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To reveal the chemical composition profile of Camellia ptilophylla, a rare natural low-caffeine tea variety, non-targeted metabolomics based on high-resolution mass spectrometry (HR-MS) was employed to identify the metabolite composition of green tea and black tea from C. ptilophylla and C. sinensis var. assamica. Additionally, the metabolomic differences between the two types of tea and between the two tea varieties were analyzed using principal component analysis (PCA), cluster analysis (CA), and orthogonal partial least squares-discriminant analysis (OPLS-DA). Differential metabolites were identified using standards and database. A total of 152 metabolites were identified in the four tea samples, the major ones being flavonoids (42%). These metabolites were categorized into four clusters. The metabolomic difference between C. ptilophylla and C. sinensis var. assamica was more pronounced than that between green and black teas. Notably, 24 metabolites including theasinensin B isomers, theobromine and 14 flavonoids such as tetrahydroxyxanthone and epitheaflagallin 3-O-gallate, which were more abundant in C. ptilophylla green tea than in C. sinensis green tea, were considered as the characteristic metabolites of C. ptilophylla green tea. In black tea from C. ptilophylla, 40 characteristic metabolites were identified including 25 flavonoids such as gallocatechin-3,5-digallate, tetrahydroxyxanthone and dihydromyricetin; 4 tannins such as theaflavin 3-gallate, theasinensin A isomers and theaflavin 3,3’-digallate; and theobromine. This study provides a reference for further exploration of bioactive compounds in C. ptilophylla.

This study analyzed the possibility of using plant-originated waste materials (black and green tea dust) as functional polyethylene fillers. The dependence between the size of the filler particles and their antioxidant potential is discussed. Six fractions were selected: below 50 µm, 50–100 µm, 100–200 µm, 200–400 µm, 400–630 µm and 630–800 µm. Significant differences between the effect of particle size and the antioxidant properties of black and green tea were found using the extraction method to analyze antioxidant activity (DPPH method) and total phenolic content (Folin-Ciocalteu method), suggesting a higher potential for using green tea as a filler with antioxidant properties, as well as the benefits of finer active filler distribution. Biomass waste fillers were mixed with low-density polyethylene LDPE SEB 853 I'm Green®, Braskem. Those samples were oxidized at 100 °C for 5 and 15 days to investigate the radical scavenging properties of fillers in composites. Fourier transform infrared spectroscopic studies show that the addition of both types of filler prevents the thermo-oxidation of polyethylene for 5 days. After 15 days, all samples except the BTW 400–630 and 630–800 µm exhibited oxidation. The mechanical properties of the LDPE and its' composites were tested, and we noted an increased brittleness of neat LDPE after thermal oxidation. The addition of black tea particles above 100 µm in size prevents this behavior. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the influence of different tea extract substrates on the biological activities of kombucha beverages was investigated. The variations in bioactive compounds such as polyphenols and flavonoids and their potential health-promoting properties represented by antioxidant activity were analyzed. Our findings shed light on the diverse effects of tea substrates on the production of bioactive compounds and their subsequent impact on the biological activities of kombucha, providing valuable insights for optimizing kombucha production and its potential health benefits. The new tea substrate for kombucha, called horchata, an Ecuadorian tea, shows a similar trend but with a low content of phenolics (4.511 ± 0.111 mg gallic acid equivalent (GAE)/g dry weight (DW)) and flavonoids (1.902 ± 0.0455 mg quercetin equivalent (QE)/g DW), and antioxidant activity (DPPH—33.569 ± 1.377 µmol TROLOX/g DW, ABTS—20.898 ± 2.709 µmol TROLOX/g DW, FRAP—34.456 ± 2.0618 Fe2+ mM/100 g DW compared to black and green tea as substrates for kombucha. Through HPLC-DAD, several polyphenols were registered, and homovanillic acid showed the highest concentration (74.45 mg/100 g). Horchata kombucha scored the highest in sweetness and smell, reflecting its popularity among the tasters, making it a valuable candidate as a kombucha substrate. [ABSTRACT FROM AUTHOR]

Gas chromatography–ion mobility spectrometry (GC-IMS) is a smart method that has been applied to determine the volatile compounds in Chinese teas, but its use in comparing the volatile compounds of different types of tea has not been mentioned. In this study, the volatile compounds found in four types of samples (green, yellow, white, and black teas) made with fresh leaves of Camellia sinensis (L.) Kuntze 'Zhongcha 111' were analyzed using GC-IMS. The results showed that 93 volatile compounds were identified from our tea samples and that the average volume of aldehydes was higher than that for other compounds, especially in white tea. The different samples were successfully categorized using multivariate statistical analysis. Using partial least squares discriminant analysis (PLS-DA), we found 15 key compounds, including four differential components: (E)-2-hexenal, 2-furanmethanethio, 2-hexanol, and 1-octene. There were 29 common components, and their total content reached 386.0 μg/g. Moreover, the 3-methyl-2-butenal and dimethyl disulfide detected in the four samples were also differential compounds, varying according to the manufacturing technology. Thus, this study demonstrates that different types of teas can be discriminated easily using GC-IMS and that this is helpful to shorten the time for improving tea quality and developing new products. [ABSTRACT FROM AUTHOR]

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. Monosaccharide composition revealed that Alduronic acid (77.8 mol%) considerably predominated in the fraction. TP conformation analysis indicated that three components in TPs were all typical of high-branching structures. Oral administration of TPs could effectively alleviate fasting blood glucose in type 2 diabetes mellitus (T2D) mice, with the values 23.6 ± 1.42, 19.6 ± 2.25, and 16.4 ± 2.07 mmol/L in the 200, 400, and 800 mg/kg·BW groups, respectively. Among these TPs groups, the 800 mg/kg·BW groups significantly decreased by 37.88% when compared with the T2D+water group (p < 0.05). Further studies demonstrated that TP treatment upregulated the expression of p-Akt/p-PI3K (p < 0.001). Additionally, TP treatment significantly promoted glucose transporter protein 2 (GLUT2) translocation in the liver (p < 0.001). These findings suggest that TPs from black tea protect against T2D by activating PI3K/Akt/GLUT2 signaling and might serve as a novel therapeutic candidate for T2D. [ABSTRACT FROM AUTHOR]

