Synergistic effects of oxidized konjac glucomannan on rheological, thermal and structural properties of gluten protein

Oxidation is an effective way to prepare depolymerized konjac glucomannan (KGM). The oxidized KGM (OKGM) differed from native KGM in physicochemical properties due to different molecular structure. In this study, the effects of OKGM on the properties of gluten protein were investigated and compared with native KGM (NKGM) and enzymatic hydrolysis KGM (EKGM). Results showed that the OKGM with a low molecular weight and viscosity could improve rheological properties and enhance thermal stability. Compared to native gluten protein (NGP), OKGM stabilized the protein secondary structure by increasing the contents of & beta;-sheet and & alpha;-helix, and improved the tertiary structure through increasing the disulfide bonds. The compact holes with shrunk pore size confirmed a stronger interaction between OKGM and gluten protein through scanning electron microscopy, forming a highly networked gluten structure. Furthermore, OKGM depolymerized by the moderate ozone microwave treatment of 40 min had a higher effect on gluten proteins than that by the 100 min treatment, demonstrating that the excessive degradation of KGM weakened the interaction between the gluten protein and OKGM. These findings demonstrated that incorporating moderately oxidized KGM into gluten protein was an effective strategy to improve the properties of gluten protein.

Automated summary

Oxidation is an effective method to prepare depolymerized konjac glucomannan (KGM), which has different physicochemical properties compared to native KGM. This study investigated the effects of oxidized KGM (OKGM) on gluten protein properties and compared it with native KGM (NKGM) and enzymatic hydrolysis KGM (EKGM). The results showed that OKGM with low molecular weight and viscosity improved rheological properties and thermal stability of gluten protein. The interaction between OKGM and gluten protein formed a highly networked gluten structure, and the excessive degradation of KGM weakened this interaction. Therefore, incorporating moderately oxidized KGM into gluten protein is an effective strategy to improve its properties.