Evaluation of Commercial Milk-Specific Lateral Flow Devices

Abstract

The requirement for validation of allergen cleaning processes is increasing. The use of lateral flow devices (LFDs) to identify allergens has rapidly expanded, but the best practices for use of these devices are still developing. The goal of this study was to compare commercially available milk-specific LFDs and a general protein identification method. Five milk proteins and seven milk-derived ingredients were tested at several concentrations with eight milk-specific LFDs and a general protein identification kit. Nonfat dry milk (NFDM) was prepared at 100 to 10,000 ppm of milk protein and analyzed by the LFDs to determine the concentration at which a false-negative result (overload concentration or hook effect) was obtained. NFDM was also prepared in 0.025 M phosphate-buffered saline (pH 7.4, 0.85% NaCl) and applied to stainless steel panels (100, 30, 10, or 3 μg of NFDM protein) with various drying methods and sampled with various swab methods to determine the level of detectability. Several total milk LFD kits did not detect whey proteins or whey-derived ingredients. The overload concentration of the various kits ranged from 100 to 10,000 ppm of milk protein. The small dynamic range observed for some kits would necessitate multiple dilutions of a sample to ensure that the result would fall within the range of detection. For swab sampling of stainless steel for LFD analysis, milk protein residues from surfaces onto which the residues were dried with high heat were more difficult to detect than were residues dried with low heat. No differences in sensitivity were observed as a result of moistening the residue or the swab before sampling. These results highlight the importance of understanding the detection capabilities of LFDs as indicated by the variability in the performance of the milk-specific LFDs tested.

Bovine Milk Allergens: A Comprehensive Review

“…The lack of quantitative information and the susceptibility of these devices in providing false‐negative results are the major drawbacks associated with their use. However, they are largely applied in the food industry to monitor the cleaning of food processing equipment and food product contamination (Courtney and others ). There are several LFD kits in the market that detect milk allergens in food products in a few minutes and on‐site, with LOD down to 0.5 mg/L, as demonstrated in Table .…”

Synthesis of Molecularly Imprinted Polymer Nanoparticles for α-Casein Detection Using Surface Plasmon Resonance as a Milk Allergen Sensor

“…Immunological techniques such as ELISA and lateral flow assay (LFA) are the most widely used techniques for identifying and quantifying milk protein allergens with several commercially available kits on the market 9,10 . They offer simple, rapid and cheap analysis but suffer from high variation in recoveries across different commercial kits and in different analysis conditions [11][12][13] . Hybrid liquid chromatography-mass spectrometry techniques have proven to be the bench mark technique for quantifying allergens in a number of processed foods displaying good sensitivity and accuracy [14][15][16] .…”

Lateral flow immunoassay for small-molecules detection in phytoproducts: a review

“…The system has been continuously refined and simplified, enabling non-skilled operators to perform the assay. Various commercially available strip tests for various antigens or antibodies have been launched [25][26][27]. Although the classical chromatography and ELISA methods offer high accuracy, the LFA is advantageous over them in scenarios where laboratory equipment is not available.…”