Emulsion gels stabilized by millet chaff prolamin-gallic acid or -sucralose conjugates: characterization, application in curcumin, and mechanism insights.

Abstract

To develop a safe, low-cost, and efficient curcumin delivery system, emulsion gels were prepared using millet chaff prolamin (MCP) and the conjugates of MCP with gallic acid (MCP-GA) and MCP with sucralose (MCP-S). Gallic acid-binding and sucralose-glycosylation improved the emulsifying properties of MCP, increased hydrophobic interactions (from 0.43 to 0.67), crystallinity (from 27.34% to 67.58%), bound water content, and viscosity of the MCP-emulsion gel, and reduced the loss factor, thereby improving its gel structure, thermal and oxidative stability, hardness, elastically, and cohesiveness. Moreover, gallic acid-binding and sucralose-glycosylation facilitated intestinal digestion of the MCP-emulsion gel, increased curcumin encapsulation (from 84.64% to 94.33%) and loading efficiencies (from 197.35 to 241.58 μg/g), and improved curcumin's photostability, thermal stability, and bioaccessibility (from 31.33% to 76.99%). Furthermore, the MCP-GA-emulsion gel exhibited superior textural and rheological performance, highest thermal and oxidative stability, curcumin-encapsulation and loading efficiencies, and the greatest capacity to enhance curcumin stability and bioaccessibility.