Tea Leaves Research Articles

Caffeine consumption of medical students in Korea: amount and symptoms based on a 2023 survey.

To investigate the form and level of daily caffeine intake recommended above 400 mg in medical students expected to consume caffeinated beverages to enhance their performance. From May to June 2023, freshman through senior medical students at a medical school in Korea were administered a seven-item questionnaire designed to measure the amount of caffeine-containing foods consumed, the weekly interval between consumption, the reason for consumption, and the level of caffeine-induced symptoms experienced. Out of 443 students, 361 responded (81.5%). The most commonly consumed caffeine beverages were coffee (79.2%), followed by soda (33.2%), tea (27.4%), chocolate (25.2%), and energy drinks (20.5%). The estimated (average±standard deviation) daily intake was estimated to 274.6±276.5 mg, and they consumed caffeine on an average of 4.25±2.26 days per week. Students who consumed 400 mg or more of caffeine daily consumed 19.9%. The primary motivation for caffeine intake was "to improve academic performance" (60.9%) and "preferred food" (51.8%). Among the responders, 98% of them replied they had symptoms that could be caused by caffeine, in order of palpitations (47.4%), frequent urination (42.9%), anxiety (27.1%), indigestion (17.5%), and excitement (17.5%). A total of 45.7% reported two symptoms, and 24.7% reported three or more. Caffeinated beverage consumption was routine among current medical students, with 20% consuming more than the recommended daily amount. Most students experienced at least one caffeine-induced symptom, with two symptoms in half, suggesting the need for policy measures and warnings about caffeine-containing foods.

Evaluation of the Antioxidant Potential of Fermented Persimmon Leaf Tea

Evaluation of the Antioxidant Potential of Fermented Persimmon Leaf Tea

Preparation and Analysis of Physicochemical Properties, Antioxidant and Antibacterial Activities of Kombucha Tea Produced from Beijing Bamboo Leaf Tea (Dendrocalamus sp.) and Green Tea

Beijing bamboo (Dendrocalamus sp.), belonging to the Poaceae family, has been largely neglected and underutilized, particularly its leaves. This study aims to investigate the physicochemical properties, antioxidant, and antimicrobial activities of Beijing bamboo leaf and Beijing bamboo leaf kombucha. Hot air drying was conducted at temperatures of 60, 65, and 70ºC, with results indicating that 65ºC is the optimal drying temperature for achieving the highest levels of total phenolic compounds, flavonoids, and antioxidant activities. Beijing bamboo leaf tea underwent a 21-day fermentation process with a kombucha consortium comprising yeasts and acetic acid bacteria. The results showed that the changing trends of pH, total acidity, and total soluble solids were similar between kombucha produced from Beijing bamboo leaf tea and green tea. Fermentation notably enhanced the antioxidant activity of the kombucha, as evidenced by DPPH and FRAP assays, which correlated with increases in phenolics and flavonoids. The antimicrobial efficacy was assessed through the agar diffusion method and minimum inhibitory concentration (MIC), revealing that both Beijing bamboo leaf tea and green tea suppressed the growth of pathogenic bacteria, including Salmonella Typhimurium DMST 562, E. coli DMST 4242, Bacillus cereus DMST 5040, Staphylococcus aureus DMST 8840, and Pseudomonas aeruginosa DMST 4739. Notably, kombucha from green tea exhibited superior antimicrobial effects compared to Beijing bamboo leaf tea kombucha. Additionally, fermentation of Beijing bamboo leaf tea resulted in higher counts of yeast, acetic acid bacteria, and lactic acid bacteria throughout the fermentation process than those observed in green tea kombucha. These findings highlight the potential of Beijing bamboo leaves as a valuable resource for developing functional properties in underutilized plant resources, offering promising applications in the food and health industries.

Analysis Of Microbial and Chemistry Contamination Thai Tea Drink in Junior High School

Thai Tea drink is the current favorite drink of the current millennial generation. Thai Tea beverage products are usually sold in places that are easily accessible to consumers, such as on the side of the highway. This thing makes Thai Tea beverage products have potential to become a medium for foreign object to enter the body if they are not processed properly. This study aims to determine the safety of Thai Tea beverage products that are sold around junior high schools in Central Bogor District. This study used seven samples taken from 7 junior high schools in seven different sub-districts and used a purposive sampling method. Product analysis was carried out twice, including testing the microbial contamination levels of Total Plate Number, Coliforms, Escherichia coli, heavy metal lead chemical contamination and sucrose content in Thai Tea drinks. Research is also supported by field observations and interviews. The research showed that all samples of Thai Tea drinks contained TPC microbial contamination that exceeded the standard, twelve repetition were contaminated with coliform bacteria and Escherichia coli, all repetition were not detected by heavy metal lead contamination and the sucrose content of all repetition did not exceed the maximum daily sugar intake limit.

