Active Packaging Film Based on Poly Lactide-Poly (Butylene Adipate-Co-Terephthalate) Blends Incorporated with Tannic Acid and Gallic Acid for the Prolonged Shelf Life of Cherry Tomato

The antimicrobial property is the key feature of active packaging. Biological macromolecules such as tannic and gallic acids are naturally found in plants such as tea, fruits, berries, and grapes. The incorporation of tannic acid (TA) and gallic acid (GA) in the biodegradable polymer blend Poly Lactide-Poly (Butylene Adipate-Co-Terephthalate) (PLA-PBAT) was used in this study to assess the potential of active packaging. TA and GA (10 wt%) composite films showed a 65%-66% increase in the UV barrier property. The tensile strength value increased after the incorporation of TA and GA (10 wt%), respectively. Overall, 1.67 and 2.2 log reductions in E. coli and L. monocytogenes growth were observed, respectively, in the presence of TA (10 wt%) composite film. In addition, TA composite film was able to maintain and enhance the quality of cherry tomatoes for up to 20 days of storage at room temperature. For cherry tomatoes packed in PLA-PBAT-TA10 (wt%), TSS decreased by 6.3%, pH was 4.3, and a microbial reduction of 2.70 log CFU/mL was observed. In conclusion, TA composite film had confirmed significant UV blocking properties, surface hydrophobicity, and antibacterial properties, which show its potential as an active packaging film.

Automated summary

The incorporation of tannic acid and gallic acid in a biodegradable polymer blend resulted in composite films with improved UV barrier properties and increased tensile strength. These composite films also exhibited antibacterial effects, inhibiting the growth of E. coli and L. monocytogenes. Additionally, the tannic acid composite film showed potential for maintaining and enhancing the quality of cherry tomatoes during storage.