Open sesame: Shedding light on an emerging global allergen

Irradiation alters the structure and reduces the sensitization of sesame proteins in the liquid state

Irradiation is extensively utilized in food processing as an effective and convenient method. At present, numerous studies have investigated the potential of irradiation to reduce food allergenicity. The objective of this study was to investigate the effects of irradiation treatment on the structure and allergenicity of liquid and solid sesame proteins. Sesame protein extracts and lyophilized powders were irradiated at doses of 0, 2.5, 5, 7.5, and 10 kGy, respectively. The effects of irradiation on sesame proteins were investigated by CD spectroscopy, fluorescence spectroscopy, indirect competitive ELISA, western blot and degranulation experiments on KU812 cells. The experimental results demonstrated that irradiation had a more pronounced effect on liquid sesame proteins. Irradiation altered the secondary structure and increased the surface hydrophobicity, with the α-helix content decreasing from 14.27% to 13.53% and the β-sheet content increasing from 33.91% to 39.53%. Additionally, protein aggregation resulted in a reduction of free sulfhydryl groups. Following irradiation, the IC50 value obtained by indirect competitive ELISA increased from 0.695 μg mL-1 to 18.546 μg mL-1, while the release of cellular β-Hex and IL-6 was reduced, indicating that irradiation diminished the IgE binding capacity of liquid sesame proteins and their ability to induce cell degranulation. Western blotting results corroborated the findings from the ELISA assay. In conclusion, irradiation modifies the structure and reduces the potential allergenicity of liquid sesame proteins.

Natural history of sesame allergy in pediatric patients: Insight from a retrospective analysis

BACKGROUND

Sesame allergy (SA) is a growing concern because of its association with severe reactions and the limited knowledge of long-term outcomes.

OBJECTIVE

This retrospective study aimed to identify the risk factors influencing persistent SA (PSA) in children to improve management and select suitable candidates for oral immunotherapy (OIT).

METHODS

We analyzed the electronic medical records of 84 children with confirmed SA, as defined by consistent clinical reactions and immunoglobulin E (IgE)-mediated sensitization. Patients were followed for a median (IQR) of 56.5 (46.0-82.5) months.

RESULTS

Most participants were male (72.6%) with concurrent food allergies (71.4%). They experienced a median (IQR) of 3.0 (2.0-3.7) allergic episodes, with 46.4% experiencing at least one anaphylactic reaction. PSA was observed in 82.1% (69/84) of the patients. A larger skin prick test (SPT) wheal size at the first reaction (adjusted OR = 1.79, CI:1.05-3.04; p = .03) and allergic reaction grade≥2 (adjusted OR = 19.93, CI:1.37-289.13; p = .02) were independent risk factors for persistence. A 3-fold increase in the likelihood of persistence was observed in patients with SPT results greater than 6.7 mm at first reaction compared with those with results less than 6.7 mm during follow-up (HR = 3.08; CI:1.17-8.12; p = .02). Patients with sustained or increased SPT wheal size (93% remained allergic) and specific IgE (95% remained allergic) at the final visit were more likely to have PSA, whereas those with decreased levels (37% and 39% developed natural tolerance, respectively) were less likely to have resolved SA.

CONCLUSIONS

This study identified novel risk factors for PSA, including SPT wheal size at the first reaction, reaction severity, and sustained sensitization markers. These findings can inform management strategies and the selection of OIT candidates. Further long-term studies are crucial to elucidate the natural history of SA across populations and to evaluate early interventions, such as OIT.

Screening, identification, and application of aptamers against allergens in food matrices

Food allergies have become one of the most pressing issues in food safety and public health globally along with their incidence increasing in recent years. The reliable recognition of allergens from different sources, especially food-hidden allergens, is essential for preventing and controlling food allergies. Recently, aptamers, as emerging recognition elements, have gained considerable attention in food allergy, especially in the detection of food allergens. This review systematically summarizes the latest progress in screening, identification, and application of aptamers against food allergens over the past five years. We first introduce a brief overview of food allergy and aptamers, followed by a detailed focus on the aptamers' research against different food allergens broadly based on the major categories of the Big-8 allergens: highlighting the newly screened aptamers and their applied systematic evolution of ligands by exponential enrichment (SELEX) strategies, and emphasizing their practical applications including aptasensors, allergy inhibitors, or affinity adsorptions. Finally, the remaining challenges and future exploitations faced by aptamers in food allergens are comprehensively discussed and depicted. This review holds the promise of inspiring a broader range of researchers to gain an in-depth understanding of food allergy assisted by aptamer recognition and to facilitate improved biochemical analyses and successful application.

