A new smartphone app is able to check for the presence of cancer-causing chemicals in food. Scientists have developed a color-changing film that shoppers can stick on processed meats.
Taking a photo quickly scans for levels of preservatives called nitrates and nitrites. The device, described in log Applied materials and ACS interfacesis easy to use and helps consumers make informed decisions, according to its researchers.
These chemicals give sausages and bacon their characteristic pink hue and distinctive flavor, but can form tumor-causing compounds. The more there are, the darker the image.
People have been advised to limit their intake of nitrates and nitrites. Knowing how much is in a product has been difficult to determine, until now.
Corresponding author Dr Jose Garcia, from the University of Burgos in Spain, said: “It determines the concentration of nitrite in processed meats which can also be used by untrained personnel.
“It’s based on a sensory polymer that changes color on contact with meat.
“A mobile application that automatically calculates the manufacture and residual concentration of nitrite by taking only digital photographs of sensory films and analyzing digital color parameters.”
Cured and processed meats also include ham, pâté and salami. They are treated with nitrite or nitrate salts to give them a fresh look and taste.
Dr Garcia said: “Although nitrate is relatively stable, it can be converted into the more reactive nitrite ion in the body.
“When in the acidic environment of the stomach or under the high heat of a frying pan, nitrite can undergo a reaction to form nitrosamines, which have been linked to the development of various cancers.
“Some methods for determining nitrite levels in foods already exist, but they are not very consumer-friendly and often require expensive and labor-intensive techniques and instruments.”
It was named “Polysen” for “polymeric sensor”. It is composed of four monomers and hydrochloric acid.
Discs cut from the material were placed on meat samples for 15 minutes, allowing the film to react with the nitrite.
The discs were then removed and immersed in a sodium hydroxide solution for one minute to develop the color.
When nitrite was present, the yellowish tint of the film increased with higher nitrite levels in the food.
To quantify the color change, the researchers created a smartphone app that self-calibrates when an array of reference disks is photographed in the same image.
The team tested the film on prepared and nitrite-treated meats, in addition to store-bought meats.
The Polysen-based method produced results similar to those obtained with a traditional, more complex nitrite detection technique.
In addition, Polysen has complied with European regulations on the migration of substances from film to food.
The researchers say the new approach could provide a cheap alternative to other devices.
“Our method represents a big step forward in terms of analysis time, simplicity and guidance for use by average citizens,” said Dr. Garcia.
Produced in collaboration with SWNS.
This story was provided to Newsweek by Zenger News.