Enzyme-linked immunosorbent assay kit for beta-lactoglobulin determination: interlaboratory study

Area of Science:

• Food Science
• Analytical Chemistry
• Immunology

Background:

• Accurate quantification of beta-lactoglobulin (BLG) is crucial for food allergen management and quality control.
• Existing methods may lack specificity or sensitivity for complex food matrices.
• Validation of reliable detection methods is essential for regulatory compliance and consumer safety.

Purpose of the Study:

• To validate an Enzyme-Linked Immunosorbent Assay (ELISA) method for the quantitative determination of beta-lactoglobulin (BLG) in diverse food products.
• To assess the performance of the ELISA kit across multiple laboratories and food matrices.
• To establish the method's limits of quantification (LOQ) and detection (LOD).

Main Methods:

• An interlaboratory study involving six laboratories was conducted.
• A commercially available ELISA kit utilizing rabbit polyclonal antibodies against BLG was employed.
• A range of food samples, including cereals, dairy, meat, and plant-based products, were analyzed, along with spiked samples.

Main Results:

• The ELISA method demonstrated no false-positive results or cross-reactivity in milk-free food matrices during in-house validation.
• Most non-milk food samples showed BLG content below the lowest standard, while some showed higher levels.
• All milk-containing and spiked samples were correctly identified as positive.
• The calculated LOQ was 0.22 mg BLG/kg, and LOD was 0.07 mg BLG/kg.

Conclusions:

• The validated ELISA method is suitable for the accurate and reliable quantitative determination of beta-lactoglobulin in various food products.
• The interlaboratory study confirmed the robustness and reproducibility of the ELISA kit.
• This method provides a valuable tool for monitoring BLG levels in food for allergen labeling and safety assurance.