflammasome activation

Diabetes mellitus (DM) is a factor with great risk in the course of non-alcoholic fatty liver disease (NAFLD) due to its high glucotoxicity and lipotoxicity. Trilobatin, a glycosylated dihydrochalcone derived from the leaves of the Chinese sweet tea Lithocarpus polystachyus Rehd, is reported to possess various pharmacological activities. Nevertheless, it is still unclear regarding if trilobatin can alleviate liver injury in diabetic mice with NAFLD and its mechanism. Our aim was to investigative the protective effects of trilobatin against DM with NAFLD and its mechanism of action. A DM mice model was established by high-fat diet (HFD) feeding with streptozocin (STZ) injections, and treated with trilobatin for 10 weeks. The biochemical results showed that trilobatin restored glucose metabolic disorder and liver function in diabetic mice. The histopathological evaluation revealed that trilobatin improved liver injury by alleviating lipid accumulation and liver fibrosis. Mechanistically, trilobatin decreased expression of NLRP3, p65 NF-κB, cleaved-Caspase-1 and N-GSDMD, as well as the release of IL-18 and IL-1β, leading to a alleviation of inflammation and pyroptosis. Taken together, we determined for the first time found that trilobatin could prevent liver injury in diabetic mice with NAFLD by suppressing NLRP3 inflammasome activation to reduce inflammation and pyroptosis.

Spent Chinese Green Tea as an Adsorbent for Simultaneous Removal of Potentially Toxic Metals from Aqueous Solution

Spent Chinese Green Tea as an Adsorbent for Simultaneous Removal of Potentially Toxic Metals from Aqueous Solution

Discrimination of chrysanthemum varieties using lipidomics based on UHPLC-HR-AM/MS/MS.

Chrysanthemum is one of the most important and popular ornamentals over the world. Chrysanthemum drink is a type of traditional healthy drink like Chinese tea. Owing to the differences in the chemical compositions, different chrysanthemum varieties have different medicinal effects on human health. Thus, the identification of different chrysanthemum varieties is very important and necessary. This study aims to distinguish seven chrysanthemum varieties that are widely used in China. First, total lipids were obtained from chrysanthemums. After that, lipid profiles were characterized using ultra-high-performance liquid chromatography hyphenated with a Q Exactive™ high resolution-accurate-mass mass spectrometer. A total of 163 lipid molecular species from 17 types of lipid classes in seven varieties of chrysanthemums were determined. Principal component analysis indicated that three lipid molecules, lysophosphatidylethanolamine(18:2) (LPE(18:2)), LPE(16:0), and phosphatidic acid(18:2/18:3) (variable importance in projection >3, P < 0.001), can be used as potential biomarkers to distinguish seven chrysanthemum varieties. Hierarchical cluster analysis showed that the lipid molecular profiles of 'Gongju' were most similar to 'Jinzijianju', followed by 'Huaibaiju', 'Boju', 'Hangbaiju', 'Chuju', and 'Fubaiju'. This comprehensive analysis provided a new method to identify chrysanthemum varieties through the perspective of lipidomics combined with chemometrics. © 2022 Society of Chemical Industry.

Potential role of tea drinking in preventing hyperuricaemia in rats: biochemical and molecular evidence

