Recent advance in sesame allergens: Influence of food processing and their detection methods

Sesame (Sesamum indicum L.) is a valuable oilseed crop with numerous nutritional benefits containing a diverse range of bioactive compounds. However, sesame is also considered an allergenic food that triggers various mild to severe adverse reactions (e.g., anaphylaxis). Strict dietary avoidance of sesame components is the best option to protect the sensitized consumers. Sesame or sesame-derived foods are always consumed after certain food processing operations, which would cause a considerable impact on the structure of sesame proteins, changing their sensitization capacity and detectability. In the review, the molecular structure properties, and immunological characteristics of the sesame allergens were described. Meanwhile, the influence of food processing techniques on sesame proteins and the relevant detection techniques used for the sesame allergens quantification are also emphasized critically. Hopefully, this review could provide valuable insight into the development and management for the new "Big Eight" sesame allergen in food industry.

Reported food-related symptoms and food allergen sensitization in a selected adult population in Hyderabad, India: A hospital-based survey

Background

Research on reported food-related triggers of atopic disease in South Asian adults is lacking despite the region's large population and the global significance of allergic diseases.

Objectives

The study aimed to identify prevalent local food items and assess allergic sensitization rates to potential trigger foods for atopic diseases via skin prick and specific IgE testing.

Methods

The study began with a pilot survey of 100 subjects recruited from 4 hospitals in Hyderabad, India, focusing on foods perceived to relate to asthma, allergic rhinitis, atopic dermatitis, urticaria, and gastrointestinal allergic symptoms. A subsequent main study evaluated 2010 participants, 1754 of whom were diagnosed with an aforementioned atopic disease and who reported allergic symptoms related to any of 77 foods identified in the pilot study. Ultimately 1622 patients who consented to skin prick and specific IgE testing and who reported at least 1 food item triggering allergic diseases were included in the final analysis.

Results

Among 1622 patients (average age, 42.6 ± 12.9 years; 55.5% male), asthma was the most commonly diagnosed atopic disease (26.4%), with itching and rash being frequently reported symptoms (22.7%). Notably, 94.9% of patients had total serum IgE > 144 kU/L. Chickpea, cabbage, eggplant, walnut, cumin, and betel leaf were the most commonly reported trigger foods.

Conclusion

In this sample of South Indian adults diagnosed with allergic disease, reported food triggers were most commonly local dietary staples, while reported reactions to priority allergens like peanut and sesame were conspicuously absent. Observed concordance between patient-reported food triggers and sensitization to reported food triggers was low, highlighting the need for improved clinical evaluation of suspected triggers.

Assessment of the effect of glycation on the allergenicity of sesame proteins

Sesame allergy is a growing concern worldwide. In this study, sesame proteins was glycated with glucose, galactose, lactose and sucrose respectively, and the allergenicity of different glycated sesame proteins were assessed by a comprehensive strategy, including simulated gastrointestinal digestion in vitro, a BALB/c mice model, a rat basophilic leukemia (RBL)-2H3 cell degranulation model and a serological experiment. Firstly, simulated gastrointestinal digestion in vitro showed that glycated sesame proteins were more easily to digest than raw sesame. Subsequently, the allergenicity of sesame proteins was assessed in vivo by detecting the allergic indexes of mice, and results showed that the levels of total immunoglobulin E (IgE) and histamine were reduced in glycated sesame proteins treated mice. Meanwhile, the Th2 cytokines (IL-4, IL-5, and IL-13) were downregulated significantly, demonstrating that sesame allergy was relieved in glycated sesame treated mice. Thirdly, the RBL-2H3 cell degranulation model results showed that the release of β-hexosaminidase and histamine were decreased to different degrees in glycated sesame proteins treated groups. Notably, the monosaccharide glycated sesame proteins exhibited lower allergenicity both in vivo and in vitro. Furthermore, the study also analyzed the structure alteration of sesame proteins, and the results showed that the secondary structure of glycated sesame proteins were changed (the content of α-helix and β-sheet were reduced), and the tertiary structure of sesame proteins after glycation modification was also changed (microenvironment around aromatic amino acids was altered). Besides, the surface hydrophobicity of glycated sesame proteins was also reduced except sucrose glycated sesame proteins. In conclusion, this study demonstrated that glycation reduced the allergenicity of sesame proteins effectively, especially glycation with monosaccharides, and the allergenicity reduction might be related to structural changes. The results will provide a new reference for developing hypoallergenic sesame products.

Evaluating the influence of cold plasma bubbling on protein structure and allergenicity in sesame milk

BACKGROUND

Sesame is a traditional oilseed comprising essential amino acids. However, the presence of allergens in sesame is a significant problem in its consumption; thus, this study attempted to reduce these allergens in sesame oilseeds.

OBJECTIVE

The present study aimed to evaluate the effect of cold plasma processing on structural changes in proteins, and thereby the alteration of allergenicity in sesame milk. Method: Sesame milk (300 mL) was processed using atmospheric pressure plasma bubbling unit (dielectric barrier discharge, power: 200 V, and airflow rate: 16.6 mL/min) at different exposure times (10, 20, and 30 min).

