Glycosylated α-lactalbumin-based nanocomplex for curcumin: Physicochemical stability and DPPH-scavenging activity

Low stability at high salt concentrations, iso-electric point, and high temperature restricted the application of proteins as stabilizers in nutraceutical encapsulation. Protein-polysaccharide conjugates made with Maillard reactions may be better alternatives. In this study, the characteristics of curcumin nanocomplexes prepared with both α-lactalbumin (ALA) and ALA-dextran conjugates as well as the effects of encapsulations on the physicochemical stability and the antioxidant activity of curcumin were evaluated. Curcumin aqueous dispersibility was boosted with nanoencapsulation. The sizes of nanoparticles coated with ALA and ALA-dextran conjugates were 63.5 ± 1.2 and 68.1 ± 2.9, respectively. Encapsulation efficiency (EE) and loading amount (LA) was not influenced with glycosylation. Stability under environmental stresses has significantly improved with ALA-dextran conjugates, compared to ALA. The oxidative stability of curcumin was also remarkably increased, especially with ALA-dextran conjugates at 95 °C. Curcumin coated in ALA and ALA-dextran conjugates had higher DPPH-scavenging activity, compared to free curcumin. ALA-dextran conjugates based nanocarrier may be an excellent delivery system for curcumin to expand the application in a wide range of food products.