Comparative Study of the Peptide Profiles of A1/A2 and A2/A2 Yogurts during In Vitro Gastrointestinal Digestion

Abstract

The production of A2 milk and its use in dairy products processing are driven by potential health benefits related to the absence or reduced release of β-casomorphin-7, an opioid peptide generated from β-casein hydrolysis during digestion. Although the release of higher concentrations of β-casomorphin-7 has been consistently reported following the digestion of isolated A1 β-casein and milk containing A1 β-casein, the impact of complex dairy matrices on this peptide release remains underexplored. This study evaluated the peptide profiles of yogurts produced from milks with different β-casein genotypes (A1A2 and A2A2) during in vitro gastrointestinal digestion. The release of β-casomorphin-7 was observed in both products’ digestion, but differences in peptide profiles were observed along the β-casein sequence, extending beyond the site of the A1/A2 amino acid substitution.