Displaying publications 61 - 80 of 108 in total

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  1. Nwidu LL, Elmorsy E, Carter WG
    Malays J Med Sci, 2018 Mar;25(2):27-39.
    PMID: 30918453 DOI: 10.21315/mjms2018.25.2.4
    Background: Polyherbal standardised extracts used in ethnomedicine of Eastern Nigeria for memory improvements were evaluated for anti-cholinesterases and anti-oxidant properties.

    Methods: Anti-cholinesterase, anti-oxidant, and total phenolic and flavonoid contents were established using standard procedures.

    Results: The three polyherbal extracts exhibited significant concentration dependent acetylcholinesterase (AChE) inhibitory activity (P = 0.001). The highest AChE inhibition was observed with the Neocare Herbal Tea (NHT) with 99.7% (IC50 = 324 μg/mL); whereas the Herbalin Complex Tea (HCT) and Phytoblis Herbal Tea (PHT) exhibited 73.8% (IC50 = 0.2 μg/mL) and 60.6% (IC50 = 0.7 μg/mL) inhibition, respectively, relative to eserine at 100% inhibition (IC50 = 0.9 μg/mL) at 200 μg/mL. The order of percentage increase in inhibition of AChE was NHT > HCT > PHT; while the order of decrease in potency was HCT > PHT > NHT.Radical scavenging activities of HCT, NHT and PHT were 82.13% (IC50 = 0.08 μg/mL), 77.43% (IC50 = 0.01 μg/mL) and 76.28% (IC50 = 0.3 μg/mL), respectively, at 1 mg/mL concentrations. The reducing power revealed a dose-dependent effect, with NHT > PHT > HCT. The order of total phenolics content in the extracts were PHT > HCT > NHT, and for total flavonoids content: PHT > NHT > HCT.

    Conclusion: The three polyherbal standardised products possess significant acetylcholinesterase inhibitory activity and secondary metabolites that could collectively contribute to their memory-enhancing effects.

    Matched MeSH terms: Teas, Herbal; Tea
  2. Bhoo-Pathy N, Uiterwaal CS, Dik VK, Jeurnink SM, Bech BH, Overvad K, et al.
    Clin Gastroenterol Hepatol, 2013 Nov;11(11):1486-92.
    PMID: 23756220 DOI: 10.1016/j.cgh.2013.05.029
    BACKGROUND & AIMS: Few modifiable risk factors have been implicated in the etiology of pancreatic cancer. There is little evidence for the effects of caffeinated coffee, decaffeinated coffee, or tea intake on risk of pancreatic cancer. We investigated the association of total coffee, caffeinated coffee, decaffeinated coffee, and tea consumption with risk of pancreatic cancer.

    METHODS: This study was conducted within the European Prospective Investigation into Nutrition and Cancer cohort, comprising male and female participants from 10 European countries. Between 1992 and 2000, there were 477,312 participants without cancer who completed a dietary questionnaire and were followed up to determine pancreatic cancer incidence. Coffee and tea intake was calibrated with a 24-hour dietary recall. Adjusted hazard ratios (HRs) were computed using multivariable Cox regression.

    RESULTS: During a mean follow-up period of 11.6 y, 865 first incidences of pancreatic cancers were reported. When divided into fourths, neither total intake of coffee (HR, 1.03; 95% confidence interval [CI], 0.83-1.27; high vs low intake), decaffeinated coffee (HR, 1.12; 95% CI, 0.76-1.63; high vs low intake), nor tea were associated with risk of pancreatic cancer (HR, 1.22, 95% CI, 0.95-1.56; high vs low intake). Moderately low intake of caffeinated coffee was associated with an increased risk of pancreatic cancer (HR, 1.33; 95% CI, 1.02-1.74), compared with low intake. However, no graded dose response was observed, and the association attenuated after restriction to histologically confirmed pancreatic cancers.

    CONCLUSIONS: Based on an analysis of data from the European Prospective Investigation into Nutrition and Cancer cohort, total coffee, decaffeinated coffee, and tea consumption are not related to the risk of pancreatic cancer.

