Effect of Beeswax on the Stability of W/O Emulsion and Its Mechanism

ABSTRACT

Wax‐containing water‐in‐oil (W/O) emulsions are widely used in industries such as food, pharmaceuticals, and petroleum. However, waxy materials pose challenges to the stability of emulsions. This study investigated the relationship between beeswax (BW) crystallization behavior and W/O emulsion stability in five different oil systems: straight‐chain alkanes, esters, branched‐chain alkanes, and triglycerides. EM90 was chosen as an emulsifier. Results showed that BW crystallization behavior depended on its compatibility with emulsifiers and oils, directly impacting the stability of the emulsion. Specifically, in alkanes, poor compatibility with undecane and tridecane (C11–13) or isohexadecane (IHD) led to wax crystal agglomeration and reduced stability. In contrast, longer chain oils like squalane (SQU) and white oil (WHO) showed lower polarity and better compatibility with BW, forming robust crystal networks and improving stability. Moreover, the heterogeneous structure enhanced stability. In the triglycerides caprylic/capric triglyceride (GTCC) system, the compatibility between the oil‐phase ingredients reached a relatively balanced state, allowing BW crystals to adsorb at the oil–water interface, providing an additional mechanism to enhance emulsion stability.

Practical Applications: In cosmetic formulations, wax‐based emulsions enhance moisturization while maintaining desirable sensory properties. However, the inherent crystallization behavior of wax components often compromises emulsion stability. This investigation systematically examines wax crystallization dynamics in cosmetic‐grade W/O emulsions, establishing key structure–function relationships between crystal morphology and emulsion stability. The findings advance formulation optimization strategies for lip care and facial cream products, particularly in balancing wax content reduction with structural integrity preservation.