Improvement of vitamin C stability in vitamin gummies by encapsulation in casein gel

Abstract Vitamin gummies have gained popularity in recent years due to ease of swallowing, appealing appearance, and tasty flavors. Water-soluble vitamins such as vitamin C are susceptible to degradation when exposed to oxygen, moisture, light, heat, and change in pH during manufacturing and shelf life. Therefore, it is essential to improve vitamin stability and delay the degradation process. In this study, microencapsulation of vitamin C inside casein gel followed by spray drying produced vitamin C capsules in powder form referred to as micro cheese powder (MCP). The Fourier transform infrared spectroscopy results confirmed an increase in hydrogen bonding between vitamin C and casein, as well as vitamin C and the gummy. In addition, Quartz crystal microbalance with dissipation technology was utilized to provide insights into the physical interaction between micellar casein, rennet treated casein, and vitamin C. The storage studies showed that microcapsules integrated into the gummy retained 92% of vitamin C during accelerated tests within a ten-week period, while the unencapsulated vitamin C in the gummy only retained 79%. In addition, compared to the unencapsulated vitamin C in the gummy, encapsulated vitamin C in the gummy showed better retention of vitamin C and color at different temperatures, humidity, and light conditions. MCP showed slower release and better protection of vitamin C from gummy in the simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). The developed vitamin C microencapsulation is promising to improve the stability of water-soluble vitamins in gummies during processing and storage.