    Matched MeSH terms: Tea/adverse effects*
  3. Panneerselvam P, Morad N, Tan KA
    J Hazard Mater, 2011 Feb 15;186(1):160-8.
    PMID: 21146294 DOI: 10.1016/j.jhazmat.2010.10.102
    The removal of Ni(II) from aqueous solution by magnetic nanoparticles prepared and impregnated onto tea waste (Fe(3)O(4)-TW) from agriculture biomass was investigated. Magnetic nanoparticles (Fe(3)O(4)) were prepared by chemical precipitation of a Fe(2+) and Fe(3+) salts from aqueous solution by ammonia solution. These magnetic nanoparticles of the adsorbent Fe(3)O(4) were characterized by surface area (BET), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Fourier Transform-Infrared Spectroscopy (FT-IR). The effects of various parameters, such as contact time, pH, concentration, adsorbent dosage and temperature were studied. The kinetics followed is first order in nature, and the value of rate constant was found to be 1.90×10(-2) min(-1) at 100 mg L(-1) and 303 K. Removal efficiency decreases from 99 to 87% by increasing the concentration of Ni(II) in solution from 50 to 100 mg L(-1). It was found that the adsorption of Ni(II) increases by increasing temperature from 303 to 323 K and the process is endothermic in nature. The adsorption isotherm data were fitted to Langmuir and Freundlich equation, and the Langmuir adsorption capacity, Q°, was found to be (38.3)mgg(-1). The results also revealed that nanoparticle impregnated onto tea waste from agriculture biomass, can be an attractive option for metal removal from industrial effluent.
    Matched MeSH terms: Tea/chemistry*
  4. Ayatollahi MR, Yahya MY, Karimzadeh A, Nikkhooyifar M, Ayob A
    PMID: 26046269 DOI: 10.1016/j.msec.2015.05.004
    The aim of this study was to investigate the effects of temperature change and immersion in two common beverages on the mechanical and tribological properties for three different types of dental restorative materials. Thermocycling procedure was performed for simulating temperature changes in oral conditions. Black tea and soft drink were considered for beverages. Universal composite, universal nanohybrid composite and universal nanofilled composite, were used as dental materials. The nanoindentation and nanoscratch experiments were utilized to determine the elastic modulus, hardness, plasticity index and wear resistance of the test specimens. The results showed that thermocycling and immersion in each beverage had different effects on the tested dental materials. The mechanical and tribological properties of nanohybrid composite and nanocomposite were less sensitive to temperature change and to immersion in beverages in comparison with those of the conventional dental composite.
    Matched MeSH terms: Carbonated Beverages*; Composite Resins/chemistry*; Dental Materials/chemistry*; Tea*; Temperature*; Nanotechnology; Nanocomposites/chemistry*
  5. Dinh TC, Thi Phuong TN, Minh LB, Minh Thuc VT, Bac ND, Van Tien N, et al.
    Diabetes Metab Syndr, 2019 03 15;13(2):1667-1673.
    PMID: 31336539 DOI: 10.1016/j.dsx.2019.03.021
    Obesity is one of the top global issues, which induces several serious health consequences both physically and mentally, such as type 2 diabetes, cardiovascular diseases, dyslipidemia, eating disorders, depression and stress. However, the effective therapy to prevent and treat obesity and overweight, up to now, cannot be found nowadays. Several methods/medicines namely diet control, energy balance, environmental changes, genetic and stem cell therapies, new drugs/chemicals have been extensively studied to enhance the ability to control bodyweight and prevent obesity. Of all the aforementioned methods, green tea, used as a daily beverage, has shown beneficial impacts for the health, especially its anti-obesity effects. Available evidence shows that green tea can interrupt lipid emulsification, reduce adipocyte differentiation, increase thermogenesis, and reduce food intake, thus green tea improves the systemic metabolism and decreases fat mass. Here, we highlight and sum up the update investigations of anti-obesity effect of green tea as well as discuss the potential application of them for preventing obesity and its related metabolic disorders.
    Matched MeSH terms: Tea/chemistry*
  6. Rawangkan A, Kengkla K, Kanchanasurakit S, Duangjai A, Saokaew S
