Emulsion Prepared with Auricularia polytricha (Mont.) Sacc. As a Direct Emulsifier for β-Carotene Encapsulation: Stability and Digestibility

β-Carotene is widely utilized in food systems due to its biological activities, but exhibits poor chemical stability and low bioavailability. This study utilized whole Auricularia polytricha (Mont.) Sacc. powder as a direct emulsifier to establish a natural emulsion-based delivery system designed to enhance the stability of β-carotene. Under optimal conditions, using 7% Auricularia polytricha (Mont.) Sacc. powder (120 μm) and 1% oil phase fraction, microscopic analysis revealed that emulsion droplets were small and uniformly distributed, resulting in excellent long-term stability. After UV irradiation, the degradation rate of β-carotene in the emulsion was significantly lower than that of β-carotene directly dispersed in the oil phase. In vitro simulated digestion indicated that β-carotene retention in the intestinal phase reached 9.2% in the emulsion system, 1.2 ± 0.23% higher than in the conventional oil-dissolved system. This strategy offers a practical approach for the high-value utilization of this fungal resource, streamlining industrial processes and reducing production costs.