Daily consumption of various teas is a popular tradition in many countries especially in Turkey and although it shouldn’t be in tea, carbonate can be added to obtain more brew from teas especially in local coffeehouses. In this study, the effect of carbonate addition on the essential element concentrations of some black teas (black, earl grey and green tea), herbal teas (fennel, mint and sage tea) and fruit teas (apple, lemon and rosehip) is analysed by inductively coupled plasma optical emission spectrometer (ICP-OES), after the infusion process of tea brewing with carbonate. Afterwards, the total element contents of the tea grains in are determined by again ICP-OES prior to microwave digestion process. Considering the data obtained from the experiments, carbonate addition increased or decreased some elements with respect to the tea types. According to the results obtained after the microwave digestion method, although the major elements in all types of teas are found as Ca, K, P, Mg and Mn, which do not reach 2% brewing from the tea grains, carbonated infusion is not recommended due to its increasing effect on the concentration of the major elements contained in teas. [ABSTRACT FROM AUTHOR]

SARS-CoV-2 infects the oral mucosa and is shed in salivary fluids. Traditionally, tea has been used by various cultures to treat respiratory ailments. The objective of this study was to identify commercially available teas that can rapidly inactivate infectious SARS-CoV-2 in saliva. Initially, tea (n = 24) was prepared as 40 mg/mL infusions and incubated with SARS-CoV-2 resuspended in water, for 5 min at 37 °C. Then, five teas that showed >3 log reduction in virus infectivity were further investigated at 40 and 10 mg/mL infusions for 60 and 10 s contact time with SARS-CoV-2 resuspended in saliva. Tea polyphenols were measured using the Folin-Ciocalteu assay. SARS-CoV-2 infectivity was quantified on Vero-E6 cell line using TCID50 assay. At 10 mg/mL infusion, black tea showed the highest reduction (3 log, i.e., 99.9%) of infectious SARS-CoV-2 within 10 s. Green, mint medley, eucalyptus-mint, and raspberry zinger teas showed similar inactivation of SARS-CoV-2 (1.5–2 log, i.e., 96–99% reduction). At 40 mg/mL infusions, all five teas showed >3 log reduction in virus infectivity within 10 s. Tea polyphenol but not pH was significantly correlated to virus reduction. Time-of-addition assay revealed that the five teas displayed preventive effects (0.5–1 log, i.e., 68–90% reduction) against SARS-CoV-2 infection of Vero-E6 cells as well as during post-virus infection (1.2–1.9 log, i.e., 94–98%). However, the highest inhibitory effect was observed when the teas were added at the time of virus infection (2–3 log, i.e., 99–99.9%). Our results provide insights into a rapid at-home intervention (tea drinking or gargling) to reduce infectious SARS-CoV-2 load in the oral cavity which might also mitigate infection of the oral mucosa. [ABSTRACT FROM AUTHOR]

Hypertension is a serious condition that affects both industrialized and developing nations’ public health. It is an important medical condition that can raise the chance of developing heart, brain, kidney, and other problems. Objective: • To evaluate the effect of green tea and black tea on blood pressure (BP). • To compare the levels of BP among black tea- and green tea-consuming hypertensive patients. • To find out the association between effects of green tea- and black tea-consuming hypertensive patients with selected demographic variables. Methodology: A quasiexperimental research design with the purposive sampling technique was adopted to conduct a study among 60 hypertensive patients. Thirty patients consume black tea, and 30 consume green tea. Data were gathered by structured questionnaires using demographic variables and biological parameters. Result: The calculated Student independent ‘t’ test value of t = 3.216 in the post-test shows that there was a statistically significant difference between the post-test levels of systolic BP between the two groups, which was statistically significant at P < 0.01 level. The calculated student independent‘t’ test value of t = 2.986 in the post-test shows that there was a statistically significant difference between the post-test levels of diastolic BP between the two groups, which was statistically significant at P < 0.01 level. Conclusion: Green tea was found to be more effective than black tea in reducing the level of hypertension among the hypertensive clients.

The following study analyzed the potential of Near Infrared Spectroscopy (NIRS) to predict the metal composition (Al, Pb, As, Hg and Cu) of tea and for establishing discriminant models for pure teas (green, red, and black) and their different blends. A total of 322 samples of pure black, red, and green teas and binary blends were analyzed. The results showed that pure red teas had the highest content of As and Pb, green teas were the only ones containing Hg, and black teas showed higher levels of Cu. NIRS allowed to predict the content of Al, Pb, As, Hg, and Cu with ratio performance deviation values > 3 for all of them. Additionally, it was possible to discriminate pure samples from their respective blends with an accuracy of 98.3% in calibration and 92.3% in validation. However, when the samples were discriminated according to the percentage of blending (>95%, 95–85%, 85–75%, or 75–50% of pure tea) 100% of the samples of 10 out of 12 groups were correctly classified in calibration, but only the groups with a level of pure tea of >95% showed 100% of the samples as being correctly classified as to validation. [ABSTRACT FROM AUTHOR]

After water, tea is the most popular drink in the world, and its relationship with heart diseases, stroke, and cancer has been always considered by researchers. The aim of the present study is to assess the relationship between green tea or black tea consumption and stroke risk using systematic review and meta-analysis methods. To assess the required resources, PubMed, Scopus, Web of science, Cochrane electronic databases, and the Google Scholar search engine were searched. To assess the study heterogeneity, I2 indexes was used. Data were analyzed using STATA 14 software. P

‘Ming guan’ is a new excellent albino tea variety bred from the descendants of Bai jiguan. In order to explore the quality difference of Ming guan multi tea processing, the fresh leaves of Ming guan were used as raw materials to make the corresponding tea types according to the processing methods of green tea, black tea and white tea, and sensory quality evaluation, aroma and taste analysis were conducted. The results showed that the aroma of Ming guan green tea was tender, floral and fruity, with a mellow taste, the aroma of Ming guan black tea was sweet, floral, with a sweet taste, the aroma of Ming guan white tea was millets, floral, with a fresh taste, and the different processes of Ming guan tea had their own unique floral characteristics. Among the aroma components of Ming guan green tea, terpene aroma components with floral aroma were relatively more abundant, followed by ester aroma components with fruit aroma, which played an important role in the formation of the aroma of Ming guan green tea. The representative aroma components of Ming guan green tea were leaf alcohol ester of foliol caproate, 3-hexenyl caproate, 2-hexenyl caproate, nerolidol, leaf alcohol ester of butyric acid, olivetol and α-farnesene, the representative components of which were mainly esters with fruity aroma and alcohols with floral and fruity aroma, creating the characteristic of Ming guan green tea floral and fruity varieties. The representative components of Ming guan black tea were dihydrolinalool, α-cephalene, β-Ionone, γ-cadinene, methyl hexadecanoic acid and benzaldehyde, which were mainly terpenes and alcohols with floral and sweet aromas, contributing to the floral and sweet aromatic characteristics of Ming guan black tea. The representative components of Ming guan white tea were geraniol, myrcene, 3-carene, linalyl acetate and linalool, and the representative components are mainly alcohols and terpenes with floral aroma. The non-volatile components of Ming guan green tea, Ming guan black tea and Ming guan white tea vary greatly overall. The content of catechins, anthocyanins, some flavonols and flavonoid glycosides (quercetin-3-O-galactoside, quercetin-3-O-glucoside, quercetin-3-O-glucoside 7-O-rhamnoside, etc.) in Ming guan green tea was generally higher than that in Ming guan black tea and Ming guan white tea. The contents of theaflavins, phenolic acids, a few flavonol and flavonoid glycoside compounds (vitexin-2-O-galactoside, vitexin-2-O-rhamnoside, apigenin-6,8-di-C-glucoside, apigenin-6-C-glucoside, etc.) and some amino acid compounds (L-phenylalanine, L-tryptophan, L-isoleucine, L-valine, L-aspartic acid) in Ming guan black tea were higher than those in Ming guan green tea and Ming guan white tea.The content of some amino acid compounds (L-arginine, L-glutamine, L-lysine, L-histidine, L-tyrosine) in Ming guan white tea was higher than that in Ming guan green tea and Ming guan black tea, which may be affected by different processing technologies. This study could provide a theoretical basis for a comprehensive understanding of the chemical basis and quality differences of Ming guan green tea, Ming guan black tea and Ming guan white tea.

