Impact of alfalfa (Medicago sativa L.) galactomannan on the microstructural and physicochemical changes of milk proteins under static in-vitro digestion conditions

•The impact of alfalfa galactomannan (AAG) on the digestibility of milk proteins was studied.•AAG mediated the intragastric aggregation of both sodium caseinate and whey protein isolate.•AAG affected only the peptic cleavage of caseins and β-lactoglobulin in the gastric chymes.•AAG enhanced the free amino acids release in the gastric chymes regardless of the protein type.•The free amino acids release rate in the intestinal chymes were adversely related to AAG content.