After harvesting, vegetables and fruit are subject to a loss of quality. This leads to large food losses every year. Particularly with very perishable soft fruit such as strawberries, raspberries and blueberries, this results in major economic losses in the trade. To counteract these post-harvest losses, packaging is traditionally used to influence the environmental conditions of the product in a favourable way. Sustainability of the current situation can be improved by replacing traditional plastic packaging materials by more sustainable options and by further improving the performance of the packaging system minimising food losses. Still, alternative packaging suitability and performance should be tested with respect to preserving major quality traits that guarantee at least similar shelf life of the fruit in the supply chain as before, thus reducing losses and waste.
Recycled PET (Polyethylene terephthalate), biodegradable PLA (Polylactic Acid) and carton-based punnets with microperforated top seal foils and paper-based punnets were identified as suitable and available alternatives to plastic materials for fruit consumer packaging which can be relatively easily implemented in current supply chains. These new materials were approved as potentially useful by industry end users (Belgian fruit cooperatives) that confirmed an interest in testing for replacing existing plastic unit containers. Blueberries and strawberries were chosen as commodities for testing because of their high commercial relevance and their high sensitivity to decay in suboptimal conditions. Eventually the PLA based packaging was not feasible to implement at this stage as their commercial availability for testing was hampered by the current lack of industrial interest due to practical issues related to material stability and their waste management. While performance of this PLA based packaging is expected to be as good as the recycled PET version when applied to soft fruit like strawberry or blueberry, they are considered less sustainable than recycled PET.
KU Leuven has measured and analysed quality indicators (decay and weight loss) at different time points during typical supply chain conditions for standard plastic and alternative packaging to compare the alternatives to the baseline condition. For blueberry it was shown that sealed recycled PET (rPET) punnets, packaged in modified atmosphere (MAP), were able to further reduce fruit losses while the carton punnets were more similar in their performance to the reference.
Figure 1: Sustainable blueberry packages evaluated during the 2024 trial
INRAE has developed a model to predict heat and mass transfer in a container filled with blueberries considered as a porous food medium. The model simulates temperature change as well as evaporation and condensation on the surface of stored product stacks at the container (punnet) scale with respect to the outside conditions, and the presence of vent holes.
The model will be used to study the impact of temperature dynamics, moisture migration and condensation on fruit mass loss. The model has a very good agreement with the experimental results. Work on these models will continue in 2025.
Figure 2: Blue berries of good and bad quality.
These findings on sustainable fruit packaging alternatives directly contribute to Demo 6 – Climate Neutral Packaging, which aims to reduce post-harvest losses and improve sustainability in fruit supply chains. By evaluating innovative packaging solutions such as recycled PET and carton-based punnets, and integrating predictive modeling, this research supports the demo’s goal of identifying high-TRL, low-carbon packaging solutions for immediate industry application. The collaboration between INRAE, KU Leuven, and VCBT further strengthens the scientific foundation of Demo 6, ensuring robust testing and validation under real-world conditions.