Researchers have recently been interested in employing nanoparticles (NPs) obtained from herbal extracts through green synthesis for various applications. This study investigated the detoxification of aflatoxins, which are toxic substances produced by molds Aspergillus flavus and Aspergillus parasiticus. The present work examined the levels of aflatoxins in hazelnut and peanut puree. Turkish black tea extract (BTE), Turkish green tea extract (GTE), green synthesized black tea-based iron oxide nanoparticles (BTFeONPs), and green tea-based iron oxide nanoparticles (GTFeONPs) were produced for aflatoxin removal. Characterizations and various antioxidant and antimicrobial activities of the tea extracts and iron oxide nanoparticles (FeONPs) were investigated. The aflatoxin levels of hazelnut puree used for this study were 6.57 ± 0.06 µg/kg for aflatoxin B1 and 13.03 ± 0.16 µg/kg for total aflatoxin, whereas the aflatoxin levels of (AFLB1) peanut puree were 7.79 ± 0.15 µg/kg for AFLB1 and 15.21 ± 0.12 µg/kg for total aflatoxin. Using soluble BTE resulted in a 40 to 50% decrease in aflatoxin levels in hazelnut and peanut purees, while soluble GTE led to a 30 to 45% decrease. Meanwhile, using BTFeONPs and GTFeONPs resulted in a 33 to 48% and 40 to 50% decrease, respectively, in aflatoxin levels in hazelnut and peanut purees.

People consume black tea and green tea with certain characteristics in accordance with their wishes and needs. The rating of the product shows the attitude of the people towards a product as well and also reflects their preferences in spending and consuming a product. The aim of this research is to analyse the characteristics of black tea and green tea consumers, to analyse green tea and black tea consumption patterns, and to analyse the components that consideration the preferences of black tea and green tea consumers. Research was held in Southern Purwokerto Sub-district, started from February until March 2020. The number of samples for each black tea and green tea consumers are 50 respondents taken by using multistage random sampling. The analysis which is used is Descriptive Analysis and Factor Analysis. The results show that characteristics of black tea and green tea consumers are women in various range of age. Additionally, married consumers buy black tea and green tea to be consumed together with their family. Perspective of consumption patterns black tea and green tea once a day in the morning breakfast for black tea and in other activities for green tea. The consumption number for family is an average of 50g/months. There are three main components that form preferences on green tea, those are: personality from the tea, identity, and the image of the product. On the other hand, main components that form preferences on black tea are two, those are: image, and identity product.

Researchers have recently been interested in employing nanoparticles (NPs) obtained from herbal extracts through green synthesis for various applications. This study investigated the detoxification of aflatoxins, which are toxic substances produced by molds Aspergillus flavus and Aspergillus parasiticus. The present work examined the levels of aflatoxins in hazelnut and peanut puree. Turkish black tea extract (BTE), Turkish green tea extract (GTE), green synthesized black tea-based iron oxide nanoparticles (BTFeONPs), and green tea-based iron oxide nanoparticles (GTFeONPs) were produced for aflatoxin removal. Characterizations and various antioxidant and antimicrobial activities of the tea extracts and iron oxide nanoparticles (FeONPs) were investigated. The aflatoxin levels of hazelnut puree used for this study were 6.57 ± 0.06 µg/kg for aflatoxin B1 and 13.03 ± 0.16 µg/kg for total aflatoxin, whereas the aflatoxin levels of (AFLB1) peanut puree were 7.79 ± 0.15 µg/kg for AFLB1 and 15.21 ± 0.12 µg/kg for total aflatoxin. Using soluble BTE resulted in a 40 to 50% decrease in aflatoxin levels in hazelnut and peanut purees, while soluble GTE led to a 30 to 45% decrease. Meanwhile, using BTFeONPs and GTFeONPs resulted in a 33 to 48% and 40 to 50% decrease, respectively, in aflatoxin levels in hazelnut and peanut purees. [ABSTRACT FROM AUTHOR]

Kombucha is a fermented tea drink produced by a symbiotic culture of bacteria and yeast, known as SCOBY. Its base has traditionally been black tea, which has been recognized for its health-promoting properties, particularly its antioxidant activity based on its high content of pol-yphenolic compounds. A number of previous studies have demonstrated the equally favourable biochemical and phytochemical composition of green tea. The aim of this study was to analyse and compare the basic biochemical composition, microbiological composition and antioxidant properties of black and green tea-based Kombucha. The green tea-based Kombucha showed a quantitatively more abundant microbial composition (Lactic Acid Bacteria, Acetobacter sp., Yeast), a higher reducing potential (FRAP—4326.58 Fe(II)µM/L) and a higher content of total polyphenols (23.84 mg GAE/100 mL, reducing sugars (3212.00 mg/100 mL) as well as free amino acids (849.00 mg GLY/mL). Kombucha made from black tea, on the other hand, showed a higher anti-oxidant potential (1.17 Trolox (mM) TEAC), neutralising the DPPH radical at 94.33% and ABTS at 97.74%. It also had a higher level of acetic acid (0.08 g/100 mL). Green tea kombucha had a higher scavenging capacity of 90.6% for superoxide radical (O2−) and 69.28% for hydroxyl radical (·OH) than black tea kombucha. In the present study, both kombucha drinks tested were shown to be source of potent antioxidants. In addition, green tea, as a kombucha base, has proven to be as beneficial a raw material that will provide full nutritional and health-promoting values as traditional kombucha. [ABSTRACT FROM AUTHOR]

