Development of a Method for Determination of Buckwheat Allergens Using Liquid Chromatography with Tandem Mass Spectrometry.

An analysis technique using LC with tandem MS (MS/MS) has been developed for the determination of buckwheat proteins, including major allergens. A protein solution extracted from buckwheat was reduced, alkylated, and digested by trypsin. Peptide spectra were obtained using full-scan LC-MS/MS analysis, and peptide sequences were determined through a protein search. Nine peptides of the 13S globulin seed storage protein and one peptide of a 16 kDa allergen were selected as the marker peptides, and multiple reaction monitoring conditions were optimized. Using the conditions, different kinds of buckwheat noodles, powders, and other food ingredients were analyzed. As a result, buckwheat samples present all the fragment peaks, whereas other foods, including Sesamum indicum, wheat, and soybeans, are not detected at all. These findings indicate that LC-MS/MS analysis may be applied to the detection of buckwheat food allergens.