Valorizing Tea Waste: Green Synthesis of Iron Nanoparticles for Efficient Dye Removal from Water.

This study explores the valorization of tea leaf waste by extracting polyphenols through reflux extraction, subsequently using them to synthesize zero-valent iron nanoparticles (nZVI). The in situ generated nanoparticles, when combined with fixed amounts of hydrogen peroxide, facilitated the removal of various dyes (methylene blue, methyl orange, and orange G) via a hetero-catalytic Fenton process. The iron nanoparticles were thoroughly characterized by gas adsorption of N2 at 77 K, scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM), FT-IR spectroscopy, X-ray diffraction (XRD), and thermal analysis, including thermogravimetric analysis (TG) and temperature-programmed reduction (TPR). A statistical design of experiments and response surface methodology were employed to analyze the influence of polyphenol, Fe(III), and H2O2 concentrations on dye removal efficiency. The results demonstrated that optimizing the operational conditions could achieve 100% dye removal efficiency. This study highlights the potential of nZVI synthesized through eco-friendly methods as a promising solution for water decontamination involving diverse model dyes, thus contributing to sustainable waste management and environmental protection.

Pengaruh Suhu dan Waktu Penyeduhan Teh Daun Kelakai (Stenochlarna Palutris) Dengan Treatmen Asam Lemon (Citrus Limon) Terhadap Kadar Besi (Fe)

Iron (Fe) is one of the many nutrients found in kelakai. Lemon acid treatment (Citrus lemonade) is used in the processing of kelakai tea powder as an effort to increase the nutritional value of the plant. The aim of this research is to determine how temperature and brewing time affect the iron (Fe) content in kelakai leaf tea (Stenochlarna palutris) prepared with lemon acid (Citrus lemonade). This research used a 2 factorial completely randomized design (CRD) and was experimental. There are two factors: the first is the temperature at which the brewing is done (40, 50 and 60 degrees Celsius), and the second is the brewing time (1, 5 and 10 minutes) with three repetitions. Two-Way Analysis of Variance (ANOVA) was used in data analysis, along with an additional 5% Honestly Significant Difference (BNJ) test. These findings show a very significant influence of brewing temperature, brewing time, and the combination of temperature and brewing time. The results of the research show that moderate temperatures produce high iron (Fe) levels, moderate brewing results in high iron (Fe) levels. The brewing temperature treatment T2 (50oC) had the highest amount of calcium at 2.73778 ppm. Iron (Fe) levels are low at temperature T1 (400C) of 1.42000 ppm. The effect of brewing time on high iron (Fe) levels at F2 time (5 minutes) is 2.73778 ppm. The lowest iron (Fe) content was located at the longest brewing time, namely F3 (10 minutes) at 1.12267 ppm. T3F2 (600C, 5 Minutes) with iron (Fe) content of 3,707 ppm. The treatment that produces the lowest iron (Fe) content is T2F3 (500C, 10 minutes) with a value of 0.702 ppm

High-Throughput Transcriptomic Analysis of Circadian Rhythm of Chlorophyll Metabolism under Different Photoperiods in Tea Plants.

Tea plants are a perennial crop with significant economic value. Chlorophyll, a key factor in tea leaf color and photosynthetic efficiency, is affected by the photoperiod and usually exhibits diurnal and seasonal variations. In this study, high-throughput transcriptomic analysis was used to study the chlorophyll metabolism, under different photoperiods, of tea plants. We conducted a time-series sampling under a skeleton photoperiod (6L6D) and continuous light conditions (24 L), measuring the chlorophyll and carotenoid content at a photoperiod interval of 3 h (24 h). Transcriptome sequencing was performed at six time points across two light cycles, followed by bioinformatics analysis to identify and annotate the differentially expressed genes (DEGs) involved in chlorophyll metabolism. The results revealed distinct expression patterns of key genes in the chlorophyll biosynthetic pathway. The expression levels of CHLE (magnesium-protoporphyrin IX monomethyl ester cyclase gene), CHLP (geranylgeranyl reductase gene), CLH (chlorophyllase gene), and POR (cytochrome P450 oxidoreductase gene), encoding enzymes in chlorophyll synthesis, were increased under continuous light conditions (24 L). At 6L6D, the expression levels of CHLP1.1, POR1.1, and POR1.2 showed an oscillating trend. The expression levels of CHLP1.2 and CLH1.1 showed the same trend, they both decreased under light treatment and increased under dark treatment. Our findings provide potential insights into the molecular basis of how photoperiods regulate chlorophyll metabolism in tea plants.