Gas chromatography–ion mobility spectrometry (GC-IMS) is a smart method that has been applied to determine the volatile compounds in Chinese teas, but its use in comparing the volatile compounds of different types of tea has not been mentioned. In this study, the volatile compounds found in four types of samples (green, yellow, white, and black teas) made with fresh leaves of Camellia sinensis (L.) Kuntze ‘Zhongcha 111’ were analyzed using GC-IMS. The results showed that 93 volatile compounds were identified from our tea samples and that the average volume of aldehydes was higher than that for other compounds, especially in white tea. The different samples were successfully categorized using multivariate statistical analysis. Using partial least squares discriminant analysis (PLS-DA), we found 15 key compounds, including four differential components: (E)-2-hexenal, 2-furanmethanethio, 2-hexanol, and 1-octene. There were 29 common components, and their total content reached 386.0 μg/g. Moreover, the 3-methyl-2-butenal and dimethyl disulfide detected in the four samples were also differential compounds, varying according to the manufacturing technology. Thus, this study demonstrates that different types of teas can be discriminated easily using GC-IMS and that this is helpful to shorten the time for improving tea quality and developing new products.

In this study, the influence of different tea extract substrates on the biological activities of kombucha beverages was investigated. The variations in bioactive compounds such as polyphenols and flavonoids and their potential health-promoting properties represented by antioxidant activity were analyzed. Our findings shed light on the diverse effects of tea substrates on the production of bioactive compounds and their subsequent impact on the biological activities of kombucha, providing valuable insights for optimizing kombucha production and its potential health benefits. The new tea substrate for kombucha, called horchata, an Ecuadorian tea, shows a similar trend but with a low content of phenolics (4.511 ± 0.111 mg gallic acid equivalent (GAE)/g dry weight (DW)) and flavonoids (1.902 ± 0.0455 mg quercetin equivalent (QE)/g DW), and antioxidant activity (DPPH—33.569 ± 1.377 µmol TROLOX/g DW, ABTS—20.898 ± 2.709 µmol TROLOX/g DW, FRAP—34.456 ± 2.0618 Fe2+ mM/100 g DW compared to black and green tea as substrates for kombucha. Through HPLC-DAD, several polyphenols were registered, and homovanillic acid showed the highest concentration (74.45 mg/100 g). Horchata kombucha scored the highest in sweetness and smell, reflecting its popularity among the tasters, making it a valuable candidate as a kombucha substrate.

Tea (Camellia sinensis L.) is a high valued beverage worldwide since ancient times; more than three billion cups of tea are consumed each day. Leaf extracts of the plant are used for food preservation, cosmetics, and medicinal purposes. Nevertheless, tea contaminated with mycotoxins poses a serious health threat to humans. Mycotoxin production by tea fungi is induced by a variety of factors, including poor processing methods and environmental factors such as high temperature and humidity. This review summarizes the studies published to date on mycotoxin prevalence, toxicity, the effects of climate change on mycotoxin production, and the methods used to detect and decontaminate tea mycotoxins. While many investigations in this domain have been carried out on the prevalence of aflatoxins and ochratoxins in black, green, pu-erh, and herbal teas, much less information is available on zearalenone, fumonisins, and Alternaria toxins. Mycotoxins in teas were detected using several methods; the most commonly used being the High-Performance Liquid Chromatography (HPLC) with fluorescence detection, followed by HPLC with tandem mass spectrometry, gas chromatography and enzyme-linked immunosorbent assay. Further, mycotoxins decontamination methods for teas included physical, chemical, and biological methods, with physical methods being most prevalent. Finally, research gaps and future directions have also been discussed. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Continuing caution is required against the potential emergence of SARS-CoV-2 novel mutants that could pose the next global health and socioeconomical threats. If virus in saliva can be inactivated by a beverage, such a beverage may be useful because the saliva of infected persons is the major origin of droplets and aerosols that mediate human-to-human viral transmission. We previously reported that SARS-CoV-2 was significantly inactivated by treatment in vitro with tea including green tea and black tea. Catechins and its derived compounds galloylated theaflavins (gTFs) bound to the receptor-binding domain (RBD) of the S-protein and blocked interaction between RBD and ACE2. Black tea is often consumed with sugar, milk, lemon juice, etc., and it remains unclarified whether these ingredients may influence the anti-SARS-CoV-2 effect of black tea. Here, we examined the effect of black tea on Omicron subvariants in the presence of these ingredients. The infectivity of Omicron subvariants was decreased to 1/100 or lower after treatment with black tea for 10 s. One or two teaspoons of milk (4~8 mL) completely blocked the anti-viral effect of a cup of tea (125 mL), whereas an addition of sugar or lemon juice failed to do so. The suppressive effect was dose-dependently exerted by milk casein but not whey proteins. gTFs were coprecipitated with casein after acidification of milk-supplemented black tea, strongly suggesting the binding of gTFs to casein. The present study demonstrates for the first time that an addition of milk cancelled the anti-SARS-CoV-2 effect of black tea due to binding of casein to gTFs. [ABSTRACT FROM AUTHOR]

Since its first publication in 2013, the Tea Bag Index (TBI) has attained widespread ecological application, generating scientific data on stabilization and turnover of organic matter in soils. As a result of manufacturing changes (net structure, net material, tea varieties) in the past years, a critical examination of alternative tea bag products is necessary. The present study for the first time generated decomposition data on a wide range of potential alternative tea brands (four brands tested) and varieties (rooibos [RB], green [GT], black [BT], and peppermint tea [PM]). They were tested in both a laboratory and a field experiment lasting 90 days. Under controlled laboratory conditions GT, BT, and PM corresponded well to the kinetic assumptions of an asymptote model of the TBI, but RB did not. In the field experiment, the tea mass remaining after 90 days was determined for all tea bags across different land uses (arable land, grassland, and forest). BT imitated the decomposition behavior of Lipton's original GT even better than any of the GT tested. The finer structure of Lipton's new tea bag nets did not negatively affect the precision of resultant remaining masses and thus can be recommended for future studies. In conclusion, alternative tea bags should be explored across brands as well as varieties. Based on our findings, we proposed an update of the TBI, which is based on the readily feasible modeling of the decomposition curve. Crucial is the combined consideration of both multiple tea varieties and incubation intervals of different durations. [ABSTRACT FROM AUTHOR]

Abstract Background There is no study in the world on the relationship between consuming black and green tea as beverages containing polyphenols and the risk of MS. This study aimed to determine the association between the consumption of green and black tea, coffee, non-alcoholic beer, milk, fruit juices and carbonated beverages with the risk of MS. Methods and materials This case–control study was performed on 150 patients with MS and 300 healthy individuals as a control group among patients who were referred to the ophthalmology ward of a referral hospital in Ahvaz with the groups matching for age. The data collection tool was a researcher-made questionnaire including demographic information and beverage consumption. Analysis was performed using univariate and multiple logistic regression models. Results The mean age of patients at the time of diagnosis was 38.55 ± 8.88 years. The results showed that drinking milk (OR = 5.46), natural juice (OR = 2.49), and carbonated beverages (OR = 16.17) were associated with an increased chance of developing MS. However, drinking non-alcoholic beer (OR = 0.48), black tea (OR = 0.20), green tea (OR = 0.29) and coffee (OR = 0.07) were associated with a reduced chance of developing MS. Conclusion The results show that drinking black and green tea, non-alcoholic beer, and coffee are associated with a decrease in the chance of developing MS. The results of this study can be used to design interventional research and to change people's lifestyles to prevent MS.

