Tea and Caffeine

People have enjoyed caffeinated beverages for many years Caffeine is a naturally occurring substance found in the leaves, seeds or fruits of at least 100 different species worldwide and is part of a group of compounds known as methylxanthines. The most commonly known sources of caffeine are coffee, cocoa beans, cola nuts and tea leaves. Caffeine is also added to specifically formulated 'energy drinks' and pharmaceutical products such as cold and flu remedies.

The amount of caffeine present in products depends on the type of the product, the serving size and the preparation method. For example a 6 oz. cup of tea contains 50mg of caffeine, one third less than the same amount of an instant cup of coffee (75mg). The following table gives an indication of the amount of caffeine found in other drinks compared to tea:
 

On average we consume 1.8mg of caffeine/lb body weight per day ie 239mg/day for a 132 lb person.

What is a safe intake of caffeine?
Up to 300mg/day or 6 cups of tea (one cup=6 oz.) is considered moderate, with no evidence of harmful effects in the vast majority of the adult population. Some individuals are sensitive to caffeine and will feel effects at smaller doses than other individuals who are less sensitive. For this reason, these individuals may need to limit their caffeine intake.

Decaffeination of Tea

It has only been since the 1980s that advances in production technology have resulted in the availability of good quality decaffeinated tea. The process involves bringing the tea leaves into contact with a fluid capable of extracting the caffeine from the leaf, separating the leaves from the fluid, then drying the tea. The most commonly used agents include ethyl acetate (technically classified as a natural element) and methylene chloride, an FDA-approved solvent. (It should be noted that some "naturally decaffeinated" teas use the ethyl acetate method.)

Less common is the use of natural carbon dioxide (CO2) for decaffeination. Although it is more expensive, the CO2 method preserves natural flavors better, resulting in a better tasting tea. Harrisons & Crosfield uses the CO2 process for decaffeination and has selected a blend of teas that have proven successful in maintaining their flavor. Decaf English Breakfast is available in tagged tea bags.

According to research results published in Prevention Magazine, the commonly used method of removing caffeine with ethyl acetate also removes up to 70% of tea's polyphenols - the compounds that can help prevent cancer and heart disease. The more expensive carbon dioxide method of decaffeination leaves about 90% of the polyphenols.

How to Decaffeinate Tea in a Pinch
If you run out of your favorite decaffeinated blend, follow these steps to remove caffeine from traditional tea.

• Pour water just off the boil over the tea leaves or tea bag and let them brew for 30 seconds. (Most of the caffeine is released in the first 30 seconds.)

• Discard the liquid, keeping the tea leaves or tea bag.

• Add more boiling water to the tea leaves or tea bag and brew for the recommended time.