    Molecules, 2021 Jun 30;26(13).
    PMID: 34209247 DOI: 10.3390/molecules26134014
    Influenza is one of the most serious respiratory viral infections worldwide. Although several studies have reported that green tea catechins (GTCs) might prevent influenza virus infection, this remains controversial. We performed a systematic review and meta-analysis of eight studies with 5,048 participants that examined the effect of GTC administration on influenza prevention. In a random-effects meta-analysis of five RCTs, 884 participants treated with GTCs showed statistically significant effects on the prevention of influenza infection compared to the control group (risk ratio (RR) 0.67, 95%CIs 0.51-0.89, P = 0.005) without evidence of heterogeneity (I2= 0%, P = 0.629). Similarly, in three cohort studies with 2,223 participants treated with GTCs, there were also statistically significant effects (RR 0.52, 95%CIs 0.35-0.77, P = 0.001) with very low evidence of heterogeneity (I2 = 3%, P = 0.358). Additionally, the overall effect in the subgroup analysis of gargling and orally ingested items (taking capsules and drinking) showed a pooled RR of 0.62 (95% CIs 0.49-0.77, P = 0.003) without heterogeneity (I2= 0%, P = 0.554). There were no obvious publication biases (Egger's test (P = 0.138) and Begg's test (P = 0.103)). Our analysis suggests that green tea consumption is effective in the prophylaxis of influenza infections. To confirm the findings before implementation, longitudinal clinical trials with specific doses of green tea consumption are warranted.
    Matched MeSH terms: Tea/chemistry*
  7. Zokti JA, Sham Baharin B, Mohammed AS, Abas F
    Molecules, 2016 Jul 26;21(8).
    PMID: 27472310 DOI: 10.3390/molecules21080940
    Green tea polyphenols have been reported to possess many biological properties. Despite the many potential benefits of green tea extracts, their sensitivity to high temperature, pH and oxygen is a major disadvantage hindering their effective utilization in the food industry. Green tea leaves from the Cameron Highlands Malaysia were extracted using supercritical fluid extraction (SFE). To improve the stability, green tea extracts were encapsulated by spray-drying using different carrier materials including maltodextrin (MD), gum arabic (GA) and chitosan (CTS) and their combinations at different ratios. Encapsulation efficiency, total phenolic content and antioxidant capacity were determined and were found to be in the range of 71.41%-88.04%, 19.32-24.90 (g GAE/100 g), and 29.52%-38.05% respectively. Further analysis of moisture content, water activity, hygroscopicity, bulk density and mean particles size distribution of the microparticles were carried out and the results ranged from; 2.31%-5.11%, 0.28-0.36, 3.22%-4.71%, 0.22-0.28 g/cm³ and 40.43-225.64 µm respectively. The ability of the microparticles to swell in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was determined as 142.00%-188.63% and 207.55%-231.77%, respectively. Release of catechin polyphenol from microparticles in SIF was higher comparable to that of SGF. Storage stability of encapsulated catechin extracts under different temperature conditions was remarkably improved compared to non-encapsulated extract powder. This study showed that total catechin, total phenolic content (TPC) and antioxidant activity did not decrease significantly (p ≥ 0.05) under 4 °C storage conditions. The half-life study results were in the range of 35-60, 34-65 and 231-288 weeks at storage temperatures of 40 °C, 25 °C and 4 °C respectively, therefore, for improved shelf-life stability we recommend that microparticles should be stored at temperatures below 25 °C.
    Matched MeSH terms: Tea/chemistry*
  8. Abdulbaqi HR, Himratul-Aznita WH, Baharuddin NA
    BMC Complement Altern Med, 2016 Dec 01;16(1):493.
    PMID: 27903262
    BACKGROUND: In the author's earlier in vitro investigation, a combination of 0.25 mg/ml green tea and 7.82 mg/ml Salvadora persica L. aqueous extracts was found to exhibit significant synergistic anti-bacterial and anti-adherence effects against primary plaque colonizers biofilm. A clinical trial was needed to support these preliminary in vitro results and to investigate its efficacy as a mouthwash in the control of dental plaque.

