The Experts below are selected from a list of 15582 Experts worldwide ranked by ideXlab platform
Jian Wei Liu - One of the best experts on this subject based on the ideXlab platform.
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Fluoride levels in various Black Tea commodities: measurement and safety evaluation.
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2006Co-Authors: Jin Cao, Yan Zhao, Hui Jun Deng, Jian Wei LiuAbstract:Abstract In order to determine the fluoride content of various products of Black Tea and to make safety evaluations, 37 commodities in the different manufactured forms of Tea were assessed by means of ion-selective electrode and spectrophotometric methods. The results showed wide differences in fluoride levels. The fluoride content was found 0.95–1.41 mg/L in Black Tea sticks, 0.70–2.44 mg/L in Black Tea granules and 1.15–6.01 mg/L in Black Tea bags. Of the products tested, the fluoride content was greatest in Black Tea bags, presumably because Black Tea bags are made of low cost, and older Tea leaves. According to WHO’s recommendation, fluoride exposure threshold for children is 2 mg of daily intake and for adult, 4 mg. Assuming that children’s daily intake of Black Tea was 800 ml and adult’s 1500 ml, 56% of Black Tea bags should be considered unsafe for children and 44% should be considered unsafe for adults. At average rates of consumption, 24% of the Black Tea bags could result in an increasing risk of osteofluorosis and fractures (WHO). In the areas with drinking water fluoridation or other fluoride supplements, excessive fluoride exposure can become even more severe with even lower intake Tea made from Black Tea bags. The potential hazards of fluoride arising from consumption of Black Tea has not aroused due public attention. Therefore, it is necessary to establish reliable fluoride surveillance in food and beverage commodities and conduct additional epidemiological research on fluoride hazards. In addition, it is urgent that governmental and international agencies adopt safe standards of fluoride content in Tea commodities.
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Safety evaluation on fluoride content in Black Tea
Food Chemistry, 2004Co-Authors: Jin Cao, Sha Fei Luo, Jian Wei LiuAbstract:Abstract Fluoride content in Black Tea in various commodities, packages, and preparation processess was assayed and its safety evaluated. A fluoride ion selective electrode method was used to determine the fluoride content in 20 Tea samples, in various Black Tea commodities, namely stick-shaped, granular, and canned or bottled Tea beverage, originally produced in India, Sri Lanka, China, Japan and UK, and milk–Tea after addition of milk and sugar. The fluoride content of 5 stick-shaped Black Teas was 96.9–148 mg/kg, that of 8 granular Black Tea was 139–223 mg/kg, and that of 3 canned or bottled beverage Black Tea beverages was 0.70–0.96 mg/l, respectively. Neither the bagged Black Tea paper nor the addition of milk and sugar affected the ionic fluoride level within the Tea. These results suggest that, for heavy Black Tea drinkers, the fluoride intake in areas with drinking water fluoridation, and also other probable sources of fluoride, may approach or reach the level of risk from chronic fluoride intoxication.
L. Jagan Mohan Rao - One of the best experts on this subject based on the ideXlab platform.
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A Thought on the Biological Activities of Black Tea
Critical reviews in food science and nutrition, 2009Co-Authors: Vasundhara Sharma, L. Jagan Mohan RaoAbstract:Tea is the most widely used ancient beverage in the world and Black Tea possesses many biological effects on the organisms. It acts as an effective antioxidant because of its free radical-scavenging and metal-chelating ability. Due to this, it is active against inflammation, clastogenesis, and several types of cancer. Tea reduces DNA damage and mutagenesis due to oxidative stress or the presence of pro-mutagens through antioxidant function, blocking activation pathways of mutagens, suppressing transcription of enzymes involved etc. Inhibition of low-density lipoprotein (LDL) peroxidation, suppression of fatty acid synthase etc., suggest that Tea may have a role in preventing cardiovascular diseases. Some epidemiological studies support the protective role of Black Tea against cardiovascular diseases but some do not. Besides, Black Tea has beneficial effects on the gastrointestinal tract; it affects motility, absorption, microflora etc., by influencing the hormonal balance and antioxidant function Black te...
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Influence of milk and sugar on antioxidant potential of Black Tea
Food Research International, 2008Co-Authors: Vasundhara Sharma, H. Vijay Kumar, L. Jagan Mohan RaoAbstract:Black Tea is often consumed with milk and sugar. It is still unknown with certainty whether addition of milk and (or) sugar affects its antioxidant activity. The present study is aimed to investigate the effect on antioxidant and radical scavenging activities of Black Tea on addition of milk and sugar. Four types of Black Tea brew samples are prepared, viz., plain Black Tea (B), Black Tea with sugar (BS), Black Tea with milk (BM) and Black Tea with milk and sugar (BMS). The freeze-dried solids of all the brew samples are evaluated for their biological activities. The radical scavenging and antioxidant activities are estimated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and β-carotene-linoleic acid model systems, respectively. It is observed that radical scavenging activity of B was highest followed by BS and BMS. BM shows lowest activity. The antioxidant activity of Black Tea enhances and stabilizes with milk or sugar. The total polyphenol content is also determined and found to be higher in Black Tea sample compared to other samples. Both activities are compared with that of butylated hydroxy anisole (BHA) as a standard antioxidant and found to be less in all cases.
Jin Cao - One of the best experts on this subject based on the ideXlab platform.
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Fluoride levels in various Black Tea commodities: measurement and safety evaluation.
