Smartphone app can warn you of cancer-causing chemicals in meat

A new smartphone app could alert users to carcinogenic chemicals in processed meats like sausage, ham, bacon and salami.

Scientists in Spain have developed a system with a color-changing film called “POLYSEN” that consumers can attach to meat products.

Labels darken when they detect high levels of nitrite, a meat preservative that can form potentially carcinogenic compounds.

Users can then photograph the film with a smartphone, and a specially developed app analyzes the color and provides a nitrite concentration value.

The image from the researchers’ article shows that the system is working. The discs pierced by the film are placed on the meat samples for 15 minutes to react with the nitrite. The discs are then removed and immersed in a sodium hydroxide solution for one minute to develop the color. The higher the nitrite present, the deeper the yellowish hue of the film. A smartphone app calibrates itself when photographing a reference disk table in the same image

The system was developed by experts from the Universidad de Burgos in Spain and is detailed in a new study published in ACS Applied Materials and Interfaces.

“There is a need for detection and control of the various chemical compounds added to processed foods, such as processed meat,” they say.

“Our method represents a significant step forward in terms of analysis time, simplicity and orientation for use by the average citizen”.

Processed meats and processed meats such as bacon, hot dogs, ham and sausage (including mortadella, an Italian dish) are often treated with nitrites or nitrates to keep them looking and tasting fresh.

Nitrites are widely used in processed meats to extend shelf life by removing bacteria that can cause diseases such as salmonella, listeriosis, and botulism.

Basically, they add a tempting spicy flavor and pink color to products like bacon, making them look tastier.

Although nitrate is relatively stable, it can be converted into the more reactive nitrite ion in the body.

In the acidic environment of the stomach or under the high heat of a frying pan, nitrites can react to form nitrosamines, which have been linked to the development of various cancers.

Therefore, consumers want to limit their consumption of these preservatives, but determining how much is in a food has been difficult.

Nitrites add an enticing spicy flavor and a seductive fresh pink color to products such as sausage, ham, bacon and salami for shoppers (archive photo)

Here a worker packs Mortadella slices at the factory (archive photo)

Next, the researchers created the new POLYSEN film, short for “polymer sensor,” made up of four monomers and hydrochloric acid.

To create a “reference map”, the first punctured discs were placed on five different meat samples for 15 minutes and the monomer units and acid in the film were allowed to react with the nitrite.

The meat samples all had different nitrite concentrations, so the researchers knew the slices would change color.

The discs were then removed and immersed in sodium hydroxide solution for one minute to develop the color.

The higher the nitrite content in the meat, the more intense the yellowish hue of each film becomes.

To calibrate the system, perforated discs were placed on five different meat samples for 15 minutes and the monomer units and acid in the film were allowed to react with the nitrite.

Then the researchers created the smartphone app that uses colorimetry using light to determine the concentration of certain compounds.

If photographed in the same image as the reference map, the application can give a nitrite estimate for the sample disc.

The team tested the film on meat they had prepared and treated with nitrite in addition to store-bought meat.

They found that the POLYSEN-based method produced results comparable to those obtained with a traditional and more complex nitrite detection method.

In addition, POLYSEN has complied with European regulations for the transition of substances from film to food.

While the team has only been able to demonstrate the system for now, it could provide consumers with an easy-to-use and cost-effective way to determine nitrite levels in foods in the future.

“This study was designed as a proof-of-concept demonstrating that the methodology is practical and works,” they conclude.