BURGOS, Spain — Trying to avoid over-processed beef for your next barbecue? A new smartphone app is able to check your Meat for preservatives that lead to cancer-causing chemicals before you eat it.

Scientists have developed a color-changing Film that buyers can stick on Processed meats. Taking a Shot quickly scans for levels of preservatives known as nitrates and nitrites. They 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 are advised to limit their intake of nitrites. Knowing how much is in a product has been difficult to determine, until now.

“We have developed an in situ methodology to determine the concentration of nitrite in processed meats which can also be used by unqualified personnel. It is based on a film-like colorimetric sensory polymer that changes color on contact with meat and a mobile application that automatically calculates the manufacture and residual concentration of nitrite by taking only digital photographs of sensory films and analyzing the digital color settings,” the authors write. .

Their article is published in the journal Applied materials and ACS interfaces.

Cured and processed meats also include ham, pates and salami. They are treated with nitrite or nitrate salts to give them a fresh look and taste.

“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“, explain the researchers. “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.”

The device is easy to use and helps consumers make more informed decisions. It was named “POLYSEN” for “polymer 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 which self-calibrates when a reference disk array is photographed in the same frame. 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 the film to food. The researchers say the new approach could provide a cheap alternative to other devices.

“Our method represents a great advance in terms of analysis time, simplicity and orientation for use by the average citizen,” conclude the authors.

South West News Service writer Mark Waghorn contributed to this report.