Normally, DNA barcoding food to determine its makeup is a time-consuming process that can demand several days for a response. However, teams of scientists from the Italian Institute of Technology IIT, Genoa, and from the University of Milano-Bicocca (M. Labra), led by IIT’s Pier Paolo Pompa have developed a simplified version of the test called NanoTracer, which they announced in the journal Angewandte Chemie in June.
By breaking long barcodes up into shorter sections that still allow species to be numerically identified, the NanoTracer technology cuts through much of the information involved in a traditional DNA barcoding, while remaining capable of identifying DNA that’s been altered by cooking. Using a polymerase chain reaction process, the NanoTracer offers a testing chemical that shows a clear color change in order to indicate a DNA sequence match. And rather than two days, the NanoTracer takes only two to three hours.
“Barcodes is definitely the way to do speciation and look at food fraud. How they’re combining it is definitely unique,” says Robert Brooks, manager of technical operations at Microbac Laboratories.
Nicola Temple, co-author of Sorting the Beef from the Bull: The Science of Food Fraud Forensics, however, warns that in shortening the DNA barcoding process, the NanoTracer is also shortening the amount of information it can make available.
“The strength of DNA barcoding is that it can be used to identify unknown species by comparing the sequence of the unknown species to a database of known sequences,” Temple explains. “From what I understand of the NanoTracer DNA scanning technology, it can only confirm whether a species is what it says it is. While this is useful as a quick fraud check, there are already existing protein-based assays that are capable of doing this rapidly and also require very little equipment or expertise. I’m also unclear whether the NanoTracer DNA scanning technology would work in mixtures, such as minced meat. If someone wanted to know whether some lean ground beef was truly beef, this technology could give a positive result even if pork, horse or other species were present.”
Brooks agrees, noting that, “Trying to do it for every fish species out there—you’re going to have to create a single test for each one of them. I don’t know how they’re going to do with samples where you have a mixture of different fish, or different products.”
However, Brooks goes on to note that for large-scale retailers evaluating batches of product coming directly off ships, this test may provide peace-of-mind that buyers are receiving precisely what they’ve paid for.
“Let’s say you only want to look and find out if it’s tuna, or grouper. If this tests for that and allows you to verify it, this could be very big,” he says. “You’re not waiting days to find out what it is: It’s a same-day answer that allows you to go to market quicker. Going to market quicker then extends that shelf life available to have the product on-market.”
Acknowledging that to date, the data available about the NanoTracer in action is fairly limited, Brooks underlines that the speeding up DNA-positive testing could be an enormous boon to those dealing in perishables.
“Getting DNA results two days quicker extends your shelf life by two days,” he says. “Instead of having to use preservatives to extend shelf life on the back-end, you’re actually getting it up front. That could make a huge impact to the market.”
Temple, meanwhile, is happy to see the development of another technology in the fight against food fraud.