Effect of Nano Urea on Leaf Nutrients and Some Quality Parameters of Tea (Camellia sinensis (L) O. Kuntze)

Some important parameters of tea on mature plants of TV 23 clone were studied after application of Nano-urea as foliar spray at Experimental Garden for Plantation Crops, Assam Agricultural University, Jorhat during the period 2021-2022. The usage of "Nano Urea" (Liquid), a novel product created and patented by Indian Farmers Fertilizer Cooperative Limited (IFFCO), is projected to replace the use of urea granules, one of the most widely used fertilizers in the world. Leaf nutrients i.e., nitrogen, phosphorus, potassium and quality parameters i.e., Caffeine, polyphenol were observed after application of nano urea. Leaf nitrogen, leaf phosphorus and leaf potassium were found to be increased with the application of higher dose of Nano Urea. Leaf nitrogen was observed maximum (4.57%) in the plot where 0.4% Nano-urea applied in three sprays. Total phosphorus content of leaf was found to be the highest in treatment T7(0.423%) the lowest was observed in treatment T0 (0.370%). Total potassium content of leaf was the highest in treatment T7 (2.517%) and lowest K2O content was observed in treatment T0 (2.013%) which was a control. In quality parameters, it was found that application of Nano Urea showed significant impact on the total caffeine content of tea leaf. The highest value of caffeine was found in treatment T7 (3.233%) and lowest was found in treatment T0 (3.10%) (control).

Green tea beverage protects against thiabendazole-induced kidney and liver injury through antioxidant actions in rats in vivo

ABSTRACT Thiabendazole (TBZ) is an important molecule used in several different areas. Two percent of green tea leaf extracts (GTE) obtained by maceration were tested against TBZ-induced liver and kidney toxicity, by using four groups of male Wistar rats controls, control-tea (2%), TBZ-treated, and TBZ+GTE. The results revealed, after 4 weeks of treatment, an increase in nitric oxide (NO), advanced oxidation protein products (AOPP) and protein carbonyl (PC) levels and a decrease in catalase activity in the tissues homogenates on TBZ-treated rats. The administration of GTE to TBZ-treated rats attenuated the increase in NO, AOPP and PC levels and improved activities of catalase and markers. Histological examination demonstrated marked tissue damage in the liver and kidney of TBZ-treated animals. Co-administration of TBZ and green tea reduced tissue damage. Acute exposure to TBZ leads to acute inflammation through oxidant – antioxidant imbalance. GTE could therefore be a useful therapeutic option for reversing TBZ-induced oxidative stress.

Fusarium Dieback: Scientific Challenges and Priorities to Safeguard Indian tea Industry

Fusarium Dieback: Scientific Challenges and Priorities to Safeguard Indian tea Industry

Efficacy of mindfulness-based Taoist embodiment group therapy on depression, anxiety and stress in an integrated community mental health service in Hong Kong: a preliminary exploration

Existing Taoist psychotherapy often feature indoctrination-heavy formats and hierarchical structures, which can undermine the experiential connection to Taoist principles central to their therapeutic value. This mixed-methods study evaluated a novel, 4-week, mindfulness-based, "Embodied Taoism" group therapy intervention, designed to address these limitations, at a government-funded Integrated Community Centers for Mental Wellness in Hong Kong. The program aimed to mitigate depressive, anxiety, and stress symptoms, and cultivate cognitive flexibility, interpersonal connectedness, and Taoist principle integration. The majority of the 29 participants, aged 25-78, had diagnosed mental health disorders, while three were suspected cases. Rather than didactic presentation, the intervention employed experiential activities like mindful tea drinking, calligraphy, philodrama and philosophical discussion to facilitate embodied mindfulness practice and promote experiential understanding of the Taoist tenets such as non-interference, flowing with natural order, and “walking two roads”. Quantitative analysis of pre-post assessments (Depression Anxiety Stress Scales-21) and qualitative thematic analysis of participant questionnaires and focus groups were conducted.

