Black Tea Research Articles (Page 1)

Polyphenolic profiles, antioxidant capacity, and antibacterial activity of green tea, matcha tea, black tea, and yerba mate extracts

Improving summer black tea quality via vibratory withering and piling fermentation: Insights from metabolomics and sensory analysis.

Effect of the use of black and green tea (Camellia sinensis), honey, and guarana (Paullinia cupana) syrup on the chemical properties and microbiological composition of kombucha

Dual mode unity-SPME-GC-MS unlocks the low-volatile flavour profiles of oolong, black, and Pu-erh teas: Revealing aroma diversity shaped by processing techniques

Metabolomics profiling of black tea and its antioxidant activity using proton nuclear magnetic resonance

Development of a validated efficient HPLC-DAD analysis for assessing polyphenol transformation during black tea processing

LC-MS and GC-MS analyses reveal that amino acid-induced ammoniation of EGCG in different tea types enhances its structural stability.

Effects of different leaf colors on the quality of hawk black tea: sensory evaluation and metabolomics.

Abstract Polyphenols and flavonoids are abundant in herbal teas and are necessary in antioxidant defense. Although the black and green teas are well researched, there is little information on herbal teas. This paper examined the polyphenol and flavonoid composition of 20 organic herbal teas and their roles in antioxidant activity, in terms of DPPH radical inhibition. The Folin-Ciocalteu colorimetry and the aluminum nitrate colorimetry were used to measure total phenolics and flavonoids, whereas the DPPH, ABTS, and hydroxyl radical scavenging assays were used to measure antioxidant activity. There were strong correlations between antioxidant activity and phenolic content (DPPH: r = 0.876; ABTS: r = 0.928; hydroxyl: r = 0.905), with the highest activity observed in dandelion, kuding, mint, peony, and lotus leaf teas. The structure-activity relationships of flavonoid were investigated by means of Cu 2 + chelation, UV-visible spectroscopy, and DNA binding. The copper-flavonoid complexes exhibited redshifts of the UV and improved DNA binding (without strand breaks) suggesting structural changes that lead to bioactivity. Finally, polyphenols are the main source of antioxidant activity of herbal teas, and flavonoids contribute to the effects through metal binding and interaction with DNA. These findings justify the creation of effective herbal teas in the management of oxidative stress.

Gardenia black tea (GBT) is a prized Chinese scented tea, renowned for its pleasant aroma. However, the influence of repeated scenting rounds on its volatile profile remains poorly characterized. This study investigated the aroma profiles of GBT produced with zero, two, and three scenting rounds (T0, T1, T2) using sensory evaluation and Headspace Solid-Phase Microextraction–Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS). Sensory analysis revealed that GBTs (T1, T2) scored significantly higher in aroma and taste than the black tea base (T0). GC-MS analysis identified numerous volatile compounds, with esters, terpenoids, and ketones being predominant. Multivariate analysis identified 52 key volatiles (VIP > 2.0) that differentiated the tea samples. Among these, 28 compounds had odor activity values (OAVs) > 1, indicating significant sensory contributions. Ultimately, 11 volatiles, including (Z)-hex-3-enyl acetate, linalool, and (E)-hex-2-enal, were identified as the crucial basis for the characteristic fresh and floral scent of GBTs. The specific abundance levels of these compounds are hypothesized to underlie the superior, fresh, and elegant aroma of T1, compared to the slightly ripe and stuffy floral notes of T2. Therefore, it is advisable to prioritize two rounds of scenting during the production of gardenia black tea. These findings provide a theoretical foundation for optimizing the scenting process and enhancing the quality of GBT.

Iron (Fe3+) metal complex synthesis via green approach as a straightforward methodology to improve the optical and optoelectronic properties of chitosan (CS) biopolymer.

