Tea Time

  • Author: ChemistryViews
  • Published: 06 October 2010
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
  • Source / Publisher: Food Chemistry/Elsevier
thumbnail image: Tea Time

Flavanols and theanine found in tea have a variety of potential health benefits. Green tea, in particular, is renowned for containing flavanols.

Benno Zimmermann and Maike Gleichenhagen, University of Bonn, Germany, have studied the effects of temperature and steeping time on the main flavanols contained in green tea. Concentrations of flavanols in tea without additives are highest after 7 min of steeping at a constant 100 °C. Additives such as lemon juice increase flavanol concentrations by up to 20 %, due to its pH lowering effect.

Emma Keenan and co-workers, University of Bristol, UK, have used HPLC to measure L-theanine concentrations. Steeping time was again found to be a major factor in theanine concentration, with small amounts of additives having little or no effect. Black tea was found to contain the most L-theanine (24.2 ± 5.7 mg) while a cup of green tea contained the least (7.9 ± 3.8 mg).

Article Views: 3458

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission and consult our permission guidance prior to making your request

Follow on Facebook Follow on Twitter Follow on YouTube Follow on LinkedIn Follow on Instagram RSS Sign up for newsletters

Magazine of Chemistry Europe (16 European Chemical Societies) published by Wiley-VCH