Key Metabolites Influencing Astringency and Bitterness in Yinghong 9 Large-Leaf Dark Tea Before and After Pile-Fermentation.

Understanding the impacts of pile-fermentation on the taste quality of dark tea (DT) is crucial. Although the large-leaf DT, Yinghong 9 DT, was successfully developed, its taste quality was not systematically studied. This research aims to analyze how pile-fermentation affects taste.

Widely targeted metabolomic analysis reveals metabolite changes induced by incorporating black tea fermentation techniques in oolong tea processing for quality improvement.

Oolong tea, a semi-fermented tea, has a prominent fruity and floral aroma, resembling green tea's astringency and pungency but lacking black tea's mellowness. Oolong tea incorporating black tea fermentation techniques (OT-IBTFT) not only retained its excellent floral and fruity aroma but also reduced astringency and enriched taste. However, metabolite changes remain unknown.

Effect of Black Tea Polysaccharides on Alleviating Type 2 Diabetes Mellitus by Regulating PI3K/Akt/GLUT2 Pathway.

The bioactivity of tea polysaccharides (TPs) has been widely reported, but studies to date have focused on green tea. Some human health investigations have implied that black tea may possess potential antidiabetic effects, but less is known about their potential role and related antidiabetic mechanism. The present study was, therefore, conducted to investigate the chemical properties and antidiabetic activity of TPs from black tea.

Mechanisms and quality variations of non-volatile and volatile metabolites in black tea from various ages of tea trees: Insights from metabolomics analysis.

The sensory quality of black tea (BT) influenced by various factors, among which tree age is particularly significant. People prefer BT produced by fresh leaves from old tea trees, yet the correlation between tree age and tea quality has not been thoroughly investigated. In this study, we analyzed the quality of BT from young trees (H-JYH) and old trees (H-OJYH) using e-tongue technology and sensory evaluation.

Study on flavor quality formation in green and yellow tea processing by means of UPLC-MS approach.

Yellow tea (YT) has an additional process of yellowing before or after rolling than green tea (GT), making YT sweeter. We analyzed the variations of composition and taste throughout the withering, fixing and rolling steps using UPLC-MS/MS and sensory evaluation, and investigated the influence of various yellowing times on flavor profile of YT. 532 non-volatile metabolites were identified.

Microbial Fermentation Enhances the Effect of Black Tea on Hyperlipidemia by Mediating Bile Acid Metabolism and Remodeling Intestinal Microbes.

Black tea (BT), the most consumed tea worldwide, can alleviate hyperlipidemia which is a serious threat to human health. However, the quality of summer BT is poor. It was improved by microbial fermentation in a previous study, but whether it affects hypolipidemic activity is unknown.

Analysis of aroma quality changes of large-leaf black tea in different storage years based on HS-SPME and GC-MS.

The reasons for the change in volatile metabolites and aroma of black tea during storage remain unclear. Therefore, we used HS-SPME and GC-MS methods to analyze the aroma compounds of new tea (2021) versus aged tea groups (2015, 2017, and 2019). A total of 109 volatile components were identified.

Effects of pile-fermentation on the aroma quality of dark tea from a single large-leaf tea variety by GC × GC-QTOFMS and electronic nose.

Aroma is one of the significant quality factors of dark tea (DT). However, for a single large-leaf tea variety, there are few studies analyzing the effect of pile-fermentation on the aroma quality of DT. The GC × GC-QTOFMS, electronic nose (E-nose) and GC-olfactometry (GC-O) techniques were employed to analysis the difference of tea products before and after pile-fermentation.

Aged black tea alleviates constipation in mice by modulating intestinal neurotransmitters and decreasing AQP3 and AQP9 expression.

Background: Black tea is fully fermented tea with abundant functional components that benefit the gastrointestinal tract. But whether black tea extract relieves constipation is unknown. Therefore, we used loperamide to induce constipation in mice to assess the therapeutical effect of extracts from aged black tea with different storage times.

Metabolome and Microbiome Analysis to Study the Flavor of Summer Black Tea Improved by Stuck Fermentation.

Tea is the most popular and widely consumed beverage worldwide, especially black tea. Summer tea has a bitter and astringent taste and low aroma compared to spring tea due to the higher content of polyphenols and lower content of amino acids. Microbial fermentation is routinely used to improve the flavor of various foods.

The formation mechanism of aroma quality of green and yellow teas based on GC-MS/MS metabolomics.

Aroma is a crucial determinant of tea quality. While some studies have examined the aroma of yellow tea, there are no reports of the difference and formation mechanism of aroma quality between yellow and green teas from the same tea tree variety. This study employed gas chromatography-mass spectrometry to investigate the difference and formation mechanism of the aroma of yellow and green tea at the omics level, based on sensory evaluation.

Recent insights into the physicochemical properties, bioactivities and their relationship of tea polysaccharides.

Tea polysaccharides (TPS) is receiving global concern in past years due to their therapeutic effects in many diseases such as obesity and diabetes. Many publications imply that the unique physicochemical properties and bioactivities of TPS are prerequisites for its use as a biofilm, drug carrier and emulsifier. Despite numerous healthy benefits, studies on the in-deep structure-activity relationship of TPS still not well explored and explained yet.

Metabolomics reveals the effects of different storage times on the acidity quality and metabolites of large-leaf black tea.

Most aged tea has superior sensory qualities and good health benefits. The content of organic acids determines of the quality and biological effects of aged tea, but there are no reports of the effect of storage on the composition and relative proportion of acidic compounds in black tea. This study analyzed and compared the sourness and metabolite profile of black tea produced in 2015, 2017, 2019 and 2021 using pH determination and UPLC-MS/MS.

