Oregano essential oil-based natural antimicrobial packaging film to inactivate Salmonella enterica and yeasts/molds in the atmosphere surrounding cherry tomatoes

Abstract

This study investigated the effectiveness of a polyvinyl alcohol (PVA) film containing the natural antimicrobial oregano essential oil (OEO) as an active packaging application for decreasing the microbial growth. The film exerted an antimicrobial effect via the atmosphere surrounding the food rather than direct contact, thereby preserving the quality of cherry tomatoes. A packaging film containing microencapsulated OEO was developed. The loading content increased gradually (104.29–234.29 μg OEO/mg film) with the amount of OEO incorporated (1%, 2%, and 3%), where the PVA films containing 2% OEO had the highest loading efficiency (91.64%), followed by 1% OEO (90.96%) and 3% OEO (88.38%). The antimicrobial activities of the films were evaluated by applying it to fresh cherry tomatoes at 4 °C and 22 °C for 7 days. The large 2% OEO film as well as both the small and large 3% OEO films had strong antimicrobial effects against Salmonella enterica, molds and yeasts, and mesophilic aerobic bacteria. The changes in the hardness, weight, and color of the cherry tomatoes during storage did not differ significantly. The films could be utilized as a packaging material for fresh produce with antimicrobial effects because of the controlled atmosphere surrounding the food rather than by direct contact.