Tea polyphenols in bottled drinks are usually less than what consumers get brewing their own tea, according to a Consumer Council study. Polyphenols are antioxidant phytochemicals that may help prevent the damaging effects of free radicals.

The council tested 30 samples of bottled green tea drinks in the wake of Mainland reports that some contained less than 1-30th of the standard required of tea polyphenols.

The test found 0.04% to 0.17% of tea polyphenols among the samples, which comply with Mainland standards. The tea polyphenol content of 25 samples was below 0.1%.

However, tea polyphenols in bottled drinks, in most probabilities, will be less than what consumers get by brewing their own tea, the council said. A cup of tea brewed with a 2g tea bag in 100ml of water in three minutes can yield as much as 0.2% of tea polyphenols and up to 0.27% in 10 minutes.

Green tea drinks may have more calories than soda

Many bottled green tea drinks, like soft drinks, have added sugar. In the test, 14 of the 30 samples were found to contain 0.4% to 9.2% sugar, generally consistent with the claimed sugar content on their label.

In the case of a 500ml sample with the highest sugar content, at 9.2%, its calorie content may exceed even that of a can of cola. People should watch the intake of sugar when drinking bottled tea.

The test also showed different claims were used to indicate sugar content to consumers, with six bottles claiming to be "sugar-free" or "no sugar", four "low sugar", and one "little sweet". These samples were found to contain 4% to 4.6% sugar, with one sample undetected. For samples without any claim on their sugar content, only three contained a level higher than 4%.

As one sample labelled "low sugar" failed to specify the amount of sugar it contained, the case was referred to the Food & Environmental Hygiene Department for follow-up action.