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

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.