Analysis of Peptides by Capillary Electromigration Methods

These peptides themselves and especially as products of enzymatic or chemical cleavage of parental proteins, belong to the important components of foodstuffs. They significantly influence their nutritional, biological, technological, and functional properties. Some of these peptides were found to have effects on human health and nutrition, e.g., by affecting human digestive, endocrine, cardiovascular, immune, and nervous systems. Hence, qualitative and quantitative analysis of peptides in foods is of great importance. For the separation and quantification of peptides in foods, capillary electromigration methods represent one of the most suitable analytical methods. This chapter presents a comprehensive overview of the developments and applications of high performance capillary and microchip electromigration methods (zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography and electrochromatography) for separation and analysis of peptides in foods and food products in the time period since 2010 up to the middle of 2020. Various aspects of the application of capillary electromigration methods for peptide analysis in foods, such as sample preparation, peptide preseparation, preconcentration, derivatization, adsorption suppression, and detection, are described and discussed. Several particular applications of capillary electromigration methods for separation and analysis of peptides in various food samples of animal, plant, and microbial origin are demonstrated.