The main sources of quality teas in the UK trade are from the Darjeeling and Assam regions of India. These high quality teas are sold to the consumer at a premium based on the stated provenance, but the authentication of the stated provenance is notoriously difficult. There are frequently a number of steps between producer/grower and consumer, such as processing, wholesale buying, blending, shipping, and packaging. Each of these steps offers opportunity for unscrupulous traders to adulterate high quality produce with cheaper material. It is already known that an estimated 100-200% more Darjeeling tea is marketed compared to production in the region, indicating a high level of fraudulent trading, which the Darjeeling producers association are aiming to combat with a certification scheme. There is, however, no method of reliably authenticating such material in place.
In this project, highly informative DNA-based markers (Sequence Tagged Microsatellite Sites, STMS) will be developed and characterised for tea by the Genetics Department of Cambridge University. These markers will be used to generate genetic profiles ('fingerprints') of tea from all regions of production, to construct a database, that will provide a powerful tool in authentication of stated provenance. Fingerprints from samples of produce claiming a specific, high-value provenance could be checked against this database to establish that:
The product contains fingerprints consistent with the fingerprints known to exist in that region,
<li>No fingerprints unique to plants from other regions can be detected. The method will be powerful and sensitive, enabling individual fragments from tea samples to be tested.
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.