Tea waste products were thrown out without any intention to utilize their potential benefits. This waste will help to improve industries to absorb rhodamine-B (RhB) dye pollutants currently used by various industries. This study evaluated the application of tea waste products to remove Rh-B from aqueous systems by investigating adsorption kinetics in a batch process. The ability and mechanism of Indonesian black and green tea in RhB adsorption were determined by optimizing temperature, pH, contact time, and concentration of dye solution. Achievement of equilibrium attained at 40 min for black tea (BT) and green tea (GT). Subsequently, the adsorption capacity reached optimum at 80 and 70 °C for GT, and the maximum adsorption capacities for BT and GT were 22 and 47 mg/g, respectively, at pH 2.5. The absorption of RhB in both bio-sorbents was an exothermic process that well fit the Langmuir model and a pseudo-second-order reaction. The presented R2 values from the Langmuir isotherm are 0.9967 (BT) and 0.9979 (GT). The separation factor was determined as 0.026 (BT) and 0.055 (GT). Thermodynamic studies were carried out to calculate free energy, enthalpy, and entropy changes. The result showed that the removal study of BT and GT is 59.06 and 60.25%, respectively, using 10% acetic acid. Study comparisons were carried out on both teas with other bio-sorbents for more improvement. These results show that tea waste products can be used as alternative adsorbents to absorb RhB from wastewater.

Given the substantial world coffee production, tons of coffee fruit cascara rich in bioactive compounds are discarded annually. Using this by-product to produce potentially healthy and acceptable foods is a sustainable practice that aggregates value to coffee production and may help improve people's lives. This study aimed to elaborate kombuchas from coffee cascara tea, evaluate their microbial profile, and monitor the changes in the volatile profile during fermentation, together with sensory attributes and acceptance by consumers from Rio de Janeiro (n = 113). Arabica coffee cascaras from Brazil and Nicaragua were used to make infusions, to which black tea kombucha, a Symbiotic Culture of Bacteria and Yeasts (SCOBY), and sucrose were added. Fermentation of plain black tea kombucha was also monitored for comparison. The volatile profile was analyzed after 0, 3, 6, and 9 days of fermentation via headspace solid phase microextraction GC-MS. A total of 81 compounds were identified considering all beverages, 59 in coffee cascara kombuchas and 59 in the black tea kombucha, with 37 common compounds for both. An increase mainly in acids and esters occurred during fermentation. Despite the similarity to black tea kombucha, some aldehydes, esters, alcohols, and ketones in coffee cascara kombucha were not identified in black tea kombucha. Potential impact compounds in CC were linalool, decanal, nonanal, octanal, dodecanal, ethanol, 2-ethylhexanol, ethyl acetate, ethyl butyrate, ethyl acetate, β-damascenone, γ-nonalactone, linalool oxide, phenylethyl alcohol, geranyl acetone, phenylacetaldehyde, isoamyl alcohol, acetic acid, octanoic acid, isovaleric acid, ethyl isobutyrate, ethyl hexanoate, and limonene. The mean acceptance scores for cascara kombuchas varied between 5.7 ± 0.53 and 7.4 ± 0.53 on a nine-point hedonic scale, with coffee cascara from three-day Nicaragua kombucha showing the highest score, associated with sweetness and berry, honey, woody, and herbal aromas and flavors. The present results indicate that coffee cascara is a promising by-product for elaboration of fermented beverages, exhibiting exotic and singular fingerprinting that can be explored for applications in the food industry. [ABSTRACT FROM AUTHOR]

Insulin resistance is one of the main characteristics of metabolic syndrome (MetS) and the main cause of the development of type II diabetes. The high prevalence of this syndrome in recent decades has made it necessary to search for preventive and therapeutic agents, ideally of natural origin, with fewer side effects than conventional pharmacological treatments. Tea is widely known for its medicinal properties, including beneficial effects on weight management and insulin resistance. The aim of this study was to analyze whether a standardized extract of green and black tea (ADM® Complex Tea Extract (CTE)) prevents the development of insulin resistance in mice with MetS. For this purpose, C57BL6/J mice were fed for 20 weeks with a standard diet (Chow), a diet with 56% kcal from fat and sugar (HFHS) or an HFHS diet supplemented with 1.6% CTE. CTE supplementation reduced body weight gain, adiposity and circulating leptin levels. Likewise, CTE also exerted lipolytic and antiadipogenic effects in 3T3-L1 adipocyte cultures and in the C. elegans model. Regarding insulin resistance, CTE supplementation significantly increased plasma adiponectin concentrations and reduced the circulating levels of insulin and the HOMA-IR. Incubation of liver, gastrocnemius muscle and retroperitoneal adipose tissue explants with insulin increased the pAkt/Akt ratio in mice fed with Chow and HFHS + CTE but not in those fed only with HFHS. The greater activation of the PI3K/Akt pathway in response to insulin in mice supplemented with CTE was associated with a decrease in the expression of the proinflammatory markers Mcp-1, IL-6, IL-1β or Tnf-α and with an overexpression of the antioxidant enzymes Sod-1, Gpx-3, Ho-1 and Gsr in these tissues. Moreover, in skeletal muscle, mice treated with CTE showed increased mRNA levels of the aryl hydrocarbon receptor (Ahr), Arnt and Nrf2, suggesting that the CTE's insulin-sensitizing effects could be the result of the activation of this pathway. In conclusion, supplementation with the standardized extract of green and black tea CTE reduces body weight gain, exerts lipolytic and antiadipogenic effects and reduces insulin resistance in mice with MetS through its anti-inflammatory and antioxidant effects. [ABSTRACT FROM AUTHOR]

