Pickering Emulsions Stabilized by Pea Protein Isolate–Cellulose Conjugates Prepared via the Maillard Reaction and Their Application in Active Substance Protection

The development of innovative solid particles from renewable resources possessing high biocompatibility and exceptional emulsification capabilities is crucial for stabilizing Pickering emulsions and advancing carrier systems. In this study, a pea protein isolate (PPI)-cellulose conjugate particle was prepared by the Maillard reaction. Compared to the isoelectric point of pH 4.6 of pure PPI, the isoelectric point of these conjugate particles decreased to pH ∼1. The prepared conjugates could stabilize Pickering emulsions with a high oil phase content (65%), and the prepared emulsion demonstrates long-term storage stability (more than 5 weeks), pH stability (stable from pH 5 to 9 for at least 14 days), and thermal stability (maintained at 80 °C for 48 h). Furthermore, the emulsion demonstrates good protective capabilities for curcumin, with its activity decreasing by only 10% after storage for 10 days. Therefore, the prepared emulsions can be widely used in various fields, such as the food, cosmetic, and pharmaceutical industries.