Encapsulation of essential oils and their application in antimicrobial active packaging

Contamination of food by spoilage and pathogenic microorganisms is a major challenge to public health, food security and sustainability. As a response, there has been a growing interest in the exploration of alternative antimicrobial agents such as essential oils. Although essential oils can be potent antimicrobials, they are chemically and biologically labile and have strong aromas which limit their application as food antimicrobial additives. This has shifted essential oil research from direct food applications towards the use of encapsulated essential oils in active packaging. Various encapsulation methods are increasingly being explored as a way of stabilizing essential oils, masking their aromas and possibly improving their antimicrobial activity with a more sustained release of the antimicrobials. Encapsulated essential oils have mainly been investigated as direct preservatives but their merit in active packaging is comparatively less explored. The current review will critique some currently available encapsulation techniques and their effect on the antimicrobial efficacy, release profiles, stability and sensory properties of the essential oils. Furthermore, the application of encapsulated essential oils in biodegradable active packaging will be explored by focusing on the antimicrobial efficacy, release properties and physicochemical properties of the packaging.