Analysis of Phenolic Content in Green Tea Kombucha and Rosella (Hibiscus sabdariffa) Kombucha Using Spectrophotometer Uv-Vis

Phenolic compounds are compounds that have hydroxyl groups and are most abundant in plants. Green tea and rosella flowers are types of plants that contain phenolic compounds and can be used as ingredients to make kombucha tea drinks. Kombucha is a fermented drink made from tea and sugar which is fermented by a colony of bacteria and yeast. The aim of this research was to determine the levels of phenolic compounds in green tea kombucha and rosella flowers through experimental tests using spectrophotometry uv-vis. The results showed that the phenolic content of green tea kombucha was 162.35 mg/L GAE, while rosella kombucha had a level of 101.30 mg/L GAE. Thus, the phenolic content of green tea kombucha is higher compared to rosella kombucha.

Chemometrics and sensomics-assisted identification of key odorants responsible for retort odor in shelf-stored green tea infusion: A case study of Biluochun

The deterioration of aroma quality in tea beverages during the shelf life is a significant issue. In this study, sensomics techniques were employed to identify the characteristic factor contributing to aroma degradation in green tea infusion. Samples A (no/faint retort odor) and B (high intensity retort odor) were selected based on their retort-like odor intensity after heat treatment simulating shelf-life conditions. The key odorants were identified through a combination of chemometrics analysis, comparative aromatic extract dilution analysis (cAEDA), detection frequency analysis (DFA), and odor-specific magnitude estimation (OSME). Subsequently, eight odorants, including linalool (892.451 μg/L), (E)-β-damascenone (5.105 μg/L), phenylacetaldehyde (27.720 μg/L), nonanal (2201.439 μg/L), α-terpineol (7.166 μg/L), geraniol (0.499 μg/L), theaspirane (0.044 μg/L), and 2-hydroxy-5-methylacetophenone (2.973 μg/L), were identified as the key substances contributing to the retort-like odor in sample B. Aroma recombination and omission test further demonstrated that elevated concentrations of nonanal, geraniol, phenylacetaldehyde, and theaspirane might be the primary reasons for the retort odor observed in samples.

Evaluation of the effects of storage time and temperature on the beverages

Beverages are an important part of the food sector their storage is also one of the most critical issues. This study investigated the effects of different storage temperatures and times on physicochemical properties, flavonoid and organic acid contents of soda, sherbet and ice tea produced by adding sour grape concentrate. Changes in the flavan-3-ol content of ice tea were also measured during the storage period. The beverages were stored in three different conditions, cold storage (~4°C), room temperature (~24°C) and controlled storage (20±1°C), for six months and analyzed every two months. Storage temperatures and time affected the total soluble solids and acidities of the beverages (p≤0.05). Tartaric acid decreased during storage, especially during the first two months in sherbets. Ice tea and soda drinks were found more stable than sherbets. The malic acid was found the major organic acid in beverages. Flavonoid content in ice tea was higher than others. The flavonoid concentrations of ice tea stored at 20 and 24°C and of sherbet at 4°C were statistically significant as a function of storage time while these values were not significant for ice tea stored at 4°C and of sherbet at 20 and 24°C (p≤0.05). Concentrations of flavan-3-ols varied with storage conditions. The levels of epicatechin, epigallocatechin and epigallocatechin gallate in ice tea samples decreased between an average of 43.72 and 71.15% at the end of six months of storage. Principal component analysis separated two months storage from other storage periods and perfectly discriminated the studied flavan-3-ols except catechin. Soluble solid and brix-acid ratio also dissociated similarly to flavan-3-ols.

Biosynthesis of silver nanoparticles using green tea aqueous leaf extract and their biological and chemotherapeutic activity

Green tea leaf extract-mediated silver nanoparticles (GT-AgNPs) were synthesized and characterized for their biological and chemotherapeutic activity. The synthesis process involved the reduction of silver ions by green tea leaf extract (GTLE), resulting in the formation of GT-AgNPs. Characterization techniques including UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and zeta potential analysis were employed to study the physicochemical properties of GT-AgNPs. The GT-AgNPs exhibited a characteristic color change and a noticeable shift in the surface plasma resonance (SPR) absorption peak at 458 nm, confirming their successful formation of nanoparticles. XRD analysis indicated a cubic structure with a crystallite size of 9 ± 1 nm. Both SEM and TEM images revealed that the spherical shape and size of the synthesized nanoparticles. The SEM analysis confirmed that the average grain size of GT-AgNPs is 20.27 ± 1 nm, while the TEM analysis determined the average particle size of 9 ± 0.025. GT-AgNPs have a negative zeta potential of -19.7 mV indicating a hydrodynamic diameter of 140.90 nm with a polydispersity index (PDI) of 25.8 %. XPS confirmed the oxidation state of Ag0/+1 in GT-AgNPs. The energy band gap (Eg) value of GT-AgNPs is 3.38 eV, indicating semiconducting properties, while fluorescence activity was observed at 506.17 nm. CT-DNA and BSA protein binding studies demonstrated the formation of CT-DNA-GT-AgNPs and BSA-GT-AgNPs complexes with binding constants of 1.366×1010 M−1 and 6.77×109 M−1, respectively. GT-AgNPs exhibited exceptional anti-oxidant activity by effectively scavenging stable 2, 2ʹ - diphenyl-1-picryl hydroxyl (DPPH) radicals. Cytotoxicity assays using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) demonstrate moderate activity against KB3 and AGS cancer cells while showing no detectable cytotoxicity in Caco-2 cells. This indicates a safe therapeutic window for human eukaryotic cells.

