Enhancing meat preservation with eco-friendly, antibiotic-free yeast-encapsulated essential oils

The application of essential oils as biopreservatives is hindered by their high volatility, chemical instability, and potential sensory impact. This study presents an eco-friendly preservation strategy by encapsulating the most potent antimicrobial EOs within Saccharomyces cerevisiae cells. These oils were subsequently encapsulated into autolyzed yeast cells, a process optimized at 45 °C to maximize cell integrity and oil loading. Encapsulation efficiency varied with EO chemistry, being highest for cinnamon (eugenol-rich) and lowest for rosemary (camphor-rich). In vitro assays showed encapsulation differentially modulated efficacy. It reduced the minimum inhibitory concentration (MIC) of cinnamon EO by 50% (from 6.25 to 3.12 µL, p < 0.05) while increasing the MIC for thyme and oregano. Importantly, in a real-world ham model, yeast-encapsulated EOs applied at their MIC achieved a superior, sustained bactericidal effect against E. coli over a six-day storage period. Encapsulated thyme and cinnamon reduced bacterial survival to below detectable limits within 24 h under specific packaging, outperforming free EO treatments (p < 0.001). These findings demonstrate that yeast microencapsulation successfully overcomes the key limitations of EOs, transforming them into stable, effective, and natural preservatives. The study provides proof-of-concept for S. cerevisiae as a GRAS, biodegradable delivery system, offering a promising antibiotic-free approach to enhance the safety and shelf-life of meat products.