Variation in Seed Allergen Content From Three Varieties of Soybean Cultivated in Nine Different Locations in Iowa, Illinois, and Indiana

Analysis of allergen positivity rates in relation to gender, age, and cross-reactivity patterns

OBJECTIVE

This study aims to gain a deeper understanding of the patterns of allergen detection positivity rates among different age and gender groups, and to explore cross-reactivity patterns among allergens.

METHODS

We conducted a retrospective analysis of patients who underwent allergen testing at our hospital. The sample for this study included all patients who underwent allergen testing. We utilized immune blotting to detect specific IgE antibodies to 20 allergens in patient sera.

RESULTS

The study results showed a higher proportion of female samples (72.35%) compared to male samples (27.65%). Among all participants, the age distribution was primarily concentrated in the 25-35 age group, accounting for 37.43% of the total sample, followed by the 45 years and older age group, accounting for 27.00%. This indicates that allergic symptoms may occur not only in children and adolescents but also at any time after adulthood. We further observed significant influences of factors such as gender and age on individual sensitivity to specific allergens. For example, compared to males, females were found to be more sensitive to certain allergens such as cat hair, dust mites, and dog epithelium. Similarly, we also found variations in sensitivity to specific allergens among different age groups.

CONCLUSION

Close monitoring of allergen distribution in populations facilitates active engagement of allergic individuals in self-management, while gender and age may be important factors influencing individual sensitivity to specific allergens. These findings provide valuable insights for understanding the pathogenesis of allergic diseases and designing more effective prevention and treatment strategies.

Comparative Seed Proteome Profile Reveals No Alternation of Major Allergens in High-Yielding Mung Bean Cultivars

Mung bean contains up to 32.6% protein and is one of the great sources of plant-based protein. Because many allergens also function as defense-related proteins, it is important to determine their abundance levels in the high-yielding, disease-resistant cultivars. In this study, for the first time, we compared the seed proteome of high-yielding mung bean cultivars developed by a conventional breeding approach. Using a label-free quantitative proteomic platform, we successfully identified and quantified a total of 1373 proteins. Comparative analysis between the high-yielding disease-resistant cultivar (MC5) and the other three cultivars showed that a total of 69 common proteins were significantly altered in their abundances across all cultivars. Bioinformatic analysis of these altered proteins demonstrated that PDF1 (a defensin-like protein) exhibited high sequence similarity and epitope matching with the established peanut allergens, indicating a potential mung bean allergen that showed a cultivar-specific response. Conversely, known mung bean allergen proteins such as PR-2/PR-10 (Vig r 1), Vig r 2, Vig r 4, LTP1, β-conglycinin, and glycinin G4 showed no alternation in the MC5 compared to other cultivars. Taken together, our findings suggest that the known allergen profiles may not be impacted by the conventional plant breeding method to develop improved mung bean cultivars.

Prospects for developing allergen-depleted food crops

In addition to the challenge of meeting global demand for food production, there are increasing concerns about food safety and the need to protect consumer health from the negative effects of foodborne allergies. Certain bio-molecules (usually proteins) present in food can act as allergens that trigger unusual immunological reactions, with potentially life-threatening consequences. The relentless working lifestyles of the modern era often incorporate poor eating habits that include readymade prepackaged and processed foods, which contain additives such as peanuts, tree nuts, wheat, and soy-based products, rather than traditional home cooking. Of the predominant allergenic foods (soybean, wheat, fish, peanut, shellfish, tree nuts, eggs, and milk), peanuts (Arachis hypogaea) are the best characterized source of allergens, followed by tree nuts (Juglans regia, Prunus amygdalus, Corylus avellana, Carya illinoinensis, Anacardium occidentale, Pistacia vera, Bertholletia excels), wheat (Triticum aestivum), soybeans (Glycine max), and kidney beans (Phaseolus vulgaris). The prevalence of food allergies has risen significantly in recent years including chance of accidental exposure to such foods. In contrast, the standards of detection, diagnosis, and cure have not kept pace and unfortunately are often suboptimal. In this review, we mainly focus on the prevalence of allergies associated with peanut, tree nuts, wheat, soybean, and kidney bean, highlighting their physiological properties and functions as well as considering research directions for tailoring allergen gene expression. In particular, we discuss how recent advances in molecular breeding, genetic engineering, and genome editing can be used to develop potential low allergen food crops that protect consumer health.

