Structure and functional properties of whey protein conjugated with carboxymethyl cellulose through maillard reaction

This study investigated the effects of reaction time in preparation of Whey Protein-Carboxymethyl Cellulose (WP-CMC) conjugates and characterized the functional properties of the conjugates. WP-CMC conjugates were prepared under the wet heating condition of the Maillard reaction. The degree of response was distinguished by variations in the pH value, browning degree, and grafting (up to 23.24%). The emulsification performance of WP-CMC was improved, which was verified by emulsifying activity (up to 4.48% increase), particle size, zeta-potential, and other indicators by conjugates. Meanwhile, the solubility (up to 24.14% increase), 1,1-Diphenyl-2-picryl-hydrazyl Radical (DPPH•) scavenging capacity (up to 3.14 times), and iron-reducing power (up to 1.98 times) of conjugates were also improved. The results of sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) confirmed the elevated molecular weight of the binders, the fluorescence spectra showed bursts and red shifts that identified changes in the hydrophobic structure of the binders, and the Fourier infrared spectroscopy analysis responded to changes in structure and functional groups. The results showed that the optimal treatment time for WP-CMC was 140 min, and the properties and functions were better than those of the simple mixture of CMC and WP, which may play a positive role in the industrial application of WP.