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Food processing can have many beneficial effects. However, processing may also alter the allergenic properties of food proteins. A wide variety of processing methods is available and their use depends largely on the food to be processed. In this review the impact of processing (heat and non-heat treatment) on the allergenic potential of proteins, and on the antigenic (IgG-binding) and allergenic (IgE-binding) properties of proteins has been considered. A variety of allergenic foods (peanuts, tree nuts, cows' milk, hens' eggs, soy, wheat and mustard) have been reviewed. The overall conclusion drawn is that processing does not completely abolish the allergenic potential of allergens. Currently, only fermentation and hydrolysis may have potential to reduce allergenicity to such an extent that symptoms will not be elicited, while other methods might be promising but need more data. Literature on the effect of processing on allergenic potential and the ability to induce sensitisation is scarce. This is an important issue since processing may impact on the ability of proteins to cause the acquisition of allergic sensitisation, and the subject should be a focus of future research. Also, there remains a need to develop robust and integrated methods for the risk assessment of food allergenicity., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Summary: Sesame has been included in the top eight food allergens, and therefore reduction of sesame allergen potency is of great practical significance. Glycation reactions are extensively researched for their role in regulating the allergic properties of food allergens due to their distinct benefits. This study involved the glycation of sesame proteins with three different reducing sugars to generate reaction products. The structure of the reaction products was characterized by the use of spectroscopic and chromatographic techniques. The impact of glycation on the allergenic properties of sesame proteins was explored by in vitro simulated digestion tests combined with immunological techniques. The study results indicated that all three reducing sugars underwent glycation with sesame proteins, with D‐ribose showing the most significant level of glycation. During the glycation reaction of sesame proteins in this study, the proteins underwent precipitation as well as structural changes, leading to reduced immunoglobulin G (IgG) binding capacity. Glycation alters the digestive stability of sesame proteins and further reduces the ability to bind to IgG. Overall, glycation modification shows promise in decreasing the allergenicity of sesame. [ABSTRACT FROM AUTHOR]

The development of novel protein sources to compensate for the expected future shortage of traditional animal proteins due to their high carbon footprint is a major contemporary challenge in the agri-food industry currently. Therefore, both industry and consumers are placing a greater emphasis on plant proteins as a sustainable source of protein to meet the growing nutritional demand of ever increasing population. In addition to being key alternatives, many plant-based foods have biological properties that make them potentially functional or health-promoting foods, particularly physiologically active peptides and proteins accounting for most of these properties. This review discusses the importance of plant-based protein as a viable and sustainable alternative to animal proteins. The current advances in plant protein isolation and production and characterization of bioactive hydrolysates and peptides from plant proteins are described comprehensively. Furthermore, the recent research on bioactivities and bioavailability of plant protein-derived bioactive peptides is reviewed briefly. The limitations of using bioactive peptides, regulatory criteria, and the possible future applications of plant protein-derived bioactive peptides are highlighted. This review may help understand plant proteins and their bioactive peptides and provide valuable suggestions for future research and applications in the food industry. [ABSTRACT FROM AUTHOR]

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With the constant increase in protein demand globally, it is expedient to develop a strategy to effectively utilize protein, particularly those extracted from plant origin, which has been associated with low digestibility, poor techno‐functional properties, and inherent allergenicity. Several thermal modification approaches have been developed to overcome these limitations and showed excellent results. Nevertheless, the excessive unfolding of the protein, aggregation of unfolded proteins, and irregular protein crosslinking have limited its application. Additionally, the increased consumer demand for natural products with no chemical additives has created a bottleneck for chemical‐induced protein modification. Therefore, researchers are now directed toward other nonthermal technologies, including high‐voltage cold plasma, ultrasound, high‐pressure protein, etc., for protein modification. The techno‐functional properties, allergenicity, and protein digestibility are greatly influenced by the applied treatment and its process parameters. Nevertheless, the application of these technologies, particularly high‐voltage cold plasma, is still in its primary stage. Furthermore, the protein modification mechanism induced by high‐voltage cold plasma has not been fully explained. Thus, this review meets the necessity to assemble the recent information on the process parameters and conditions for modifying proteins by high‐voltage cold plasma and its impact on protein techno‐functional properties, digestibility, and allergenicity. [ABSTRACT FROM AUTHOR]

The effect of thermal and ultrasound treatments on denaturation and allergenicity of Pru p 3, the major peach allergenic protein, was determined. The degree of denaturation of Pru p 3 was estimated by sandwich ELISA using specific rabbit IgG, that was previously developed. Validation of ELISA test showed high sensitivity and specificity, and acceptable results of precision and robustness. Allergenicity of Pru p 3 was determined by immunofluorescent assay using three pools of sera from peach allergic individuals. Denaturation of Pru p 3 was dependent on the intensity of the thermal treatment applied and the treatment medium. Thus, the degree of denaturation of Pru p 3 treated at 95 °C for 40 min was about 60% and 95%, for the protein heated in peach extract and in buffer, respectively. Ultrasound treatments denatured Pru p 3 up to 60%, being dependent on amplitude and pressure. However, both heat and ultrasound treatments at the most severe conditions applied inhibited less than 10% the IgE-binding of Pru p 3. These results indicate that although heat and ultrasound treatments induce a considerable denaturation of Pru p 3, they are not effective in reducing its allergenicity. [ABSTRACT FROM AUTHOR]

The high hydrostatic pressure (HHP) process has been studied for several applications in food technology and has been commercially implemented in several countries, mainly for non-thermal pasteurization and shelf-life extension of food products. HHP processing has been demonstrated to accelerate proteolytic hydrolysis at a specific combination of pressure and pressure-holding time for a given protein source and enzyme. The enzymatic hydrolysis of proteins is a well-known alternative to producing biologically active peptides, with antioxidant and antihypertensive capacity, from different food protein sources. However, some of these protein sources contain allergenic epitopes which are often not degraded by traditional hydrolysis. Moreover, the peptide profile and related biological activity of a hydrolysate depend on the protein source, the enzymes used, the parameters of the proteolysis process (pH, temperature, time of hydrolysis), and the use of other technologies such as HHP. The present review aims to provide an update on the use of HHP for improving enzymatic hydrolysis, with a particular focus on studies which evaluated hydrolysate antihypertensive and antioxidant capacity, as well as residual allergenicity. Overall, HHP has been shown to improve the biological properties of hydrolysates. While protein allergenicity can be reduced with traditional hydrolysis, HHP can further reduce the allergenicity. Compared with traditional hydrolysis methods, HHP-assisted protein hydrolysis offers a greater opportunity to add value to protein-rich products through conversion into high-end hydrolysate products with enhanced nutritional and functional properties. [ABSTRACT FROM AUTHOR]

