Irradiation technology: An effective and promising strategy for eliminating food allergens

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.

Irradiation-Assisted Enhancement of Foaming and Thermal Gelation Functionality of Liquid Egg White

Ionizing radiation has its unique popularity as a non-thermal decontamination technique treating with protein-rich foodstuffs to ensure the microbial and sensory quality, particularly for shell eggs. However, the changes in the functional properties of egg protein fractions such as liquid egg white (LEW) with macro/microstructural information are still controversial. Hence, this study was designed to elaborate the foaming and heat-set gelation functionality of LEW following different γ-ray irradiation dose treatments (0, 1, 3 or 5 kGy). For such, the physicochemical properties (active sulfhydryl and the hydrophobicity of protein moieties), structural characteristics (through X-ray diffraction, Fourier-transform infrared spectroscopy and differential scanning calorimetry) and interfacial activities (rheological viscosity, interfacial tension, microrheological performance) were investigated. Then, the thermal gelation of LEW in relation to the texture profile and microstructure (by means of a scanning electron microscope) was evaluated followed by the swelling potency analysis of LEW gel in enzyme-free simulated gastric juice. The results indicated that irradiation significantly increased the hydrophobicity of liquid egg white proteins (LEWPs) (p < 0.05) by exposing non-polar groups and the interfacial rearrangement from a β-sheet to linear and smaller crystal structure, leading to an enhanced foaming capacity. Microstructural analysis revealed that the higher dose irradiation (up to 5 kGy) could promote the proteins' oxidation of LEW alongside protein aggregates formed in the amorphous region, which favored heat-set gelation. As evidenced in microrheology, ≤3 kGy irradiation provided an improved viscoelastic interface film of LEW during gelatinization. Particularly, the LEW gel treated with 1 kGy irradiation had evident swelling resistance during the times of acidification at pH 1.2. These results gave new insight into the irradiation-assisted enhancement of foaming and heat-set gelation properties of LEW.

Food irradiation: an effective but under-utilized technique for food preservations

While food borne pathogens constitute a major public health problem world-wide, food post-harvest losses is considered to be the leading cause of hunger and malnutrition globally. Food irradiation is a process of preserving food in which food are exposed to appropriate doses of ionizing radiation in order to kill insects, molds and other potentially harmful microbes and allergens. The process involves carefully exposing food to a measured amount of ionizing radiation in a special processing room on a conveyor belt for a specified duration. The radiation sources could be gamma ray, electron beam or X-ray. The radiation doses could be high, low or medium depending on the products to be irradiated and the target organism to be eradicated. Irradiation technology has various applications including sprout inhibition in root and tubers, disinfestation in cereals and pulses, reduction or elimination of food borne pathogens in vegetables and animal products and delayed ripening of fruits. All these applications are intended to increase shelf life and eliminate food allegenicity. Despite consumer concern on the safety and quality of irradiated foods, it is gradually gaining acceptance due to increased awareness and the perceived safety and quality as symbolized by the Radura symbol. With the increasing acceptance and commercialization of food irradiation, it could play an important role in solving the problems of food insecurity and food borne illnesses in the world.

New Perspectives on Food Matrix Modulation of Food Allergies: Immunomodulation and Component Interactions

Food allergy is a multifactorial interplay process influenced not only by the structure and function of the allergen itself but also by other components of the food matrix. For food, before it is thoroughly digested and absorbed, numerous factors make the food matrix constantly change. This will also lead to changes in the chemistry, biochemical composition, and structure of the various components in the matrix, resulting in multifaceted effects on food allergies. In this review, we reveal the relationship between the food matrix and food allergies and outline the immune role of the components in the food matrix, while highlighting the ways and pathways in which the components in the food matrix interact and their impact on food allergies. The in-depth study of the food matrix will essentially explore the mechanism of food allergies and bring about new ideas and breakthroughs for the prevention and treatment of food allergies.

Insight into the IgE-binding sites of allergenic peptides of tropomyosin in shrimp (Penaeus chinensis) induced by cold plasma active particles

Tropomyosin (TM) is a major allergen in crustaceans, and its allergenicity mainly depends on epitopes. In this study, the locations of IgE-binding sites between plasma active particles and allergenic peptides of TM in shrimp (Penaeus chinensis) during cold plasma (CP) treatment were explored. Results showed that the IgE-binding ability of two critical peptides (P1 and P2) increased and then decreased by 9.97 % and 19.50 % after 15 min of CP treatment. It was the first time to show that the contribution rate of target active particles was •O > e_(aq)^- > •OH for reducing IgE-binding ability by 23.51 %-45.40 %, and the contribution rates of other long-lived particles including NO₃^- and NO₂^- was about 54.60 %-76.49 %. In addition, Glu131 and Arg133 in P1 and Arg255 in P2 were certified as the IgE sites. These results were helpful for accurately controlling TM allergenicity, shedding more light on allergenicity mitigation during food processing.

