Ranking of 10 legumes according to the prevalence of sensitization as a parameter to characterize allergenic proteins

Heat/non-heat treatment alleviates β-conglycinin-triggered food allergy reactions by modulating the Th1/Th2 immune balance in a BALB/c mouse model

BACKGROUND

With the increasing popularity of plant protein-based diets, soy proteins are favored as the most important source of plant protein worldwide. However, potential food allergy risks limit their use in the food industry. This work aims to reveal the mechanism of β-conglycinin-induced food allergy, and to explore the regulatory mechanism of heat treatment and high hydrostatic pressure (HHP) treatment in a BALB/c mouse model.

RESULTS

Our results showed that oral administration of β-conglycinin induced severe allergic symptoms in BALB/c mice, but these symptoms were effectively alleviated through heat treatment and HHP treatment. Moreover, β-conglycinin stimulated lymphocyte proliferation and differentiation; a large number of cytokines interleukin (IL)-4, IL-5, IL-10, IL-12 and IL-13 were released and interferon γ secretion was inhibited, which disrupted the Th1/Th2 immune balance and promoted the differentiation and proliferation of naive T cells into Th2-type cells.

CONCLUSION

Heat/non-heat treatment altered the conformation of soybean protein, which significantly reduced allergic reactions in mice. This regulatory mechanism may be associated with Th1/Th2 immune balance. Our results provide data support for understanding the changes in allergenicity of soybean protein within the food industry. © 2024 Society of Chemical Industry.

Food allergen analysis: A review of current gaps and the potential to fill them by matrix-assisted laser desorption/ionization

Food allergy remains a public health, business, and regulatory challenge. Risk analysis (RA) and risk management (RM) of food allergens are of great importance and analysis for food allergens is necessary for both. The current workhorse techniques for allergen analysis (enzyme linked immunosorbent assay [ELISA] and real-time polymerase chain reaction) exhibit recognized challenges including variable and antibody specific responses and detection of species DNA rather than allergen protein, respectively. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) enables protein identification, with potential for multiplex analysis and traceability to the System of International units (SI), aiding global measurement standardization. In this review, recent literature has been systematically reviewed to assess progress in LC-MS/MS and define the potential and benefits of matrix-assisted laser desorption/ionization-time-of-flight MS (MALDI-ToF-MS) technology for allergen analysis. MALDI-ToF-MS of initially intact protein is already applied to verify in silico-derived peptide sequences for LC-MS/MS analysis. We describe the origins of MALDI and its future perspectives, including affinity bead-assisted assays coupled to MALDI. Based on the proliferation of reliable and reproducible MALDI-based clinical applications, the technique should emulate the detection capability (sensitivity) of established allergen detection techniques, whilst reducing technical support and having equivalent multiplexing potential to competing techniques, for example, LC-MS/MS and ELISA. Although unlikely to offer inherent SI traceability, MALDI-based allergen analysis will complement existing MS approaches for allergens. Affinity bead-MALDI appears capable of higher throughput at lower cost per sample than almost any existing technique, enabling repeated sub-sampling as a way to reduce representative sampling issues.

Pollen Sensitization Can Increase the Allergic Reaction to Non-Cross-Reactive Allergens in a Soy-Allergic Patient

During and after the pollen season, an increase in food-triggered allergic symptoms has been observed in pollen-food syndrome patients, possibly due to seasonal boosting of pollen-IgE levels. It has been suggested that consumption of birch-pollen-related foods plays a role in seasonal allergenic inflammation. However, whether this increased pollen sensitization during the pollen season can also affect the allergenicity of allergens that are non-cross-reactive with birch pollen remains in question. This study presents the case of a patient with soy allergy and pollinosis, who experiences worsening of gastrointestinal (GI) symptoms during the birch pollen season even though the eliciting food factor does not cross-react with birch pollen allergens and their homologs (e.g., Bet v 1 and Gly m 4). The results showed a notable increase in sIgE for Gly m 4 (3.3 fold) and Bet v 1 (2.6 fold) during the birch pollen season compared to outside the birch pollen season, while Gly m 5 and Gly m 6 showed only a slight increase (1.5 fold). The basophil activation test (BAT) showed that in this patient Gly m 5 and Gly m 6 are clinically relevant soy allergens, which correlates with the reported clinical symptoms to processed soy. Moreover, the BAT against raw soy shows an increase in basophil activation during the birch pollen season and a negative basophil activation result outside the birch pollen season. Thus, the worsening of GI symptoms could possibly be due to an increase in IgE receptors, an over-reactive immune system, and/or significant intestinal allergic inflammation. This case highlights the importance of including allergens that do not cross-react with birch pollen and using a functional assay such as the BAT to evaluate clinical relevance when assessing birch pollen seasonal influence on soy allergenicity.

