Tailoring dysphagia-oriented deacetylated konjac glucomannan matrices via oxidative modification.

Conventional diets for individuals with dysphagia are often deficient in dietary fiber. To address this nutritional gap, a safe and comfortable dysphagia-oriented food was developed in this study using deacetylated konjac glucomannan (DKGM) modified via ozonation. Increasing the oxidation levels significantly reduced the hardness (from 454 g to 90 g) and adhesiveness (from 182 to 8) of the DKGM gel, meeting International Dysphagia Diet Standardization Initiative Level 6 requirements. The oxidized gels exhibited improved water-binding, along with substantial modulus attenuation (yield stress and apparent viscosity decreasing by more than 90 % and 75 %, respectively) and enhanced thixotropic recovery rates (exceeding 10 %) and lubricity. Nonetheless, excessive oxidation impaired gel formation and increased the gelation temperature. FTIR, 1H NMR, and SEM scanning electron microscopy revealed the changes in DKGM molecules and gel structure induced by oxidation modification. Main-chain scission and carboxyl introduction restructured the hydrogen-bond networks and rearranged the three-dimensional polymer network, forming discontinuous microstructures with localized rigid regions within the gel.