Rosemary Essential Oil as a Natural Additive in Food Industry: Recent Developments in Encapsulation Techniques

Rosemary essential oil (REO) is a complex mixture of volatile organic compounds (VOCs), predominantly oxygenated monoterpenes such as 1,8-cineole, camphor, and borneol, which together exhibit antioxidant and antimicrobial activities. These properties make REO a promising natural alternative to synthetic food additives; however, its high volatility, low water solubility, chemical instability, and intense aroma significantly limit its direct application in food systems. Encapsulation has therefore emerged as a key strategy to enhance REO stability, preserve bioactivity, and enable controlled release while reducing sensory impact. This review critically examines conventional and advanced techniques for REO encapsulation. These techniques are comparatively evaluated by addressing their advantages and limitations, with particular emphasis on wall material selection and its role in controlling release behaviour and functional performance in real food matrices. In addition to summarising current applications in food preservation, functional ingredients, and active packaging, this review highlights a key research gap: the limited post-encapsulation characterisation of REO chemical composition, especially minor VOCs responsible for synergistic biological effects. Addressing this gap is essential for the design of encapsulation systems that effectively integrate aroma, preservation, and functionality in clean-label food products.