    METHODS: A 24 h plaque re-growth, double-blinded, randomized crossover trial was carried out. Participants (n = 14) randomly rinsed with test formulation, 0.12% chlorhexidine (control) and placebo mouthwashes for 24 h. A week before the trial, all participants received scaling, polishing and oral hygiene education. On the trial day, the participants received polishing at baseline and rinsed with 15 ml of randomly allocated mouthwash twice daily without oral hygiene measures. After 24 h, plaque index was scored and then the participants entered a 6-days washout period with regular oral hygiene measures. The same protocol was repeated for the next 2 mouthwashes.

    RESULTS: The results were expressed as mean (±SD) plaque index. The test mouthwash (0.931 ± 0.372) significantly reduced plaque accumulation when compared with placebo (1.440 ± 0.498, p  0.0167).

    CONCLUSIONS: The test mouthwash has an anti-plaque effect for a 24 h period. Longer-term clinical studies are highly encouraged to investigate its anti-plaque effect for longer periods.

    TRIAL REGISTRATION: This study was registered in ClinicalTrials.gov as NCT02624336 in December 3, 2015.

    Matched MeSH terms: Tea*
  9. Chen YW, Lee HV
    Int J Biol Macromol, 2018 Feb;107(Pt A):78-92.
    PMID: 28860064 DOI: 10.1016/j.ijbiomac.2017.08.143
    In the present work, four types of newly chosen municipal solid wastes (Panax ginseng, spent tea residue, waste cotton cloth, and old corrugated cardboard) were studied as the promising sources for nanocellulose, which has efficiently re-engineered the structure of waste products into highly valuable nanocellulose materials. The nanocellulose was produced directly via a facile one-pot oxidative hydrolysis process by using H2O2/Cr(NO3)3 solution as the bleaching agent and hydrolysis medium under acidic condition. The isolated nanocellulose products were well-characterized in terms of chemical composition, product yield, morphological structure and thermal properties. The study has found that the crystallinity index of the obtained nanocellulose products were significantly higher (62.2-83.6%) than that of its starting material due to the successive elimination of lignin, hemicellulose and amorphous regions of cellulose, which were in good agreement with the FTIR analysis. The evidence of the successful production of nanocellulose was given by TEM observation which has revealed the fibril widths were ranging from 15.6 to 46.2nm, with high cellulose content (>90%), depending on the cellulosic origin. The physicochemical properties of processed samples have confirmed that the isolation of high purity nanocellulose materials from different daily spent products is possible. The comparative study can help to provide a deep insight on the possibility of revalorizing the municipal solid wastes into nanocellulose via the simple and versatile one-pot isolation system, which has high potential to be used in commercial applications for sustainable development.
    Matched MeSH terms: Tea/chemistry
  10. Khaleel AK, Shaari RB, Nawi MAA, Al-Yassiri AMH
    Asian Pac J Cancer Prev, 2022 Sep 01;23(9):3195-3199.
    PMID: 36172684 DOI: 10.31557/APJCP.2022.23.9.3195
    OBJECTIVE: Green tea (GT) contains polyphenolic flavonoids, different minerals like magnesium, calcium, and zinc, vitamins, amino acids, carbohydrates, proteins, and others. It has a different health benefit. The aim of the present study was to investigate the effect of intragastric gavage of a high dose GT extract on serum biochemical analysis of magnesium, calcium, and zincin juvenile Wistar albino rats.

    METHODS: Twelve rats were used in the study and divided in to two equal groups. All the animals in the control group were intragastically gavaged by distilled water and continues for ten days, from day 24 to day 34 of age, while the animals in the study group were intragastically gavaged by GT extract (300mg/kg/day) which continues also for ten days from day 24 to day 34 of age. On day 34 of age, and two hours after the last dose, the rats were anaesthetized and blood collection by cardiac puncture was taken.

    RESULTS: The results showed that the intragastric gavage of a high dose of GT extract caused a non-significant increase in serum magnesium, and calcium levels (p>0.05), but a significant increase in zinc serum level was seen(p< 0.05).

    CONCLUSION: GT can cause a significant increase in zinc serum level, and this may explain the significant role of GT in the response to different oxidative stress. It is recommended to measure the Zn serum level in rats after a period longer than two hrs from the time of the last dose of intragastric gavage of GT extract.

