In vitro assessment of addition of soy protein isolate on milk protein digestion and conformational behaviour

Soy protein (SP) and milk protein are nutritionally complementary proteins, while they have different postprandial kinetic manifestations. In this study, different sources of proteins (casein, whey protein and SP isolate) were compounded in different concentrations and ratios. An in vitro dynamic gastrointestinal digestive system for children was used to study the digestive behaviour. For all the concentrations assessed, a consistently high level of small peptide release was demonstrated at 2.67 g/100 mL protein concentration, while the addition of 10% SP isolate would increase the release of small peptides. Overall, the study offers novel perspectives on children's products with diverse protein sources.