Food safety issues associated with sesame seed value chains: Current status and future perspectives

Sesame (Sesamum indicum) is an oilseed crop which is increasingly recognised as a functional food by consumers due to its nutritional and nutraceutical components. Consequently, global demand for sesame has increased significantly over the last three decades. Sesame is an important export crop in producing countries, contributing to their socio-economic development. However, in recent years, major foodborne incidents have been associated with imported sesame seeds and products made with these seeds. Foodborne hazards are a potential risk to consumer health and hinder international trade due to border rejections and increased import controls. An insight into the routes of contamination of these hazards across the value chain and factors affecting persistence may lead to more focused intervention and prevention strategies. It was observed that Salmonella is a significant microbial hazard in imported sesame seeds and has been associated with several global outbreaks. Sesame is mainly cultivated in the tropical and subtropical regions of Africa and Asia by smallholder farmers. Agricultural and manufacturing practices during harvesting, storage, and processing before export may allow for the contamination of sesame seeds with Salmonella. However, only a few studies collect data on the microbiological quality of sesame across the value chain in producing countries. In addition, the presence of mycotoxins and pesticides above regulatory limits in sesame seeds is a growing concern. Eliminating foodborne hazards in the sesame value chain requires urgent attention from researchers, producers, processors, and regulators and suggestions for improving the safety of these foods are discussed.

Oral immunotherapy with sunflower seed butter and a review of seed allergy

Food allergy to seeds is increasingly more common, with sesame being the most prevalent. Allergy to other seeds, including sunflower, pumpkin, poppy, mustard, and flaxseed, have been reported. Diagnosing a seed allergy is challenging, with many seeds being hidden additives in processed foods and cross-reactive testing. Food labels in the United States are now required to indicate the presence of sesame but other seeds are not required. Oral immunotherapy (OIT) protocols for peanut, milk, and egg are clinically being extrapolated to other foods, including sesame and sunflower seed. This article highlights a case of a patient in whom sunflower seed OIT was administered in a clinical setting.

[Skin test (Skin Prick Test) in food allergy]

Skin tests, also known as prick tests, in food allergies are restricted to IgE-mediated food allergies, with results that barely indicate sensitization to a certain food and do not necessarily suggest food allergy. The clinical context of the patient is the decisive point before performing any type of food allergy skin test; Contextualizing and relating the patient's clinical picture with the immunological mechanism of IgE-mediated allergies will allow a better selection of the allergy test for each case. Positive tests should be interpreted more carefully, and consider that during early childhood it is common that several patients may have negative specific serum IgE tests in the blood for food allergens compared to those performed on the skin, which are positive. Skin testing can be carried out with standardized strata of foods, but they are not always available for all foods and some are very unstable. Skin tests can even be performed with raw foods, using the prick to prick technique to perform the puncture with fresh foods (especially fruits or vegetables) or other products that are not commercially available. The skin prick test is a test where, after having placed the allergenic extract in drops or with fresh food itself, the puncture must be carried out with a standardized lancet.

Composition, functional properties, health benefits and applications of oilseed proteins: A systematic review

Common oilseeds, such as soybean, peanut, rapeseed, sunflower seed, sesame seed and chia seed, are key sources of edible vegetable oils. Their defatted meals are excellent natural sources of plant proteins that can meet consumers' demand for health and sustainable substitutes for animal proteins. Oilseed proteins and their derived peptides are also associated with many health benefits, including weight loss and reduced risks of diabetes, hypertension, metabolic syndrome and cardiovascular events. This review summarizes the current status of knowledge on the protein and amino acid composition of common oilseeds as well as the functional properties, nutrition, health benefits and food applications of oilseed protein. Currently, oilseeds are widely applied in the food industry regarding for their health benefits and good functional properties. However, most oilseed proteins are incomplete proteins and their functional properties are not promising compared to animal proteins. They are also limited in the food industry due to their off-flavor, allergenic and antinutritional factors. These properties can be improved by protein modification. Therefore, in order to make better use of oilseed proteins, methods for improving their nutrition value, bioactive activity, functional and sensory characteristics, as well as the strategies for reducing their allergenicity were also discussed in this paper. Finally, examples for the application of oilseed proteins in the food industry are presented. Limitations and future perspectives for developing oilseed proteins as food ingredients are also pointed out. This review aims to foster thinking and generate novel ideas for future research. It will also provide novel ideas and broad prospects for the application of oilseeds in the food industry.

Cross-Serological Reaction of Glandless Cottonseed Proteins to Peanut and Tree Nut Allergic IgE

Food allergy is a potentially life-threatening health concern caused by immunoglobulin E (IgE) antibodies that mistakenly recognize normally harmless food proteins as threats. Peanuts and tree nuts contain several seed storage proteins that commonly act as allergens. Glandless cottonseed, lacking the toxic compound gossypol, is a new food source. However, the seed storage proteins in cottonseed may act as allergens. To assess this risk, glandless cottonseed protein extracts were evaluated for IgE binding by peanut and tree nut allergic volunteers. ELISA demonstrated that 25% of 32 samples had significant binding to cottonseed extracts. Immunoblot analysis with pooled sera indicated that IgE recognized a pair of bands migrating at approximately 50 kDa. Excision of these bands and subsequent mass-spectrometric analysis demonstrated peptide matches to cotton C72 and GC72 vicilin and legumin A and B proteins. Further, in silico analysis indicated similarity of the cotton vicilin and legumin proteins to peanut vicilin (Ara h 1) and cashew nut legumin (Ana o 2) IgE-binding epitopes among others. The observations suggest both the cotton vicilin and legumin proteins were recognized by the nut allergic IgE, and they should be considered for future allergen risk assessments evaluating glandless cottonseed protein products.