Computed microtomography and mechanical property analysis of soy protein porous hydrogel prepared by homogenizing and microbial transglutaminase cross-linking

A novel, safe and rapid method for preparing soy protein-based porous hydrogel was described in this work. The porous hydrogel was synthesized by high speed homogenizing in the presence of microbial transglutaminase (MTGase) that catalyzed the cross-linking of the proteins. Computed microtomography (μCT) was used to characterize the porous structure of the formed gels. The extent of cross-linking and mechanical properties of the hydrogel were also evaluated. The influence of MTGase addition, homogenizing speed and soy protein isolates (SPI) dispersion pre-heating temperature on the porosity and mechanical properties of the hydrogel was investigated. The amount of MTGase, which determined the degree of cross-linking, gelation time and gel strength, played a critical role in preparation. With this method, soy protein porous hydrogel with controllable porous architecture was able to be prepared in a fast and simple way. This porous structure provided a special texture and some potential applications such as nutrients and flavors carrier for the hydrogel.