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

## TL;DR

This study compares how different types of yogurt release peptides during digestion, focusing on potential opioid effects from A1 and A2 milk proteins.

## Contribution

The novelty lies in evaluating peptide release differences in yogurt matrices from A1/A2 and A2/A2 milks during digestion.

## Key findings

- β-casomorphin-7 was released in both A1/A2 and A2/A2 yogurt digestions.
- Peptide profiles differed beyond the A1/A2 substitution site in β-casein.
- Complex dairy matrices influence peptide release patterns during 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.