Indonesia, a major black tea, exported approximately 89% of black tea between 2018-2022, faces a substantial surplus, highlighting the need for producers to understand domestic consumer behavior amidst evolving tea consumption patterns. This study analyzes the influence of product attributes and the purchasing decisions of tea consumers in Central Java, Indonesia. This study employed a survey method. The study site was selected from the Banyumas District. Data were collected using purposive sampling techniques from 300 respondents and interviews with consumers who consumed black tea in tea bag packaging of original tea variants and/or jasmine tea, and made tea buying decisions. Data were analyzed using a combination of quantitative and structural equation modelling (SEM) with the analysis software AMOS 24. The results show that taste and brand have a significant effect on consumer attitudes; consumer attitudes have a significant effect on consumer purchasing decisions; consumer purchasing decisions have a significant effect on consumer satisfaction; and consumer satisfaction has a significant effect on consumer loyalty. The Ministry of Agriculture wants to reduce the export of raw materials and make the most of extra tea production. They plan to do so by promoting local tea brands. This will help Indonesian tea to become more known both internationally and locally. This will also improve the income of farmers and small businesses by increasing the value of their products.

To investigate the effect of adding microbial agents in the fermentation stage on the quality of tobacco leaves prepared by imitating black tea method. Using Yunyan 87 middle leaves as materials, two microbial agents of Schwanniomyces occidentalis and Bacillus subtilis were sprayed onto the leaves before fermentation, and the effects of different microbial treatments on the main chemical composition, sensory quality, microbial diversity of tobacco leaves were analyzed. The starch content in tobacco leaves treated with S. occidentalis and B. subtilis decreased by 25.00 and 47.64%, and the total pigment content decreased by 46.15 and 30.77%, respectively. Tobacco leaves treated with two microbial agents can increase the characteristic aroma of burnt sweet and sour sweet respectively. The treatment of the two agents can improve the community richness and species diversity of tobacco leaves, and effectively improve the abundance of dominant bacteria such as Firmicutes and Candida. Both exogenous microorganisms can effectively reduce the starch and pigment contents in tobacco leaves, improve the sensory quality of tobacco leaves, improve the diversity of microbial community, and then improve the quality of tobacco leaves prepared by imitating black tea method. Bangladesh J. Bot. 54(3): 783-790, 2025 (September) Special

Tea (Camellia sinensis (L.)O. Kuntze) converts inorganic selenium into organic selenium, including selenomethionine (SeMet). Drying improves tea flavor, but the thermal mechanism by which drying time affects flavor compounds and proteins in selenium-enriched black tea remains unclear. 98 different flavor components and 87 proteins were identified by metabolomics and proteomics at 12-54 min of hot-air drying (70 °C, 7.0-0.1% moisture). Amino acid biosynthesis and glutathione metabolic pathways were significantly affected under heat. Key flavor compounds (SeMet, cysteine, serine, etc.) and proteins (methionine synthase, etc.) were maintained at high abundance. SeMet peaked at 36 min (1.23 mg kg-1), which increased by 19.4, 17.1, 16.0, and 61.8% compared with 12, 24, 48, and 54 min (1.03, 1.05, 1.06, and 0.76 mg kg-1, respectively). Optimal drying (70 °C for 36 min; 3.0% moisture) minimized thermal degradation losses of flavor components like SeMet, providing a theoretical basis for maintaining the high-quality of tea.

Elucidating the taste profile in black tea through molecular docking and molecular sensory science.

Dynamic changes in composition during processing of Lonicerae japonicae flos black tea.

Theaflavins in black tea ameliorate high-fat diet-induced obesity and inflammation via gut microbiota, AMPK-mediated metabolism, and NF-κB pathway.

A green and effective determination of derivatized chiral amino acids in the six types of Chinese tea using supercritical fluid chromatography-triple quadrupole mass spectrometry.

Revealing the characteristic honey-like aroma formation in honey-scented black tea via molecular sensory analysis.

Electrochemical detection and specific recognition of anti-bacterial flavonoid in food and biological samples using NiMnCo-S/rGO substrate.