Peanut (Arachis hypogaea L.) is the fourth important oilseed in the world. After oil extraction, defatted peanut is a protein‐rich by‐product containing around 50% of protein that can enable the production of protein isolates (90% protein) and concentrates (70% protein). Peanut protein has an excellent amino acid profile, a desirable volatile profile, a low level of antinutritional factors and a steady supply. Despite these advantages, peanut protein is underutilised because of its poor functional properties caused by the native globular structure and extraction conditions. Nutritional limitations are its deficiency in methionine and lysine and its association with allergic reaction for genetically predisposed subjects. To promote the valorisation of peanut protein in foods, it is very important to ensure a better functionality and a better nutritional value. This review intends to cover the properties of native peanut protein and to discuss innovative strategies including physical, chemical, and biological methods to improve the functionality and to mitigate allergens. These strategies have different degree of success in terms of protein quality and functionality, yield, sustainability and convenience. More investigation is required to select the processing or the combination of processing to boost the application of peanut protein as a valid alternative protein. [ABSTRACT FROM AUTHOR]

Current demand of consumers for healthy and sustainable food products has led the industry to search for different sources of plant protein isolates and concentrates. Legumes represent an excellent nonanimal protein source with high‐protein content. Legume species are distributed in a wide range of ecological conditions, including regions with drought conditions, making them a sustainable crop in a context of global warming. However, their use as human food is limited by the presence of antinutritional factors, such as protease inhibitors, lectins, phytates, and alkaloids, which have adverse nutritional effects. Antitechnological factors, such as fiber, tannins, and lipids, can affect the purity and protein extraction yield. Although most are removed or reduced during alkaline solubilization and isoelectric precipitation processes, some remain in the resulting protein isolates. Selection of appropriate legume genotypes and different emerging and sustainable facilitating technologies, such as high‐power ultrasound, pulsed electric fields, high hydrostatic pressure, microwave, and supercritical fluids, can be applied to increase the removal of unwanted compounds. Some technologies can be used to increase protein yield. The technologies can also modify protein structure to improve digestibility, reduce allergenicity, and tune technological properties. This review summarizes recent findings regarding the use of emerging technologies to obtain high‐purity protein isolates and the effects on techno‐functional properties and health. [ABSTRACT FROM AUTHOR]

Lupines (Lupinus spp.) have emerged as a cheap functional food with the advantages of being non-genetically modified crop, able to adapt to harsh conditions and low-input farming. Lupines are rich in protein and poor in starch, similar to soy. The factor limiting the use of lupine is the presence of quinolizidine alkaloids especially in bitter species. Nevertheless, modern breeding programs ensured the selection of sweet lupine species with reduced alkaloid content (≤ 0.2 g/kg DM). Numerous techniques have been employed to produce lupine protein isolates, concentrates and hydrolysates. These proteins are rich in bioactive peptides associated with health-related benefits and have been reported with interesting techno-functional properties. Lupine Protein isolates and concentrates are used mostly for developing healthy foods, while hydrolysates are more applied in nutraceutical and cosmetic industries. Further research is needed to ensure better safety and wider spectrum of application through adequate strategies for allergenicity mitigation and improving techno-functionality. [ABSTRACT FROM AUTHOR]

The comprehensiveness of the allergen database used to bioinformatically compare a novel food protein with known allergens is critical to the ability to assess the allergenic risk of newly expressed proteins in genetically engineered crops. The strength of the relationship between a candidate GE protein's amino acid sequence and that of known allergens is used to predict cross-reactive risk. The number of truly novel allergen sequences added annually to the COMPARE database reflects on the comprehensiveness of our knowledge of allergen amino acid sequence diversity. Here, we investigated the most recent five years of updates to the COMPARE allergen database for truly novel entries. Results indicate that few truly novel sequences are added each year, suggesting that the database and our knowledge of allergen sequence diversity is currently quite comprehensive, and that current in silico prediction of allergenic risk for novel food proteins is robust. [ABSTRACT FROM AUTHOR]

Plant proteins are spreading due to growing environmental, health and ethical concerns related to animal proteins. Proteins deriving from cereals, oilseeds, and pulses are witnessing a sharp growth showing a wide spectrum of applications from meat and fish analogues to infant formulations. Bakery products are one of the biggest markets of alternative protein applications for functional and nutritional motives. Fortifying bakery products with proteins can secure a better amino-acids profile and a higher protein intake. Conventional plant proteins (i.e., wheat and soy) dominate the bakery industry, but emerging sources (i.e., pea, chickpea, and faba) are also gaining traction. Each protein brings specific functional properties and nutritional value. Therefore, this chapter gives an overview of the main features of plant proteins and discusses their impact on the quality of bakery products. [ABSTRACT FROM AUTHOR]

Background: Previous reports identified proteins associated with 'apoptosis' following cross-linking PrPC with motif-specific anti-PrP antibodies in vivo and in vitro. The molecular mechanisms underlying this IgG-mediated neurotoxicity and the role of the activated proteins in the apoptotic pathways leading to neuronal death has not been properly defined. Previous reports implicated a number of proteins, including apolipoprotein E, cytoplasmic phospholipase A2, prostaglandin and calpain with anti-PrP antibody-mediated 'apoptosis', however, these proteins are also known to play an important role in allergy. In this study, we investigated whether cross-linking PrPC with anti-PrP antibodies stimulates a neuronal allergenic response. Methods: Initially, we predicted the allergenicity of the epitope sequences associated with 'neurotoxic' anti-PrP antibodies using allergenicity prediction servers. We then investigated whether anti-PrP antibody treatment of mouse primary neurons (MPN), neuroblastoma cells (N2a) and microglia (N11) cell lines lead to a neuronal allergenic response. Results: In-Silico studies showed that both tail- and globular-epitopes were allergenic. Specifically, binding regions that contain epitopes for previously reported 'neurotoxic' antibodies such as ICSM18 (146-159), ICSM35 (91-110), POM 1 (138-147) and POM 3 (95-100) lead to activation of allergenic related proteins. Following direct application of anti-PrPC antibodies on N2a cells, we identified 4 neuronal allergenic-related proteins when compared with untreated cells. Furthermore, we identified 8 neuronal allergenic-related proteins following treatment of N11 cells with anti-PrPC antibodies prior to co-culture with N2a cells when compared with untreated cells. Antibody treatment of MPN or MPN co-cultured with antibody-treated N11 led to identifying 10 and 7 allergenic-related proteins when compared with untreated cells. However, comparison with 3F4 antibody treatment revealed 5 and 4 allergenic-related proteins respectively. Of importance, we showed that the allergenic effects triggered by the anti-PrP antibodies were more potent when antibody-treated microglia were co-cultured with the neuroblastoma cell line. Finally, co-culture of N2a or MPN with N11-treated with anti-PrP antibodies resulted in significant accumulation of NO and IL6 but not TNF-α in the cell culture media supernatant. Conclusions: This study showed for the first time that anti-PrP antibody binding to PrPC triggers a neuronal hypersensitivity response and highlights the important role of microglia in triggering an IgG-mediated neuronal hypersensitivity response. Moreover, this study provides an important impetus for including allergenic assessment of therapeutic antibodies for neurodegenerative disorders to derive safe and targeted biotherapeutics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Innovative technologies for protein extraction from oilseed meals are summarized. • Oilseed meal proteins could be used as nanocarriers of bioactive compounds. • The allergenic potential of oilseed meal proteins is also evaluated. • Oilseed meal proteins provide great potential for enhancing the stability of bioactives. The global demand for animal proteins is predicted to increase twofold by 2050. This has led to growing environmental and health apprehensions, thereby prompting the appraisal of alternative protein sources. Oilseed meals present a promising alternative due to their abundance in global production and inherent dietary protein content. The alkaline extraction remains the preferred technique for protein extraction from oilseed meals in commercial processes. However, the combination of innovative techniques has proven to be more effective in the recovery and functional modification of oilseed meal proteins (OMPs), resulting in improved protein quality and reduced allergenicity and environmental hazards. This manuscript explores the extraction of valuable proteins from sustainable sources, specifically by-products from the oil processing industry, using emerging technologies. Chemical structure, nutritional value, and functional properties of the main OMPs are evaluated with a particular focus on their potential application as nanocarriers for bioactive compounds. [ABSTRACT FROM AUTHOR]