    Matched MeSH terms: Tea/chemistry
  11. Brza MA, Aziz SB, Anuar H, Al Hazza MHF
    Int J Mol Sci, 2019 Aug 11;20(16).
    PMID: 31405255 DOI: 10.3390/ijms20163910
    The present work proposed a novel approach for transferring high-risk heavy metals tometal complexes via green chemistry remediation. The method of remediation of heavy metals developed in the present work is a great challenge for global environmental sciences and engineering because it is a totally environmentally friendly procedure in which black tea extract solution is used. The FTIR study indicates that black tea contains enough functional groups (OH and NH), polyphenols and conjugated double bonds. The synthesis of copper complex was confirmed by the UV-vis, XRD and FTIR spectroscopic studies. The XRD and FTIR analysis reveals the formation of complexation between Cu metal complexes and Poly (Vinyl Alcohol) (PVA) host matrix. The study of optical parameters indicates that PVA-based hybrids exhibit a small optical band gap, which is close to inorganic-based materials. It was noted that the absorption edge shifted to lower photon energy. When Cu metal complexes were added to PVA polymer, the refractive index was significantly tuned. The band gap shifts from 6.2 eV to 1.4 eV for PVA incorporated with 45 mL of Cu metal complexes. The nature of the electronic transition in hybrid materials was examined based on the Taucs model, while a close inspection of the optical dielectric loss was also performed in order to estimate the optical band gap. The obtained band gaps of the present work reveal that polymer hybrids with sufficient film-forming capability could be useful to overcome the drawbacks associated with conjugated polymers. Based on the XRD results and band gap values, the structure-property relationships were discussed in detail.
    Matched MeSH terms: Tea/chemistry*
  12. Sen A, Papadimitriou N, Lagiou P, Perez-Cornago A, Travis RC, Key TJ, et al.
    Int J Cancer, 2019 Jan 15;144(2):240-250.
    PMID: 29943826 DOI: 10.1002/ijc.31634
    The epidemiological evidence regarding the association of coffee and tea consumption with prostate cancer risk is inconclusive, and few cohort studies have assessed these associations by disease stage and grade. We examined the associations of coffee (total, caffeinated and decaffeinated) and tea intake with prostate cancer risk in the European Prospective Investigation into Cancer and Nutrition. Among 142,196 men, 7,036 incident prostate cancer cases were diagnosed over 14 years of follow-up. Data on coffee and tea consumption were collected through validated country-specific food questionnaires at baseline. We used Cox proportional hazards regression models to compute hazard ratios (HRs) and 95% confidence intervals (CI). Models were stratified by center and age, and adjusted for anthropometric, lifestyle and dietary factors. Median coffee and tea intake were 375 and 106 mL/day, respectively, but large variations existed by country. Comparing the highest (median of 855 mL/day) versus lowest (median of 103 mL/day) consumers of coffee and tea (450 vs. 12 mL/day) the HRs were 1.02 (95% CI, 0.94-1.09) and 0.98 (95% CI, 0.90-1.07) for risk of total prostate cancer and 0.97 (95% CI, 0.79-1.21) and 0.89 (95% CI, 0.70-1.13) for risk of fatal disease, respectively. No evidence of association was seen for consumption of total, caffeinated or decaffeinated coffee or tea and risk of total prostate cancer or cancer by stage, grade or fatality in this large cohort. Further investigations are needed to clarify whether an association exists by different preparations or by concentrations and constituents of these beverages.
    Matched MeSH terms: Tea*
  13. Zamora-Ros R, Alghamdi MA, Cayssials V, Franceschi S, Almquist M, Hennings J, et al.
    Eur J Nutr, 2019 Dec;58(8):3303-3312.
    PMID: 30535794 DOI: 10.1007/s00394-018-1874-z
    PURPOSE: Coffee and tea constituents have shown several anti-carcinogenic activities in cellular and animal studies, including against thyroid cancer (TC). However, epidemiological evidence is still limited and inconsistent. Therefore, we aimed to investigate this association in a large prospective study.

    METHODS: The study was conducted in the EPIC (European Prospective Investigation into Cancer and Nutrition) cohort, which included 476,108 adult men and women. Coffee and tea intakes were assessed through validated country-specific dietary questionnaires.

    RESULTS: During a mean follow-up of 14 years, 748 first incident differentiated TC cases (including 601 papillary and 109 follicular TC) were identified. Coffee consumption (per 100 mL/day) was not associated either with total differentiated TC risk (HRcalibrated 1.00, 95% CI 0.97-1.04) or with the risk of TC subtypes. Tea consumption (per 100 mL/day) was not associated with the risk of total differentiated TC (HRcalibrated 0.98, 95% CI 0.95-1.02) and papillary tumor (HRcalibrated 0.99, 95% CI 0.95-1.03), whereas an inverse association was found with follicular tumor risk (HRcalibrated 0.90, 95% CI 0.81-0.99), but this association was based on a sub-analysis with a small number of cancer cases.

    CONCLUSIONS: In this large prospective study, coffee and tea consumptions were not associated with TC risk.

