The detection and regulation advances of food allergens

Food allergy has become an important food quality and safety issue,posing a challenge to the food industry and affecting consumer health.On the one hand,from the perspective of food processing industry,the diversity of food raw material ingredients,exogenous additives,and processing forms make the presence of allergens in modern food processing more complex.In addition,due to the lack of allergen identification,effective detection and allergenicity evaluation systems,there are serious deficiencies in the current theories and techniques for food allergen screening and detection,tracking and prediction,intervention and control;On the other hand,from the perspective of public health,meeting consumers'right to know whether there are raw materials containing food allergens in processed foods,and improving the credibility of government and people's satisfaction have become urgent matters;In addition,as people come into contact with more and more new borne novel foods,the probability of food allergy is also increasing.The food safety and health problems induced by increasingly complex,widespread and severe food allergy are difficult to avoid.In view of this,in response to the increasingly serious food allergy issues,this paper introduced the detection methods of food allergens,summarized the reduction and control techniques of food allergens,and elaborated hypoallergenic foods,which aims to provide the basis for preventing and controlling food allergy and ensuring the physical health of food allergy patients.

Nanobody-based food allergen surveillance:current status and prospects

The incidence of food allergy has increased in recent decades,posing drastic risks to sensitive individuals,leading to mild to severe allergic symptoms.There is still no effective immune therapeutic strategy for food allergy that addresses accurate analytical methods to indicate the presence of allergens to prevent exposure of sensitive individuals.Currently,the most commonly applied detection method is immunoassay developed with food allergen-specifc antibodies,especially the conventional formats of monoclonal antibodies(mAbs)and polyclonal antibodies(pAbs),which serve as dominant detection reagents for food allergen analysis,although with the disadvantages of being labor-intensive,costly,batch differences,and signifcant cross-reaction,etc.Camelid-derived nanobodies(Nbs)have attracted tremendous attention to explore their application in food hazard analysis because of robust characteristics like unique paratopes,high stability and affnity that strongly contribute to the benefcial effect.However,extensive analysis is needed to validate the potential use of Nbs as detection reagents and the advantages for food allergen surveillance.Previous reports have demonstrated the potential of Nbs for immunoassay development against food allergens,such as macadamia allergen Mac i 1,peanut allergens Ara h 1 and Ara h 3,lupin allergen Lup an 1,milk allergenβ-lactoglobulin,etc.In this review,we comprehensively summarize the structural and biochemical properties of Nbs that beneft the application of Nb-based immunoassay,as well as the representative detection strategies,to provide research data for newly developed Nb formats for food allergen analysis,and investigate the future establishment of Nb-based surveillance against major food allergens.

Recent advances in the study of epitopes,allergens and immunologic cross-reactivity of edible mango

Mango(Mangifera indica L.)is a tropical fruit that is widely consumed as both fresh fruits and processed products around the world.The high incidence of mango allergy,on the other hand,has sparked widespread concern.Therefore,a summary and analysis of the current status and issues in mango allergen research can guide in-depth study on the mechanism of mango allergy and reveal effective desensitization methods.We described the incidence of fruit allergy,as well as the mechanism and clinical symptoms of mango allergy,in this review.We also looked into the structural properties of mango allergens,the effect of processing methods on mango allergens,prediction methods for mango allergen epitopes,and the current state of research on mango cross-reactive allergens and preventive measures.Finally,the research directions and ideas for the future are proposed and discussed.

Adulteration detection of plant protein beverages by UPLC-MS/MS based on signature peptide of allergen

Plant protein beverage adulteration occurs frequently,which may cause health problems for consumers due to the hidden allergens.Hence,a novel method was developed for authentication by ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).Almond,peanut,walnut and soybean were hydrolyzed,followed by separation by NanoLC-Triple TOF MS.The obtained fingerprints were identified by ProteinPilotTM combined with Uniprot,and 16 signature peptides were selected.Afterwards,plant protein beverages treated by trypsin hydrolysis were analyzed with UPLC-MS/MS.This method showed a good linear relationship with R2>0.99403.The limit of quantification(LOQ)were 0.015,0.01,0.5 and 0.05 g/L for almond,peanut,walnut and soybean,respectively.Mean recoveries ranged from 84.77%to 110.44%with RSDs<15%.The developed method was successfully applied to the adulteration detection of 31 plant protein beverages to reveal adulteration and false labeling.Conclusively,this method could provide technical support for authentication of plant protein beverages to protect the rights and health of consumers.

