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Objective: This study aimed to explore the quality features of basal tea of noval-jasmine tea. Methods: Taking three kinds of basal tea（Fujian Xianghao, Yunnan Maojian, Sichuan Xiangming）of noval-jasmine tea beverage scenting tea dhool from Fujian, Yunnan and Sichuan as the research objects, the quality of the base tea including main biochemical components, taste, aroma were analyzed by electronic tongue, solid phase microextraction combined with gas chromatography-mass spectrometry (GC-MS), sensory evaluation and chemical analysis. Results: Water extracts of three kinds of basal tea was 49.40%~51.40%, tea polyphenols was 18.00%~23.20%, caffeine was 3.20%~4.30%, free amino acid was 3.32%~3.50%. The main biochemical components and 16 kinds of amino acids of Yunnan Maojian were higher than the other two. The response values of acerbity, salty, richness of Yannan Maojian were the maximum, but the response value of sweet was the minimum, and tea soup was heavy and strong. The response values of acerbity and salty of Fujian Xianghao were the minimum, but the water extracts were high, and tea soup was thick and mellow. The contents of esters were the maximum, followed by alcohols and olefins. The order of aroma quality from high to low was Fujian Xianghao, Yunnan Maojian and Sichuan Xiangming，which were all middle degree by aroma evaluation. Conclusion: The inclusion of the three kinds of basal tea of noval-jasmine tea beverage were abundant, but the aroma quality needed improvement.

To evaluate the tea processing suitability of the leaves of ‘Guixing’ tea, a wild tea plant germplasm resource in Guangxi, the water extract content, polyphenolic composition, sensory properties and volatile aroma composition of the tea leaves as well as green, oolong, white and black tea processed from the tea leaves were measured and compared with each other. The results showed that ‘Guixing’ tea was a unique tea germplasm resource with low caffeine content and a ratio of phenol to ammonia of 11.8, which was more suitable for black tea production. After processing into white and black tea, the epigallocatechin content in the leaves decreased to 0, and the catechin content of green tea decreased significantly compared with that of the leaves. The results of sensory evaluation showed that white and black tea had a rich almond-like aroma, while the other kinds of tea did not. A total of 53 aroma components were detected, which could be divided into two types. Each type had same aroma components. The first type included tea leaves, green tea and oolong tea, without almond-like aroma, and had 40 aroma components, the major ones being β-linalool and limonene. The second type included white tea and black tea, with strong almond-like aroma, and contained 42 aroma components, the main one being benzaldehyde. A total of 28 aroma components were found to be common to these tea samples, all of which contained benzaldehyde. The decreasing order of the relative contents of benzaldehyde in them was black tea (61.97%) > white tea (31.73%) > oolong tea (14.65%) > leaves (4.24%) > green tea (2.88%). Benzaldehyde was mainly produced during withering, rolling and fermentation. With extended withering time, the content of benzaldehyde increased. The higher the content of benzaldehyde, the stronger the almond-like aroma of tea. Therefore, benzaldehyde is key for almond-like aroma formation.

Black tea, a traditional drink, can induce urination and quench thirst. Black brick tea with fungal growth, prepared by steaming, pressing, inducing fungal growth, and drying the black tea, is a new type of black tea with different sensory qualities and is suitable for storage. However, the effects of black brick tea with fungal growth on lowering uric acid are still unexplored. Therefore, the potassium oxonate was administered for 7 consecutive days to establish the hyperuricemic mice. Then allopurinol, black tea, and black brick tea with fungal growth were orally administered with hyperuricemic mice for 14 days. Serum uric acid levels, liver xanthine oxidase (XOD) and adenosine deaminase (ADA) activities, and expression of renal urate transporters and inflammatory response were detected. Compared to the model group, both types of black tea lowered serum uric acid by decreasing the uric acid production with inhibiting the activities of XOD and ADA, and increasing uric acid excretion because of downregulating urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) expressions, and upregulating organic anion transporter 1 (OAT1), organic anion transporter 3 (OAT3), and organic cation transporter 1 (OCT1) expressions. They could also improve renal injury by suppressing the activation of the NOD‐like receptor family, pyrin domain containing 3 (NLRP3) inflammasome, and nuclear factor‐κB (NF‐κB) signaling, thereby reducing renal proinflammatory cytokine levels. Compared with black tea, black brick tea with fungal growth with a higher content of theabrownins had a better effect on lowering serum uric acid. Practical applications: Black tea accounts for approximately 78% of the total consumed tea in the world. Black brick tea with fungal growth is a new kind of black tea product with different sensory qualities and is suitable for storage. The study found that black brick tea with fungal growth is superior to black tea in reducing serum uric acid levels, which make a significant contribution to promote people's health and stimulate the production and consumption of black brick tea with fungal growth. In addition, it provides a clue for future research to identify the effective components of black brick tea with fungal growth lowering uric acid. [ABSTRACT FROM AUTHOR]

