Food allergen worries? There’s an app for that

Caren B. Les, caren.les@photonics.com

Food allergy sufferers: Wouldn’t it be nice if you could simply scan food with your smartphone to check for potentially lethal allergens? Well, get ready: A personalized food allergy testing system called iTube could bring peace of mind a step closer to your daily bread.

The mini lab – which uses colorimetric assays, test tubes, LEDS and a smartphone-based digital reader – was created by Aydogan Ozcan and colleagues at the University of California, Los Angeles. The system must be installed on the camera unit of a cellphone so that an app can perform highly sensitive testing of a food sample inserted into a tube. It can test for a variety of common allergens, including peanuts, almonds, eggs, gluten and hazelnuts, Ozcan said.

But the iTube is not a “fast food” technology. You can’t just scan your French fries and be on your gastronomical way. Sample preparation and incubation take about 20 minutes: You have to grind up the food sample, mix it in a test tube with hot water and an extraction solvent, then allow it to set. It is then mixed with a series of other reactive testing liquids.

The sample is then measured optically for allergen concentration. Raw images from the phone’s camera are digitally converted into concentration measurements detected in the food samples to determine not only whether an allergen is present, but also how much of the allergen is in the sample in parts per million.

The team successfully tested the iTube by analyzing samples of store-bought cookies to determine whether they contained a harmful amount of peanuts; the research was published in Lab on a Chip (doi: 10.1039/c2lc41152k).

Food test results could be uploaded to iTube servers, the researchers say, to create data archives for personal and public use.

“We envision that this cellphone-based allergen testing platform could be very valuable, especially for parents, as well as for schools, restaurants and other public settings,” Ozcan said.