Dietary polyphenols reduced the allergenicity ofβ-lactoglobulin via non-covalent interactions:a study on the structure-allergenicity relationship

Studies showed that complexation of polyphenols with milk allergens reduced their immunogenic potential.However,the relationship between structures of polyphenols and their hypoallergenic effects on milk allergens in association with physiological and conformational changes of the complexes remain unclear.In this study,polyphenols from eight botanical sources were extracted to prepare non-covalent complexes withβ-lactoglobulin(β-LG),a major allergen in milk.The dominant phenolic compounds bound toβ-LG with a diminished allergenicity were identified to investigate their respective role on the structural and allergenic properties ofβ-LG.Extracts from Vaccinium fruits and black soybeans were found to have great inhibitory effects on the IgE-and IgG-binding abilities ofβ-LG.Among the fourteen structure-related phenolic compounds,flavonoids and tannins with larger MWs and multi-hydroxyl substituents,notably rutin,EGCG,and ellagitannins were more potent to elicit changes on the conformational structures ofβ-LG to decrease the allergenicity of complexedβ-LG.Correlation analysis further demonstrated that a destabilized secondary structure and protein depolymerization caused by polyphenol-binding were closely related to the allergenicity property of formed complexes.This study provides insights into the understanding of structure-allergenicity relationship ofβ-LG-polyphenol interactions and would benefit the development of polyphenol-fortified matrices with hypoallergenic potential.

Characterization of physicochemical and immunogenic properties of allergenic proteins altered by food processing:a review

Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding epitopes.Understanding the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether and how food processing techniques reduce allergenicity.We here discuss the impacts of food processing technologies on the modification of physicochemical,structural,and immunogenic properties of allergenic proteins.Detection techniques for characterizing changes in these properties of food allergens are summarized.Food processing helps to reduce allergenicity by aggregating or denaturing proteins,which masks,modifies,or destroys antigenic epitopes,whereas,it cannot eliminate allergenicity completely,and sometimes even improves allergenicity by exposing new epitopes.Moreover,most food processing techniques have been tested on purified food allergens rather than food products due to potential interference of other food components.We provide guidance for further development of processing operations that can decrease the allergenicity of allergenic food proteins without negatively impacting the nutritional profile.

Allergen degradation of bee pollen by lactic acid bacteria fermentation and its alleviatory effects on allergic reactions in BALB/c mice

Food allergy as a global health problem threatens food industry.Bee pollen(BP)is a typical food with allergenic potentials,although it performs various nutritional/pharmacological functions to humans.In this study,lactic acid bacteria(LAB)were used to ferment Brassica napus BP for alleviating its allergenicity.Four novel allergens(glutaredoxin,oleosin-B2,catalase and lipase)were identified with significant decreases in LAB-fermented BP(FBP)than natural BP by proteomics.Meanwhile,metabolomics analysis showed significant increases of 28 characteristic oligopeptides and amino acids in FBP versus BP,indicating the degradation of LAB on allergens.Moreover,FBP showed alleviatory effects in BALB/c mice,which relieved pathological symptoms and lowered production of allergic mediators.Microbial high-throughput sequencing analysis showed that FBP could regulate gut microbiota and metabolism to strengthen immunity,which were closely correlated with the alleviation of allergic reactivity.These findings could contribute to the development and utilization of hypoallergenic BP products.

Validation of Molecular Detection Methods for Gluten Allergens in Infant Formula

[Objectives]To verify the specificity,sensitivity,precision and negative-positive deviation of the foodproof gluten component de-tection kit for the detection of gluten allergens in milk powder matrix,and to establish a real-time fluorescent PCR legal method for the detec-tion of gluten allergens in milk powder.[Methods]The specificity,sensitivity,precision and negative-positive deviation of the detection method of foodproof gluten component detection kit(PCR-probe method)were verified by artificially adding different concentrations of wheat bran and extracting sample DNA by kit method,and applied to sample detection.[Results] The specific detection results of two kinds of milk powder with wheat bran and buckwheat added showed that the foodproof gluten component detection kit(PCR-probe method)had good speci-ficity for wheat gluten.The results of artificially added wheat bran positive samples showed that the false positive rate and false negative rate of the kit in the milk powder matrix were O,and the sensitivity and precision were high.[Conclusions]The kit is simple to operate and has high accuracy,which is suitable for the detection of gluten allergen components in milk powder.

