Mendes, C., J. Costa, A.A. Vicente, M.B.P.P. Oliveira, I. Mafra, 2019. Cashew nut allergy: Clinical relevance and allergen characterisation. Clin Rev Allergy Immunol. 57(1):1-22.
Cashew plant (Anacardium occidentale L.) is the most relevant species of the Anacardium genus. It presents high economic value since it is widely used in human nutrition and in several industrial applications. Cashew nut is a well-appreciated food (belongs to the tree nut group), being widely consumed as snacks and in processed foods by the majority of world’s population. However, cashew nut is also classified as a potent allergenic food known to be responsible for triggering severe and systemic immune reactions (e.g. anaphylaxis) in sensitised/allergic individuals that often demand epinephrine treatment and hospitalisation. So far, three groups of allergenic proteins have been identified and characterised in cashew nut: Ana o 1 and Ana o 2 (cupin superfamily) and Ana o 3 (prolamin superfamily), which are all classified as major allergens. The prevalence of cashew nut allergy seems to be rising in industrialised countries with the increasing consumption of this nut. There is still no cure for cashew nut allergy, as well as for other food allergies; thus, the allergic patients are advised to eliminate it from their diets. Accordingly, when carefully choosing processed foods that are commercially available, the allergic consumers have to rely on proper food labelling. In this sense, the control of labelling compliance is much needed, which has prompted the development of proficient analytical methods for allergen analysis. In the recent years, significant research advances in cashew nut allergy have been accomplished, which are highlighted and discussed in this review.
Zaffran, V.D., S.K. Sathe, 2018. Immunoreactivity of biochemically purified amandin from thermally processed almonds (PrunusdulcisL.). J Food Sci. 83(7):1805-1809.
Almond seeds were subjected to select thermal processing and amandin was purified from processed and unprocessed (control) seeds using cryoprecipitation. Amandin immunoreactivity was assessed using two murine monoclonal antibodies (mAbs)–4C10 and 4F10 detecting human IgE-relevant conformational and linear epitopes, respectively. Overall amandin immunoreactivity following thermal treatment ranged from 64.9% to 277.8% (4C10) and 81.3% to 270.3% (4F10). Except for autoclaving (121°C, 15 psi, 30 min) and roasting (160°C, 30 min), the tested processing conditions resulted in increased immunoreactivity as determined by mAbs 4C10 and 4F10-based enzyme-linked immunosorbent assays (ELISAs). A significant, yet not complete, reduction in immunoreactivity was caused by autoclaving (121°C, 15psi, 30 min) and roasting (160°C, 30 min). Western- and dot-blot immunoassays corroborated the ELISA results, confirming amandin thermal stability.
Liu, C., S.K. Sathe, 2018. Food allergen epitope mapping. J. Agric. Food Chem. 66:7238−7248.
With the increased global awareness and rise in food allergies, a multifold interest in food allergens is evident. The presence of undeclared food allergens results in expensive food recalls and increased risks of anaphylaxis for the sensitive individuals. Regardless of the allergenic food, the immunogen needs to be identified and detected before making any efforts to inactivate/eliminate it. In type I food allergies, protein immunogen cross-links immunoglobulin E, leading to basophil/mast cell degranulation, resulting in the symptoms that range from mild irritation to anaphylaxis. A portion/part of the protein, known as the epitope, can interact with either antibodies to elicit allergic reactions or T-cell receptors to initiate allergic sensitization. Antibody-recognized epitopes can be either a linear sequence of amino acids (linear epitope) or a three-dimensional motif (conformational epitope), while T-cell-receptor-recognized epitopes are exclusively linear peptides. Identifying and characterizing human-allergy-relevant epitopes are important for allergy diagnosis/prognosis, immunotherapy, and developing food processing methods that can reduce/eliminate immunogencity/immunoreactivity of the allergen.
Mandalari, G., A.R. Mackie, 2018. Almond Allergy: An Overview on Prevalence, Thresholds, Regulations and Allergen Detection. Nutrients. 10(11), 1706; https://doi.org/10.3390/nu10111706
Food allergy has been on the increase for many years. The prevalence of allergy to different foods varies widely depending on type of food, frequency of consumption and geographic location. Data from the literature suggests that the prevalence of tree nut allergy is of the order of 1% in the general population. Almond is one such tree nut that is frequently eaten in many parts of the world and represents a potential allergenic hazard. Given the need to label products that contain allergens, a number of different methods of direct and indirect detection have been developed. However, in the absence of population-based threshold data, and given that almond allergy is rare, the sensitivity of the required detection is unknown and thus aims as low as possible. Typically, this is less than 1 ppm, which matches the thresholds that have been shown for other allergens. This review highlights the lack of quantitative data on prevalence and thresholds for almonds, which is limiting progress in consumer protection.
