Aggregated-state remodeling of quinoa protein gels by thermal pretreatment and transglutaminase

This study elucidated the aggregated-state remodeling of quinoa protein (QP) gels driven by thermal pretreatment and transglutaminase (TGase). This restructuring transformed weak gels into dense, homogeneous networks with significantly enhanced gel strength (40-fold increase) and water-holding capacity (97.8%). Multi-scale analyses revealed that this improvement originated from structural reorganization across multiple scales, including the molecular, aggregated, and morphological levels. TGase-induced cross-linking also modulated protein digestibility, reducing overall digestibility, particularly in the gastric phase (digestibility decreased from 61.7% to 47.7%), while accelerating initial hydrolysis in the intestinal phase (digestibility decreased from 77.5% to 70.5%). Segmented digestion kinetic fitting and correlation analysis revealed that changes in nanoscale compactness of the aggregates (fractal dimension α increased from 2.33 to 3.10) were the central factor that influenced texture and digestion properties. These findings demonstrated that targeted remodeling of the aggregated state was a powerful strategy to design plant-based foods with customized textural and digestive functionalities.