Chromatographic separation of black tea polyphenols is too difficult to supply sufficient quantities of pure compounds for biological experiments. Thus, facile methods to prepare black tea constituents were desired. Treatment of epigallocatechin gallate with copper(II) chloride efficiently afforded an unstable quinone dimer, dehydrotheasinensin A, and subsequent treatment with ascorbic acid ste...

BACKGROUND AND PURPOSE Experimental models of stroke provide consistent evidence of smaller stroke volumes in animals ingesting tea components or tea extracts. To assess whether a similar association of black or green tea consumption with reduced risk is evident in human populations, we sought to identify and summarize all human clinical and observational data on tea and stroke. METHODS We se...

A 37-year old woman was referred to our clinic with severe iron-deficiency anemia which failed to respond to iron replacement therapy. Continued blood loss and compliance problems were excluded. Since the patient reported a daily intake of two liters of black tea, it was suspected that the tea had adverse effects on intestinal iron absorption. When the patient stopped drinking black tea her bod...

Epidemiological studies have demonstrated inconsistent associations between tea consumption and mortality of all cancers, CVD and all causes. To obtain quantitative overall estimates, we conducted a dose-response meta-analysis of prospective cohort studies. A literature search in PubMed and Embase up to April 2015 was conducted for all relevant papers published. Random-effects models were used ...

Several studies have demonstrated that tea flavonoids protect cells and tissues against free radicals which have been implicated in the etiology of oxidative stress-related disease disorders. However, black tea is commonly consumed with additives that could otherwise affect the bioavailability of the active tea molecules. In this study, the biochemical parameters of Kenyan teas were determined ...

Black tea consumption has been shown to improve peripheral vascular function. Its effect on brain vasculature is unknown, though tea contains small amounts of caffeine, a psychoactive substance known to influence cerebral blood flow (CBF). We investigated the effects on CBF due to the intake of tea components in 20 healthy men in a double-blinded, randomized, placebo-controlled study. On separa...

Tea is consumed by a big part of the world’s population. It has an enormous importance for the Turkish culture. Nearly it is brewed every morning and evening at the all houses. Also it is consumed with lemon wedge. Habitual drinking of tea infusions may significantly contribute to daily dietary requirements of elements. Different instrumental techniques are used for determination of these eleme...

objectives: the aim of this study was to evaluate the effect of six herbal teas on the color stability of two types of nanohybrid and one microhybrid resin composite.  materials and methods: 70 disc-shaped specimens, 210 in total (7*2mm), were fabricated from each of the following materials in metal mould : tetric n ceram, grandio, gradia direct anterior. specimens were stored in distilled wate...

in this study, the effects of different types of hand plucking were studied on green leaf yield and black tea quality. bud and a leaf, bud and two leaves, bud and three leaves and bud and four leaves were the types of hand plucking. plucking was down on chine’s hybrid tea and clone 100 in fuman tea research station. shoots were plucked in flashing period regularly during three years. green leaf...

Data in the food composition analytical literature were reviewed. They were then aggregated and assembled into a provisional database for the major flavonoids in brewed tea. As levels of fermentation increased from green to oolong to black tea, the major flavan-3-ol profiles changed. Total catechins were 13.6 g/100 g in green and 4.2 g/100 g dry weight in black tea. A discussion of methods to c...