[Development of a Method for Simultaneous Analysis of Egg and Milk Major Allergens in Beverage Products Using High-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry].

A method for simultaneous analysis of egg and milk allergens using LC-QTOF-MS was developed. The proteins measured were α-casein, β-lactoglobulin, and ovalbumin, which are the main protein allergens in milk and eggs. The proteins were digested using trypsin, and the digests were analyzed by LC-QTOF-MS. Sixteen peaks were detected that confirmed the amino acid sequences of the digests, and a MRM method with high resolution (MRM-HR) using product ions of these peaks was applied for quantification. Next, validation studies were performed using beverage products to which milk and egg standard protein solutions had been added. Good linearity was achieved over the concentration range of 1.25 to 20 μg/g of milk and egg protein, and acceptable reproducibility and accuracy were obtained at 10 μg/g. Moreover, good agreement was also observed between LC-QTOF-MS and ELISA. These findings suggest that this LC-QTOF-MS method may be useful for determining the milk and egg protein contents of beverages.