Designing emulsion droplets of foods and beverages to enhance delivery of lipophilic bioactive components – a review of recent advances

Lipophilic bioactive compounds such as lipids, vitamins and phytochemicals serve important antioxidant, functional, nutritional and structural roles in the human body. Colloidal systems such as emulsions are particularly suitable matrices for the protection and delivery of these compounds. This article summarises the principal lipophilic bioactives important for human health and challenges associated with their delivery. It discusses the compositional and physical characteristics of emulsions in relation to bioactive delivery, and chemical stability aspects to consider when engineering efficient emulsion delivery systems. The literature shows that aspects such as oil type, droplet size, interfacial composition and solubilisation capacity impact bioactive availability and that their effects are bioactive specific. Therefore, emulsions must be tailored to the bioactives delivered. Much of the present knowledge is based on in vitro studies, and more data from animal and human models are required to better understand the relationship between emulsion characteristics and bioavailability of lipophilic bioactives.