BackgroundLifestyle and diet play a significant role in hyperuricaemia. Accumulating evidence indicates that tea consumption is associated with hyperuricaemia and gout. However, diverse compounds in different types of tea make it quite difficult to determine the relevant molecular mechanism. Here, we compared the effects of six types of tea on hyperuricaemia induced by potassium oxonate (PO) and hypoxanthine in rats and investigated the possible underlying mechanisms.MethodsRats were randomly assigned to ten groups: the control, hyperuricaemia model, benzbromarone positive control, traditional Chinese medicine Simiao San positive control, green tea, yellow tea, black tea, white tea, red tea, and cyan tea treatment groups. After 21 days, uric acid (UA), xanthine oxidase (XOD), alanine aminotransferase (ALT),blood urea nitrogen (BUN), and creatinine (CRE) were assessed. Serum levels of interleukin-1β (IL-1β) were measured with an enzyme-linked immunosorbent assay. Haematoxylin–eosin staining and immunohistochemistry were used to assess liver and kidney injury.ResultsThe levels of UA, CRE, and BUN in the treatment group were decreased to varying degrees. There was a significant reduction in UA, CRE, and BUN levels for yellow tea compared to the positive control drugs. Yellow tea suppressed XOD activity and alleviated hepatic and kidney injury. Network pharmacology and untargeted metabolomics indicated that ten yellow tea bioactive ingredients and 35 targets were responsible for preventing hyperuricaemia, which was mediated by 94 signalling pathways, including IL-1β and TNF.ConclusionThese findings indicate that green tea cannot reduce the serum uric acid level of hyperuricaemic rats. Yellow tea can significantly improve hyperuricaemia by regulating the inflammatory response, autophagy, and apoptosis. This study provides a potential candidate for the treatment of hyperuricaemia and a basis for selecting therapeutic tea for patients with hyperuricaemia.

Brewer’s Spent Grain Biochar: Grinding Method Matters

The present work is based on the principle of biomass waste valorization. Brewer’s spent grains (BSG) come from breweries as by-products. Their huge amount of production on an industrial scale should focus our attention on their valorization, which creates challenges as well as opportunities. One way to valorize BSG by-products is to convert them into biochar, a functional material with multiple potential applications. With an emphasis on sustainable development and the circular economy, in this work, we focused on a comparative study of the different mechanical processes of BSG grinding and their effect on the resulting biochar formed after pyrolysis. Home appliances such as blenders, coffee mills, and mortar and pestles were used for this purpose. FESEM images confirmed the successful creation of five different morphologies from the same BSG under the same pyrolysis conditions. Interestingly, a novel Chinese tea leaf egg-like biochar was also formed. It was found that a series of physical pretreatments of the biomass resulted in the reduced roughness of the biochar surface, i.e., they became smoother, thus negatively affecting the quality of the biochar. XRD revealed that the biomass physical treatments were also reflected in the crystallinity of some biochar. Via a Raman study, we witnessed the effect of mechanical pressure on the biomass for affecting the biochar features through pressure-induced modifications of the biomass’s internal structure. This induced enhanced biochar graphitization. This is a good example of the role of mechanochemistry. DSC revealed the thermochemical transformation of the five samples to be exothermic reactions. This study opens up an interesting possibility for the synthesis of biochar with controlled morphology, crystallinity, degree of graphitization, and heat capacity.

Multiomic analysis of dark tea extract on glycolipid metabolic disorders in db/db mice.

Glycolipid metabolic disorder is a serious threat to human health. Dark tea is a kind of traditional Chinese tea, which may regulate the glycolipid metabolic disorders. Dark tea extract (DTE) is the water extraction obtained from dark tea. Compared with traditional dark tea, DTE has the benefits of convenient consumption and greater potential for promoting health. However, the regulation of DTE on glycolipid metabolism and its molecular mechanism is rarely investigated. In our study, DTE was used as raw material to study the effect and molecular mechanism of its intervention on the glycolipid metabolic in db/db diabetic mice by using multiomics analysis and modern biological techniques. (1) DTE could significantly reduce fasting glucose in diabetic db/db mice, and the higher dose group has a better effect. Histopathological examination showed that DTE slightly improve the number of islets and decrease the number of islet β cells in the pancreatic tissue in db/db mice. (2) RNA-Seq was used to analyze the gene expression in liver tissue. In terms of biological processes, DTE mainly affected the inflammation and fatty acid metabolism. In terms of cell components, the lipoprotein and respiratory chain are mainly affected. In the aspect of molecular function, DTE mainly affected the redox related enzyme activity, iron ion binding and glutathione transferase. Arachidonic acid metabolism pathway, glutathione metabolism and PPAR signaling pathway were enriched by DTE with the results of KEGG pathway enrichment. In addition, real-time PCR results confirmed that DTE could significantly activate key genes of PPAR signaling pathway like Fabp1, Cyp4a1, Ehhadh, Cyp4a32, Aqp7 and Me1. (3) 16s rDNA showed that DTE could significantly decrease the ratio of Firmicutes/Bacteroidetes and the abundance of Proteobacteria, and increased the relative abundance of Verrucomicrobia at the phylum level. At the genus level, the relative abundance of Akkermansia, Prevotellaceae, Bacteroides and Alloprevotella was significantly increased after DTE treatment. This study provides multiomics molecular evidence for the intervention effect of DTE on abnormal glucose and lipid metabolism and the application of precise nutritional diet intervention of dark tea extract.