Tea (Camellia sinensis L.) is an important beverage consumed worldwide. In Uganda, it is the second-largest and highly prioritized export crop after coffee and provides the much-needed jobs to more than 800,000 people. Despite its importance in the country, the crop has received very limited research attention for its improvement and optimal utilization. This study was aimed at characterizing existing tea germplasm in Uganda to inform future breeding initiatives for market-preferred tea varieties. Fifty-eight advanced tea clones were randomly selected from the tea germplasm conserved at Uganda's Tea Research Center in Rwebitaba and analyzed in the laboratory for eight physicochemical descriptors. Hierarchical cluster analysis performed on the 58 clones using Cluster-R package revealed four main clusters, indicating the existence of variation for physicochemical parameters within tested germplasm. This variation can be exploited to select among and/or improve the studied germplasm genetically for quality. High fermentation rate, which is one of the key indicators for good-quality black teas, revealed 15 fast-fermenter tea clones. Clone "UTR12/12" was identified as the most rapid fermenter, fully fermenting within 30 min, which implies a good clone for black tea. The clone also had the highest polyphenol content (26.7%), higher than the high-quality clone "UTR6/8" (control). Other tea clones whose polyphenol content was within the range of the control black tea clone were: "UTR144/10" (20.9%) and 'UTR144/17, (20.66%). The identified promising black tea clones can be advanced to multi-location trials for further evaluation and selection for eventual variety release as commercial black-tea clones. [ABSTRACT FROM AUTHOR]

Aim: The present study investigated the efficacy of Camellia sinensis regarding its antifungal activity toward Candida albicans and compared the various forms such as Japanese green tea, Chinese Oolong tea, Sabha black tea, and Sri Lanka black tea in relation to their antifungal property toward C. albicans. Materials and Methods: In this in vitro experimental study, the C. albicans were grown and maintained in their respective agar. Four different concentrations of 500 mg/mL and 250 mg/mL aqueous solution; 250 mg/mL ethanolic solution and 250 mg/mL methanolic solutions were prepared from four different forms of C. sinensis such as Japanese green tea, Oolong Chinese tea, Sabah black tea, and Sri Lanka black tea. The Kirby-Bauer disc diffusion method determined the activity of tea. The standard drug of Nystatin 100 IU (international units) was used as the positive control. After an incubation period of 48 h at 37ºC, the zone of inhibition was measured in millimeters. Results: Japanese green tea at its aqueous concentrations of 500 mg/mL and 250 mg/mL exhibited significantly higher mean zone of inhibition of 20.63 mm and 20.92 mm, respectively against C. albicans at P < 0.001. However, a mean zone of inhibition of 21.26 mm was shown by positive control Nystatin. Conclusion: The aqueous extract of Japanese green tea showed higher antifungal activity against C. albicans in comparison to black teas. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The increasing prevalence of gluten-related disorders has led to higher consumer demand for convenient, gluten-free bakery products with health-promoting properties. In this study, non-gluten shortbread cookies were incorporated with various kinds of spent (green, oolong, and black) tea leaves powder (STLP) at 8% w/w. Cookies with STLP had significantly higher (p < 0.05) moisture (2.18–2.35%), crude fibre (14.5–14.9%), total dietary fibre (22.38–22.59%), insoluble dietary fibre (15.32–15.83%), soluble dietary fibre (7.06–7.66%), and ash (1.9–2.0%) contents, but were significantly lower (p < 0.05) in carbohydrate (53.2–53.9%) and energy value (426.4–428.2 kcal) compared to control cookies (1.62%; 1.43%; 6.82%; 4.15%; 2.67%; 7.70%; 62.2%; and 457.8 kcal, respectively). The addition of STLP significantly enhanced (p < 0.05) the antioxidant properties of the cookies. Non-gluten shortbread cookies with spent green tea leaves powder (GTC) received the highest (p < 0.05) score for all sensory attributes, including overall acceptability. In addition, the shelf-life quality of the formulated cookie samples in terms of the moisture content, water activity, colour, texture, microbiology, and sensory properties was maintained (p > 0.05) for at least 22 days at 25 °C. STLP, which would have been previously thrown away, could be utilized as a potential functional ingredient to produce non-gluten shortbread cookies with enhanced nutritional, physicochemical, microbiological, sensory, and antioxidative properties. [ABSTRACT FROM AUTHOR]

Background: There is no study in the world on the relationship between consuming black and green tea as beverages containing polyphenols and the risk of MS. This study aimed to determine the association between the consumption of green and black tea, coffee, non-alcoholic beer, milk, fruit juices and carbonated beverages with the risk of MS. Methods and materials: This case–control study was performed on 150 patients with MS and 300 healthy individuals as a control group among patients who were referred to the ophthalmology ward of a referral hospital in Ahvaz with the groups matching for age. The data collection tool was a researcher-made questionnaire including demographic information and beverage consumption. Analysis was performed using univariate and multiple logistic regression models. Results: The mean age of patients at the time of diagnosis was 38.55 ± 8.88 years. The results showed that drinking milk (OR = 5.46), natural juice (OR = 2.49), and carbonated beverages (OR = 16.17) were associated with an increased chance of developing MS. However, drinking non-alcoholic beer (OR = 0.48), black tea (OR = 0.20), green tea (OR = 0.29) and coffee (OR = 0.07) were associated with a reduced chance of developing MS. Conclusion: The results show that drinking black and green tea, non-alcoholic beer, and coffee are associated with a decrease in the chance of developing MS. The results of this study can be used to design interventional research and to change people's lifestyles to prevent MS. [ABSTRACT FROM AUTHOR]

The following study analyzed the potential of Near Infrared Spectroscopy (NIRS) to predict the metal composition (Al, Pb, As, Hg and Cu) of tea and for establishing discriminant models for pure teas (green, red, and black) and their different blends. A total of 322 samples of pure black, red, and green teas and binary blends were analyzed. The results showed that pure red teas had the highest content of As and Pb, green teas were the only ones containing Hg, and black teas showed higher levels of Cu. NIRS allowed to predict the content of Al, Pb, As, Hg, and Cu with ratio performance deviation values > 3 for all of them. Additionally, it was possible to discriminate pure samples from their respective blends with an accuracy of 98.3% in calibration and 92.3% in validation. However, when the samples were discriminated according to the percentage of blending (>95%, 95–85%, 85–75%, or 75–50% of pure tea) 100% of the samples of 10 out of 12 groups were correctly classified in calibration, but only the groups with a level of pure tea of >95% showed 100% of the samples as being correctly classified as to validation.

