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18i6_Fingerprinting_Tea
All living organisms share the same base:combinations of four building blocks called nucleotides arranged in a double helix.
DNA fingerprinting is part of the shift in tea science from the chemistry of the leaf to the biogenetics of the molecules that comprise it. It is core to meeting the growing priority of transparency along the entire bush to cup supply chain: accurate and honest information about the tea, certification of its source, and traceability of its history, as well as protection from fraud.
18i6_Finferprinting_tea
DNA in the plant leaf is extracted, snipped and its genetic banding mapped.The bands can be shown as a bar code pictured above,compared with other samples and known varietals. This is like a fingerprint as it uniquely identifies the leaf, its source,composition, and heritage.
The term tea “fingerprinting” comes from the human analogy. A fingerprint is unique to a person, as is his or her DNA. A forensic scientist can state with near perfect statistical certainty that this is, say, Daniel Cong, born in Phoenix. Labs can now use DNA profiling and mapping to pin down that this tea sample is a true Dan Cong oolong, from the Phoenix Mountains of Guangdong. And that this sample claimed to be a Dayi puer is an impostor.
The science behind tea fingerprinting is complex and the technology needed even more so. The principle is simple. All living organisms are formed by their DNA. The building blocks are nucleotides: a combination of pairs of molecular units – adenine (A), guanine (G), thymine (T), and cytosine (C) – a sugar and a phosphate. These ACGT bases are hooked together in a chain of the famed double helix and are unique to the person, plant, fish or fowl.
Tea fingerprinting begins by extracting these DNA elements and snipping them into strands. They are processed to reveal their “markers” – banded patterns -- via a wide range of techniques of intimidating detail, sophistication, and precision. The gene profiling and mapping produce the same picture as you see on TV programs such as CSI, where DNA is used in forensic crime labs to uniquely identify a suspect, witness or dead body.
The next stage is to standardize the data so that it can be presented in barcode form, substituting what may be thought of as a universal biodata code for the ubiquitous UPC (universal product code.) That code can be accessed through scanners, incorporated into block chains, and integrated into corporate logistical systems.
Fingerprinting will also radically reduce fraud. Lab studies and pilot applications show include 99% successes in identifying the origins of Japanese clonal varieties, detecting counterfeit Taiwan premium oolongs that are actually low-grade Vietnam imports, and classifying the exact composition of puers.
The need is urgent and far-reaching. Just a few headline instances are the Pakistan factory that was caught making a ton of counterfeit tea bags a day, the confiscation of eight tons of fake Dayi puer, and the oft-noted historical sales of tea of four times the volume of Darjeeling than is actually produced. Droopy Dragonwell and too-good-to-be-true prices of other top-of-the-line teas are commonplace examples of adulteration and “passthrough” – tea identity theft.
Tea fingerprinting will catch them all. Tea barcoding will ensure certification and tracking. There are a large number of road bumps on the path to commercialization – standardization of methods, creation of reference data bases for comparisons, oversight, and certification – but no road blocks.