The Endogenous Development Mechanism of the Baiyankeng Geocultural Village in China

This study aims to clarify a new endogenous model of geocultural villages by examining land use change, industrial transformation, and their impacts on rural society and the economy of Baiyankeng village, Zhejiang Province, China. This empirical study focuses on the actions of residents and their effects after Baiyankeng was registered as the pilot geocultural village in China. To address the dual configuration of urban/rural areas and three-dimensional rural issues, the Chinese government released a set of policies for rural vitalization in the early 2000s, which included the establishment and promotion of geocultural villages in 2013. This study found that the local leadership—the township government and the village committee—played a significant role in leveraging the unique geological resources of the village. They aggressively pitched for Baiyankeng village to be recognized as the first-ever geocultural village, and successfully established an effective model of self-governance that empowered villagers to actively and enthusiastically participate in the process. By doing so, they successfully created a booming tourism industry while boosting local production of Chinese Torreya nuts and green tea. From the perspective of the land system in China, the mechanism of geocultural villages (henceforth known as rural geoparks) in this study shows new endogeneities of rural vitalization in China.

Hybridity with exclusion: Chinese tea rebrewed in Australia

This article aims to deepen understanding of the concept of cultural hybridity through ethnographic investigation of Australian engagement with Chinese practices of tea drinking. The consumption of tea in urban Australia, despite its apparent novelty, embeds a story of decline. Unlike the development of coffee and wine consumption, a mature Australian tea drinking style is yet to arise. Whilst being influenced by Chinese tea culture, the actors in Australian tea culture also adopt a strategy of distancing and exclusivity, demonstrating “hybridity with exclusion.” When unable to articulate what denotes an Australian style, they instead locate themselves by declaring what they don't belong to. I argue that the concept of cultural hybridity should not be taken for granted as a totally blurred boundary between different cultures; rather, it critically demands to be understood in terms of rejection and exclusion, and it could incorporate an intentional distinction and distance between the self and the other.

Effect of thermal process on the key aroma components of green tea with chestnut‐like aroma

Chestnut-like aroma is one of the unique qualities of Chinese green tea and has become an important factor influencing consumer decisions. However, the chemical formation mechanism of chestnut-like aroma during green tea processing remains unclear. In this study, the dynamic changes of key components contributing to chestnut-like aroma and their precursors were analyzed in fresh leaves, fixation leaves, first baking tea leaves, and green tea. The thermal process had an important effect on volatile components in tea leaves, causing a significant decrease of alcohols and esters and a significant increase of ketones, acids, phenols, and sulfur compounds. Furthermore, 31 volatiles were identified as the key odorants responsible for chestnut-like aroma of green tea, including dimethyl sulfide, methyl isobutenyl ketone, 2-methylbutanal, 2,4-dimethylstyrene, d-limonene, methyl 2-methylvalerate, linalool, decanal, longifolene, phenylethyl alcohol, l-α-terpineol, jasmone, and so on. And the majority of these odorants were only formed in the drying stage. Additionally, isoleucine, theanine, methionine, and glucose were found to be involved in the formation of chestnut-like aroma of green tea. The drying process played a vital important role in the formation of chestnut-like aroma of green tea. © 2022 Society of Chemical Industry.