Vegan diets from an allergy point of view - Position paper of the DGAKI working group on food allergy

Vegan diets are currently attracting a great deal of attention. However, avoiding animal-based foods restricts the diet and is associated with risks, the extent and medical implications of which are at present not sufficiently understood. Elimination diets represent the usual therapeutic long-term management in the presence of food allergy. In order to understand the risks of vegan diets and to discuss these critically from the perspective of food allergies, the expertise of a nutritionist/dietitian with expertise in this area is indispensable. This position paper deals with the incentives behind and the benefits of a plant-based diet. The knowledge required to cover macro- and micronutrient dietary requirements is presented. Using the avoidance of cow's milk as an example, the challenges of adequately meeting nutritional needs are identified and (so-called) milk alternatives are evaluated from an allergy and nutritional point of view. Finally, other plant-based (substitute) products are evaluated from the same perspective, as significant protein sources in vegan diets (e.g., legumes, nuts, and seeds) are at the same time potential and potent triggers of allergic reactions. However, the allergic potential of many substitute products cannot be fully assessed at present due to gaps in research. Wheat as the most important trigger for anaphylaxis in adults is also evaluated. Finally, the increase in ultra-processed products in the (vegan) food sector and their potential consequences for the immune system are discussed.

Co-sensitization between legumes is frequently seen, but variable and not always clinically relevant

Background

Food allergy to peanut and soybean, both legumes, is highly prevalent. The consumption of other legumes and legume protein isolates, some of which may be considered novel foods, is increasing. This may lead to an increase in sensitization and allergy and may pose a risk for legume-allergic (e.g. peanut and soybean) patients due to cross-reactivity.

Objective

This study investigated the frequency of co-sensitization and co-allergy between legumes and the role of different protein families.

Methods

Six legume-allergic patient groups were included: peanut (n = 30), soybean (n = 30), lupine (n = 30), green pea (n = 30), lentil (n = 17), bean (n = 9). IgE binding to total extracts, protein fractions (7S/11S globulin, 2S albumin, albumin), and 16 individual proteins from 10 legumes (black lentil, blue lupine, chickpea, faba bean, green lentil, pea, peanut, soybean, white bean, and white lupine) was measured by line blot

Results

Co-sensitization varied from 36.7% to 100%. Mono-sensitization was only found in soybean (16.7%), peanut (10%), and green pea-allergic (3.3%) patients. A high frequency of co-sensitization between the 7S/11S globulin fractions of all 10 legumes and individual 7S and 11S globulins was observed. In peanut and soybean-allergic patients, co-allergies for other legumes were uncommon (≤16,7%), while in green pea, lupine, lentil, and bean-allergic patients co-allergy for peanut (64.7%–77.8%) or soybean (50%–64.7%) was frequently seen.

Conclusion

Co-sensitization between legumes was high, but generally not clinically relevant. Co-allergy to other legumes was not often seen in peanut- and soybean allergic patients. The 7S and 11S globulins were likely responsible for the observed co-sensitization.

Effectiveness of enzymatic hydrolysis for reducing the allergenic potential of legume by-products

The interest in agri-food residues and their valorization has grown considerably, and many of them are today considered to be valuable, under-exploited sources of different compounds and notably proteins. Despite the beneficial properties of legumes by-products, there are also some emerging risks to consider, including their potential allergenicity. In this work the immunoreactivity of chickpea, pea, and white bean by-products was assessed, and whether the production of enzymatic hydrolysates can be an effective strategy to reduce this allergenic potential. The results presented clearly indicate that the efficiency of this strategy is strongly related to the enzyme used and the food matrix. All legume by-products showed immunoreactivity towards serum of legume-allergic patients. Hydrolysates from alcalase did not show residual immunoreactivity for chickpea and green pea, whereas hydrolysates from papain still presented some immunoreactivity. However, for white beans, the presence of antinutritional factors prevented a complete hydrolysis, yielding a residual immunoreactivity even after enzymatic hydrolysis with alcalase.

Faba Bean: An Untapped Source of Quality Plant Proteins and Bioactives

Faba beans are emerging as sustainable quality plant protein sources, with the potential to help meet the growing global demand for more nutritious and healthy foods. The faba bean, in addition to its high protein content and well-balanced amino acid profile, contains bioactive constituents with health-enhancing properties, including bioactive peptides, phenolic compounds, GABA, and L-DOPA. Faba bean peptides released after gastrointestinal digestion have shown antioxidant, antidiabetic, antihypertensive, cholesterol-lowering, and anti-inflammatory effects, indicating a strong potential for this legume crop to be used as a functional food to help face the increasing incidences of non-communicable diseases. This paper provides a comprehensive review of the current body of knowledge on the nutritional and biofunctional qualities of faba beans, with a particular focus on protein-derived bioactive peptides and how they are affected by food processing. It further covers the adverse health effects of faba beans associated with the presence of anti-nutrients and potential allergens, and it outlines research gaps and needs.