Over the last decades, interest in oats (Avena sativa L.) as healthy foods increased due to their multiple functional and bioactive components such as dietary fibers, polyphenols, and proteins. Protein extracted from oats received considerable attention being more abundant (12–20%) and having a distinct composition compared to other cereal grains. Oat proteins also present pleasant sensorial attributes compared to proteins deriving from legumes and oil seeds. Protein isolates or concentrates can be dry- or wet- extracted, and subsequent enzymatic hydrolysis can release peptides with bioactive properties. Several strategies have been successfully applied to improve the techno-functionality of oat proteins. In terms of food application, there are few oat protein-based food products available in the market, which urge food developers to build tailored strategies and food portfolios of these ingredients. This review will address oat proteins extraction technologies and pre/post-treatment strategies, main characteristics, and applications. Future research is still required to take advantage of breeding progress to select high grain-protein oat varieties and to boost the incorporation of oat proteins in foods while keeping in mind the cost and the environmental impact. [ABSTRACT FROM AUTHOR]

Background: Kiwifruit is a popular fruit consumed worldwide and is also used as a cosmetic ingredient. However, it is known to cause allergic reactions in humans. Recent studies have suggested an association between food allergy and food allergens entering the body via the skin. However, percutaneously sensitizing kiwifruit allergens have not been identified in human studies or in animal models. Objective: This study aimed to identify kiwifruit proteins that percutaneously sensitized mice through the epidermal application of crude extracts from green and gold kiwifruit on the dorsal skin, and serum IgE and IgG1 levels were used as sensitization markers. Design: BALB/c mice were back-shaved and their skin was exposed to crude extracts from green and gold kiwifruit that contained sodium dodecyl sulfate. Specific IgE and IgG1 antibodies generated and secreted in response to antigens were measured using enzyme-linked immunosorbent assay or immunoblotting. Results: Skin exposure to kiwifruit extract induced an increase in the levels of kiwifruit-specific IgE and IgG1, which are helper T cell 2-related allergenic antibodies in mice. These antibodies reacted with 18, 23, and 24 kDa proteins found in both green and gold kiwifruits. Thus, three percutaneously sensitizing allergens were identified and purified. Their amino acid sequences partially matched with that of kiwellin (Act d 5). Discussion and conclusion: Kiwellin has been identified as a plant defense-related protein. Interestingly, many plant allergens are biodefense-related proteins belonging to the pathogenesis-related protein family. Kiwellin, which was discovered to be a transdermal sensitizing antigen, might also be categorized as a biodefense-related protein. This study is the first to identify kiwellin (Act d 5) as a percutaneously sensitizing kiwifruit allergen in a mouse model. [ABSTRACT FROM AUTHOR]

In recent years, various oilseeds have been increasingly used for food purposes. Whole seeds, oils, meal and cake by-products are valuable sources of nutritional and bioactive components. Their properties are widely promoted by nutritionists and food producers, and therefore the interest of consumers in new pro-health ingredients is growing rapidly around the world. Nowadays, new trends are being evaluated by food scientist and industry to partially replace animal proteins with proteins of vegetable origin, contributing not only to improvement of the pro-health values of meat products, but also corresponding to the need of many scientists, activists and government agencies to reduce meat production for ethical reasons and care for the environment. This review summarizes the nutritional and pro-health properties of eleven selected oilseeds, namely, chia, coconut, evening primrose, hemp, flax, milk thistle, nigella, pumpkin, rapeseed, sesame and sunflower, with emphasis on their application to improve food products characteristics, oilseed protein composition and proteins and peptides biological activity, as well as potential allergenicity. The presence of biologically active proteins and peptides having antioxidant, antihypertensive or neuroprotective properties, as well as a relatively well-balanced profile of exogenous amino acids with sulphur-containing amino acids, makes oilseed proteins a valuable functional component or an alternative source of protein, especially for bakery and meat industries. The low allergenicity of pumpkin and hemp seeds and potential non-allergenicity of chia, evening primrose, milk thistle, and nigella also weighs in favour of their application as functional ingredients in newly-formulated foods. •The review summarizes the nutritional and pro-health properties of ten oilseeds. •Whole seeds and by-products have a well-balanced profile of exogenous amino acids. •Some peptides have antioxidant, antihypertensive or neuroprotective properties. •The allergenic potential of selected oilseed proteins is also evaluated. •Protein-rich oilseed components have the potential as functional ingredients in newly-formulated foods. [ABSTRACT FROM AUTHOR]

Serendipity berry plant (Dioscoreophyllum cumminsii (Stapf) Diels) is the source of a naturally sweet protein referred to as monellin. The safety of serendipity berry sweet protein (SBSP) containing single polypeptide monellin (MON) expressed in Komagataella phaffii (formerly Pichia pastoris) and produced via precision fermentation was examined comprehensively through assessments of in vitro and in silico protein digestion , in silico allergenicity, in vitro genotoxicity (reverse mutation and mammalian micronucleus assays), and 14-day and 90-day oral (dietary) toxicity studies in rats. There was no indication of allergenicity for SBSP in the in silico analyses. Results from both in vitro and in silico protein digestibility assessments indicated that SBSP is digested upon ingestion and would therefore be unlikely to pose a toxigenic or allergenic risk to consumers. SBSP was non-genotoxic in in vitro assays and showed no adverse effects in the 14-day or 90-day toxicity studies up to the highest dose tested. The 90-day toxicity study supports a NOAEL for SBSP of 1954 mg/kg bw/day, which corresponds to a NOAEL for MON of 408 mg/kg bw/day. • Serendipity Berry Sweet Protein can be used as a sweetener in food and beverages. • Serendipity Berry Sweet Protein is digestible and not a toxigenic/allergenic risk. • Serendipity Berry Sweet Protein was non-genotoxic. • Serendipity Berry Sweet Protein 90 day oral no adverse effect level of 1954 mg/kg/d. • Oobli is producing the Serendipity Berry Sweet Protein via precision fermentation. [ABSTRACT FROM AUTHOR]