Kombucha is a fermented tea drink produced by a symbiotic culture of bacteria and yeast, known as SCOBY. Its base has traditionally been black tea, which has been recognized for its health-promoting properties, particularly its antioxidant activity based on its high content of pol-yphenolic compounds. A number of previous studies have demonstrated the equally favourable biochemical and phytochemical composition of green tea. The aim of this study was to analyse and compare the basic biochemical composition, microbiological composition and antioxidant properties of black and green tea-based Kombucha. The green tea-based Kombucha showed a quantitatively more abundant microbial composition (Lactic Acid Bacteria, Acetobacter sp., Yeast), a higher reducing potential (FRAP—4326.58 Fe(II)µM/L) and a higher content of total polyphenols (23.84 mg GAE/100 mL, reducing sugars (3212.00 mg/100 mL) as well as free amino acids (849.00 mg GLY/mL). Kombucha made from black tea, on the other hand, showed a higher anti-oxidant potential (1.17 Trolox (mM) TEAC), neutralising the DPPH radical at 94.33% and ABTS at 97.74%. It also had a higher level of acetic acid (0.08 g/100 mL). Green tea kombucha had a higher scavenging capacity of 90.6% for superoxide radical (O2−) and 69.28% for hydroxyl radical (·OH) than black tea kombucha. In the present study, both kombucha drinks tested were shown to be source of potent antioxidants. In addition, green tea, as a kombucha base, has proven to be as beneficial a raw material that will provide full nutritional and health-promoting values as traditional kombucha.

Tea was known as one popular and power-consuming beverage. The purpose of the current study was to determine the concentration of heavy metals in infused tea consumed in Kashan City. This cross-sectional study was carried out on 29brands of dry tea purchased from Kashan city stores. The samples were placed under acidic digestion based on the cited method in the standard method. Measuring heavy metals such as chromium, cadmium, copper, nickel, lead, arsenic, zinc, and iron was performed through ICP-OES device.SPSS16 and Excel software was used to evaluate the statistical parameters. The evaluation carcinogenic risk was performed using related formula. The obtaining results indicated that mean concentration of heavy metals in infused black tea were related to iron, zinc, copper, lead, nickel, chromium, cadmium, arsenic which was equal to 0.819 ± 0.139, 0.419 ± 0.314, 0.173 ± 0.107, 0.125 ± 0.103, 0.097 ± 0.078, 0.059 ± 0.061, 0.045 ± 0.064, 0 mg/kg, respectively. According to their associated potential health risk assessment, HQ of some heavy metals including Cd, Pb, Cr, Ni, Cu, Zn, Fe and As was 0.642, 0.51, 0.2806, 0.0692, 0.0618, 0.0199, 0.0167 and 0 mg/kg-day and THQ or HI was upper than one(1.601).The results of the present study revealed that the concentration of copper, zinc and arsenic metals in all samples of infused tea was considered standard, but the concentration of lead, chromium, cadmium and nickel elements in some samples and the concentration of iron in all studied samples exceeded the maximum permissible limit presented by Iran National Standard and WHO. In addition, risk assessment analysis indicated that the consumption of the studied black tea on average(1 litre per day) had no adverse effect on the health of tea consumers.so, continuous monitoring of the concentration of heavy metals in black tea samples is essential. [ABSTRACT FROM AUTHOR]

BACKGROUND People brew tea to drink an infusion that only contains 25% water‐soluble constituents, leading to most of the insoluble materials being wasted. Tea powder could be drunk directly by mixing with water without producing any waste. Tea powder can also be used as a natural additive to improve the flavour and taste in beverages and foods. Much detailed information on the particle properties of tea powder is required with its increasing consumption. The aim of this study was to investigate the effects of particle size ranging from median diameter D50 = 4.32 to 26.59 μm on the composition, physical, rheological, and bioactive properties of black tea powder. RESULTS: The results indicate that large powder sizes had high bulk density and flowability, whereas small powder sizes possessed good swelling ability and wettability. The contents of water extract, total polyphenols, crude fibre, catechins, and thearubigins reduced with a decrease in particle size. To change the particle size and concentration could adjust the elastic modulus and the viscous modulus of the black tea powder suspension. Moreover, black tea powder with small particle size could regulate blood lipids in a hyperlipidaemic rat model by lowering triacylglycerols and elevating high‐density lipoprotein cholesterol, whereas large particles presented an advantage in reducing body weight. CONCLUSION: Our investigation extended the knowledge of commercial black tea powder in composition, physical, rheological, and bioactive properties. These results lay the foundation for future exploration of the use of tea powder in the food industry. © 2022 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Prunella vulgaris is a traditional herb commonly consumed as brewed tea in Asian and European countries. The therapeutic antioxidant and anti-inflammatory activity of this traditional herbal tea are relatively unknown. The study examined, using established in vivo markers of oxidative stress and inflammation, the antioxidant and anti-inflammatory actions of Prunella vulgaris tea in-vitro, which were compared with those measured from green and black tea. Prunella vulgaris tea significantly decreased the human neutrophilic formations of F2-isoprostanes, lipid hydroperoxides, and leukotriene B4, while increasing those of nitrite and nitrate. The measured antioxidant and anti-inflammatory effects were greater than those from green and black tea. Prunella vulgaris tea exerted antioxidant effects via electron-transfer radical scavenging and up-regulated antioxidant enzyme activities, and anti-inflammatory effects by modulating 5-lipoxygenase, myeloperoxidase, and inducible nitric oxide pathways. The study results provide evidence supporting further investigations in the in vivo conditions. [ABSTRACT FROM AUTHOR]

Conclusions In conclusion, supplementation with two new standardized tea extracts, one of white tea (WTE) and another of green and black tea (CTE), attenuates endothelial dysfunction and prevents the development of hypertension in mice with metabolic syndrome by decreasing arterial inflammation and oxidative stress. Keywords: hypertension; obesity; metabolic syndrome; white tea; green tea; black tea; extract; antioxidant EN hypertension obesity metabolic syndrome white tea green tea black tea extract antioxidant N.PAG N.PAG 17 08/29/22 20220801 NES 220801 1. Commercial Tea Extracts Two different commercial tea powdered extracts were employed in the present study: (1) a proprietary blend of green and black tea leaves named ADM SP ® sp Complex Tea Extract (CTE), standardized to total flavan-3-ols (monomeric and theaflavins) and methylxanthines (caffeine, theobromine and theophylline), and (2) ADM SP ® sp White Tea extract (WTE), a white tea extract standardized to monomeric flavan-3-ols and xanthines. [Extracted from the article]

