Caracterización proteómica de digeridos gástricos simulados de proteínas de suero lácteo

Whey from bovine milk derived from cheese making, has been considered as a waste product or a product with non-highly valued uses. This uses represent one of the most serious problems of the industry worldwide. There are products in the market that include the whey as an ingredient, used to increase the milk solids at low cost and; in a lower magnitude, they are used to take advantage of some of its functional properties of whey proteins, such as foaming, retention free water and thickener. Due to continuous research activity, it is increasing the number of functional applications (as a source of peptides with biological activity: hypotensive, antioxidant, antithrombotic and immunomodulatory, etc.) and nutritional applications (as a source of energy, essential amino acids, vitamins and minerals), promoting both: the use of whey as an ingredient and as a functional food. In recent years, only few studies have been reported about whey principal proteins characterization. In contrast, those resulting from casein proteins have received more attention. In the present research, the protein fractions of whey main proteins, β- lactoglobulin and α- lactalbumin were characterized as an input for future researches that include evaluation of bioactive peptides. The enzymatic hydrolysis of β- lactoglobulin and α- lactalbumin was carried out using pepsin as enzyme. To evaluate the hydrolysis, it was measured: the hydrolysates molecular weight (SDS- PAGE); the grade of hydrolysis achieved in the reaction (TNBS) and the amount of present protein on each hydrolysate (BCA). Finally, peptides derived from 20 and 120 minutes of hydrolysis reaction were characterized by obtaining a peptide profile using HPLC MS/ MS and the fragments obtained were evaluated by comparing them with bibliographic information.