Narrow-Leafed Lupin Main Allergen β-Conglutin (Lup an 1) Detection and Quantification Assessment in Natural and Processed Foods

Abstract

The increasing prevalence of lupin allergy as a consequence to the functional characteristics of a growing number of sweet lupin-derived foods consumption makes the imperious necessity to develop analytical tools for the detection of allergen proteins in foodstuffs. The current study developed a new highly specific, sensitive and accurate ELISA method to detect, identify and quantify the lupin main allergen β-conglutin (Lup an 1) protein in natural and processed food. The implementation of accurate standards made with recombinant conglutin β1, and an anti-Lup an 1 antibody made from a synthetic peptide commonly shared among β-conglutin isoforms from sweet lupin species was able to detect up to 8.1250 ± 0.1701 ng (0.0406 ± 0.0009 ppm) of Lup an 1. This identified even lupin traces present in food samples which might elicit allergic reactions in sensitized consumers, such as β-conglutin proteins detection and quantification in processed (roasted, fermented, boiled, cooked, pickled, toasted, pasteurized) food, while avoiding cross-reactivity (false positive) with other legumes as peanut, chickpea, lentils, faba bean, and cereals. This study demonstrated that this new ELISA method constitutes a highly sensitive and reliable molecular tool able to detect, identify and quantify Lup an 1. This contributes to a more efficient management of allergens by the food industry, the regulatory agencies and clinicians, thus helping to keep the health safety of the consumers.

Lupine allergens: Clinical relevance, molecular characterization, cross‐reactivity, and detection strategies

“…Owing to the increasing demand for specific allergen detection, a wide range of commercial kits for lupine detection has become available in the market and summarized in Table 5. Moreover, in-house developed-systems are frequently reported in the literature (Table 4) (Ecker & Cichna-Markl, 2012;Ecker, Ertl, Pulverer, et al, 2013;Holden, Faeste, & Egaas, 2005;Holden, Moen, Sletten, & Dooper, 2007;Kaw, Hefle, & Taylor, 2008;Koeberl et al, 2018;Lima-Cabello, Alché, & Jimenez-Lopez, 2019;Revák, Golian, Židek, Capla, & Zajác, 2014;Röder, Kleiner, Sachs, Keil, & Holzhauser, 2013). The majority of these systems relies on polyclonal antibodies (IgY from hen's eggs or IgG from rabbit) targeting lupine proteins from one or more Lupinus spp., normally providing suitable specificity for all the sweet lupine species used as food ingredients or technological aids.…”

Narrow‐leafed lupin (Lupinus angustifolius L.) β‐conglutin: A multifunctional family of proteins with roles in plant defence, human health benefits, and potential uses as functional food

“…Two recently published studies on allergic responses to recombinant NLL β‐conglutin proteins (Jimenez‐Lopez et al, ; Lima‐Cabello, Alché, & Jimenez‐Lopez, ) would contribute to a more reliable and operative control of allergens by the food industry, the regulatory agencies and clinicians, thus helping in protecting the health of sensitized/allergic consumers.…”

“…For these reasons, high‐purity individual recombinant β‐conglutins proteins are an invaluable tool for studying lupin molecular allergy. This constitutes a reliable and accurate molecular tool helping to develop immunological test systems able to identify and quantify these allergens in foodstuffs (Lima‐Cabello, Alché, & Jimenez‐Lopez, ), and for diagnosis and alternativetherapies development for food allergies.…”

Soy Preparations Are Potentially Dangerous Factors in the Course of a Food Allergy

“…Allergic reactions after consuming food containing soy may also appear in people allergic to other legumes [8][9][10][11]. They were also observed in people with atopic diseases and those allergic to cow's milk [12].…”