Can Tannin-coated Paper Packaging Extend the Shelf Life of Fresh Fruits?

This study explores the potential of tannin-coated paper-based packaging to extend the shelf life of highly perishable fruits, with strawberries used as a model. Firstly, the antimicrobial properties of a tannin extract were assessed, demonstrating the most promising results against Staphylococcus xylosus. From this findings, two types of packaging were developed: untreated paper containers and containers coated with the tannin extract. Fresh strawberries were stored in these containers under controlled conditions (5°C, 85% relative humidity) for 19 days. Several parameters were monitored, including microbial growth, texture, colour evolution, weight loss and the fungicidal efficacy of the coated paper, with analysis performed every two days. The results revealed no significant differences in microbial growth or quality parameters between the treated and untreated containers at the different time points. In addition, fungal growth was more pronounced in the tannin-coated containers. These findings suggest that the tannin coating did not enhance key preservation parameters. Instead, it may have accelerated degradation, possibly due to the presence of undesirable compounds that could have fostered fungal growth. These findings serve as the basis for future research that will refine coating formulations and application methods for wider adoption in the food packaging industry.