Allergenicity mitigation strategies of seafood allergens for hypoallergen

Introduction Seafood is a widely consumed and nutritionally rich food source,but it ranks among the top allergens,with shellfish and fish being major triggers of allergic reactions.These reactions,primarily caused by proteins such as tropomyosin(TM)in shellfish and parvalbumin(PV)in fish,can lead to life-threatening anaphylaxis in susceptible individuals.The development of hypoallergenic seafood is becoming increasingly important to provide safe alternatives for those with seafood allergies.This comment reviews recent advances in allergenicity mitigation strategies,highlighting the progress made and future potential in producing hypoallergenic seafood products.

Analysis of Allergens in 5473 Patients with Allergic Diseases in Harbin, China

Objective To analyze the allergic status to common inhalant allergens and food allergens in clinical patients in Harbin in northeastern China and provide evidence to develop the prevention strategy of allergic disease. Methods The data were collected from 5 473 patients with clinical suspected allergic diseases seeking medical care in the Second Affiliated Hospital of Harbin Medical University. Among these patients, 2 530 （46.2%） were males aged 0-86 years, the youngest was only 1 month old and 2 579 （47.1%） were young children and teenagers. The serum specific Immunoglobulin E （slgE） to 14 kinds of common allergens and serum total IgE were detected by using AllergyScreen test （Mediwiss Analytic GmbH, Moers, Germany）. Results In 5 473 subjects the positive rate of slgE was 33.1% （n=1 813）. Cow milk （6.9%） and wheat （3.1%） were the most common food allergens, followed by house dust mite mix （12.5%） and mould mix （9.4%） and the age and gender specific differences in the positive rate were significant. For the children aged 〈7 years the positive rates to cow milk, beef-mutton, and egg white/egg yolk were high, but the positive rates to house dust mite mix, ragweed estragon, and mould mix were low （P〈0.05）. For the adults the positive rates to aeroallergens were high while the rates to food allergens were low. Conclusion The results from this study showed that the food allergens in Harbin had geographic characteristics, which support the viewpoint that the environment factors play an important role in the incidence of allergic diseases. Also, the detection of slgE and total IgE are essential to identify relevant allergens for the purpose of early diagnosis, management and prevention of allergic disease.

Effect of high intensity ultrasound on the allergenicity of shrimp

The tropomyosin fraction of shrimp proteins is potentially responsible for allergic reaction in individuals with genetic predisposition to allergy. However, there are no efficient and safe methods to reduce its allergenicity. High intensity ultrasound is known to change the structure of proteins. This study is aimed at assessing high intensity ultmsound＇s effect on the allergenicity of shrimp allergen. Shrimp and purified shrimp allergen were treated with high intensity ultrasound for 30-180 min. Extracts of treated samples were analyzed by enzyme-linked immunosorbent assay （ELISA） with pool serum of shrimp allergy patients and polyclonal anti-allergen antibodies and by immunoblotting after polyacrylamide gel electrophoresis. Shrimp treated with high intensity ultrasound showed a decrease in allergenicity measured with ELISA. A linear relationship between the immune response induced by treated shrimp allergen and the applied treatment time was observed. The decrease in allergenicity was confirmed by immunoblot assays with shrimp allergic patients serum. Allergenicity of shrimp allergen extracted from treated shrimp was higher than that of purified shrimp allergen with the same treatment time. Gel-filtration HPLC was applied for analysis of shrimp allergen after treatment with high intensity ultrasound. Some fractions were appeared with increasing treatment time. The results suggested that high intensity ultrasound could be used to reduce the allergenicity of shrimp.

A Study on Pollen Allergens in China

Objective Allergic disease caused by airborne pollen is a major health problem in China. Intensive study on pollen allergens can be of great help for preventing and treating pollinosis. Four aspects of the study on pollen allergens in China including major allergic pollen in our country, analysis and purification of pollen allergen composition, recombinant pollen allergens and clinical application of pollen allergens are described in this paper.