Food allergies are worldwide public health problems. Enzymatic hydrolysis has mild conditions, and high efficiency and stability, meaning it is widely used to reduce the allergenicity of food allergens. However, using only enzymatic hydrolysis allows allergens to retain some allergenicity, thereby limiting its application; combining enzymatic hydrolysis with processing represents a potentially effective solution to solve this issue. Here, the effects of three combinations of enzymatic hydrolysis and processing on food allergen allergenicity were reviewed: pre-processing before hydrolysis, hydrolysis under processing , and hydrolysis before processing. The mechanisms, advantages, and limitations of each combination were discussed. Combing pre-processing and enzymatic hydrolysis more effectively reducing allergenicity than a single treatment. However, each combination affects allergenicity through different mechanisms: (1) most pre-processing procedures (heating, ultrasound, high hydrostatic pressure, pulsed electric field, and pulsed ultraviolet light) disrupted conformational epitopes and increased enzyme accessibility by altering protein spatial structures; (2) cold plasma and fermentation reduced allergenicity mainly by hydrolyzing epitopes , yet combined with enzymatic hydrolysis further reduced allergenicity owing to the differences in hydrolysis sites; (3) glycation and polyphenols binding reduce allergenicity by masking linear epitopes , whereas enzymatic hydrolysis eliminates unmasked epitopes. Hydrolysis under processing improves hydrolysis efficiency; however, only limited research exists on the enzymatic changes that occur during processing. Hydrolysis before processing (especially fermentation) produces proteins with hypoallergenic, good sensory, and functional properties. The allergen allergenicity may increase, decrease, or remain unchanged depending on the processing method, conditions, enzyme type, and allergen source. [Display omitted] • Enzymatic hydrolysis combined with processing can effectively reduce allergenicity. • Optimal conditions and enzymes need to be explored for different allergens. • Hydrolysis before fermentation is used to produce superior hypoallergenic foods. • Safety of hydrolyzed proteins produced by new methods needs more evaluation. • Allergenicity reduction should not come at the expense of other characteristics. [ABSTRACT FROM AUTHOR]

The popularity of quinoa seeds has increased in the last decade due to their high nutritional value and natural gluten-free composition. Consumption of new proteins may pose a risk of introducing new allergies. In the present study the immunogenicity and sensitising capacity of quinoa proteins were assessed in a dose-response experiment in Brown Norway rats in comparison to proteins from spinach and peanut. Cross-reactivity between quinoa proteins and known allergens was evaluated by in silico analyses followed by analyses with 11 selected protein extracts and their anti-sera by means of ELISAs and immunoblotting. Further, an in vitro simulated gastro-duodenal digestion was performed. Quinoa proteins were found to have an inherent medium to high immunogenicity and sensitising capacity, being able to induce specific IgG1 and IgE levels higher than spinach but lower than peanut and elicit reactions of clinical relevance similar to peanut. Quinoa proteins were generally shown to resist digestion and retain capacity to bind quinoa-specific antibodies. Quinoa proteins were shown to be cross-reactive with peanut and tree nut allergens as high sequence homology and antibody cross-binding were demonstrated. Present study suggests that quinoa pose a medium to high level of allergenicity that should be further investigated in human studies. [Display omitted] • Quinoa had an inherent medium to high sensitising capacity in an animal model. • Likely the basic subunit of 11S globulin was the most sensitising allergen. • Quinoa proteins were in general resistant to digestion retaining antibody binding capacity. • Quinoa proteins showed potential cross-reactivity to certain tree nut allergens. [ABSTRACT FROM AUTHOR]

Humans have practiced entomophagy for thousands of years; yet until recently, interest from Western countries has emerged toward using insects as alternative proteins to feed the growing world population. Research shows that western cultures are in favor of consuming familiar foods formulated with insect protein. This has led to the productions of insect-derived flours, primarily from crickets and mealworms, which are now available in North American and European markets. Studies have shown limited functional properties of these insect flours. Food scientists have long used controlled enzymatic protein hydrolysis as means for improving the functionality of different animal and plant proteins. Consequently, the production of insect protein hydrolysates seems like a logical approach to improve the functionality and nutritional quality of insect flours. This article provides an overview of the application of controlled enzymatic hydrolysis to produce insect protein hydrolysates with improved protein functionality, as well as opportunities and challenges faced during their use in food and feed formulations. [ABSTRACT FROM AUTHOR]

Many food innovations rely on the introduction and use of new or modified proteins. New or modified food proteins may lead to major health risks due to their inherent potential to cause food allergy. Currently, the pre-market allergenicity assessment for new or modified food proteins and protein sources relies on methods for identifying allergenic hazards based on characteristics of known allergens. However, there is no general consensus on the allergenicity parameters to use and the criteria that should apply for the evaluation and decisions to be made. In this paper, we propose that the strategy for allergenicity risk assessment of new or modified food proteins and the methodologies applied should be governed by the risk management questions to be answered, reflected in the information needed by risk managers to enable their informed decision making. We generated an inventory of health outcome-related assessment parameters and criteria potentially important for risk management decision-making and we discuss the implications of selecting different optional criteria (e.g. cut-off values) for what could be accepted as safe with regards to the health outcomes in the (at risk) population. The impact of these various options on both method development and risk management practices was investigated. • New or modified food proteins may lead to food allergy and require risk assessment. • There is no guidance on allergenicity parameters and evaluation criteria to use. • Allergenicity risk assessment should be governed by the risk management questions. • Methodologies should be governed by the information needed by the risk manager. • We present an inventory of optional assessment parameters and evaluation criteria. [ABSTRACT FROM AUTHOR]

[Display omitted] • The effect of UHP treatment on the structure of peach proteins was analyzed. • Changes in allergenicity of UHP-treated peach proteins were investigated. • Changed regions of Pru p 3B-cell linear epitopes in UHP treatment were found. Peach is a common plant-derived allergenic food and ultrahigh-pressure treatment is often used in peach products. In our study, an in-depth analysis of the structural and allergenicity changes of peach allergenic proteins after UHP treatment was performed by spectroscopy, mass spectrometry combined with serology and cytology. The results indicated that UHP treatment could reduce the content of peach soluble proteins and cause changes in secondary and tertiary structures. In addition, more hydrophobic residues were exposed and proteins tended to polymerize after UHP-treatment. The results of immunological assays showed that UHP treatment could reduce the IgE binding capacity of peach proteins and affect the ability of basophil degranulation, the upregulation of some cytokines may contribute to the reduction of peach protein allergenicity. Notably, UHP treatment may lead to the masking of some digestion sites in Pru p 3 epitopes, thus impeding human digestion and increasing the potential risk of allergenicity. [ABSTRACT FROM AUTHOR]

• The allergenicity of PPE declines through covalent conjugation with polyphenols (EGCG and CA). • Covalently conjugation with polyphenols enhances the digestibility of PPE. • The functional properties of PPE improved after covalent conjugation with polyphenols. Peanut protein is a common food allergen. Our previous study demonstrated that the allergenicity of Ara h1 declines after covalent conjugation with polyphenols in vitro ; however, how polyphenols affect the structure, function, and allergenicity of peanut protein extract (PPE) after covalent conjugating needs clarifying. Here, we assessed how the structure, function, and allergenicity of PPE changed after covalent conjugation with epigallocatechin-3-gallate (PPE-EGCG) and chlorogenic acid (PPE-CA). PPE covalently conjugated with EGCG and CA using the alkali treatment method. Multi-spectroscopy showed that the structure of PPE-EGCG/CA conjugate changed, becoming less folded. In contrast, the functional properties of PPE significantly improved. The allergenicity of PPE-EGCG/CA significantly declined in vitro and in vivo experiments. Our findings confirm that covalent conjugation of PPE with EGCG and CA reduces the allergenicity and improves the functional properties of PPE by changing the structure of the protein. [ABSTRACT FROM AUTHOR]

