On-Chip Discovery of Allergens from the Exudate of Large Yellow Croaker (Larimichthys Crocea) Muscle Food by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

It is extremely crucial to establish facile, accurate, and fast methods for testing allergenic proteins (allergens) in seafood. The current study focuses on the evaluation of fish muscle exudate proteins in an effort to discover potential allergens in fish exudate for allergy tests. Large yellow croaker (Larimichthys crocea) was studied as a seafood model. Magnetic beads (MBs) modified with an IgE antibody were utilized to isolate allergens existing in the exudate sample. Immunoglobulin E (IgE) in blood is a class of antibodies that is mainly associated with allergic reactions. Potential allergens in the muscle exudate were fished by IgE-biofunctional MBs in microfluidic channels. The protein-attached MBs were isolated under a magnetic field, eluted, and collected. The collected eluent was digested and analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to identify allergens. Eight allergens from large yellow croaker exudate were identified, i.e., parvalbumin beta, parvalbumin, protein S100, histone H4, cytochrome c, fatty acid binding protein 3 (FABP3), microsomal glutamate S-transfer 3 (MGST3), and C–C motif chemokine 21 (CCL21). The presently proposed microfluidic-magnetic-based allergen extraction protocol enables a facile and rapid test of potentials of seafood allergies, providing a solution to circumvent food safety issues, especially for allergic populations.