Technological Challenges for Spray Chilling Encapsulation of Functional Food Ingredients

Spray chilling technology (also known as spray cooling and spray congealing technology) has been widely studied and used in the pharmaceutical field. In the food industry, this technique is gaining interest and can become useful because functional food formulations can be developed. Spray chilling is a fat-based system, which involves the addition of the component of interest to a molten lipid carrier, and the resulting mixture is fed through an atomiser nozzle. When the nebulised material is put into contact with the environment, which is cooled below the melting point of the matrix material, the vehicle solidifies (due to heat exchange between the molten material and cold air), and solid lipid microparticles are formed at the same time. This technology is fat based, and lipid carriers, such as wax and oil (e.g. palm oil, beeswax, cocoa butter, and kernel oil) can be used. This encapsulation technique can potentially change the functionality, reduce the hygroscopicity, mask taste or odour, change solubility, and provide physical protection in addition to allowing the controlled release of these ingredients. This low-cost technology is relatively simple to apply and scale up, and it does not require the use of organic solvents and the application of high temperatures in the process. Therefore, spray chilling encapsulation may facilitate the development and production of functional and enriched foods as it may solve some technological problems associated with the use of certain ingredients, such as those that have high reactivity and low stability.