Preparation of soybean β-conglycinin epitope antibody and its preliminary application in frozen surimi detection

Food allergy has become one of the food safety issues in the world. As a common source of food allergy, soybean poses a dietary risk to allergic individuals due to the presence of β-conglycinin, a main allergenic protein in soybean. Therefore, an efficient and sensitive detection method using highly specific antibody materials is necessary for the detection of allergens. In this study, we have used soybean major allergen β-conglycinin as research object, using analysis software such as DNAStar subroutine Protean, SOPMA server, etc. Three main subunits (α, α′ and β subunits) of β-conglycinin were sequenced. After a series of predictions, screenings and validations, we have obtained the most active epitope peptide with the sequence SNLNFLAFGINAENNQ from the β subunit. This epitope peptide was used to prepare rabbit-derived polyclonal antibodies. Using this antibody, we developed a quantum-dot-based fluorescent lateral flow immunoassay (LFIA) to detect β-conglycinin in frozen surimi. In this detection method, relevant conditions were optimized, and the detection limit was found to be 1.6 mg/g. In conclusion, the epitope peptide SNLNFLAFGINAENNQ was synthesized and using this epitope peptide as the immunogen, rabbit-derived polyclonal antibodies were prepared. A QD-based fluorescent LFIA detection method was developed for a simple, sensitive and specific detection of soybean major allergen β-conglycinin in surimi. This method is beneficial to the healthy development of the frozen surimi industry.