To what extent do we trust labels? Does food really contain what is claimed? These are questions which can be resolved by simply testing the DNA present in food, a process currently performed using a labour-intensive, barcoding method. A ‘barcode’ is a short sequence of DNA unique to a specific species. The barcode is used in complex and time-consuming procedure to ensure the packaging matches the food-type inside.
A simplified version of food authentication has now been developed by Italian scientists. Known as NanoTracer, the method combines DNA Barcoding, Nanotechnology and PCR to create a Universal Colorimetric Test. This new test also uses fewer and cheaper reagents, requires less instrumentation, and features a simple colour change as its output.
The principle behind this new test is as follows:
The barcode is broken down into shorter sub-regions enabling DNA within the food to be identified even if it is no longer intact, a common feature of food products. DNA within the food is extracted before being amplified by PCR using barcode primers and DNA-functionalized gold nano-particles. If the DNA present in the food is a match to the barcode primers, the DNA segment is amplified causing the gold nano-particles to aggregate and the solution to turn from red to violet.
This simplified food authentication procedure will be greatly beneficial and provide a cheaper, faster, more sensitive method to that which is currently used.
The full article can be accessed at the Wiley Online Library: http://tinyurl.com/ya8r8sjr