Progress on water-in-oil-in-water (w/o/w) double emulsions: bioactive delivery, stability optimization, and sports nutrition applications

There is a growing global demand for healthy and nutritious foods, especially among specialized groups such as athletes and bodybuilders. Water-in-oil-in-water (W/O/W) double emulsions have garnered significant interest due to their ability to simultaneously deliver both hydrophilic and hydrophobic bioactive compounds. This review discusses the cargo release mechanism of W/O/W emulsions, along with their inherent advantages and limitations. The primary preparation methods and fabrication techniques for such emulsions are subsequently summarized. Additionally, the instability mechanisms of W/O/W emulsions are verified, and corresponding strategies to enhance their stability are proposed. Furthermore, the application of double emulsions as nutritional supplements in sports nutrition is critically reviewed, alongside key directions for future research. This review provides a theoretical foundation for the design and development of stable, functionally tailored double emulsions intended for application in athlete-specific food nutrition.