Efficacy of pomelo oil gelatin coatings on polylactic acid thin films for enhanced antibacterial properties in food packaging

Abstract A sustainable and cost-effective future is anticipated from biodegradable food packaging. Polylactic acid (PLA) films have received momentous attention in food packaging due to their sustainability and biodegradability. However, improving their functionality with antibacterial potential while guaranteeing cell viability remains challenging. In this study, we investigated the encapsulation of natural additives, such as pomelo essential oil (EO), within gelatin and their subsequent spraying on PLA films to develop active food packaging materials. The PLA films coated with gelatin/pomelo oil emulsion (EO + PLA) demonstrated microstructural architecture that contributed to the functional properties of the coating. The water contact angles of PLA and EO + PLA are 74 ± 3° and 63 ± 1°, respectively, still preserving moisture barrier properties. EO + PLA showed a stronger UV absorption peak compared to PLA, thereby showing improved light barrier properties. Antibacterial studies showed a significant reduction of Staphylococcus aureus and Pseudomonas aeruginosa for EO + PLA. Overall, the pomelo oil-infused gelatin coatings on PLA films effectively inhibited bacterial growth without causing any cytotoxicity, contributing to more sustainable and safer food preservation strategies. Further research is required to explore their scalability and long-term performance for various applications in the industry.