Epigallocatechin gallate (EGCG) and L-theanine (LTA) are important bioactive components in tea that have shown promising effects on nutrient metabolism. However, whether EGCG alone or combined with LTA can regulate the glucose, lipid, and protein metabolism of healthy rats remains unclear. Therefore, we treated healthy rats with EGCG or the combination of EGCG and LTA (EGCG+LTA) to investigate the effects of EGCG on nutrient metabolism and the role of LTA in the metabolism-regulatory effects of EGCG. The results showed that compared with the control group, EGCG activated insulin and AMP-activated protein kinase (AMPK) signals, thus regulating glucose, lipid, and protein metabolism. Compared with EGCG, EGCG+LTA enhanced hepatic and muscle glycogen levels and suppressed phosphorylation of AMPK, glycogen synthase 2, mammalian target of rapamycin, and ribosomal protein S6 kinase. In addition, EGCG+LTA inhibited the expression of liver kinase B1, insulin receptor and insulin receptor substrate, and promoted the phosphorylation level of acetyl-CoA carboxylase. Furthermore, both EGCG and EGCG+LTA were harmless for young rats. In conclusion, EGCG activated AMPK and insulin pathways, thereby promoting glycolysis, glycogen, and protein synthesis and inhibiting fatty acid (FA) and cholesterol synthesis. However, LTA cooperated with EGCG to promote glycogen metabolism and suppressed the effect EGCG on FA and protein synthesis via AMPK signals. [ABSTRACT FROM AUTHOR]

Redox and inflammation imbalances are associated with increased levels of advanced glycation end products (AGEs), leading to the degeneration of body function. l -Theanine, derived from tea, reportedly inhibits AGE formation in vitro. We investigated the effects on AGE content, oxidative stress, and inflammatory factors in d -galactose-induced aging rats for prevention and treatment of age-related liver dysfunction. l -Theanine increased activities of antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase, thus enhancing total antioxidant capacity, and decreasing malondialdehyde and nitric oxide synthase levels in serum and liver. Levels of the pro-inflammatory factors, interleukin (IL)-1β, tumour necrosis factor-alpha, and IL-6 were decreased in serum and liver, whereas those of anti-inflammatory factors, IL-4 and IL-10, were increased in the serum. Further, l -theanine inhibited AGE production and decreased the levels of the liver function markers, alanine aminotransaminase and aspartate aminotransferase. It also significantly increased the mRNA expression levels of FoxO1 and downregulated NF-κB(p65) but suppressed the phosphorylation of both FOXO1 and NF-κB (p65). Moreover, l -theanine effectively attenuated d -galactose-induced oedema and vacuole formation, thus protecting the liver. Overall, l -theanine reversed the d -galactose-induced imbalance in oxidative stress and inflammatory responses, reduced AGEs content in aging rats, maintained homeostasis in the body, and ameliorated liver aging. • Tea-derived l -theanine inhibited AGE production in d-galactose-induced aging rats. • l -Theanine increased FoxO1 expression and antioxidative enzymes in aged livers. • l -Theanine could reduce oxygen free radicals and maintain the redox balance. • l -Theanine supplementation could protect against age-related liver damage. [ABSTRACT FROM AUTHOR]