• High-intensity ultrasound is recently used in protein modification. • Various edible proteins are successfully ultrasonicated to enhance their bioactivity and bioavailability. • Ultrasonication can also substantially decrease the allergenicity and anti-nutritional factors in allergy-causing proteins. • Besides the various advantages of ultrasound in protein modification, it is still not universal and has limitations. High-intensity ultrasound (HIU) is considered one of the promising non-chemical eco-friendly techniques used in food processing. Recently (HIU) is known to enhance food quality, extraction of bioactive compounds and formulation of emulsions. Various foods are treated with ultrasound, including fats, bioactive compounds, and proteins. Regarding proteins, HIU induces acoustic cavitation and bubble formation, causing the unfolding and exposure of hydrophobic regions, resulting in functional, bioactive, and structural enhancement. This review briefly portrays the impact of HIU on the bioavailability and bioactive properties of proteins; the effect of HIU on protein allergenicity and anti-nutritional factors has also been discussed. HIU can enhance bioavailability and bioactive attributes in plants and animal-based proteins, such as antioxidant activity, antimicrobial activity, and peptide release. Moreover, numerous studies revealed that HIU treatment could enhance functional properties, increase the release of short-chain peptides, and decrease allergenicity. HIU could replace the chemical and heat treatments used to enhance protein bioactivity and digestibility; however, its applications are still on research and small scale, and its usage in industries is yet to be implemented. [ABSTRACT FROM AUTHOR]

[Display omitted] • Glycation with glucose, galactose, lactose and sucrose decreased the allergenicity of sesame proteins. • Glycation with glucose, galactose, lactose and sucrose changed the secondary structure, the tertiary structure and the surface hydrophobicity of sesame proteins. • Glycation with glucose was most effective in decreasing the allergenicity and changing the structure 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. [ABSTRACT FROM AUTHOR]

The protein Bet v 1 represents the main cause for allergic reactions to birch pollen in Europe and North America. Structurally homologous isoforms of Bet v 1 can have different properties regarding allergic sensitization and Th2 polarization, most likely due to differential susceptibility to proteolytic cleavage. Using NMR relaxation experiments and molecular dynamics simulations, we demonstrate that the initial proteolytic cleavage sites in two naturally occurring Bet v 1 isoforms, Bet v 1.0101 (Bet v 1a) and Bet v 1.0102 (Bet v 1d), are conformationally flexible. Inaccessible cleavage sites in helices and strands are highly flexible on the microsecond-millisecond time scale, whereas those located in loops display faster nanosecond-microsecond flexibility. The data consistently show that Bet v 1.0102 is more flexible and conformationally heterogeneous than Bet v 1.0101. Moreover, NMR hydrogen-deuterium exchange measurements reveal that the backbone amides in Bet v 1.0102 are significantly more solvent exposed, in agreement with this isoform's higher susceptibility to proteolytic cleavage. The differential conformational flexibility of Bet v 1 isoforms, along with the transient exposure of inaccessible sites to the protein surface, may be linked to proteolytic susceptibility, representing a potential structure-based rationale for the observed differences in Th2 polarization and allergic sensitization. [ABSTRACT FROM AUTHOR]

[Display omitted] • US principles and parameters affecting protein extraction from alternative sources. • US modes of operation and new technological developments for protein extraction. • US impacts on protein quality, digestibility, antinutritional factors, and allergens. • US effects on chemical degradation and oxidative damage of proteins. • Prospects and challenges of upscaling US technology for protein recovery applications. Proteins from alternative sources including terrestrial and aquatic plants, microbes and insects are being increasingly explored to combat the dietary, environmental and ethical challenges linked primarily to conventional sources of protein, mainly meat and dairy proteins. Ultrasound (US) technologies have emerged as a clean, green and efficient methods for the extraction of proteins from alternative sources compared to conventional methods. However, the application of US can also lead to modifications of the proteins extracted from alternative sources, including changes in their nutritional quality (protein content, amino acid composition, protein digestibility, anti-nutritional factors) and allergenicity, as well as damage of the compounds associated with an increased degradation resulting from extreme US processing conditions. This work aims to summarise the main advances in US equipment currently available to date, including the main US parameters and their effects on the extraction of protein from alternative sources, as well as the studies available on the effects of US processing on the nutritional value, allergenicity and degradation damage of these alternative protein ingredients. The main research gaps identified in this work and future challenges associated to the widespread application of US and their scale-up to industry operations are also covered in detail. [ABSTRACT FROM AUTHOR]

Background: we successfully reconstituted the gene from group 1 allergens of dust mites, and obtained a body of shuffled genes. In order to verify the prediction on the chimeric gene, we tentatively cloned R8 into the vector that was prokaryoticly expressed, purified and assessed for its bio-activities.Methods: the expressed product was detected by SDSPAGE and the target protein was purified. The purified protein R8 was detected by ELISA. 75 BALB/c mice were divided into 5 groups, namely PBS, rDer f1, rDer p1, R8 and asthma group. The mice were treated with dust mite allergens at 0, 7, 14 day by intraperitoneal injection and inhaled challenge as aerosol on day 21 for 7 days. Specific allergen immunotherapy was performed using rDer f1, rDer p1 and R8 allergens respectively. The level of IFN and IL- 4 in BALF was detected by ELISA.Results: the chimeric gene R8 was expressed with a band of approximately Mr 35000. Compared with groups of rDer f 1 and rDer p 1 [(80.44±15.50) and (90.79±10.38) μg/ml respectively], IgE binding capacity of the protein R8 (37.03±12.46) μg/ml was statistically lower (P<0.001). The level of IFN in sera of R8 group [(343.43±38.79) pg/ml] was higher than that of the PBS and asthma groups [(393.93±50.68) and (208.44±46.11) pg/ml respectively] (P<0.01), but no statistical difference to that of the rDer f 1 and rDer p 1 groups (P>0.05). IL-4 level in R8 group was lower markedly than the others (P<0.05 or P<0.01).Conclusions: chimeric protein R8 derived from the group 1 allergens of dust mites has been expressed with low allergenicity and high immunogenicity. [ABSTRACT FROM AUTHOR]

The objective of this work was to identify the main allergenic proteins and to assess the influence of high hydrostatic pressure on the potential allergenicity of high hydrostatic pressure pineapple juice. Fresh pineapple juice was treated with different pressures and the allergenic proteins were extracted and analyzed by sodium dodecyl sulfate polyacrylamide gel electropheresis, Western bloting and liquid chromatography-tandem mass spectrometry. The main allergenic proteins were detected as 24-kDa and 14-kDa bands by serum of pineapple-allergic patients. liquid chromatography-tandem mass spectrometry analysis of these bands showed that they actually consisted of a mixture of several isotypes of cysteine proteinases. Among these, bromelain (Ananas comosus) is a known allergen named Ana c 2 and it is highly homologous to other cysteine proteinases. Enzyme-linked immunosorbent assay assay of high hydrostatic pressure pineapple juice carried out at ambient temperature (18–22°C) showed that the higher the pressure, the higher the reduction in allergenicity, yielding a maximum reduction of about 20% under 500 MPa. However, in the case of 400 MPa and 50°C, the reduction rate of allergenicity was higher, up to 50% compared to that of the sample at 20°C without high hydrostatic pressure treatment. Taken together, the results suggested that high-pressure treatment could alter the potential allergenicity of pineapple juice allergens and identified Ana c 2 and a few other related cysteine proteinases as the main allergens. [ABSTRACT FROM AUTHOR]

