Encapsulation of rosemary essential oil in alginate–locust bean gum microcapsules for enhanced control of Salmonella Enteritidis in chicken meat

Salmonella Enteritidis, associated with poultry products, is a significant foodborne pathogen known to cause high rates of hospitalization and mortality. Although rosemary essential oil (REO) is a potent natural antimicrobial agent, its high volatility limits its direct use in foods. This study investigated the antimicrobial efficacy of free and encapsulated REO against S. Enteritidis under both in vitro and in situ conditions. REO was encapsulated using a sodium alginate (SA) and locust bean gum (LBG) wall matrix at ratios of 1:1 (F1), 1:3 (F2), and 3:1 (F3), yielding encapsulation efficiencies of 43.0%, 35.4%, and 22.9%, respectively. Release rates followed the order 3% acetic acid > distilled water > 85% ethanol. After 48 h, F2 showed the highest release in distilled water (90.1%), whereas F3 showed the lowest (47.5%). While in vitro tests indicated that encapsulation slightly reduced antimicrobial potency, in situ trials on chicken meat demonstrated superior performance. Encapsulated REO reduced the S. Enteritidis load in heavily contaminated meat by 3.01 log CFU/g within 120 h, representing a substantially greater reduction than that achieved with free REO (0.98 log CFU/g). These findings indicate that REO-loaded SA:LBG (1:3) capsules effectively improve the microbiological safety of chilled poultry products through controlled release.