Arid grown coriander essential oil and linalool: effects of microencapsulation on the control of Staphylococcus aureus in minced sheep meat

Abstract

Natural preservation strategies using essential oils are gaining momentum, but their volatility and reactivity limit their application in complex food systems where pathogenic bacteria like Staphylococcus aureus remain a persistent challenge. This study addresses this gap by first evaluating Coriander essential oil (CEO) from water-stressed plants and then applying its primary component, linalool, to control S. aureus in minced sheep meat stored at 4 °C. Gas chromatography–mass spectrometry confirmed that the CEO was predominantly composed of linalool (76.52%). We then compared the antimicrobial efficacy of free linalool (FL) and a multilayer microencapsulated linalool (EL) at concentrations of 0.5% and 1% (w/w). In the meat matrix, the delivery method's impact was starkly concentration-dependent. At 0.5%, EL provided superior sustained activity, maintaining a 1-log CFU/g reduction through Day 9, whereas FL’s effect diminished after Day 3. Conversely, at 1%, FL achieved the greatest overall reduction by Day 9 (3.3 log CFU/g), significantly outperforming the EL form. This suggests that factors like limited solubility or release efficiency may hinder the encapsulated form at higher concentrations. These results demonstrate that microencapsulation enhances stability for a sustained effect at lower concentrations, revealing a critical interplay between dose and delivery for optimizing natural food preservatives.