Non-thermal processing of cashews: irradiation reduces allergenicity by altering the structure of Ana o 3

Traditional thermal processing of cashews not only results in nutrient loss and harmful by-products, but also does not significantly reduce allergenicity. Irradiation could be an important non-thermal processing method to reduce cashew allergens' allergenicity and retain their nutritional properties. This study aimed to evaluate the effects of gamma irradiation processing on the structure and potential allergenicity of Ana o 3. The Ana o 3 solutions were gamma-irradiated at 0, 1, 3, 5, and 10 kGy. The structure change was monitored by Tricine-SDS-PAGE, circular dichroism spectroscopy, and fluorescence spectroscopy. The potential allergenicity was tested by immunoblotting, indirect competitive ELISA, and the human basophil KU812 degranulation assay using serum from cashew allergy patients. The results of CD spectroscopy showed that the content of α-helices decreased from 46.8% to 30.9% after 3 to 10 kGy, while the content of random coils increased from 23.7% to 33.3%. Meanwhile, a large number of hydrophobic regions were exposed, resulting in an increase in the hydrophobic surface of the protein. In terms of allergenicity, the IC₅₀ values obtained by the competitive inhibition ELISA after irradiation increased from 0.628 to 4.054 μg mL^-1, indicating that irradiation reduced the IgE binding capacity of Ana o 3, which was consistent with the results of western blotting. In addition, the basophil degranulation analysis showed that the release of IL-6, TNF-α, and histamine was decreased. It was shown that the potential allergenicity of the irradiated Ana o 3 was remarkably decreased since irradiation could mask or destroy the allergen epitopes, providing a new approach to reduce the allergenicity of cashew products.

Alteration of the allergenicity of cow's milk proteins using different food processing modifications

Milk is an essential source of protein for infants and young children. At the same time, cow's milk is also one of the most common allergenic foods causing food allergies in children. Recently, cow's milk allergy (CMA) has become a common public health issue worldwide. Modern food processing technologies have been developed to reduce the allergenicity of milk proteins and improve the quality of life of patients with CMA. In this review, we summarize the main allergens in cow's milk, and introduce the recent findings on CMA responses. Moreover, the reduced effects and underlying mechanisms of different food processing techniques (such as heating, high pressure, γ-ray irradiation, ultrasound irradiation, hydrolysis, glycosylation, etc.) on the allergenicity of cow's milk proteins, and the application of processed cow's milk in clinical studies, are discussed. In addition, we describe the changes of nutritional value in cow's milk treated by different food processing technologies. This review provides an in-depth understanding of the allergenicity reduction of cow's milk proteins by various food processing techniques.

Effect of radiation processing on phenolic antioxidants in cereal and legume seeds: A review

Phenolic compounds in cereal and legume seeds show numerous benefits to human health mainly because of their good antioxidant capacity. However, long-term storage and some improper preservation may reduce their antioxidant potential. It is necessary to retain or modify the phenolic antioxidants with improved technology before consumption. Radiation processing is usually applied as a physical method to extend the shelf life and retain the quality of plant produce. However, the effect of radiation processing on phenolic antioxidants in cereal and legume seeds is still not well understood. This review summarizes recent research on the effect of radiation, including ionizing and nonionizing radiation on the content and profile of phenolic compounds, and antioxidant activities in cereal and legume seeds, the influencing factors and possible mechanisms are also discussed. The article will improve the understanding of radiation effect on phenolic antioxidants, and promote the radiation modification of natural phenolic compounds in cereal and legume seeds and other sources.

The Risk of Undeclared Allergens on Food Labels for Pediatric Patients in the European Union

The dietary avoidance of allergens has been widely recognized as the key intervention in the management of food allergies, but the presence of undeclared allergens makes compliance difficult. The aim of this study was to analyze the presence of undeclared allergens in food labeling through RASFF notifications in the European Union, focusing on those allergens that frequently affect the pediatric population and the implicated products, so as to provide useful information for its risk evaluation and the development of educational materials for patients. The results showed milk (20.5%), gluten (14.8%), and nuts (10.9%) to be the pediatric allergens with higher presences. In 80% of the notifications concerning milk and milk derivatives, the specific compound present (lactose or lactoprotein) was not identified. They were mainly present in cereal and bakery products, prepared dishes and snacks, and cacao and confectionery products, all of which are frequently consumed by the pediatric population. The large quantity (7.6%) of undeclared allergens in “free-from-allergen” products was also remarkable, especially in regard to the supposedly not-present allergens. Undeclared allergens in food products pose an evident risk for allergic patients and knowledge of them should take a relevant role in a patient’s nutritional education. It is also necessary to raise awareness among manufacturers and safety authorities.