Preparation and Characterization of Highland Barley Distillers’ Grains Gliadin–Chitosan Nanoparticles and Composite Properties

In embedding systems, protein–polysaccharide complexes can be utilized as wall materials to improve the bioavailability and activity of bioactive substances during delivery. This study used the antisolvent precipitation method to manufacture gliadin from highland barley distillers’ grains (HBDGG)–chitosan (Cs) nanoparticles. Using a variety of characterization techniques, the microstructure and interaction mechanism of HBDGG-Cs nanoparticles were examined, and their stability was assessed. In comparison to HBDGG, the results indicated that the addition of Cs enhanced the intensity of UV absorption and reduced the intensity of fluorescence. The content of α-helix dropped, while β-sheet, β-turn, and irregularly coiled content rose in the complexes. Hydrogen bonding, hydrophobic interactions, and electrostatic interactions were the primary forces that formed the nanoparticles. The contact force between HBDGG and Cs enhanced the stability of the nanoparticles. The particle size, polydispersity index (PDI), and zeta potential were 526.10 ± 11.78 nm, 0.20 ± 0.06, and 51.31 ± 0.66 mV, respectively, at a mass ratio of 1:1 between HBDGG and Cs. The nanoparticles exhibited good ionic, acid-base, and storage stability in addition to being widely distributed. This work offers a theoretical foundation for employing HBDGG-Cs nanoparticles to deliver bioactive components in food as well as a novel method for the comprehensive usage of HBDGG and Cs.