Accurate determination of sesame allergens in processed food by LC-MS/MS based on isotope-labelled derived peptides as internal standard

As one of the eight major allergens recognized by the World Health Organization and the Food and Agriculture Organization of the United Nations, it is crucial to determine sesame allergens in food. Employing liquid chromatography-tandem mass spectrometry (LC-MS/MS), which exhibits exceptional precision and sensitivity, enables the identification of sesame allergen proteins. In this investigation, we established and validated a methodology for quantifying sesame allergen protein (Ses i 1-7) in processed foods utilizing LC-MS/MS. The key innovation lies in screening sesame allergen characteristic peptides with processing robustness and using isotope labeled derived peptides as internal standards to correct trypsin digestion efficiency, significantly improving quantitative accuracy. The quantitative method showed excellent sensitivity (limit of detection: 1.0-28 μg/g; limit of quantitation: 2.9-56 μg/g), accuracy (recovery rate: 90%-110%), and repeatability (intra/inter-day precision: 1.06%-7.59%/2.68%-6.98%). In addition, this method has been successfully employed in the examination of commercial food. The quantitative method established in this study is beneficial for the management of sesame allergens in processed foods.