Sense‐making in Taiwan's tea art ritual

This paper analyzes Taiwan's contemporary public tea gatherings from the perspective of “sense-scape,” the cultural world of sensory experiences. Performing elegance by way of tea brewing, bodily gestures and movements, costumes, utensil arrangements, and spatial design represents what is innovative about Taiwan's tea art culture, often referred to as “literati tea.” As the fragrance and flavors of tea, light and shadows, sounds and music, visual presentations of utensils, and space, as well as the general atmosphere of these events are captured by the senses and organized by the emotions, they inform us about who we are and who the other is. Despite its Japanese cultural infusion and Chinese cultural legacy, which have always complicated claims of a truly Taiwanese origin, Taiwan's tea art has been eagerly adopted by mainland Chinese tea communities since the late 2000s. That a local practice and invented tradition strongly identified with Taiwan has been embraced as “traditional” cultural practice in contemporary China presents a paradox that deserves our attention.

Expanded authenticity? Changing standards for identifying longjing tea

Due to the power of premium brand identities, West Lake Longjing tea (西湖龙井茶), the most famous representative of Chinese tea varieties, faces competition around the matter of its authenticity. The 2001 adoption of production area classifications by local governments promoting rural economic and social development has fueled the expansion of the Longjing tea brand. By introducing the idea that Longjing tea (龙井茶) could be identified with areas outside West Lake, this policy has made room for new views of varietal authenticity. For China's new consumer society, traditional standards of authentic taste and appearance have also been challenged. Based on long-term observations and interviews, this paper explores the conflict and compatibility between politics and markets, land and technology, tradition and innovation. It analyzes how Longjing tea has created a social narrative for “expanded authenticity", which provides a case for the development of China's consumer society under market demand and policy management.

Metabolomic characterization of the chemical compositions of Dracocephalum rupestre Hance

Maojian tea (MJT) is a traditional Chinese herbal tea beverage manufactured from the leaves of the Dracocephalum rupestre Hance plant. In this study, a nontargeted metabolomics approach combined with absolute quantifications was applied to comprehensively investigate the chemical compositions of MJT and to determine the effects of the processing methods on compounds. Flavones (apigenin and luteolin, 0.06–1.35 mg/g), flavanones (eriodictyol and naringenin, 0.1–2.3 mg/g), flavone 7-O-glycosides (0.15–5.98 mg/g), flavanone 7-O-glycosides (0.28–19.41 mg/g), and triterpenoids were presumed to be characteristic components of MJT. Applying imitative green and black tea processing methods to MJT led to increases in flavone/flavanone aglycones, lipids, and triterpenoids and decreases in flavone/flavanone glycosides, amino acids, organic acids, and most phenolic acids. This study offers novel insights into the chemical compositions and the influences of processing methods on MJT and will be utilized for the quality control of MJT.

Accumulation of potentially toxic elements in Chinese tea (Camellia sinensis): Towards source apportionment and health risk assessment

Tea (Camellia sinensis) is a popular beverage that is consumed globally. However, a better understanding of potentially toxic elements (PTEs) content in tea leaves and infusion is necessary to minimize risk on human health. Therefore, 249 tea samples (grown in different areas) covering six types of tea were collected in China to investigate the PTEs contents, identify their potential source and assess the health risk associated with drinking tea. PTE contents in tea leaves across six tea types were ND–0.900 (Cd), 0.005–2.133 (As), ND–5.679 (Pb), ND–13.86 (Cr), 1.601–22.93 (Ni), ND–2.048 (Se), 0.109–622.4 (F), 13.02–269.9 (Rb), 1.845–50.88 (Sr), and 2.796–53.23 (Ba) mg/kg. The result of tea infusion showed that 14.3 %–44.1 % (green tea), 14.5 %–46.7 % (black tea), 10.5 %–25.3 % (dark tea), 13.6 %–34.2 % (oolong tea), 16.9 %–40.7 % (yellow tea), and 19.9 %–35.1 % (white tea) of F were released. All tea types, except green tea, exhibited comparatively low leachability of Cd, As, Pb and Cr in tea infusion. The source apportionment revealed that PTEs in tea leaves mainly originated from soil parental materials, while industrial activities, fertilizer application, and manufacturing processes may contribute to exogenous Se, Cd, As, and Cr accumulation. Health risk assessment indicated that F in tea infusion dominated the health risk. Humans may be exposed to a higher health risk by drinking green tea compared to that of other tea types. Nevertheless, the long-term tea consumption is less likely to contribute to pronounced non-carcinogenic and carcinogenic risks. This study confirmed that tea consumption is an important and direct pathway of PTEs uptake in humans. The health risk associated with drinking tea should be of concern.

