Ethanol-induced Lentinus edodes β-glucan emulsion gels for curcumin encapsulation: Physicochemical property, microstructure and in vitro digestive property.

The poor solubility and instability of curcumin severely limit their wide application in functional foods. In the present study, a novel ethanol-induced Lentinus edodes β-glucan (LEBG) emulsion gel was fabricated for encapsulation and delivery of curcumin. Ethanol volume fraction affected the gelling capacity of LEBG, and a solid LEBG gel with a compact three-dimensional network structure was formed at 30% (v/v). When the volume fraction of ethanol exceeded 30%, the β-conformation structure of LEBG tended to overfold, resulting in disordered aggregation and a consequent weakening of gel structure. Furthermore, LEBG concentrations and oil volume fractions significantly impacted the physicochemical properties and rheological properties of emulsion gels as well as the stability of encapsulated curcumin. At 1.5% (w/v) LEBG and 50% oil volume fractions, the emulsion gel achieved optimum encapsulation efficiency of curcumin (87.2%) and over 80% retention rate after storage at 50 °C for 2 h. Meanwhile, the in vitro digestion results also showed that LEBG-based emulsion gel with 1.5 wt% LEBG and 50% oil fractions exhibited the slowest release rate of curcumin and free fatty acids (FFA), due to a strengthened emulsion gel structure. The ethanol-induced β-glucan emulsion gel offers a promising strategy for encapsulating and protecting alcohol-soluble and thermal sensitive nutraceuticals.