Simultaneous determination of multi-allergens in surimi products by LC-MS/MS with a stable isotope-labeled peptide

A novel LC-MS/MS method for simultaneous quantification of the allergens of soy, milk and egg in surimi products was established based on three signature peptides, namely EAFGVNMQIVR (soy glycinin G2), YLGYLEQLLR (milk α-S1-casein), GGLEPINFQTAADQAR (egg ovalbumin) and a stable isotope-labeled peptide EAFGVNMQI* (I*, ¹³C₆, ¹⁵N) VR. After protein extraction and tryptic digestion, four selected marker peptides were measured by HPLC-MS/MS. The determination coefficient R² was higher than 0.9914 at the range of 0.5-200 ng/mL and both the intra and interday precision RSD were less than 6.7% for three peptides. Limit of quantitation was shown as 0.054 μg/g for soy, 0.024 μg/g for milk and 0.032 μg/g for egg. Current validated method was successfully applied to analyze surimi products, which can not only provide accurate quantification information of allergens for sensitive consumers, but also it may be used for label management for surimi market.