The effect of pre-treatment of protein ingredients for infant formula on their in vitro gastro-intestinal behaviour

Abstract

Three milk products, skim milk powder (SMP), demineralised whey powder (DWP) and a whey dominant infant formula (60/40IF) and their corresponding partially hydrolysed products (SMPhyd, DWPhyd and 60/40hyd, respectively) were subjected to static infant in vitro gastro-intestinal (GI) digestion and their digesta were subsequently analysed for protein breakdown. The pre-hydrolysis of proteins provided a head-start in the gastric digestion process compared with the intact proteins, resulting in a higher proportion of small peptides (<1 kDa), a higher degree of hydrolysis and lower observable protein coagulation or curd formation in the gastric phase of the casein dominant systems in particular, which may lead to an earlier onset of gastric emptying in vivo. Little or no differences were detected during the intestinal phase. Hence pre-hydrolysis of proteins may be used as a strategy to lower gastric transit times, which may ease the gastric digestion of infant formulations.