Milk protein coagulation under gastric conditions : A review

Milk protein coagulation is not only important during the processing of milk into various dairy products, but also during digestion of milk. This review focusses on the gastric coagulation of milk proteins. During this process, coagulation of casein micelles and milk fat globules can occur due to pepsin-induced hydrolysis of the proteins that provide steric stabilisation. The gastric coagulation leads to delayed gastric emptying of casein and fat. Native whey proteins are not susceptible to gastric coagulation or delayed gastric emptying. Both heat treatment and homogenisation of milk lead to weaker gastric curds being formed, which are broken down more easily due to proteolysis and deformation. Incorporation of denatured whey proteins in gastric curds of heated milk delays their emptying. Understanding gastric coagulation and digestion behaviour allows tailoring of gastric transit via compositional differences or processing