[Display omitted] • Metabolite profiles and color contributions of oxidated trichomes were investigated. • Acylated kaempferol glucosides and EPSFs as key metabolites are found in trichomes. • Golden trichomes are responsible for the lightness and yellow hue of infusion color. Tea trichomes were regarded as an essential evaluation index for reflecting tea flavor quality in terms of aroma and influence on infusion color. This study reveals the impact of golden oxidized trichomes on the color, volatile and non-volatile metabolites of black teas through comparative metabolomics combined quantitative analysis on hongbiluo (trichomes-deficiency black teas), hongjinluo (trichomes-rich black teas), and trichomes (from hongjinluo). Forty-six volatile components were detected using headspace solid-phase microextraction gas chromatography-mass spectrometry, while the results suggested that the contribution of trichomes to black teas is limited. A total of 60 marker non-volatile compounds were identified, including catechins, catechin oxidation products, flavonoid glycosides, organic acids, hydrolysable tannins and amino acids. Notably, p- coumaroyl-kaempferol glucosides, and catechin dimers demonstrated high levels in independent trichomes and showed a positive correlation with the brightness and yellow hue of black tea infusions, specifically kaempferol 3 -O- di-(p- coumaroyl)-hexoside. Furthermore, results from fractional extraction analysis of separated trichomes provided that N -ethyl-2-pyrrolidinone-substituted epicatechin gallates, acylated kaempferol glycosides, and chromogenic catechins dimers, such as theaflavins, were primary color contributors in oxidized trichomes. Especially, we found that epicatechin gallate (ECG) and its derivates, 3′- O -methyl-ECG and N -ethyl-2-pyrrolidinone-substituted ECG, highly accumulated in trichomes, which may be associated with the varieties of hongbiluo and hongjinluo black teas. Eventually, addition tests were applied to verify the color contribution of trichome mixtures. Our findings employed comprehensive information revealing that golden oxidized trichomes contributed significantly to the brightness and yellow hue of black tea infusion, but their contribution to the aroma and metabolic profile is limited. These findings may contribute to the effective modulation of the infusion color during black tea production by regulating the proportion of tea trichomes or screening trichomes-rich or deficiency varieties. [ABSTRACT FROM AUTHOR]

Tea cream formed in hot and strong tea infusion while cooling deteriorates quality and health benefits of tea. However, the interactions among temporal contributors during dynamic formation of tea cream are still elusive. Here, by deletional recombination experiments and molecular dynamics simulation, it was found that proteins, caffeine (CAF), and phenolics played a dominant role throughout the cream formation, and the contribution of amino acids was highlighted in the early stage. Furthermore, CAF was prominent due to its extensive binding capacity and the filling complex voids property, and caffeine-theaflavins (TFs) complexation may be the core skeleton of the growing particles in black tea infusion. In addition to TFs, the unidentified phenolic oxidation-derived products (PODP) were confirmed to contribute greatly to the cream formation. [Display omitted] • Proteins, CAF, phenolics played a pivotal role throughout the cream formation. • Amino acids mainly contributed in the early formation of tea cream. • Creaming affinities were ranked as TFs > proteins > CAF > catechins > amino acids. • The unidentified PODP formed in black tea contributed greatly to cream formation. • Rolling and fermentation increased cream formation, while drying reduced it. [ABSTRACT FROM AUTHOR]

The latest insights into the health benefits of various fermented teas, including dark tea, oolong tea, and black tea, underscore the significant role of polyphenols in promoting wellness. The fermentation process in these teas not only enriches their overall polyphenol content but also enhances level of specific polyphenols, improving their health-promoting effects. Dark tea, such as Pu-erh, undergoes microbial fermentation, resulting in unique polyphenol profiles particularly theabrownins that offer potent antioxidant properties. Oolong tea, which is partially oxidized contains catechins and theasinensins, contributing to its potential to enhance weight management and correct metabolic disorders. Black tea, a fully oxidized tea, has a high levels of theaflavins and thearubigins, polyphenols linked to reduced inflammation, decreased incidences of cancer, and enhanced neuroprotection. However, despite these benefits, the emerging understanding of the health risks has associated fermented teas with the presence of potentially harmful compounds formed during fermentation or processing. In dark tea, prolonged microbial fermentation may lead to the production of mycotoxins, such as aflatoxins, which have been linked to carcinogenic effects. Black tea may accumulate heavy metals from soil and processing, posing risks to human health if consumed in excessive amounts. Similarly, oolong tea, while partially fermented, can still contain heavy metals contributing to impaired health. While these risks are generally low and depend on factors such as brewing conditions and consumption frequency, they highlight the importance of conducting future studies to devise preventive measures to mitigate these risks. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Advanced Research in Health Sciences (JARHS) / Sağlık Bilimlerinde İleri Araştırmalar Dergisi (SABİAD) is the property of Journal of Advanced Research in Health Sciences (JARHS) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of current research was to determine the effect of different extraction techniques on the antioxidant capacity of green tea, black tea and ginger polyphenols. Initially, the raw materials were subjected to compositional analysis. Afterward, the bioactive moieties from all the samples were extracted through ultrasound and conventional solvent extraction method using different solvents (i.e. ethanol, methanol and water). Furthermore, the functional ingredients, namely, catechins and theaflavins were isolated by solvent partition method from green and black tea, respectively. In addition, the extracts and isolates were analyzed for their total phenolic and antioxidant profile using various spectrophotometric assays. For the quantification of theaflavins and catechins, a reverse phase HPLC system was used. Results showed that ultrasound (P > .005) proved more effectual for the extraction and isolation of polyphenols (757.33 mg/100 g GAE) from the tested materials among the other extraction techniques (741.66 mg/100 g GAE). Likewise, green tea showed better performance than the rest and in solvents ethanol performed better as compared to their counter parts. Similarly, the isolates showed higher antioxidant potential as compared to their extracts and order of effectiveness was catechins > theaflavins > Ginger freeze dried extract (GFDE).

Kombucha has been gaining prominence around the world and becoming popular due to its good health benefits. This beverage is historically obtained by the tea fermentation of Camellia sinensis and by a biofilm of cellulose containing the symbiotic culture of bacteria and yeast (SCOBY). The other substrates added to the C. sinensis tea have also been reported to help kombucha production. The type as well as the amount of sugar substrate, which is the origin of SCOBY, in addition to time and temperature of fermentation influence the content of organic acids, vitamins, total phenolics, and alcoholic content of kombucha. The route involved in the metabolite biotransformation identified in kombucha so far and the microorganisms involved in the process need to be further studied. Some nutritional properties and benefits related to the beverage have already been reported. Antioxidant and antimicrobial activities and antidiabetic and anticarcinogenic effects are some of the beneficial effects attributed to kombucha. Nevertheless, scientific literature needs clinical studies to evaluate these benefits in human beings. The toxic effects associated with the consumption of kombucha are still unclear, but due to the possibility of adverse reactions occurring, its consumption is contraindicated in infants and pregnant women, children under 4‐years‐old, patients with kidney failure, and patients with HIV. The regulations in place for kombucha address a number of criteria, mainly for the pH and alcohol content, in order to guarantee the quality and safety of the beverage as well as to ensure transparency of information for consumers. [ABSTRACT FROM AUTHOR]