Gamma-decalactone (GDL) is a naturally occurring compound with a characteristic peach-like aroma commonly found in fruits. Beyond its sensory appeal, lactone has potential antimicrobial properties, which could be valuable in developing active food packaging materials.

This research aims to assess the level of microbial inhibition by edible coatings enriched with natural lactone. Several variants of pectin coatings with different GDL concentrations were prepared—from 2.5 to 10%. Model studies were performed against the common Gram-positive bacteria Bacillus subtilis. Bacteria were grown on Mueller–Hinton liquid medium with 1 g of the coatings with different GDL concentrations. The microorganisms were multiplied for 72 h at 37℃; then, appropriate dilutions were made, and the cells were sown onto Petri dishes.

Our study demonstrates that GDL in coating films effectively inhibits the growth of Bacillus subtilis. The films containing GDL—regardless of its concentration—inhibited the growth of the bacteria, while the control samples without GDL showed visible bacterial colonies. This suggests that GDL can function as a natural antimicrobial agent when embedded into food-safe, biodegradable films.

These results support the role of GDL in extending the shelf life of fresh fruits and vegetables and open the door for further research. Upcoming experiments will investigate its effectiveness against other foodborne microorganisms, such as molds and yeasts, to evaluate its broader potential in sustainable and natural food preservation strategies.