Tea and complex induces apoptosis of human liver cancer cells via PI3K/AKT/mTOR pathway .

Objective: In this study, black tea and (BT-CM), yellow tea and (YT-CM), green tea and (GT-CM) as subjects, the active ingredient content and antioxidant activity of three tea and (T-CM) were analyzed. The effects of three T-CMs on apoptosis of liver cells and its mechanism were further explored.

Methods: National standard method and HPLC were used for active ingredient analysis.

Tea and its components reduce the production of uric acid by inhibiting xanthine oxidase.

Background: The health benefits of tea are as diverse including the reduction of uric acid levels. Xanthine oxidase is the most directly mediated enzyme in the production of uric acid.

Objective: To explore the inhibitory effects of different teas and its main bioactive components on the production of uric acid.

and tea regulate AMPK signaling pathway to retard the progress of nonalcoholic fatty liver disease.

Background: Nonalcoholic fatty liver disease (NAFLD) is a chronic metabolic disease that easily induces hepatitis, cirrhosis, and even liver cancer. The long-term use of NAFLD therapeutic drugs produces toxicity and drug resistance. Therefore, it is necessary to develop high efficiency and low-toxicity active ingredients to alleviate NAFLD.

Six Types of Tea Reduce Acute Alcoholism in Mice by Enhancing Ethanol Metabolism, Suppressing Oxidative Stress and Inflammation.

Acute alcoholic intoxication (AAI) is a pathological process of multiple system damage caused by a large amount of alcohol, especially in the liver. Although tea extracts alleviate AAI and alcohol-induced liver damage, the mechanisms underlying the protective actions of different types of Chinese tea are unclear. In this study, the AAI mice model was used to explore the functions and mechanisms of six types of tea extract (WEATs) in alleviating AAI.

Aged green tea reduces high-fat diet-induced fat accumulation and inflammation via activating the AMP-activated protein kinase signaling pathway.

Background: Obesity is a global public health concern and increases the risk of metabolic syndrome and other diseases. The anti-obesity effects of various plant-derived bioactive compounds, such as tea extracts, are well-established. The mechanisms underlying the anti-obesity activity of Jinxuan green tea (JXGT) from different storage years are still unclear.

Theaflavin-3,3'-di-gallate represses prostate cancer by activating the PKCδ/aSMase signaling pathway through a 67 kDa laminin receptor.

Prostate cancer is a major cause of morbidity and mortality in men. Theaflavin-3,3'-digallate (TF-3) is an important functional ingredient of black tea. We aimed to evaluate the cytotoxic effects of TF-3 on prostate cancer and to identify the underlying molecular mechanism.

HS-SPME and GC/MS volatile component analysis of Yinghong No. 9 dark tea during the pile fermentation process.

Each type of tea has a unique volatile profile due to its variety, processing technologies and origin. Using HS-SPME and GC/MS, we analyzed the changes of volatile components in cultivar Yinghong No. 9 during pile-fermentation every 10 days.

Mixtures of Tea and (pomelo) Alleviate Lipid Deposition in HepG2 Cells Through the AMPK/ACC Signaling Pathway.

Tea and citrus maxima are natural, medicinal homologous plants, typically used for making beverages, which have anticancer, antiobesity, and antioxidation properties. Green tea, yellow tea, and black tea were combined with citrus maxima to obtain green tea and (GTCM), yellow tea and (YTCM), and black tea and (BTCM). The biochemical components of these mixtures were analyzed, and their possible effects and mechanisms on relieving liver lipid deposition were explored.

Antiobesity and anti-inflammation effects of Hakka stir-fried tea of different storage years on high-fat diet-induced obese mice model via activating the AMPK/ACC/CPT1 pathway.

Background: As a typical representative of metabolic syndrome, obesity is also one of the extremely dangerous factors of cardiovascular diseases. Thus, the prevention and treatment of obesity has gradually become a global campaign. There have been many reports that green tea is effective in preventing obesity, but as a kind of green tea with regional characteristics, there have been no reports that Hakka stir-fried tea (HT) of different storage years has a weight loss effect.

Volatile components and nutritional qualities of Burm.f. parasitic on ancient tea trees.

Volatile flavor compounds (VFCs) and nutrients in Burm.f. parasitic on ancient tea trees (named TM) were studied in this research by headspace solid-phase microextraction (HS-SPME)/gas chromatography-mass spectrometry (GC-MS) and conventional methods.

Study on the effects of rapid aging technology on the aroma quality of white tea using GC-MS combined with chemometrics: In comparison with natural aged and fresh white tea.

The effects of rapid aging technology on aroma compounds and characteristic of white tea were investigated in comparison with natural aged white tea (NAWT) and fresh white tea (FWT). Volatile compounds of white teas were extracted using headspace-solid phase microextraction (HS-SPME), and analyzed with gas-chromatography-mass spectrometry (GC-MS) coupled with chemometrics. Aroma metabolites analysis showed that 40 compounds were identified to distinguish rapid aged white tea (RAWT) from others.

Phenotypic, histological and proteomic analyses reveal multiple differences associated with chloroplast development in yellow and variegated variants from Camellia sinensis.

Leaf colour variation is observed in several plants. We obtained two types of branches with yellow and variegated leaves from Camellia sinensis. To reveal the mechanisms that underlie the leaf colour variations, combined morphological, histological, ionomic and proteomic analyses were performed using leaves from abnormal branches (variants) and normal branches (CKs).