In vitro digestion of infant formula model systems: Influence of casein to whey protein ratio

The influence of casein-to-whey protein ratio (C:WP; 40:60, 60:40, 80:20) on the digestibility of infant formula powder was studied using an in vitro digestion model. With increasing C:WP, more extensive coagulation in samples was observed through particle size and confocal microscopy analyses. Coagulum particles consisted of a protein matrix in which emulsion droplets were embedded. The more extensive coagulation also led to significant (p < 0.05) reductions in protein and fat digestion during gastric and intestinal stages of digestion. These reductions can be attributed to reduced accessibility of digestive enzymes to their respective substrates. Gastric coagulation of the caseins was less extensive and digestion of protein and lipid was highest at C:WP of 40:60, which closely resembled human milk. The strong effects of C:WP on the digestion of infant formula further highlight the importance of the gastric coagulation process to ensure efficient digestion of protein and fat. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study investigated the impact of casein-to-whey protein ratio on the digestibility of infant formula powder using an in vitro digestion model. Increasing casein-to-whey protein ratio led to more extensive coagulation in samples and resulted in significant reductions in protein and fat digestion during gastric and intestinal stages of digestion. These findings highlight the importance of gastric coagulation in ensuring efficient digestion of protein and fat in infant formula.