Cross-reactivity between aeroallergens and food allergens

In patients with respiratory allergy,cross-reactivity between aeroallergens and foods may induce food allergy,symptoms ranging from oral allergy syndrome to severe anaphylaxis.Clinical entities due to Ig E sensitization to cross-reactive aeroallergen and food allergen components are described for many sources of plant origin(pollen-food syndromes and associations,such as birch-apple,cypress-peach and celery-mugwortspice syndromes,and mugwort-peach,mugwortchamomile,mugwort-mustard,ragweed-melon-banana,goosefoot-melon associations),fungal origin(Alternariaspinach syndrome),and invertebrate,mammalian or avian origin(mite-shrimp,cat-pork,and bird-egg syndromes).Clinical cases of allergic reactions to ingestion of food products containing pollen grains of specific plants,in patients with respiratory allergy to Asteraceae pollen,especially mugwort and ragweed,are also mentioned,for honey,royal jelly and bee polen dietary supplements,along with allergic reactions to foods contaminated with mites or fungi in patients with respiratory allergy to these aeroallergens.Medical history and diagnosis approach may be guided by the knowledge about the diverse cross-reacting allergens involved,and by the understanding of these clinical entities which may vary significantly or may be overlapping.The association between primary Ig E sensitization with respiratory symptoms to inhaled allergens and food allergy due to cross-reactive allergen components is important to assess in allergy practice.The use of molecular-based diagnosis improves the understanding of clinically relevant Ig E sensitization to cross-reactive allergen components from aeroallergen sources and foods.

Single-allergen Sublingual Immunotherapy versus Multi-allergen Subcutaneous Immunotherapy for Children with Allergic Rhinitis

It has always been controversial whether a single allergen performs better than multiple allergens in polysensitized patients during the allergen-specific immunotherapy. This study aimed to examine the clinical efficacy of single-allergen sublingual immunotherapy(SLIT) versus multi-allergen subcutaneous immunotherapy(SCIT) and to discover the change of the biomarker IL-4 after 1-year immunotherapy in polysensitized children aged 6–13 years with allergic rhinitis(AR) induced by house dust mites(HDMs). The AR polysensitized children(n=78) were randomly divided into two groups: SLIT group and SCIT group. Patients in the SLIT group sublingually received a single HDM extract and those in the SCIT group were subcutaneously given multiple-allergen extracts(HDM in combination with other clinically relevant allergen extracts). Before and 1 year after the allergen-specific immunotherapy(ASIT), the total nasal symptom scores(TNSS), total medication scores(TMS) and IL-4 levels in peripheral blood mononuclear cells(PBMCs) were compared respectively between the two groups. The results showed that the TNSS were greatly improved, and the TMS and IL-4 levels were significantly decreased after 1-year ASIT in both groups(SLIT group: P<0.001; SCIT group: P<0.001). There were no significant differences in any outcome measures between the two groups(for TNSS: P>0.05; for TMS: P>0.05; for IL-4 levels: P>0.05). It was concluded that the clinical efficacy of single-allergen SLIT is comparable with that of multi-allergen SCIT in 6–13-year-old children with HDM-induced AR.

Detection and inactivation of allergens in soybeans:A brief review of recent research advances

In the last decade,soybean allergies have been on the increases to such an extent that they have now become a public health issue thus prompting more studies and researches on the topic.The allergenicity of soybean is attributed to its protein fraction.The best way to prevent hypersensitive patients from ingesting allergenic compounds is to exclude such soybean allergens from their diet.As a result,it is essential to provide detailed and reliable knowledge of food ingredients.Therefore,precise and reliable approaches for detecting soybean allergens found in various food products must be used.The main way to reduce allergy risk is the identification of allergenic sites in food and their inactivation by various food-processing methods.It has been reported that food processing may lead to the modification of conformational structure of the protein or protein distortion that inhibit the binding of immunoglobulin E(Ig E)to epitopes on food allergens and also the mechanism of allergic reactions.Food processing technologies employed for inactivating allergenic epitopes used thermal and nonthermal techniques.Currently,several detection methods including protein-based and DNA-based approaches using analytical techniques such as enzyme-linked immunosorbent assay(ELISA),enzyme allergosorbent test(EAST),radioallergosorbent test(RAST),lateral flow immunoassay(LFIA),immunoblotting,realtime polymerase chain reaction(PCR),mass spectrometry and biosensors have been improved for identifying and quantifying these epitopes.This research focused on allergenic proteins of soybean,the most modern approaches for detecting and quantifying these allergens,and finally,the various methods used to inactivate these proteins and their effects on soy allergenicity.

Influence of Ultrasonic Treatment on the Allergenic Properties of Shrimp (Penaeus vannamei) Allergen

The present study was undertaken to determine whether high intensity ultrasound could reduce the allergic properties of shrimp allergens. Reducing the allergenic properties of these allergens will be beneficial to allergic individuals. Samples of shrimp protein extract and shrimp muscle were treated by high-intensity ultrasound with water bathing at 0 ℃ or 50 ℃ for different time periods. The treated and untreated samples were then analyzed by SDS-PAGE, Western blots and competitive inhibition ELISA （Ci-ELISA） to determine the shrimp allergenicity. The results show that high-intensity ultrasound has no effect on allergenicity when the extracts were treated at 0℃. However, a significant decrease was observed in the level of the major shrimp allergen, Pen a 1, when the samples were treated at 50 ℃. In the determination of allergenicity with CiELISA, a reduction in IgE binding was also observed.