Rabdosia serra alleviates dextran sulfate sodium salt-induced colitis in mice through anti-inflammation, regulating Th17/Treg balance, maintaining intestinal barrier integrity, and modulating gut microbiota

Rabdosia serra (R. serra), an important component of Chinese herbal tea, has traditionally been used to treat hepatitis, jaundice, cholecystitis, and colitis. However, the chemical composition of R. serra and its effect against colitis remain unclear. In this study, the chemical composition of the water extract of R. serra was analyzed using ultra performance liquid chromatography coupled with a hybrid linear ion trap quadrupole-orbitrap mass spectrometer (UPLC-LTQ-Orbitrap-MS). A total of 46 compounds, comprising ent-kaurane diterpenoids, flavonoids, phenolic acids, and steroids, were identified in the water extract of R. serra, and the extract could significantly alleviate dextran sulfate sodium salt-induced colitis by improving colon length, upregulating anti-inflammatory factors, downregulating proinflammatory factors, and restoring the balance of T helper 17/T regulatory cells. R. serra also preserved intestinal barrier function by increasing the level of tight junction proteins (zonula occludens 1 and occludin) in mouse colonic tissue. In addition, R. serra modulated the gut microbiota composition by increasing bacterial richness and diversity, increasing the abundance of beneficial bacteria (Muribaculaceae, Bacteroides, Lactobacillus, and Prevotellaceae_UCG-001), and decreasing the abundance of pathogenic bacteria (Turicibacter, Eubacterium_fissicatena_group, and Eubacterium_xylanophilum_group). Gut microbiota depletion by antibiotics further confirmed that R. serra alleviated colitis in a microbiota-dependent manner. Overall, our findings provide chemical and biological evidence for the potential application of R. serra in the management of colitis.

Pollution, source and risk assessment of PAHs in Chinese tea

In this study, multi-walled carbon nanotubes continuous solid-phase extraction (MWCNTs-CSPE) combined with high-performance liquid chromatography in series with ultraviolet and fluorescence dual detectors (HPLC-DAD-FLD) approach were employed to investigate the concentration, source, and risk of 22 PAHs from Chinese tea products, classified and analyzed seven major categories and 28 varieties of 119 tea samples. The results found that the pollution degree of different varieties of tea is different, and the total concentration range of Σ22 PAHs is 136.99–462.51 μg/kg, in which ΣPAH4 (BaA, CHR, BbF, BaP) ranges from 37.64 to 106.90 μg/kg, ∑16 EPA PAHs is 136.99–440.82 μg/kg. PAHs are mainly composed of 2–4 rings. PAHs characteristic parameter analysis shows that PAHs in Chinese tea products are mainly from fuel oil, wood burning, coal and oil combustion. Benzo[a]pyrene always plays an important role in the carcinogenicity of samples. Lifetime cancer risk assessment showed that black tea had a higher cancer risk level which was 3.75 × 10−7–2.31 × 10−6. The cancer risk of ILCR increases with age, older adults have a higher lifetime cancer risk than younger children, and females have a higher lifetime cancer risk than males, but it can be ignored.