    Matched MeSH terms: Tea*
  14. Caini S, Masala G, Saieva C, Kvaskoff M, Savoye I, Sacerdote C, et al.
    Int J Cancer, 2017 May 15;140(10):2246-2255.
    PMID: 28218395 DOI: 10.1002/ijc.30659
    In vitro and animal studies suggest that bioactive constituents of coffee and tea may have anticarcinogenic effects against cutaneous melanoma; however, epidemiological evidence is limited to date. We examined the relationships between coffee (total, caffeinated or decaffeinated) and tea consumption and risk of melanoma in the European Prospective Investigation into Cancer and Nutrition (EPIC). EPIC is a multicentre prospective study that enrolled over 500,000 participants aged 25-70 years from ten European countries in 1992-2000. Information on coffee and tea drinking was collected at baseline using validated country-specific dietary questionnaires. We used adjusted Cox proportional hazards regression models to calculate hazard ratios (HR) and 95% confidence intervals (95% CI) for the associations between coffee and tea consumption and melanoma risk. Overall, 2,712 melanoma cases were identified during a median follow-up of 14.9 years among 476,160 study participants. Consumption of caffeinated coffee was inversely associated with melanoma risk among men (HR for highest quartile of consumption vs. non-consumers 0.31, 95% CI 0.14-0.69) but not among women (HR 0.96, 95% CI 0.62-1.47). There were no statistically significant associations between consumption of decaffeinated coffee or tea and the risk of melanoma among both men and women. The consumption of caffeinated coffee was inversely associated with melanoma risk among men in this large cohort study. Further investigations are warranted to confirm our findings and clarify the possible role of caffeine and other coffee compounds in reducing the risk of melanoma.
    Matched MeSH terms: Tea*
  15. Hajiaghaalipour F, Sanusi J, Kanthimathi MS
    J Food Sci, 2016 Jan;81(1):H246-54.
    PMID: 26613545 DOI: 10.1111/1750-3841.13149
    Tea (Camellia sinensis) is the most highly consumed beverage in the world next to water. The common way of preparation is steeping in hot water which is varying for different type of tea. We investigated the antioxidant properties of 6 type of tea leaves under different time and temperatures of extraction method used. In general, all samples tested in this study demonstrated high levels of antioxidant capacity and antioxidant activity. The results indicate that the antioxidants activity is significantly affected by time and temperature of steeping and the highest was depending on the variety. White state values, green and black teas showed different levels of antioxidants under different extraction conditions. Overall, the highest activity for white tea was in prolonged hot and in some assays prolonged hot and cold extracts, whereas for green tea the highest activity observed in prolonged cold steeping while, for black tea was in short hot water infusion. The results of this study showed the antioxidant capacity of white and green tea was greater than black tea.
    Matched MeSH terms: Tea
  16. Hajeb P, Jinap S
    Crit Rev Food Sci Nutr, 2015;55(6):778-91.
    PMID: 24915349 DOI: 10.1080/10408398.2012.678422
    Umami, the fifth basic taste, is the inimitable taste of Asian foods. Several traditional and locally prepared foods and condiments of Asia are rich in umami. In this part of world, umami is found in fermented animal-based products such as fermented and dried seafood, and plant-based products from beans and grains, dry and fresh mushrooms, and tea. In Southeast Asia, the most preferred seasonings containing umami are fish and seafood sauces, and also soybean sauces. In the East Asian region, soybean sauces are the main source of umami substance in the routine cooking. In Japan, the material used to obtain umami in dashi, the stock added to almost every Japanese soups and boiled dishes, is konbu or dried bonito. This review introduces foods and seasonings containing naturally high amount of umami substances of both animal and plant sources from different countries in Asia.
    Matched MeSH terms: Tea
  17. Hossain MA, Islam JMM, Hoque MM, Nahar S, Khan MA
    Heliyon, 2021 Jan;7(1):e05881.
    PMID: 33458447 DOI: 10.1016/j.heliyon.2020.e05881
    Sodium alginate oligomers were tested for tea plant growth promoter and anti-fungal agent in this experiment. Sodium alginate solutions were irradiated by Co-60 gamma radiation with different radiation doses to produce the oligomers. Irradiated solutions were then diluted into 150, 300 and 500 ppm prior to foliar application. Solutions were applied through foliar spraying at 7 days interval and the best response of tea plants in terms of various attributes were recorded. Tea buds were collected in 10 days of interval and the growth attributes like- total number of buds, fresh weight of buds, average leaf area and weight per bud, weight of made tea etc. were calculated. The experiment was continued up to 12 weeks and the attributes were averaged to get results per plucking. 12 kGy radiation doses along with 300ppm solution showed the best results and about 36% increase in productivity was found based on the fresh weight of buds. Total fungal count in tea leaves was also found to be reduced greatly. Based on the present study, irradiated sodium alginate could be used as safe and environmentally friendly agent to increase tea production.
