Fabrication and Characterization of Konjac Glucomannan/Oat β-Glucan Composite Hydrogel: Microstructure, Physicochemical Properties and Gelation Mechanism Studies

The aim of this study was to evaluate the effect of oat beta-glucan on the formation mechanism, microstructure and physicochemical properties of konjac glucomannan (KGM) composite hydrogel. The dynamic rheology results suggested that the addition of oat beta-glucan increased the viscoelastic modulus of the composite hydrogel, which was conducive to the formation of a stronger gel network. Gelling force experiments showed that hydrogen bonds and hydrophobic interactions participated in the formation of the gel network. Textural profile analysis results found that the amount of oat beta-glucan was positively correlated with the elasticity, cohesiveness and chewiness of the composite hydrogel. The water-holding capacity of the composite hydrogel was enhanced significantly after the addition of oat beta-glucan (p < 0.05), which was 18.3 times that of the KGM gel. The thermal stability of KGM gel was enhanced after the addition of oat beta-glucan with the increase in Tmax being approximately 30 degrees C. Consequently, a composite hydrogel based on KGM and oat beta-glucan was a strategy to overcome pure KGM gel shortcomings.