Measurement by ELISA of Active Lectin in Dietary Supplements Containing Kidney Bean Protein

Detection of Lectin Protein Allergen of Kidney Beans (Phaseolus vulgaris L.) and Desensitization Food Processing Technology

With the increase of food allergy events related to not properly cooked kidney beans (Phaseolus vulgaris L.), more and more researchers are paying attention to the sensitization potential of lectin, one of the major storage and defensive proteins with the specific carbohydrate-binding activity. The immunoglobulin E (IgE), non-IgE, and mixed allergic reactions induced by the lectins were inducted in the current paper, and the detection methods of kidney bean lectin, including the purification strategies, hemagglutination activity, specific polysaccharide or glycoprotein interactions, antibody combinations, mass spectrometry methods, and allergomics strategies, were summarized, while various food processing aspects, such as the physical thermal processing, physical non-thermal processing, chemical modifications, and biological treatments, were reviewed in the potential of sensitization reduction. It might be the first comprehensive review on lectin allergen detection from kidney bean and the desensitization strategy in food processing and will provide a basis for food safety control.

Toxicity Assessment of Common Beans (Phaseolus vulgaris L.) Widely Consumed by Tunisian Population

This research aimed at assessing the content and the functional properties of phytohemagglutinin (PHA) in different varieties of beans widely consumed in Tunisia through soaking, cooking, autoclaving, germination, and their combinations. This study was carried out on three varieties of white beans grown in different localities of Tunisia, namely Twila, Coco, and Beldia, as well as on imported and local canned beans. All bean samples underwent biochemical and immunological evaluation by employing several techniques such as indirect competitive enzyme-linked immunosorbent assay (ELISA), hemagglutinating assay, Ouchterlony double immunodiffusion, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Biochemical and immunological analyses indicated that raw dry beans contained a considerable amount of proteins and PHAs. ELISA demonstrated that soaking, either in plain water or in alkaline solution, caused an increase in the concentration of PHA. A slight increase of PHA was produced equally by germination during 4 days in all bean varieties. Cooking or autoclaving of presoaked beans resulted in a complete disappearance of PHA. ELISA test also proved that both imported and local canned beans contained fingerprints of PHA. Hemagglutination assays showed that not only cooked and autoclaved presoaked beans lacked the ability to agglutinate red blood cells but also autoclaved unsoaked beans did. In agar gel immunodiffusion using rabbit anti-PHA serum, raw, soaked, cooked unsoaked, and sprouted beans gave precipitin arc reactions, indicating that PHA existed in immunoreactive form in the tested seeds. SDS-PAGE electrophoretograms showed protein isolates of Twila and Beldia beans to have different profiles through soaking, cooking, and autoclaving processes. This work revealed that the combination of soaking and cooking/autoclaving was the best way in reducing PHA content and its activity in all bean varieties when compared with germination.