Quick Test for Milk Allergen in Processed Foods

Food makers struggle to measure milk allergens in processed items. The usual lab steps can give inconsistent results because digestion varies and the food matrix interferes. This makes it hard to know exactly how much β‑casein is present. Researchers wanted a more reliable way to track this key allergen.

They created a new technique that uses a recombinant, isotope‑labeled, full‑length protein called β‑casein‑I as an internal standard. The label is almost completely heavy, and its sequence matches the natural protein closely. By adding this standard early, the method balances out errors from digestion, sample prep, and the mass spectrometer. This approach keeps measurements steady across different foods.

The team tested the method in three different processed food matrices. It worked over a range of 0.1 to 50 ng/mL with excellent linearity. Recoveries ranged from 89 % to 116 % and the relative standard deviation stayed below 13 % at each spiking level. Limits of detection were 0.2–0.5 µg/g. Two signature peptides were watched together, which helped avoid false positives from goat milk. When they ran the assay on 11 commercial products, β‑casein showed up in every single one.

This new protocol gives a trustworthy way to quantify milk allergens, beating older peptide‑based tricks. It can help manufacturers label products more accurately and protect people who are sensitive. The simple, robust design makes it useful for routine labs and quality‑control teams.