Crosslinking with transglutaminase does not change metabolic effects of sodium caseinate in model beverage in healthy young individuals

Thirteen healthy individuals (23.3？±？1.1 y, BMI 21.7？±？0.4？kg/m2) participated in a single-blind crossover design experiment in which the subjects consumed three different isovolumic (500？g) pourable beverages containing either sodium caseinate (Cas, 29？g), TG-treated sodium caseinate (Cas-TG, 29？g) or whey protein (Wh, 30？g) in a randomized order. Blood samples were collected at baseline and for 4？h postprandially for the determination of plasma glucose, insulin and amino acid (AA) concentrations. Gastric emptying (GE) was measured using the 13？C-breath test method. Appetite was assessed using visual analogue scales.All examined postprandial responses were comparable with Cas and Cas-TG. The protein type used in the beverages was reflected as differences in plasma AA concentrations between Wh and Cas, but there were no differences in plasma glucose or insulin responses. A tendency for faster GE rate after Wh was detected. Appetite ratings or subsequent energy intake did not differ among the protein beverages.Our results indicate that the metabolic responses of enzymatically crosslinked and native sodium caseinate in a liquid matrix are comparable, suggesting similar digestion and absorption rates and first pass metabolism despite the structural modification of Cas-TG.