Label-Free Quantification by Liquid Chromatography-Tandem Mass Spectrometry of the Kunitz Inhibitor of Trypsin KTI3 in Soy Products

The greater awareness of consumers regarding the sustainability of food chains has shifted part of the consumption from animal protein sources to vegetable sources. Among these, of relevance both for human food use and for animal feed, is soy. However, its high protein content is unfortunately accompanied by the presence of antinutritional factors, including Kunitz's trypsin inhibitor (KTI). Now there are few analytical methods available for its direct quantification, as the inhibitory activity against trypsin is generically measured, which however can be given by many other molecules and undergo numerous interferences. Therefore, in this work, a direct label-free liquid chromatography-mass spectrometry (LC-MS) method for the identification and quantification of trypsin Kunitz inhibitor KTI3 in soybean and derivative products has been developed. The method is based on the identification and quantification of a marker peptide, specific for the protein of interest. Quantification is achieved with an external calibration curve in the matrix, and the limit of detection and the limit of quantification of the method are 0.75 and 2.51 μg/g, respectively. The results of the LC-MS method were also compared with trypsin inhibition measured spectrophotometrically, highlighting the complementarity of these two different pieces of information.

Determination of the soybean allergen Gly m 6 and its stability in food processing using liquid chromatography-tandem mass spectrometry coupled with stable-isotope dimethyl labelling

A cost-effective method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with stable-isotope dimethyl labelling was used for the determination of Gly m 6. The validation results revealed that the recoveries and precisions obtained from five spiked levels were in the ranges of 88.8-113.0% and 8.3-22.0%, respectively. The content and stability of the major soybean allergen Gly m 6 in various food processing procedures were evaluated by the quantification results of its surrogate signature peptide. The Gly m 6 content in soybean decreased by 42% after natto fermentation, and by 31% and 35% in pasteurised soymilk and sterilised soymilk, respectively, relative to the raw soymilk. Only 19% of Gly m 6 in raw soymilk was retained in the soymilk film. This study extended the feasibility of dimethyl labelling to soy-based food samples and examined the proteolysis of Gly m 6 in natto fermentation and its thermal instability.

Characterization of the protein structure of soymilk fermented by Lactobacillus and evaluation of its potential allergenicity based on the sensitized-cell model

This study aimed to investigate the effects of fermented soymilk (FSM) with Lactobacillus brevis CICC 23,474 and L. brevis CICC 23,470 on the structural changes and allergenicity of major allergenic proteins in soymilk (SM). Spectroscopy and liquid chromatograph-tandem mass spectrometer (LC-MS/MS) were used to characterize changes in protein spatial structure and epitopes. The antigenicity and potential allergenicity were evaluated by immunoblotting, enzyme-linked immunosorbent assay (ELISA) and KU812 cell degranulation assay. Results suggested that the advanced structure of proteins was destroyed. Antigenicity was also significantly reduced, and five human IgE-binding linear epitopes (i.e., E5-E33, R27-S41, D414-A437, G253-I265 and V449-S471) were destroyed by fermentation. Furthermore, after in vitro simulated gastrointestinal digestion, FSM showed lower IgG/IgE-binding capacity and weaker degranulation ability of KU812 cells. All these findings demonstrated that fermentation with Lactobacillus can destroy the conformational and linear epitopes of proteins and reduce the potential allergenicity of SM.

Screening of Twelve Pea (Pisum sativum L.) Cultivars and Their Isolates Focusing on the Protein Characterization, Functionality, and Sensory Profiles

Pea protein concentrates and isolates are important raw materials for the production of plant-based food products. To select suitable peas (Pisum sativum L.) for protein extraction for further use as food ingredients, twelve different cultivars were subjected to isoelectric precipitation and spray drying. Both the dehulled pea flours and protein isolates were characterized regarding their chemical composition and the isolates were analyzed for their functional properties, sensory profiles, and molecular weight distributions. Orchestra, Florida, Dolores, and RLPY cultivars showed the highest protein yields. The electrophoretic profiles were similar, indicating the presence of all main pea allergens in all isolates. The colors of the isolates were significantly different regarding lightness (L*) and red-green (a*) components. The largest particle size was shown by the isolate from Florida cultivar, whereas the lowest was from the RLPY isolate. At pH 7, protein solubility ranged from 40% to 62% and the emulsifying capacity ranged from 600 to 835 mL g⁻¹. The principal component analysis revealed similarities among certain pea cultivars regarding their physicochemical and functional properties. The sensory profile of the individual isolates was rather similar, with an exception of the pea-like and bitter attributes, which were significantly different among the isolates.

