Development and validation of mass spectrometry-based method for detecting shrimp allergen tropomyosin

Shrimp allergy is a critical public health concern worldwide, and is also the most frequent cause of food allergy in Taiwan. Tropomyosin is recognized as the major shrimp allergen. However, information of tropomyosin content in Taiwanese shrimp is unknown. Therefore, it is an urgent need to develop a reliable analytical approach to detect tropomyosin. An absolute quantification method of proteins (AQUA) method was developed to detect tropomyosin in seven Taiwanese shrimps in this study. Both signature peptide, ALSNAEGEVAALNR, and its isotope-labeled peptide were used as standards and internal standards. The determination coefficient (R2) of the calibration curve is 0.9989, and the limit of detection (LOD) and limit of quantification (LOQ) were 0.072 ng/μl and 0.219 ng/μl, respectively. The intra-day and inter-day precision of this analytical method are 2.30–12.80% and 2.93–11.97%, respectively. Recovery was measured as 85.53–101.87% by adding signature peptide with 0.5, 1.0, 7.5 ng/μl into the blank matrix. The method showed no cross-reactivity with squid, tilapia and chicken. Also, the current validated method was successfully applied to shrimps and processed foods. The levels of tropomyosin in seven Taiwanese shrimps ranged from 555.50 to 973.93 μg/g. The present study demonstrated this analytical approach may be an useful technique to analyze tropomyosin in foods.