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Marco Arlorio - One of the best experts on this subject based on the ideXlab platform.
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application of 1h nmr for the characterisation and authentication of tonda gentile trilobata Hazelnuts from piedmont italy
Food Chemistry, 2014Co-Authors: Augusta Caligiani, Jean Daniel Coisson, Fabiano Travaglia, Domenico Acquotti, Gerardo Palla, Luigi Palla, Marco ArlorioAbstract:The Italian Hazelnut (Corylus avellana L.) cultivar "Tonda Gentile Trilobata" (TGT) is covered by protected geographical indication "Nocciola Piemonte" and is well-known as the best-suited Hazelnut for the industrial transformation into roasted kernel. The Hazelnut cultivar identification is primarily based on morphological characteristics, so there is the need for more objective analytical methods for high quality Hazelnut authentication. This study reports the (1)H NMR fingerprinting of raw and roasted Hazelnut, with the aim of obtaining Hazelnut classification based on their spectroscopic pattern. (1)H NMR analyses were carried out on polar extracts of TGT and other cultivars: the data were analysed with multivariate statistical methods. Results showed that (1)H NMR combined with chemometrics is useful to characterise the Hazelnuts as a function of the cultivars, both on raw and roasted form. The classification models allowed identifying molecular markers useful to distinguish TGT from other types, among these trigonelline, amino acids and an unidentified orto-disubstituted aromatic compound.
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application of 1h nmr for the characterisation and authentication of tonda gentile trilobata Hazelnuts from piedmont italy
Food Chemistry, 2014Co-Authors: Augusta Caligiani, Jean Daniel Coisson, Fabiano Travaglia, Domenico Acquotti, Gerardo Palla, Luigi Palla, Marco ArlorioAbstract:The Italian Hazelnut (Corylus avellana cultivar "Tonda Gentile Trilobata" (TGT) is covered by protected geographical indication "Nocciola Piemonte" and is well-known as the best-suited Hazelnut for the industrial transformation into roasted kernel. The Hazelnut cultivar identification is primarily based on morphological characteristics, so there is the need for more objective analytical methods for high quality Hazelnut authentication. This study reports the H-1 NMR fingerprinting of raw and roasted Hazelnut, with the aim of obtaining Hazelnut classification based on their spectroscopic pattern. H-1 NMR analyses were carried out on polar extracts of TGT and other cultivars: the data were analysed with multivariate statistical methods. Results showed that H-1 NMR combined with chemometrics is useful to characterise the Hazelnuts as a function of the cultivars, both on raw and roasted form. The classification models allowed identifying molecular markers useful to distinguish TGT from other types, among these trigonelline, amino acids and an unidentified orto-disubstituted aromatic compound. (C) 2013 Elsevier Ltd. All rights reserved.
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chemotype and genotype chemometrical evaluation applied to authentication and traceability of tonda gentile trilobata Hazelnuts from piedmont italy
Food Chemistry, 2011Co-Authors: Monica Locatelli, Jean Daniel Coisson, Fabiano Travaglia, Elisabetta Cereti, Cristiano Garino, Matteo Dandrea, A Martelli, Marco ArlorioAbstract:Italian Hazelnuts ‘‘Tonda Gentile Trilobata’’ cv are recognised as high quality products with good sensory characteristics and interesting technological properties. An approach was employed to identify the ‘‘Tonda Gentile Trilobata’’ Hazelnuts from Piedmont (Italy), differentiating them from other Hazelnuts belonging to a different cultivar and/or different geographic origin, on the basis of their chemical and genetic characteristics. Proximate composition, fatty acid profile, polyphenols content and fingerprint, antioxidant activity, and protein patterns were determined. Concerning the genetic analysis, RAPD (Random Amplified Polymorphism DNA) technique was employed to detect polymorphisms amongst different Hazelnut samples. Principal Component Analysis (PCA) on the chemical and genomic data sets permitted to identify the ‘‘Tonda Gentile Trilobata’’ cv. The analysis of chemotype allowed differentiating the Chilean sample from the other ‘‘Tonda Gentile Trilobata’’ Hazelnuts, whilst no genetic differences were observed amongst these samples. On the other hand, genomic data confirmed that RAPD is able to discriminate amongst cultivars. The common hazel plant (Corylus avellana L.) is a shrub native to Europe and Asia and belongs to the family of Betulaceae, genus Corylus. It grows in temperate climates like Turkey, Spain, Italy and the USA. Italy is the second largest Hazelnut producer in the world (13.5% of total output) ahead of the USA and behind Turkey. Hazelnut crops are spread all around the Italian territory located in specific areas, such as Piedmont region in the North, Viterbo province in the centre (Latium), Avellino province (Campania) and Sicilian region in the South. Hazelnuts in Italy are sold both as in-shell and shelled. In-shell Hazelnuts are generally sold as a snack for fresh consumption while shelled ones (both whole and milled nuts) are often used as raw material for confectionary and bakery food production. Approximately 90% of the Italian harvest goes to processing companies, whereas fresh consumption represents the remaining 10% (Baldi,