Current Trends in Proteomic Advances for Food Allergen Analysis

Food allergies are a global food challenge. For correct food labelling, the detection and quantification of allergens are necessary. However, novel product formulations and industrial processes produce new scenarios, which require much more technological developments. For this purpose, OMICS technologies, especially proteomics, seemed to be relevant in this context. This review summarises the current knowledge and studies that used proteomics to study food allergens. In the case of the allergenic proteins, a wide variety of isoforms, post-translational modifications and other structural changes during food processing can increase or decrease the allergenicity. Most of the plant-based food allergens are proteins with biological functions involved in storage, structure, and plant defence. The allergenicity of these proteins could be increased by the presence of heavy metals, air pollution, and pesticides. Targeted proteomics like selected/multiple reaction monitoring (SRM/MRM) have been very useful, especially in the case of gluten from wheat, rye and barley, and allergens from lentil, soy, and fruit. Conventional 1D and 2-DE immunoblotting have been further widely used. For animal-based food allergens, the widely used technologies are 1D and 2-DE immunoblotting followed by MALDI-TOF/TOF, and more recently LC-MS/MS, which is becoming useful to assess egg, fish, or milk allergens. The detection and quantification of allergenic proteins using mass spectrometry-based proteomics are promising and would contribute to greater accuracy, therefore improving consumer information.

Genetic variation assessment of stacked-trait transgenic maize via conventional breeding

BACKGROUND

The safety assessment and control of stacked transgenic crops is increasingly important due to continuous crop development and is urgently needed in China. The genetic stability of foreign genes and unintended effects are the primary problems encountered in safety assessment. Omics techniques are useful for addressing these problems. The stacked transgenic maize variety 12-5 × IE034, which has insect-resistant and glyphosate-tolerant traits, was developed via a breeding stack using 12-5 and IE034 as parents. Using 12-5 × IE034, its parents (12-5 and IE034), and different maize varieties as materials, we performed proteomic profiling, molecular characterization and a genetic stability analysis.

RESULTS

Our results showed that the copy number of foreign genes in 12-5 × IE034 is identical to that of its parents 12-5 and IE034. Foreign genes can be stably inherited over different generations. Proteomic profiling analysis found no newly expressed proteins in 12-5 × IE034, and the differences in protein expression between 12 and 5 × IE034 and its parents were within the range of variation of conventional maize varieties. The expression levels of key enzymes participating in the shikimic acid pathway which is related to glyphosate tolerance of 12-5 × IE034 were not significantly different from those of its parents or five conventional maize varieties, which indicated that without selective pressure by glyphosate, the introduced EPSPS synthase is not has a pronounced impact on the synthesis of aromatic amino acids in maize.

CONCLUSIONS

Stacked-trait development via conventional breeding did not have an impact on the genetic stability of T-DNA, and the impact of stacked breeding on the maize proteome was less significant than that of genotypic differences. The results of this study provide a theoretical basis for the development of a safety assessment approach for stacked-trait transgenic crops in China.

Assessment of the potential allergenicity of genetically-engineered food crops

An extensive safety assessment process exists for genetically-engineered (GE) crops. The assessment includes an evaluation of the introduced protein as well as the crop containing the protein with the goal of demonstrating the GE crop is "as-safe-as" non-GE crops in the food supply. One of the evaluations for GE crops is to assess the expressed protein for allergenic potential. Currently, no single factor is recognized as a predictor for protein allergenicity. Therefore, a weight-of-the-evidence approach, which accounts for a variety of factors and approaches for an overall assessment of allergenic potential, is conducted. This assessment includes an evaluation of the history of exposure and safety of the gene(s) source; protein structure (e.g. amino acid sequence identity to human allergens); stability of the protein to pepsin digestion in vitro; heat stability of the protein; glycosylation status; and when appropriate, specific IgE binding studies with sera from relevant clinically allergic subjects. Since GE crops were first commercialized over 20 years ago, there is no proof that the introduced novel protein(s) in any commercialized GE food crop has caused food allergy.