Construction and characterization of pickering emulsion gels stabilized by β-glucans microgel particles

Abstract

Amidst the rising demand for protein and starch, polysaccharide-based microgel particles (MPs) offer a sustainable solution as Pickering emulsion gel (PEG) stabilizer. β-glucans, known for their resistance to rapid digestion, enable targeted ingredient delivery and intestinal health modulation. A novel PEG stabilizer was developed by incorporating non-gelatinous polysaccharide 1,3-α/β-D-glucan into gelatinous polysaccharide 1,3-β-D-glucan after thermally induced gelation and microgelation. Following the blending of these polysaccharides, the three-phase contact angle of the resulting composite β-glucans MPs was modified from 126.6° to 94.7°, achieving nearly neutral wettability. Moreover, the particle size was reduced from 6.64 to 2.74 μm, accompanied by a potential of −21.55 mV. These structural modifications facilitated improved adsorption properties of MPs at the oil-water interface, subsequently leading to complete coverage of the oil droplet surface. Consequently, this process resulted in the formation of small, uniformly distributed emulsion droplets. Confocal laser microscopy revealed that the β-glucans MPs either interconnected to create gel networks or coated with oil droplets. This phenomenon established a thick barrier that prevented oil droplet aggregation and conferred semi-solid physical properties of the PEG. It is worth noting that particle concentration and oil content significantly influenced droplet size, rheological properties, and the stability of PEGs. Specifically, PEGs with prolonged stability were successfully constructed at low MP concentrations (0.6–1.0 wt%) and low oil content (20–50 wt%). This research introduces an innovative approach for structuring liquid oil, with potential applications in fat replacement.