Pectin-coated whey protein isolate/zein self-aggregated nanoparticles as curcumin delivery vehicles: Effects of heating, pH, and adding sequence

In this work, pectin was employed as a coating material to fabricate zein/whey protein isolate (WPI)/pectin complex nanoparticles via a pH-adjusted and heat-induced electrostatic adsorption process for potential oral administration applications of curcumin. Factors such as the order of raw material addition, heating temperature and pH, and zein concentration were comprehensively examined. In addition to electrostatic interactions, Fourier transform infrared and fluorescence spectroscopy indicated that hydrophobic interactions and hydrogen bonds were also involved in the development of complex nanoparticles. The complex nanoparticles obtained not only improved the antioxidant activity of curcumin in aqueous phase, but also contributed to its controlled release under gastrointestinal conditions. Our findings revealed that the heating pH and adding sequence of raw materials had a notable impact on the properties of complex nanoparticles, and that pectin coating had an exceptional stabilizing effect on complex nanoparticles under gastrointestinal circumstances. This study provides novel insights and perspectives for the preparation of polysaccharide-protein complex nanoparticles, signifying the potential use of zein/WPI/pectin complex nanoparticles as delivery vehicles in the functional food and pharmaceutical industries.