Effect of Mulberry (Morus alba) Leaf Tea on Low-Density Lipoprotein and Malondialdehyde Levels in Dyslipidemic Rats

Effect of Mulberry (Morus alba) Leaf Tea on Low-Density Lipoprotein and Malondialdehyde Levels in Dyslipidemic Rats

Green Synthesis of Silver (Ag) Nanoparticles with Green Tea Leaf, Its Characterization, and Molecular Docking Analysis against Diabetes

Green Synthesis of Silver (Ag) Nanoparticles with Green Tea Leaf, Its Characterization, and Molecular Docking Analysis against Diabetes

EFEKTIVITAS SEDUHAN DAUN ASAM JAWA TERHADAP KADAR HOMA-IR DAN HOMA-β PADA PASIEN DIABETES MELLITUS TIPE 2

This study assessed the impact of tamarind leaf tea on HOMA-IR and HOMA-β levels in patients with Type 2 Diabetes Mellitus (DM). Thirty-two patients aged 20-50 years from Sungai Ambawang District Health Center, who were not using any DM medication, participated. They were divided into control (KN) and treatment (KP) groups, with KP receiving a tamarind leaf tea infusion for 7 days. HOMA-IR and HOMA-β levels were calculated using standardized formulas based on fasting insulin and glucose levels. The Wilcoxon signed-rank test revealed a significant decrease in HOMA-IR levels in the KP group (p<0.05), while no significant change was observed in the KN group. Although no significant difference in HOMA-β levels was found between the two groups, the KP group showed a notable increase by 4. These findings suggest that a 7-day tamarind leaf tea infusion effectively reduced HOMA-IR levels in patients with type 2 DM, although it did not significantly affect HOMA-β levels. This study highlights the potential of tamarind leaf tea as a complementary approach for managing insulin resistance in Type 2 DM patients. Further research is needed to explore the long-term effects and mechanisms of action for improving β-cell function. The conclusion of this study is that steeping tamarind leaves for seven days can reduce HOMA-I levels and slightly increase HOMA-β levels in patients with type 2 Diabetes Mellitus.

Pendampingan Penentuan Harga Jual Produk di UMKM Kieran Tea

This research was conducted to determine the cost of production of one of the micro, small and medium enterprises or UMKM that has the opportunity to sell individually packaged tea drinks. Meanwhile, in marketing Kieran tea products, several stages need to be carried out, especially in determining the price in the market before this tea product is put on the market, so that prices can be adjusted to compete in the market and at the same time be accepted by people who want to enjoy this special tea treat. In this research, the HPP method was used to determine the price that can be released to the market. After going through calculations, the selling price for camellia tea was obtained, namely IDR 12,300/bag and IDR 308,600/box. Business owners also understand the influence of the cost of production and expected profits in their business in determining the selling price of their products, so there is a significant difference between determining the selling price of products without taking HPP into account and those taking HPP into account.

The Way of Tea Drinking Survival in the Internet Era----- Taking Heytea as an Example

The Internet model has promoted the development of commerce, not only the traditional retail industry has been developed, and the catering industry such as milk tea and coffee shops is booming. As the first generation to open the online operation model, although the Internet + model has begun to take shape, there are still gaps in the relevant tea drinking culture. Based on the literature research method and case analysis method, this paper analyzes the existing marketing model of Heytea and proposes relevant improvement policies, with the purpose of widening the gap with other related tea brands and improving the core competitiveness of its products. As the earliest generation of beverage stores to enter the Internet + model, Heytea has rich experience in marketing planning, online and offline marketing activities. This paper analyzes the marketing based on the Internet + model through researching the brand cross-border co-branding and innovative marketing activities of Heytea.