In vitro gastrointestinal digestibility under infant conditions of bovine milk fat emulsions stabilized using decalcified micellar casein concentrate

The gastric coagulation behavior and digestibility of bovine milk fat emulsions stabilized using bovine micellar casein concentrate (MCC) with 0–81 % decalcification was studied using in vitro gastrointestinal conditions appropriate for infants. During both the gastric and the intestinal digestion phase, smaller and looser coagula were observed for emulsions stabilized using MCC with increasing degree of decalcification, especially up to 61 % decalcification. The looser coagula promoted the hydrolysis of caseins and the concomitant formation of small peptides and free amino groups. The hydrolysis of triglycerides and the formation of diglycerides, monoglycerides and free fatty acids also increased with increasing degree of decalcification, again up to 61 % decalcification. The main free fatty acids released after both the gastric and intestinal digestion were palmitic acid, oleic acid, stearic acid and myristic acid. Fewer fatty acids in Ca-soaps and a higher bioaccessibility of fatty acids were found at the end of intestinal digestion for emulsions stabilized using MCC with a higher degree of decalcification. These results showed the effect of calcium on gastrointestinal digestibility and bioaccessibility of bovine casein micelle-stabilized emulsions, indicating a potential application of emulsions prepared with an appropriately decalcified MCC in infant formula.