Tailoring Fumaric Acid Delivery: The Role of Surfactant-Enhanced Solid Lipid Microparticles via Spray-Congealing

Fumaric acid, a naturally occurring preservative with antimicrobial properties, has been widely used in the baking industry. However, its direct addition interferes with yeast activity and negatively impacts the gluten structure. This study investigates the potential of spray-congealing as a method for encapsulating fumaric acid within solid lipid microparticles. The selection of lipid carriers and surfactants is critical, so hydrogenated palm stearin, hydrogenated rapeseed oil, and Compritol ATO 888 (glyceryl behenate) were chosen as lipid carriers, and propylene glycol monostearate and glyceryl monolaurate were utilised as surfactants with varying concentrations. Rheological properties, encapsulation efficiency, particle size, moisture content, and thermal behaviour were assessed, along with the release profiles under different temperature conditions simulating the baking process. The findings indicate that the addition of surfactants significantly impacts the viscosity and stability of the molten mixtures, which in turn affects the spray-congealing process and the release of fumaric acid. The temperature-dependent and time-dependent release profiles demonstrate the potential for customising release kinetics to suit specific applications, such as the baking industry. This study may contribute to the development of a controlled-release system that synchronises with the baking process, thereby optimising fumaric acid's functionality while preserving the quality of baked goods.