Preparation of soybean oil-based emulsions stabilized by shiitake mushroom chitosan modified in both enzymatic and non-enzymatic systems and their application in β-carotene delivery.

This study investigates the laccase-catalyzed grafting of gallic acid (GA) onto shiitake mushroom chitosan to enhance its emulsifying properties and improve β-carotene delivery. Structural characterization using FTIR, XPS, and H NMR revealed that laccase catalysis promoted the formation of amide bonds, disrupted the crystalline structure of chitosan, and enhanced both its hydration and interfacial activity. The modified chitosan emulsions exhibited significantly improved emulsification capacity and stability, with GA-grafted chitosan achieving emulsification activity of 3.34 L/g·cm and stability of 97.6 %. The β-carotene encapsulation efficiency increased to 82.1 %, with enhanced resistance to UV light and H₂O₂-induced degradation. In vitro digestion experiments demonstrated that the modified chitosan emulsion improved β-carotene bioaccessibility (75.8 %) and cellular uptake (55.3 %), significantly improving delivery efficiency. This study provides a novel approach for the development of functional emulsion carriers and lays the foundation for their application in food and drug delivery systems.