RESULTS

The efficiency of plasma-bubbling unit as measured by electron paramagnetic resonance in terms of producing reactive hydroxyl (OH) radicals proved that generation of reactive species increased with exposure time. Further, the plasma-processed sesame milk subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and differential scanning calorimetery analysis revealed that plasma bubbling increased the oxidation of proteins with respect to bubbling time. The structural analysis by Fourier transform infrared spectroscopy and circular dichroism revealed that the secondary structure of proteins was altered after plasma application. This change in the protein structure helped in changing the immunoglobulin E (IgE)-binding epitopes of the protein, which in turn reduced the allergen-binding capacity by 23% at 20-min plasma bubbling as determined by the sandwich-type enzyme-linked immunosorbent assay. However, 30-min plasma bubbling intended to increase allergenicity, possibly because of increase in IgE binding due to the generation of neo epitopes.

CONCLUSION

These changes proved that plasma bubbling is a promising technology in oxidizing protein structure, and thereby reducing the allergenicity of sesame milk. However, increase in binding at 30-min bubbling is to be studied to facilitate further reduction of the binding capacity of IgE antibodies.

Sesame-induced anaphylaxis in pediatric patients from the cross-Canada anaphylaxis registry

BACKGROUND

Sesame can cause severe allergic reactions and is a priority allergen in Canada.

OBJECTIVE

To assess clinical characteristics and management of pediatric sesame-induced anaphylaxis and identify factors associated with epinephrine treatment.

METHODS

Between 2011 and 2021, children with sesame-induced anaphylaxis presenting to 7 emergency departments (ED) in 4 Canadian provinces and 1 regional emergency medical service were enrolled in the Cross-Canada Anaphylaxis Registry. Standardized recruitment forms provided data on symptoms, severity, triggers, and management. Multivariate logistic regression evaluated associations with epinephrine treatment pre-ED and multiple epinephrine dosages.

RESULTS

Of all food-induced anaphylactic reactions (n = 3279 children), sesame accounted for 4.0% (n = 130 children), of which 61.5% were boys, and the average (SD) age was 5.0 (4.9) years. Hummus containing sesame paste triggered 58.8% of reactions. In the pre-ED setting, 32.3% received epinephrine, and it was more likely to be used in boys (adjusted odds ratio [aOR], 1.27; 95% confidence interval [CI], 1.08-1.50) and those with a known food allergy (aOR, 1.36; 95% CI, 1.11-1.68]). In the ED, 47.7% of cases received epinephrine, with older children more likely to receive multiple epinephrine doses (aOR, 1.00; 95% CI, 1.00-1.02).

CONCLUSION

In Canada, hummus is the major trigger of sesame-induced anaphylaxis. Knowledge translation focused on prompt epinephrine use and product-labeling policies are required to limit sesame reactions in communities.

Creating hypo-/nonallergenic wheat products using processing methods: Fact or fiction?

Wheat allergy is a potentiallylife-threatening disease that affects millions of people around the world. Food processing has been shown to influence the allergenicity of wheat and other major foods. However, a comprehensive review evaluating whether or not food processing can be used to develop hypo-/nonallergenic wheat products is unavailable. There were three objectives for this study: (1) to critically evaluate the evidence on the effect of fermentation, thermal processing, and enzyme or acid hydrolysis on wheat allergenicity so as to identify the potential for and challenges of using these methods to produce hypo-/nonallergenic wheat products; (2) to identify the molecular effects of food processing needed to create such products; and (3) to map the concept questions for future research and development to produce hypo-/nonallergenic wheat products. We performed literature research using PubMed and Google Scholar databases with various combinations of keywords to generate the data to accomplish these objectives. We found that: (1) food processing significantly modulates wheat allergenicity; while some methods can reduce or even abolish the allergenicity, others can create mega allergens; and (2) fermentation and enzymatic hydrolysis hold the most potential to create novel hypo-/nonallergenic wheat products; however, preclinical validation and human clinical trials are currently lacking. We also identify five specific research concepts to advance the research to enable the creation of hypo-/nonallergenic wheat products for application in food, medical, and cosmetic industries.

Sesame as an allergen in Lebanese food products: Occurrence, consumption and quantitative risk assessment

Despite the intensive use of sesame in the Middle Eastern diet, studies on this allergen in this region are lacking. A survey on the occurrence of sesame in Lebanese food products that did not contain this allergen as an ingredient, a food consumption survey conducted in Beirut schools, and the most recent sesame eliciting dose estimates were used to build a probabilistic risk assessment model providing estimates of sesame-induced allergic reactions per eating occasion and per week in Lebanese children and adolescents. Of 1270 food samples analysed, 34% contained sesame proteins (0.44-3392 mg kg^-1). Sesame was detected in 47% of unlabeled bulk samples, 43% of samples with PAL, and 27% of samples without PAL. "Sfouf" had the highest concentration of sesame proteins (mean 549 mg kg^-1), highest mean exposure per eating occasion (78 mg sesame proteins for children and 103 mg sesame proteins for adolescents), and posed the highest predicted risk per eating occasion (>20%) and per week (>13% individuals predicted in simulation experience at least 1 reaction). Bakery products (notably "sfouf") may pose a serious risk to sesame-allergic children and adolescents in Lebanon. Enhanced guidance on the use of PAL is needed to better protect allergic consumers.