Pinto bean protein ultrasonicated cold-set emulsion gels catalyzed by transglutaminase/glucono-δ-lactone: Development, characterization and in vitro release characteristics

In the present study, thermally aggregated Pinto Bean Isolate protein (TA-PBI) dispersion was exposed to high-intensity ultrasound (HUS) for 0, 25 min and 50 min, and then the gelation process was carried out through glucono-δ-lactone (GDL) or transglutaminase (MTGase). The results demonstrated that HUS treatment enhanced the intensity of intrinsic fluorescence and surface hydrophobicity of TA-PBI dispersions. HUS led to producing a uniform and dense gel structure. It also was found that HUS resulted in the formation of aggregates with high-molecular weight in TA-PBI after treatment with MTGase. HUS induced structural alterations in TA-PBI molecules, fabricating various microstructures and improving water holding capacity and gel strength. The gel produced in optimal condition was incorporated with curcumin. Cross-linking reduced the swelling ratio of the gels upon subsequent rehydration. It also changed the rate of curcumin release from the emulsion gels.