The IgE response has been associated with both allergic reactions and immunity to metazoan parasites. Recently, we hypothesized that all environmental allergens bear structural homology to IgE-binding antigens from metazoan parasites and that this homology defines the relatively small number of protein families containing allergenic targets. In this study, known allergen structures (Pfam domains) from major environmental allergen familieswere used to predict allergen-like (SmProfilin, SmVAL-6, SmLipocalin, SmHSP20, Sm triosephosphate isomerase, SmThioredoxin, Sm superoxide dismutase, SmCyclophilin, and Sm phosphoglycerate kinase) and non-allergen-like [Sm dynein light chain (SmDLC), SmAldolase SmAK, SmUbiquitin, and Sm14-3-3] proteins in Schistosoma mansoni. Recombinant antigens were produced in Escherichia coli and IgG1, IgG4, and IgE responses against them measured in a cohort of people (nD222) infected with S. mansoni. All allergen-like antigens were targeted by IgE responses in infected subjects, whilst IgE responses to the nonallergen- like antigens, SmAK, SmUbiquitin, and Sm14-3-3 were essentially absent being of both low prevalence and magnitude. Two new IgE-binding Pfam domain families, not previously described in allergen family databases,were also found, with prevalent IgE responses against SmDLC (PF01221) and SmAldolase (PF00274). Finally, it was demonstrated that immunoregulatory serological processes typically associated with allergens also occurred in responses to allergen-like proteins in S. mansoni infections, including the production of IgG4 in people responding with IgE and the down-regulation of IgE in response to increased antigen exposure from S. mansoni eggs. This study establishes that structures of known allergens can be used to predict IgE responses against homologous parasite allergen-like molecules (parallergens) and that serological responses with IgE/IgG4 to parallergens mirror those seen against allergens, supporting our hypothesis that allergenicity is rooted in expression of certain protein domain families in metazoan parasites. [ABSTRACT FROM AUTHOR]

Wasp pupa protein has triggered allergies in certain consumers. In this study, we investigated the allergenicity of alcohol-soluble wasp pupa protein (ACWP) and its effect on the gut microbiota of mice in vivo. It was found that ACWP caused skin erythema and diarrhea in mice, the up-regulation of HIS, IgE, IL-4, IL-22, and IL-17A, and down-regulation of IgG2a, IgA, and IL-2 in serum. The results also revealed that the thymus, spleen, and small intestine structures in mice also altered significantly, and the intestinal wall structure was disrupted. Fluorescein isothiocyanate (FITC) labeled dextran intestinal permeability test depicted that the intestinal permeability of mice in the ACWP group increased significantly. The gut microbiota analysis in mice depicted that five bacterial strains in the ACWP group, including s_Candidatus_Arthromitus_sp._SFB_mice_Japa , were up-regulated, and nine low-abundant strains, including s_unclassified_g_norank_f_Ruminococcaceae , were down-regulated. The association analysis of gut microbiota and serum factors showed that eight serum biochemical factors were significantly correlated with 11 strains. The results revealed that ACWP could cause disturbance of gut microbiota and its metabolism, change the integrity and permeability of the intestinal tract, destroy the intestinal mucosal immune system, and then cause skin erythema and diarrhea as the primary manifestations. [ABSTRACT FROM AUTHOR]

To provide information for allergenicity assessment in food safety assessment of genetically modified herbicide-tolerant ( GM HT) rice, digestive stability and heat stability of proteins of GMHT rice are analyzed. Temporal dynamics for degradation of proteins of GMHT rice Bar68-1 and controls ( protein of D68 as control of non-GM rice, casein as negative control, soybean trypsin inhibitor and bovine serum albumin as positive control) in vitro digestibility, and stability in simulated thermal processing environment, were detected by SDS-PAGE. Results showed that proteins of GMHT rice and non-GM rice were digested within 2 - 30 min, which means that they are digestible in simulated gastric fluid ( SGF) and simulated intestinal fluid ( SIF ); Proteins of GMHT rice and non-GM rice were stable when heating at 60, 75, 90, and 100 ℃ for 15, 30, 60, and 120 min. Results indicated that proteins of GMHT rice and non-GM rice have good heat stability, and they are digestible in SGF and SIF. The digestive stability of GMHT rice has no characteristics of food allergens. [ABSTRACT FROM AUTHOR]

Due mainly to its extremely high content of sulphur amino acids, Ber e 1 protein, the major allergen from Brazil nut, has attracted much scientific and press attention. Ber e 1 was the main target protein in early biotechnology transgenic work, in early processing studies of plant storage proteins, in plant vacuolar targeting studies and as the main protein in early nutritional supplementation experiments. Ber e 1 was also one of the first food allergens to be unintentionally transferred from one plant to another and was involved in the first reported case of systemic allergic reaction caused by a food allergen transferred in semen. In this review, many of the Ber e 1 unique biotechnological and structural functions are discussed with a particular emphasis on its use as model protein for studies of intrinsic allergenicity of food proteins. [ABSTRACT FROM AUTHOR]

The allergenicity of β-lactoglobulin (BLG) was assayed by Ussing chamber after microwave irradiation of whey proteins at different pH values, in a murine model of BLG allergy. BALB/c mice were sensitised intraperitoneally with BLG. Serum levels of BLG-specific IgG, IgG1, IgG2a and IgE were analysed by Enzyme-Linked Immunosorbent Assay (ELISA). Local anaphylactic responses and residual allergenicity of various treated whey proteins were performed in vitro in Ussing chamber. BLG immunisation was associated with strong IgG, IgG1, IgG2a and IgE production, a significant increase in short current circuit (Isc) and high conductance (G) response. The allergenic potential of BLG was markedly reduced after microwave irradiation at 300 or 700 W of whey proteins at pH values 6.8 or 4.6 (Isc and G remained unchanged after intestine challenge with treated whey proteins). The application of microwave irradiation of whey proteins at the natural milk pH (pH 6.8) or pH 4.6 induces a significant decrease in the BLG allergenicity. [ABSTRACT FROM AUTHOR]

Abstract: Common indoor and outdoor environmental fungi such as Aspergillus fumigatus produce asexual spores containing a collection of proteins that can bind IgE antibodies and trigger allergic reactions. We characterized the impact of sporulation temperature on the IgE-binding capacity (allergenicity) of A. fumigatus and explored the links between variable allergenicity and temperature-dependant expression of genes encoding these allergenic proteins. A 12-fold increase in A. fumigatus allergenicity per spore was observed when sporulation temperatures were decreased from 32°C to 17°C. Per spore protein mass and Asp f 1 allergen mass also followed this trend. Functional gene expression analysis of A. fumigatus sporulating cultures by real-time reverse-transcription PCR and gene expression microarrays revealed that a greater number of genes encoding known, major allergens are more highly expressed at lower sporulation temperatures. The results of this study indicate that environmental conditions at growth significantly influence the allergenicity of this common mould through the differential production of allergenic proteins, and highlight the importance of in vivo or in vitro allergenicity measurements for understanding environmental exposure to airborne allergenic fungi. [Copyright &y& Elsevier]