Changes in wheat protein digestibility and allergenicity: role of Pediococcus acidilactici XZ31 and yeast during dough fermentation

Wheat flour,as the most important source of food globally,is one of the most common causative agents of food allergy.This study aimed to investigate the effects of fermentation on wheat protein digestibility and allergenicity.Protein digestibility were evaluated using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and enzyme-linked immunosorbent assay.The effect of protein on intestinal permeability was investigated by Caco-2 cell monolayers.Co-culture fermentation with Pediococcus acidilactici XZ31 and yeast leads to improvement in digestibility of wheat protein compared to single strain fermentation.Fermentation leads to a decrease in albumin/globulin antigenicity and an increase in gluten R5 reactivity,with the most significant changes in the co-culture group.Digestion strengthen the decrease of protein antigenicity and counteracts the difference in antigenicity induced by fermentation between groups.However,pretreatment with P.acidilactici XZ31 reduces the amount of allergens across Caco-2 monolayer and attenuates the gluten-induced increase in permeability of Caco-2 cell monolayer by reducing actin polymerization and villous atrophy.Co-culture fermentation reduces gluten-induced cell monolayer damage to a greater extent than P.acidilactici XZ31 monoculture.These results gives valuable insight into the effects of P.acidilactici XZ31 fermentation on the allergenicity and toxicity of wheat proteins,which contribute to promoting the application of multi-strain leavening agent in hypoallergenic and gluten-free wheat products.

In Silico Analysis of the Cross-Reactivity of Pacific White Shrimp (Litopenaeus vannamei) Allergens with Other Arthropod Species

This study provided new data in the area of cross-reactivity for Pacific white shrimp (Litopenaeus vannamei). Although the cross-reactivity between the most prominent allergenic proteins of shrimp and other crustaceans has been extensively studied, few data are showing the frequency of arthropod-shrimp Litopenaeus vannamei cosensitization in an in silico analysis. A comparative analysis of “typical and non-typical” shrimp L. vannamei allergens with other species was achieved, revealing new allergens and previously characterized shrimp allergens, which validated the comprehensive identification approach used in this study. Importantly, up to 192, amino acid sequences were identified that had matches to shrimp L. vannamei allergens that matched allergenic proteins in mites, insects, fish, bacteria, mammals, birds, and plants.

Bioinformatics Analysis on B cell Epitopes of Rice Allergen RAG1

[Objective] To predict the secondary structure and B cell epitopes of the rice major allergen RAG1. [Method] The amino acid sequence of rice allergen RAG1 was acquired from Expasy protein database. The secondary structure of RAG1 was predicted by DNAStar Protean software with Gamier-Robson program, Chou-Fasman program and Karplus-Schulz program; the B cell epitopes of RAG1 was predicted with the Kyte Doolittle hydrophilic program, Emini surface accessibility program and Jameson-Wolf antigenic index program. [Result] The predictions on secondary structure and B cell epitopes showed that the regions of 33-44, 119-129, 155-163 were the dominant B cell epitopes. [Conclusion] This study predicted the potential dominant B cell epitopes in rice allergen RAG1 by comprehensive use of multi-methods and multi-parameters, and provided a theoretical basis for further researches on identification, antigen modification and epitope vaccine design of RAG1 B cell epitopes.

Major allergens in 8 types of allergenic foods and allergen detection techniques

In recent years,the prevalence of allergens in food warning notices,both domestically and internationally,has become the second leading concern after microbial contamination.Among the various factors that threaten human health reported by the World Health Organization,food allergy ranks fourth,and food allergy has become a global security problem.As of now,no definitive treatment for food allergies exists,making the avoidance of allergen-containing foods the most effective prevention method.Consequently,labeling foods with allergen information serves as a crucial warning for allergic populations.Moreover,to enhance comprehension of food allergies,this article provides a brief overview of their definition and sensitization mechanisms.The main focus lies in highlighting the structure of primary allergens found in eight commonly allergenic foods and the resulting clinical symptoms they cause.Additionally,a summary of commonly employed allergen detection techniques is presented,with an analysis of their principles,advantages,and limitations.Looking ahead,the integration of diverse technological approaches to establish an efficient,accurate,and affordable allergen detection method remains a significant trend.This article has certain reference value for understanding the direction of food allergies.