4 July 2022
The environmental risk associated with the increased use of traditional plastics has prompted European scientists to study bio-based and biodegradable solutions for food packaging.
Food packaging waste constitutes a major environmental pollutant and emerges from packages that are non-degradable such as plastic. Therefore, there is a pressing need for alternatives to fossil-based raw materials in the food packaging industry.
Bio-based food packaging
Packaging materials associated with food must guarantee food protection, freshness and overall quality during transportation and storage. The CBE JU-funded BioBarr project focused on polyhydroxyalkanoates (PHAs), conventionally produced by non-pathogenic bacteria under nutrient-limiting conditions. From a literature study, the researchers found that a member of the PHA family is a good candidate to substitute polypropylene and polyethylene and that, unlike equivalent fossil polymers, it is biodegradable in both soil and sea.
'The idea was to set up a biotechnology bacterial fermentation of waste derived from sugar beet industrial processes such as molasses and its juices for extracting PHAs,' explains Marianna Faraldi, project coordinator and senior researcher at Tecnoalimenti.
The researchers studied the processability of the PHAs in powder, granules and flexible films. This revealed its functionalisation for surface treatments or lamination for improving the barrier properties against oxygen and water vapour. BioBarr also studied their properties, resistance, biodegradability and compliance with safety standards. Significant know-how was obtained during the project, while new methods were developed to improve the state of the art. Surface treatment of PHAs using aluminium or silicon oxide did not compromise biodegradability, the key feature of PHAs.
'After 54 months of research activities, the development of compostable and biodegradable bio-based packaging material with sufficient barrier properties for food products remains a challenge,' emphasises Faraldi.
The consortium developed a biodegradable PHA-based flexible packaging reel with promising features, that complies with current legislation for food packaging. However, it cannot be exploited yet in a wide range of applications in the food sector due to limited barrier properties and brittleness issues that have yet to be solved. Further investigations are needed. Nonetheless, PHA has the potential to be produced from agricultural or food processing waste rather than sugar, leading to a scale-up of the process. Looking to the future, even if costs remain high compared to fossil-based solutions, the investment expected by PHA providers associated with an increasing demand for bioplastics from consumers will effectively reduce the final cost of the resultant bio-based packaging.
A novel bio-ink for food packaging
The adhesives and inks used in biodegradable packaging solutions should be biodegradable too or their quantity should represent a maximum of 5 % of the whole packaging. Another key goal of the BioBarr project was to replace synthetic resins and organic pigments while maintaining good printability and adhesion on the polymer’s substrate. The project tested resins from different bio-based sources, including soy protein, milk protein, rice starch, and polylactic acid emulsions. They generated prototypes of completely compostable bio-inks that matched the technical requirements for industrial implementation. The ink prototypes demonstrated printability on both conventional and biopolymer-based packaging materials. BioBarr received funding from the Bio-based Industries Joint Undertaking, a public-private partnership between the EU and industry.
Source: CORDIS EU research results