Identification of peptides from camel milk that inhibit starch digestion

Abstract

The inhibition of starch digestion activities by peptides derived from camel milk proteins was determined and the effect of their amino acids charge and/or hydrophobicity was assessed. Starch digestion by pancreatic and brush border enzymes was assessed in vitro with a peptide to starch ratio of 1:3 (w/w). Hydrolysed whey proteins were more inhibitory than hydrolysed casein. Successive chromatographic separation of peptides enriched positively charged peptides with hydrophobic amino acids. Whey protein hydrolysate inhibited starch hydrolysis by 16%; peptide fractions recovered after CEX and HIC inhibited starch hydrolysis by 33–36%. Peptides in the active fractions were identified by LC–MS/MS and the inhibitory activity of 6 synthetic peptides was evaluated. Two of these six peptides, LALDIEIATYR and VLDELTLAR, inhibited starch hydrolysis by 34–37%. In conclusion, specific peptides that are produced before or during in vitro digestion can inhibit starch digestion and may moderate postprandial blood glucose levels in vivo.