Background: In legumes, seed storage proteins are important for the developing seedling and are an important source of protein for humans and animals. Lupinus angustifolius (L.), also known as narrow-leaf lupin (NLL) is a grain legume crop that is gaining recognition as a potential human health food as the grain is high in protein and dietary fibre, gluten-free and low in fat and starch. Results: Genes encoding the seed storage proteins of NLL were characterised by sequencing cDNA clones derived from developing seeds. Four families of seed storage proteins were identified and comprised three unique α, seven β, two γ and four δ conglutins. This study added eleven new expressed storage protein genes for the species. A comparison of the deduced amino acid sequences of NLL conglutins with those available for the storage proteins of Lupinus albus (L.), Pisum sativum (L.), Medicago truncatula (L.), Arachis hypogaea (L.) and Glycine max (L.) permitted the analysis of a phylogenetic relationships between proteins and demonstrated, in general, that the strongest conservation occurred within species. In the case of 7S globulin (β conglutins) and 2S sulphurrich albumin (δ conglutins), the analysis suggests that gene duplication occurred after legume speciation. This contrasted with 11S globulin (α conglutin) and basic 7S (γ conglutin) sequences where some of these sequences appear to have diverged prior to speciation. The most abundant NLL conglutin family was β (56%), followed by α (24%), δ (15%) and γ (6%) and the transcript levels of these genes increased 10³ to 106 fold during seed development. We used the 16 NLL conglutin sequences identified here to determine that for individuals specifically allergic to lupin, all seven members of the b conglutin family were potential allergens. Conclusion: This study has characterised 16 seed storage protein genes in NLL including 11 newly-identified members. It has helped lay the foundation for efforts to use molecular breeding approaches to improve lupins, for example by reducing allergens or increasing the expression of specific seed storage protein(s) with desirable nutritional properties. [ABSTRACT FROM AUTHOR]

Abstract: Acetolactate synthase (ALS) enzymes have been isolated from numerous organisms including soybeans (Glycine max; GM-ALS) and catalyze the first common step in biosynthesis of branched chain amino acids. Expression of an ALS protein (GM-HRA) with two amino acid changes relative to native GM-ALS protein in genetically modified soybeans confers tolerance to herbicidal active ingredients and can be used as a selectable transformation marker. The safety assessment of the GM-HRA protein is discussed. Bioinformatics comparison of the amino acid sequence did not identify similarities to known allergenic or toxic proteins. In vitro studies demonstrated rapid degradation in simulated gastric fluid (<30s) and intestinal fluid (<1min). The enzymatic activity was completely inactivated at 50°C for 15min demonstrating heat lability. The protein expressed in planta is not glycosylated and genetically modified soybeans expressing the GM-HRA protein produced similar protein/allergen profiles as its non-transgenic parental isoline. No adverse effects were observed in mice following acute oral exposure at a dose of at least 436mg/kg of body weight or in a 28-day repeated dose dietary toxicity study at doses up to 1247mg/kg of body weight/day. The results demonstrate GM-HRA protein safety when used in agricultural biotechnology. [Copyright &y& Elsevier]

Abstract: Cry1ab/ac gene was fused by both the cry1ab gene (GenBank Accession No. X54939) and the cry1ac gene (GenBank Accession No. Y09787), which was widely used in genetically modified (GM) rice, cotton, maize and so on. In order to support the safety assessment of GM food or feed products containing Cry1Ab/Ac protein, sufficient quantities of Cry1Ab/Ac protein were produced in Escherichia coli for in vitro evaluation and animal studies. The Cry1Ab/Ac protein does not possess the characteristics associated with food toxins or allergens, i.e., it has no sequence homology with any known allergens or toxins, and no N-glycosylation sites, can be rapidly degraded in gastric and intestinal fluids, and is devoid of adverse effects in mice by gavage at a high dose level of 5g (Cry1Ab/Ac protein)/kg body weight. In conclusion, there is a reasonable certainty of no harm resulting from the inclusion of the Cry1Ab/Ac protein in human food or animal feed. [Copyright &y& Elsevier]

Background: Fenugreek is an ingredient in Indian-style spiced foods. Reports of adverse reactions reflect a trend toward a more international cuisine. Fenugreek allergy has not been systematically investigated so far. Objective: Study the allergenicity and antigenicity of fenugreek proteins using patient sera and a newly developed polyclonal antifenugreek antibody. Methods: Allergenic fenugreek proteins were identified by immunoblotting, using sera from 29 patients with specific IgE to peanut and other legumes. In addition, 2 patients were evaluated by skin prick test and open food challenge with native fenugreek powder. Spiced and flavored food products were analyzed for fenugreek by semiquantitative IgE and IgG immunoblotting. Results: High levels of specific IgE to both peanut and fenugreek were seen in most sera. Fenugreek sensitization is believed to be a consequence of cross-reactivity in patients with peanut allergy. Primary fenugreek allergy was suspected in only 1 case. The fenugreek dose eliciting objective symptoms was about 2 mg in the open food challenge. Major fenugreek allergens were identified at 50, 52, and 74 kd and peanut proteins at 22, 36, and 40 kd. A specific polyclonal antifenugreek antibody was found suitable for food analysis. In a food survey, about 1/3 of the fenugreek-containing products were labeled correctly. Conclusion: Fenugreek seed powder, an ingredient in spiced foods, contains several potential allergens. There is evidence for a high rate of cross-reactivity to peanut. [Copyright &y& Elsevier]

