Tea, a beverage consumed worldwide, has proven anti-hyperglycemic effects in animal models. Better efficacies of tea beverages are frequently associated with high-dose levels, whose safety attracts considerable attention. Based on the inherent nature of tea catechin oxidation, fresh tea leaves are manufactured into diverse tea types by modulating the oxidation degree of catechins. The present s...

Pu-erh tea is a kind of fermented tea with the incorporation of microorganisms' metabolites. Unlike green tea, the chemical characteristics and bioactivities of Pu-erh tea are still not well understood. Using water extracts of Pu-erh tea, we analyzed the tumor cell growth inhibition activities on several genetically engineered mouse tumor cell lines. We found that at the concentration that did ...

In contrast to the consistent results of an inhibitory effect of green tea extracts and tea polyphenols on the development and growth of carcinogen-induced tumors in experimental animal models, results from human studies are mixed. Both observational and intervention studies have provided evidence in support of a protective role of green tea intake in the development of oral-digestive tract can...

The chemopreventive effects of decaffeinated green and black tea treatment on liver and lung tumorigenesis were examined in carcinogen-treated mice. Male C3H mice were given decaffeinated green or decaffeinated black tea in their drinking water prior to, during, and after treatment with diethylnitrosamine (50 micrograms/kg bw, i.p., once per week for 8 weeks). After 40 weeks of tea treatment, m...

Oolong tea is a traditional Chinese tea that has long been believed to be beneficial to health such as decreasing body fat. We were interested in this assertion and tried to evaluate the effect of oolong tea on energy expenditure (EE) in comparison with green tea. The subjects were eleven healthy Japanese females (age 20+/-1 y; body mass index (BMI) 21.2+/-2.5 kg/m2) who each consumed of three ...

Thirty-two commercially available teas consisting of green, oolong and black teas were bought from supermarkets in Christchurch, New Zealand in June 2001. Fifteen herbal teas were also purchased at the same time. The soluble oxalate content of the infusate made from each of the teas was determined using high pressure liquid chromatography. The mean soluble oxalate contents of black tea in tea b...

Tea is particularly rich in polyphenols, including catechins, theaflavins and thearubigins, which are thought to contribute to the health benefits of tea. Tea polyphenols act as antioxidants in vitro by scavenging reactive oxygen and nitrogen species and chelating redox-active transition metal ions. They may also function indirectly as antioxidants through 1) inhibition of the redox-sensitive t...

The hypothesis of this study was that tea inhibits iron absorption in animals unaccustomed to tea onsumption but not in animals habituated to high intakes of tea. Three diets were prepared: 1) annin-free diet; 2) 5% tea solids (tea) diet; and 3) 5% tea solids 6% gelatin (T/G). Gelatin was hosen as a proxy for salivary proline–rich proteins (PRP). Five groups of rats were assigned to the ollowin...

background and purpose: most traditional tea shop owners use a bowl to wash tea cups in sari city (north of iran). there are more than 140 traditional tea shops in the city. unfortunately most people drinking at these shops as well as health authorities do not pay attention to the health criteria of the shop. the objective of this study was to examin the tea cups washing water of traditional te...

When a hot aqueous extract of black tea cools down, a colloidal complex (tea cream) is formed, which poses technological problems in industrial processes e.g. manufacture of instant tea and tea cordials. Removal of 'tea cream' by centrifugation leaves the residual liquor stripped to a great extent of the desirable characteristics of tea. The studies on the nature of tea cream, the mechanics of ...