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2006Co-Authors: Jin Cao, Yan Zhao, Hui Jun Deng, Jian Wei LiuAbstract:Abstract In order to determine the fluoride content of various products of Black Tea and to make safety evaluations, 37 commodities in the different manufactured forms of Tea were assessed by means of ion-selective electrode and spectrophotometric methods. The results showed wide differences in fluoride levels. The fluoride content was found 0.95–1.41 mg/L in Black Tea sticks, 0.70–2.44 mg/L in Black Tea granules and 1.15–6.01 mg/L in Black Tea bags. Of the products tested, the fluoride content was greatest in Black Tea bags, presumably because Black Tea bags are made of low cost, and older Tea leaves. According to WHO’s recommendation, fluoride exposure threshold for children is 2 mg of daily intake and for adult, 4 mg. Assuming that children’s daily intake of Black Tea was 800 ml and adult’s 1500 ml, 56% of Black Tea bags should be considered unsafe for children and 44% should be considered unsafe for adults. At average rates of consumption, 24% of the Black Tea bags could result in an increasing risk of osteofluorosis and fractures (WHO). In the areas with drinking water fluoridation or other fluoride supplements, excessive fluoride exposure can become even more severe with even lower intake Tea made from Black Tea bags. The potential hazards of fluoride arising from consumption of Black Tea has not aroused due public attention. Therefore, it is necessary to establish reliable fluoride surveillance in food and beverage commodities and conduct additional epidemiological research on fluoride hazards. In addition, it is urgent that governmental and international agencies adopt safe standards of fluoride content in Tea commodities.
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Safety evaluation on fluoride content in Black Tea
Food Chemistry, 2004Co-Authors: Jin Cao, Sha Fei Luo, Jian Wei LiuAbstract:Abstract Fluoride content in Black Tea in various commodities, packages, and preparation processess was assayed and its safety evaluated. A fluoride ion selective electrode method was used to determine the fluoride content in 20 Tea samples, in various Black Tea commodities, namely stick-shaped, granular, and canned or bottled Tea beverage, originally produced in India, Sri Lanka, China, Japan and UK, and milk–Tea after addition of milk and sugar. The fluoride content of 5 stick-shaped Black Teas was 96.9–148 mg/kg, that of 8 granular Black Tea was 139–223 mg/kg, and that of 3 canned or bottled beverage Black Tea beverages was 0.70–0.96 mg/l, respectively. Neither the bagged Black Tea paper nor the addition of milk and sugar affected the ionic fluoride level within the Tea. These results suggest that, for heavy Black Tea drinkers, the fluoride intake in areas with drinking water fluoridation, and also other probable sources of fluoride, may approach or reach the level of risk from chronic fluoride intoxication.
Vasundhara Sharma - One of the best experts on this subject based on the ideXlab platform.
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A Thought on the Biological Activities of Black Tea
Critical reviews in food science and nutrition, 2009Co-Authors: Vasundhara Sharma, L. Jagan Mohan RaoAbstract:Tea is the most widely used ancient beverage in the world and Black Tea possesses many biological effects on the organisms. It acts as an effective antioxidant because of its free radical-scavenging and metal-chelating ability. Due to this, it is active against inflammation, clastogenesis, and several types of cancer. Tea reduces DNA damage and mutagenesis due to oxidative stress or the presence of pro-mutagens through antioxidant function, blocking activation pathways of mutagens, suppressing transcription of enzymes involved etc. Inhibition of low-density lipoprotein (LDL) peroxidation, suppression of fatty acid synthase etc., suggest that Tea may have a role in preventing cardiovascular diseases. Some epidemiological studies support the protective role of Black Tea against cardiovascular diseases but some do not. Besides, Black Tea has beneficial effects on the gastrointestinal tract; it affects motility, absorption, microflora etc., by influencing the hormonal balance and antioxidant function Black te...
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Influence of milk and sugar on antioxidant potential of Black Tea
Food Research International, 2008Co-Authors: Vasundhara Sharma, H. Vijay Kumar, L. Jagan Mohan RaoAbstract:Black Tea is often consumed with milk and sugar. It is still unknown with certainty whether addition of milk and (or) sugar affects its antioxidant activity. The present study is aimed to investigate the effect on antioxidant and radical scavenging activities of Black Tea on addition of milk and sugar. Four types of Black Tea brew samples are prepared, viz., plain Black Tea (B), Black Tea with sugar (BS), Black Tea with milk (BM) and Black Tea with milk and sugar (BMS). The freeze-dried solids of all the brew samples are evaluated for their biological activities. The radical scavenging and antioxidant activities are estimated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and β-carotene-linoleic acid model systems, respectively. It is observed that radical scavenging activity of B was highest followed by BS and BMS. BM shows lowest activity. The antioxidant activity of Black Tea enhances and stabilizes with milk or sugar. The total polyphenol content is also determined and found to be higher in Black Tea sample compared to other samples. Both activities are compared with that of butylated hydroxy anisole (BHA) as a standard antioxidant and found to be less in all cases.
Xia Yan-shi - One of the best experts on this subject based on the ideXlab platform.
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Development of Black Tea Microbiology
Journal of Microbiology, 2006Co-Authors: Xia Yan-shiAbstract:There is a great deal of bioactive substances in Black Tea that is mainly caused by the function of microorganism in Black Tea processing course.The mechanism of quality formation,the main microorganism and its function of promotion on enzymic action in the processing course were summarized.
