Effects of processing on component interactions and peptide profiles of preterm infant formula based on peptidomics by Q Exactive plus analysis

Abstract

The study aimed to investigate the effects of processing on the component interactions, the peptide profile as well as the bioactive peptides of preterm infant formula after digestion through EASY-nLC1200 Q Exactive Plus system. Results indicated that whey proteins and caseins transferred from serum and pellet fractions to fat fraction to recombine the milk fat globule membrane destroyed after homogenization. Protein interactions caused the changes of nitrogen distribution, protein profiles, and morphology after pasteurization and spray drying. Peptidomics analysis demonstrated that the component interactions of preterm infant formula affected the peptide profiles after digestion shown by the different peptide intensities of certain amino acid compositions and the totally different abundance of the peptides in heatmap. The hydrolysates of five groups exhibited 334, 274, 421, 214, and 265 unique peptides belonging to 144, 116, 185, 101, and 231 master accession proteins respectively. The top 8 abundant proteins identified were β-casein, Lipocln, αS1-casein, αS2-casein, κ-casein, bovine Glycosylation-dependent cell adhesion molecule, α-lactalbumin, and Albumin. The number of bioactive peptides increased after processing but were different from each other. In total, component interactions during processing of preterm infant formula could change the peptide profile and bioactive peptides after in vitro digestion.