Evaluation of poly- and monoclonal antibody-based sandwich enzyme-linked immunosorbent assay (ELISA) for their performance to detect crustacean residues in processed foods

Abstract

Poly- and monoclonal antibody-based (PcAb and mAb) sandwich ELISA formats were developed to detect tropomyosin, a major crustacean allergen. Their performance was accessed by testing crustacean residue in commercial processed and model foods. Results obtained showed the constructed mAb ELISA have lower LOD (0.004 mg/kg) and LOQ (0.006 mg/kg), and higher specificity for crustacean tropomyosin than the PcAb ELISA (LOD: 0.008 mg/kg and LOQ: 0.01 mg/kg). Despite this, the PcAb ELISA system with fewer matrix interferences could discriminate against all commercial foods on the label and show higher tropomyosin recovery than the same positive samples based on a mAb ELISA test. Additionally, both ELISA systems possess adequate repeatability and precision, and can detect as low levels as 0.01% and 0.05% of incurred shrimp powder in cookies and sausages, respectively. Nevertheless, mAb ELISA system shows lower tropomyosin recovery in the same incurred foods, and fish sauce even when supplemented with 5% shrimp powder addition could not be detected by the mAb ELISA test. These findings indicated that the recovery of tropomyosin decreased with the intensity of thermal processing applied to food, while PcAb ELISA showed better matrix-tolerance and detectability in processed foods.