Smart food packaging

Spoiled food can be difficult for consumers to detect, and carries potentially severe consequences. One solution may be new combinations of packaging materials and sensors, which both help preserve food and indicate when it has gone bad.

The EU-funded SUSFOFLEX (Smart and sustainable food packaging utilizing flexible printed intelligence and materials technologies) project aimed to develop such technologies. The packaging solutions were intended to be eco-friendly and sustainable, and also able to improve food shelf life and reduce food losses using nanomaterial sensors. The 16-member consortium ran for 3 years from the start of 2012 to the end of 2014.

Work during the first reporting period began with benchmarking existing biopolymer packaging materials and smart sensors. The project selected fresh-cut fruit as an experimental focus. Next, the team determined the packaging properties required for fruit.

The consortium detailed the chemical substances produced by spoiling food, yielding a short list for both fruit and fish. Researchers then selected ethanol as most important for fruit and most compatible with the planned technologies. Before proceeding with the sensors, the group reviewed the pertinent regulations.

Sustainability studies of packaging materials led to reclamation of resources from agricultural by-products. The team chose waste orange peel for antioxidants and wheat straw as a source of cellulose. Other combinations were also tested, including silver nanoparticles.

SUSFOFLEX developed two kinds of sensor that respond to the previously identified by-products of degrading food, including ethanol. The first sensor gives an electrical response, the second responds to increasing temperature with a colour change.

The various sensors were integrated with radio frequency identification (RFID) technology. The intent was to facilitate communication between the sensor and an RFID reader. Other combinations were also tried; the project developed hardware that measures thermally related colour changes, plus the necessary software. Various printing options were also trialled.

Lastly, the consortium began assessing the environmental risks of the proposed materials and technologies. More detailed studies are planned for the project's second half.

To date, SUSFOFLEX has yielded 17 potentially exploitable results, leading to new smart food packaging materials that indicate spoilage. There are clear health benefits of such indication.