    Matched MeSH terms: Tea
  18. Ong P, Chen S, Tsai CY, Chuang YK
    PMID: 33744842 DOI: 10.1016/j.saa.2021.119657
    In this study, near-infrared (NIR) spectroscopy was exploited for non-destructive determination of theanine content of oolong tea. The NIR spectral data (400-2500 nm) were correlated with the theanine level of 161 tea samples using partial least squares regression (PLSR) with different wavelengths selection methods, including the regression coefficient-based selection, uninformative variable elimination, variable importance in projection, selectivity ratio and flower pollination algorithm (FPA). The potential of using the FPA to select the discriminative wavelengths for PLSR was examined for the first time. The analysis showed that the PLSR with FPA method achieved better predictive results than the PLSR with full spectrum (PLSR-full). The developed simplified model using on FPA based on 12 latent variables and 89 selected wavelengths produced R-squared (R2) value and root mean squared error (RMSE) of 0.9542, 0.8794 and 0.2045, 0.3219 for calibration and prediction, respectively. For PLSR-full, the R2 values of 0.9068, 0.8412 and RMSEs of 0.2916, 0.3693, were achieved for calibration and prediction. Also, the optimized model using FPA outperformed other wavelengths selection methods considered in this study. The obtained results indicated the feasibility of FPA to improve the predictability of the PLSR and reduce the model complexity. The nonlinear regression models of support vector machine regression and Gaussian process regression (GPR) were further utilized to evaluate the superiority of using the FPA in the wavelength selection. The results demonstrated that utilizing the wavelength selection method of FPA and nonlinear regression model of GPR could improve the predictive performance.
    Matched MeSH terms: Tea
  19. Rabeta, M.S., Lai, S.Y.
    MyJurnal
    Antioxidant capacity of Ocimum tenuiflorum L. or ‘ruku’ were determined in this study. Fresh
    leaves of Ocimum tenuiflorum was subjected to freeze drying, vacuum drying and processed
    into fermented and unfermented tea. The samples were extracted using distilled water and the
    total phenolics, total flavonoids, condensed tannin content, anthocyanins and total antioxidant
    capacity (TAC) were assessed, measured with ferric reducing antioxidant power (FRAP)
    and 1,1-diphenyl-1-picrylhydrazyl radical scavenging capacity (DPPH) assays. The results
    showed that drying the fresh leaves of Ocimum tenuiflorum and processing them into tea leaves
    significantly increase (P < 0.05) the antioxidant capacity, total phenolic content, total flavonoid
    content, and condensed tannin content. However, anthocyanins content showed reduction
    after drying. In the present study, it can be concluded that the vacuum drying method seem
    to produce a product with higher quality of antioxidant properties than freeze drying. Hence,
    vacuum drying can be used to replace freeze drying as it is also cheaper than freeze drying.
    Matched MeSH terms: Tea
  20. Fathilah, A.R., Rahim, Z.H.A.
    Ann Dent, 2008;15(1):1-4.
    MyJurnal
    In this study, the effect of beverages (Coke TM, Sprite™, Ribena™, Chrysanthemum tea and mineral water) on the demineralisation of the enamel surface was investigated. Demineralisation was determined by the rate of calcium released from the enamel surface on exposure to the beverages. Calcium was determined using the EDTA titration method. The pH of these beverages was measured using a pH meter and found to be in the acidic range (2.43 to 5.79) while mineral water which served as a control has a pH of 7.00. Ii was found that the rate of calcium released from Coke™(0.76 J..lg/min) showed a significant mean difference from Sprite™ (0.38 J..lg/min), Chrysanthemum tea (0.10 J..lg/min) and mineral water (0.00 J..lg/min)at p< .05, but was however not significantly different from Ribena™. Likewise, Chrysanthemum tea and mineral water also showed statistically no significant mean difference in the released of calcium during the study period. The results obtained in this study indicated that beverages with low pH may pose detrimental effect on the enamel surface which could have clinical implication, especially in people with salivary gland dysfunction or low salivary flow.
    Matched MeSH terms: Tea
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