Alleviation of structural deterioration in gluten and its components during freeze–thaw cycles by deacetylated konjac glucomannan

The cryoprotective effects of deacetylated konjac glucomannan (DKGM) on gluten and its components in frozen dough remain unclear. This study aimed to investigate the impact of DKGM with varying degrees of deacetylation (DD) on the structural stability of gluten and its components during freeze–thaw (FT) cycles. Compared with konjac glucomannan, DKGM effectively alleviated the gluten structural “depolymerization–aggregation” process during FT cycles, with DK2 (DD, 50.21%) exhibiting the optimal cryoprotective effect. The DK2 group retained higher noncovalent interactions and disulfide bonds during FT cycles, thereby stabilizing the gluten structure. Studies on glutenin and gliadin suggest that glutenin is more susceptible to FT damage. DK2 provided the best protection for glutenin, whereas DK3 (DD, 66.61%) provided the most effective protection for gliadin. These distinct effects were likely attributable to differences in the particle size and steric hindrance of DKGM, as well as the inherent structural characteristics of the protein components. • Gluten underwent a “depolymerization–aggregation” process during freeze–thaw cycles. • Deacetylated konjac glucomannan (DKGM) enhanced the structural stability of frozen gluten. • Glutenin is more vulnerable to freeze-thaw damage compared to gliadin. • DKGM with moderate DD (50.21%) optimally stabilizes the effect during freezing.