In this study, the combined effect of ultrasound pretreatment (US) and microbial transglutaminase (MTG) on the rheological, textural, and functional attributes of whey protein concentrate (WPC) were investigated. All the samples exhibited non-Newtonian shear-thinning behavior. Treatment with US lead to a significant increase in foaming capacity, gel hardness, and adhesiveness at 7.5 min, while reduced emulsifying capacity and syneresis at all levels. Moreover, consistency coefficient, foam stability, emulsifying capacity, emulsion stability, gel hardness and adhesiveness improved, whereas a slight decrease was observed in foaming capacity and syneresis of gels as a consequence of TG treatment respectively. 5 min US - 5 U·g− 1 pr TG treated sample exhibited the least syneresis value of all samples. SEM images affirmed the beneficial effects of treatments on texture, reduction of voids size and supported the textural results. Overall, ongoing US pretreatment and TG treatment were successful in modifying the functional properties of whey proteins.

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