Protein and DNA-based assays as complementary tools for fish allergen detection

Area of Science:

• Food Science
• Allergen Detection
• Molecular Biology

Background:

• Fish is a globally significant food allergen, with parvalbumin identified as the primary fish muscle allergen.
• Accurate detection and authentication of fish species in food are crucial for consumer safety.

Purpose of the Study:

• To develop and compare protein- and DNA-based methods for sensitive fish detection and authentication in food.
• To assess the applicability of these methods for identifying eight common fish species.

Main Methods:

• Purification of fish parvalbumins and generation of polyclonal antibodies for ELISA.
• Quantitative ELISA for protein analysis of food extracts.
• Cloning and sequencing of parvalbumin genes for PCR primer design.
• Specific PCR for DNA analysis of food samples.

Main Results:

• ELISA quantified parvalbumin content in fresh fish (tuna < mackerel < cod < salmon/trout < redfish < carp < herring).
• Processed fish showed up to 67% lower parvalbumin content than fresh fish.
• ELISA detected 1-15 ppm fresh fish and 30-170 ppm processed fish; PCR identified eight fish species using 0.2-10 ng DNA, detecting 3 ppm fresh and 30-150 ppm processed fish.

Conclusions:

• Both ELISA and PCR methods offer sufficient sensitivity for protecting fish-allergic consumers.
• ELISA quantifies allergens, while PCR identifies fish species.
• Method detection limits vary; careful validation is necessary for each fish and product.