Multiplex detection of food allergens and gluten

Abstract

To help safeguard the food supply and detect the presence of undeclared food allergens and gluten, most producers and regulatory agencies rely on commercial test kits. Most of these are ELISAs with a few being PCR-based. These methods are very sensitive and analyte specific, requiring different assays to detect each of the different food allergens. Mass spectrometry offers an alternative approach whereby multiple allergens may be detected simultaneously. However, mass spectrometry requires expensive equipment, highly trained analysts, and several years before a quantitative approach can be achieved. Using multianalyte profiling (xMAP®) technology, a commercial multiplex test kit based on the use of established antibodies was developed for the simultaneous detection of up to 14 different food allergens plus gluten. The assay simultaneously detects crustacean seafood, egg, gluten, milk, peanut, soy, and nine tree nuts (almond, Brazil nut, cashew, coconut, hazelnut, macadamia, pine nut, pistachio, and walnut). By simultaneously performing multiple tests (typically two) for each analyte, this magnetic bead-based assay offers built-in confirmatory analyses without the need for additional resources. Twenty-five of the assays were performed on buffer extracted samples, while five were conducted on samples extracted using reduced-denatured conditions. Thus, complete analysis for all 14 allergens and gluten requires only two wells of a 96-well microtiter plate. This makes it possible to include in a single analytical run up to 48 samples. All 30 bead sets in this multiplex assay detected 5 ng/mL of food allergen and gluten with responses greater than background. In addition, 26 of the bead sets displayed signal/noise ratios of five or greater. The bead-based design makes this 30-plex assay expandable to incorporate new antibodies and capture/detector methodologies by ascribing these new detectors to any of the unassigned bead sets that are commercially available.

Consumer-friendly food allergen detection: moving towards smartphone-based immunoassays

“…Flow cytometry can be used for both in-vivo and in-vitro quantitative allergen analysis [124, 125]. Garber et al and Cho et al have shown that by using magnetic bead sets it is possible to detect 14 food allergens (and gluten) in 12 different samples, within 6 h, with a similar LOD to existing ELISA methods (<5 ng/mL) [97, 126]. However, their methods required two extraction procedures, so although the assay could be multiplexed, the extraction could not.…”

Food Allergy

“…Can detect multiple allergens simultaneously (Cucu et al 2013, Gomaa & Boye 2015, Kirsch et al 2009, van Hengel 2007 Need special equipment, cross-reactivity (Cho et al 2015) Crustacean, egg, milk, gluten, peanut, soy, almond, cashew, Brazil nut, hazelnut, coconut, pine nut, macadamia nut, walnut (Cho et al 2015) Sandwich 5 ng/mL…”

Detection of Allergen Markers in Food: Analytical Methods

“…The major analytical Th methods, including enzyme-linked immunosorbent assay (ELISA), mass spectrometry (MS) and polymerase chain reaction (PCR) are discussed in detail in this chapter. While the majority of commercially available allergen detection methods are single allergen assays, multi-allergen detection methods have recently been developed using a multiplex enzyme immunoassay [7][8][9][10], MS [11][12][13][14][15][16] or DNA amplifi cation [17,18]. Understanding fi the limitations of available methods for food allergen quantitation, specifi-fi cally with respect to sample extraction, thermal processing, and biomarker selection, will improve method selection, establish appropriate allergen control plans, and ultimately protect allergic consumers.…”