Encapsulation of Monascus pigments in gel in oil in water (G/O/W) double emulsion system based on sodium caseinate and guar gum

In this study, a gel in oil in water (G/O/W) double emulsion system was developed with the objective of effectively encapsulating Monascus pigments and enhancing its stability. To this end, various formulations were prepared using guar gum co-dissolved with Monascus pigments in the internal phase and sodium caseinate as an outer phase surfactant. Different parameters were examined, including emulsion stability, encapsulation efficiency, rheological and tribological properties, as well as the light and thermal stability of the encapsulated Monascus pigments. The results demonstrated that Monascus pigments were effectively encapsulated in the G/O/W, with an encapsulation efficiency exceeding 90 %. The formulated system exhibited a relatively small particle size, which decreased with increasing guar gum and the external emulsifier contents. This resulted in an increase in viscosity accompanied by the formation of a gel-like structure and improved tribological properties, thereby enhancing the system's stability. The system with 1-1.25 % guar gum and 2.5 % sodium caseinate exhibited the highest stability for Monascus pigments, making them more resistant to heat and light. These findings have the potential to expand applications of Monascus pigments by providing a stable and effective encapsulation and delivery system that can also be utilized in the development of healthier food products.