Background: The increasing number of applications of sweet lupins in food is paralleled by an increase in immunoglobulin E (IgE)-mediated allergic reactions to lupin proteins. In particular, lupin allergy seems to appear in patients with an existing peanut allergy. In the present study, IgE-binding studies towards fractionated lupin seed proteins, and peanut and almond proteins were performed using sera from patients with confirmed lupin allergy. Methods:Immunoblotting and indirect ELISA were performed to investigate IgE binding to protein extracts. ELISA inhibition experiments were performed to investigate the presence of cross-reactive allergens in the protein extracts. Results: Immunoblotting and ELISA experiments demonstrated IgE binding to all lupin conglutins (α, β, γ and δ) as well as to peanut and almond proteins, with a unique IgE-binding profile for each patient. High IgE binding to α-conglutin was observed and IgE from the majority of patients similarly recognized two proteins within the α-conglutin-containing fraction, 40 and 43 kDa in size. Inhibition ELISA experiments showed that preincubation of sera with lupin conglutins, peanut and almond resulted in decreased IgE binding to lupin flour. Conclusions: Overall, these results indicate that α-, β-, γ- and δ-conglutins are candidate allergens in lupin and suggest a particularly strong allergenicity of α-conglutins. Furthermore, the results indicate the presence of cross-reactive allergens in lupin, peanut and almond. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Fruits are a major cause of food allergy in adults. Lipid transfer proteins (LTP) are implicated in severe allergic reactions to fruits, but little is known about LTP content in different cultivars. Objective: Determination of the levels of LTP in a wide range of apple cultivars. Methods: LTP was measured in apples from 53 cultivars grown in Italy and 35 grown in The Netherlands, using three different immunoassays: a competitive ELISA (cELISA), a sandwich ELISA (sELISA) and a RAST inhibition (RI). Selected cultivars were evaluated using the basophil histamine release test (BHR), skin prick test (SPT) and double-blind, placebo-controlled food challenge (DBPCFC). Results: LTP levels measured with the three immunoassays were significantly correlated, as judged by Pearson’s correlation (0.61 < Rp < 0.65; p < 0.0001), but differed with respect to the actual quantities: 3.4–253.2 (sELISA), 2.7–120.2 (cELISA) and 0.4–47.3 μg/g tissue (RI). Between cultivars, LTP titers varied over about a two-log range. Pilot in vitro and in vivo biological testing (BHR, SPT and DBPCFC) with selected cultivars supported the observed differences in LTP levels. Conclusions: Around 100-fold differences in LTP levels exist between apple cultivars. Whether the lowest observed levels of LTP warrant designation as hypo-allergenic requires more extensive confirmation by oral challenges. Determination of cultivar variation in LTP levels provides important information for growers and consumers. Comparison to earlier reported Mal d 1 levels in the same cultivars reveals that a designation as low allergenic does not always coincide for both allergens. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The rubber accelerator, 2-mercaptobenzothiazole (MBT), is known to cause allergic contact dermatitis (ACD), but the mechanism is unknown. The role of the thiol group in MBT's allergenicity was investigated in the present study. Guinea pigs were sensitized to MBT using a modified guinea pig maximization test (GPMT) and reactivity was assessed toward 2-mercaptobenzothiazole disulfide (MBTS), 2-hydroxybenzothiazole (HBT; thiol-substituted), 2-(methylthio)benzothiazole (MTBT; thiol-blocked), and benzothiazole (BT; thiol-lacking). MBT and MBTS, but not BT, HBT, or MTBT, elicited ACD in MBT-sensitized animals, demonstrating that the thiol group is critical to MBT's allergenicity. In addition, both MBT and MBTS were shown to inhibit both glutathione reductase and thioredoxin reductase, and thus contribute to the stability of MBT-protein mixed disulfides. It is concluded that the probable haptenation mechanism of MBT is through initial oxidation to MBTS with subsequent reduction to form mixed disulfides with proteins. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to assess the effect of γ-irradiation on the allergenicity of shrimp. Shrimp protein extracts and shrimp muscle was subjected to irradiation at different dose. The allergenicity of irradiated shrimp protein extracts and shrimp muscle was analyzed by immunoblotting and Ci-ELISA using pool sera from 15 patients with shrimp specific IgE. Results showed that irradiated shrimp protein extracts exhibited a decrease in allergenicity with the increase of irradiation dose. However irradiated shrimp muscle exhibited an increase of allergenicity before the irradiation dose reached to 5kGy (10kGy measured by ELISA), whereas it tended to decrease significantly when the dose exceeded 10kGy. Therefore, γ-irradiation might have an important effect on the allergenicity of shrimp. [Copyright &y& Elsevier]

Soybean is considered one of the "big eight" foods that are believed to be responsible for 90% of all allergenic reactions. Soy allergy is of particular importance, because soybeans are widely used in processed foods and, therefore, represent a particularly insidious source of hidden allergens. Although significant advances have been made in the identification and characterization of soybean allergens, scientists are not completely certain about which proteins in soy cause allergic reactions. At least 16 allergens have been identified. Most of them, as with other plant food allergens, have a metabolic, storage, or protective function. These allergens belong to protein families which have conserved structural features in relation with their biological activity, which explains the wide immunochemical cross-recognition observed among members of the legume family. Detailed analysis of the structure-allergenicity relationships has been hampered by the complexity and heterogeneity of soybean proteins. A variety of technological approaches have been attempted to decrease soybean allergenicity. This paper provides a comprehensive review of the current body of knowledge on the identification and characterization of soybean allergens, as well as an update on current hypoallergenization techniques. [ABSTRACT FROM AUTHOR]

A high-pressure treatment (>100 MPa) can change the quarternary, tertiary, and secondary structures of proteins. Experiments have shown the prospects of high-pressure treatment for the development of viral and tumour vaccines, for the inactivation of resected infection- and tumour-bearing bone segments and for the decrease of food allergenicity. Allergic patients had minor or no allergy symptoms against high pressure treated foods, which were birch pollen allergy related (hazelnut, carrot, cherry, peach, celery, and apple). Three patients with a heavy allergy against apple could be hyposensitized by means of a specific immuno-therapy with high pressure treated apple. [ABSTRACT FROM AUTHOR]

Abstract: Digestion studies constitute a functional tool for allergen characterisation. This strategy for investigating allergenic proteins relates to the observation of increased proteolytic resistance of some proteins recognised to exhibit allergenic potential. β-Lactoglobulin (βLG) is one of the major whey proteins, a potent milk allergen and shows a high stability against peptic hydrolysis in its native form. In order to study the impact of milk fermentation process on its digestibility, two complementary analytical methods were applied: capillary zone electrophoresis (CZE) to quantitatively study proteolytic degradation of βLG isolated from different fermented bovine milk products, and enzyme linked immunosorbent assay (ELISA) to assess differences in immunoreactivity. βLG, isolated from either raw or pasteurised cow''s milk (CM), as expected, showed only minimal digestibility (less than 10% in 2h). However, when raw milk or pasteurised milk was fermented, the rate of peptic digestion of the protein significantly increased (up to 45% in 2h). In accordance with changes in digestibility, the immunochemical response for all fermented samples was lower than that of non-fermented references. Raw and pasteurised milk “naturally” fermented in our laboratory only resulted in a slight reduction (βLG detected is still in the range of milligrams per gram sample), whereas the industrially manufactured sour milk as well as the “Acidophilus milk” reflected a remarkably lower level of immunoreactivity (55–56μg/g sample). [Copyright &y& Elsevier]

. [ABSTRACT FROM AUTHOR]

Cosmetics containing hydrolysed wheat proteins (HWP) can induce rare but severe allergic reactions. 9 patients, all females without common wheat allergy, but with contact urticaria to such cosmetics, were studied. 6 of them also experienced generalized urticaria or anaphylaxis to foods containing HWP. All patients had low to moderate levels of immunoglobulin (Ig)E specific of wheat flour (f4) or gluten (f79). Their sensitivity to HWP and their tolerance to unmodified wheat proteins extracted from grains were confirmed using skin tests. Immunoblotting analyses showed that IgE from all patients reacted with almost all HWP tested. Reactions generally occurred with large random peptide aggregates. IgE reacted also with unmodified grain proteins, which contrasted with skin tests results. They reacted always with salt soluble proteins but variably with gluten proteins. No reaction occurred with gliadins in patients without associated immediate hypersensitivity to food containing HWP. These results show the role of hydrolysis on the allergenicity of wheat proteins, both through skin or digestive routes. At least part of the epitopes involved is pre-existing in unmodified wheat proteins. The aggregation of peptide bearing these epitopes and others created by hydrolysis, along with the increased solubility and the route of exposure, are possible factors of the allergenicity of HWP. [ABSTRACT FROM AUTHOR]