Temperature-induced interaction with carboxymethyl cellulose affected the rheological properties and structure of wheat gluten

Carboxymethyl cellulose (CMC) is commonly used as a hydrocolloid in wheat breadmaking to improve the technological and sensory quality. The experiment focuses on effects of the interactions between different levels (0.5% and 1.0% gluten basis) of CMC and gluten on the structure and rheological properties during heating process using fourier transform infrared spectroscopy (FTIR), dynamic oscillatory rheology, confocal laser scanning microscopy (CLSM) and isothermal titration calorimetry (ITC). The results showed that the presence of 0.5% CMC could reduce the aggregation extent and reinforce the cross-linked network through the formation of protein-polysaccharide conjugates during heating process, which could increase the viscoelastic properties of gluten. Structural studies showed that 0.5% CMC-gluten mixtures have higher contents of beta-structures (46.12%) compared with control (36.81%). On the contrary, more open and heterogeneous microstructures of gluten were observed with 1.0% CMC, which led to the decreased viscoelastic properties. Structural studies showed there was a decrease in antiparallel beta-sheets (6.99%) and beta-turns (9.34%) accompanied an increase by intermolecular beta-sheets (9.75%) and alpha-helices (9.32%) for the 1.0% CMC-gluten mixture during the heating process. The analyses of ITC showed that the protein-polysaccharide conjugates formed through Maillard-type reaction during heating.