Unraveling the potential health impact of the interactions between pea hydrolysates/peptides originating under gastric digestion and bile salts

Abstract

Bile salts (BS) are biological surfactants that have important physiological functions mainly by participating in lipid digestion and intervening in the transport, absorption, and excretion of hydrophobic products. Bile salts have been shown to interact with the products of protein hydrolysis, being this interaction a key point to modulate several physiological processes.The type and size of peptides, released at different times of gastric digestion, could have different implications in these physiological processes modulated by the BS. In the present study we focused on understanding how the interactions of hydrolysates/peptides from native or commercial pea protein isolates with BS (formation of insoluble complexes or the modification of the BS micellar solubilization of poorly soluble molecules) evolve according to their residence time in a static gastric digestion model. The different residence times (10–60 min) would simulate different emptying points in which the partially hydrolyzed pea proteins by pepsin in the stomach are flushed into the duodenum and come into contact with the BS.It is observed that the longer residence times in the stomach the degree of hydrolysis of the pea isolates is greater, producing an increase in the soluble fraction. Both isolates showed a slight tendency to bind BS and form insoluble precipitates. The interaction of the soluble fraction of pea protein hydrolysates with the BS micelles, acted synergistically, increasing the solubilization capacity of oleic acid, taken as a model molecule. Likewise, it is shown that the structural changes of pea proteins due to processing have a profound influence on the interaction with BS and potentially affect the physiological reactions that they modulate.