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total antioxidant activity of Hazelnut skin nocciola piemonte pgi impact of different roasting conditions
Food Chemistry, 2010Co-Authors: Monica Locatelli, Jean Daniel Coisson, Fabiano Travaglia, Aldo Martelli, Caroline Stevigny, Marco ArlorioAbstract:Abstract The thin brown perisperm (skin) that envelops Hazelnut kernels is usually removed after roasting process, leading a phenolic-rich by-product. Principal aim of this work was to characterise the total antioxidant activity of phenolic extracts obtained from roasted “Nocciola Piemonte PGI” Hazelnuts skin. Different extraction solvents (methanol, acidified methanol, ethanol, acidified ethanol, and acetone/water) and different protocols (cold solvent-assisted extraction and semi-automated Soxhlet extraction) were employed. The influence of different roasting degree (180 °C/10 min and 180 °C/20 min) was also investigated. DPPH and ABTS + radical-scavenging methods, ferrous ions chelation activity and inhibition of lipid peroxidation investigated in this study demonstrated significant antioxidant properties for Hazelnut skin phenolics. The main mechanism involved appeared the antiradical activity, strictly related to the total phenolic content (r = −0.8798 and −0.8285 for DPPH and ABTS + assays, respectively). The acidification of extraction solvents led to a significant decrease of antiradical activity, whilst the different roasting conditions significantly influenced the chelation activity and the inhibition of lipid peroxidation, showing higher effectiveness for high-roasted Hazelnut skin extracts. Conversely, the direct measure of the antioxidant capacity of defatted Hazelnut skins revealed higher ABTS + scavenging properties for medium-roasted sample.
Cesarettin Alasalvar - One of the best experts on this subject based on the ideXlab platform.
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effects of roasting on the antioxidant status and phenolic profiles of commercial turkish Hazelnut varieties corylus avellana l
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Ebru Pelvan, Cesarettin Alasalvar, Suheyla UzmanAbstract:The effect of roasting on the antioxidant status and phenolic profiles of seven commercial Turkish Hazelnut varieties (namely, Cakildak, Fosa, Karafindik, Mincane, Palaz, Sivri, and Tombul) was assessed. Samples were examined for their total phenolics, oxygen radical absorbance capacity (ORAC) values, condensed tannins, and phenolic acids (free and bound forms). Significant losses (p < 0.05) in total phenolics (~66.3%), ORAC values (~41.6%), condensed tannins (~75.2), and phenolic acids (~42.7) were noted when the Hazelnuts were roasted. Some variations both between and within natural and roasted Hazelnuts were observed (p < 0.05). Phenolic acids were mainly found in the bound form. Gallic, protocatechuic, p-coumaric, and ferulic + sinapic acids were present in all Hazelnut varieties, albeit to different extents, and the first two were dominant. Mincane, in roasted form, had the highest total phenolics, ORAC values, condensed tannins, and phenolic acids. This was due to the presence of some skin in roasted Mincane. No skin was left in all other varieties upon roasting. The present work suggests that roasting results in a significant loss in the antioxidant status and phenolic profiles because of the removal of the skin, which is a rich source of phenolics. It is highly recommended to consume natural Hazelnut instead of the roasted counterpart to take advantage of all of the functional benefits of this nut.
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flavour of natural and roasted turkish Hazelnut varieties corylus avellana l by descriptive sensory analysis electronic nose and chemometrics
International Journal of Food Science and Technology, 2012Co-Authors: Cesarettin Alasalvar, Ebru Pelvan, Banu Bahar, Figen Korel, Hulya OlmezAbstract:Summary A total of eighteen natural and roasted Hazelnut varieties (amongst which only Tombul variety is classified as prime quality), grown in the Giresun province of Turkey, were compared for their differences in descriptive sensory analysis (DSA), electronic nose (e-nose) data and chemometrics. Differences in some descriptive of DSA between natural and roasted Hazelnuts as well as within the varieties were observed. Although Tombul Hazelnut was selected as one of the best varieties in terms of flavour attributes and received the highest intensities in general, no significant differences (P > 0.05) existed among Hazelnut varieties except in certain flavour attributes (‘after taste’ and ‘nutty’). DSA and e-nose data of natural and roasted Hazelnuts were also evaluated for discrimination using principal component analysis (PCA) and cluster analysis. Results of PCA using e-nose data showed that extracted principal components explained 99.7% and 99.8% of the total variance of the data for natural and roasted Hazelnut varieties, respectively. Both DSA and e-nose can be used for discrimination of natural and roasted Hazelnuts.
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effects of roasting on oil and fatty acid composition of turkish Hazelnut varieties corylus avellana l
International Journal of Food Sciences and Nutrition, 2010Co-Authors: Cesarettin Alasalvar, Ebru Pelvan, Bahar TopalAbstract:AbstractA total of 18 natural and roasted Hazelnut varieties (namely, Aci, Cavcava, Cakildak, Fosa, Ham, Incekara, Kalinkara, Kan, Karafindik, Kargalak, Kus, Mincane, Palaz, Sivri, Tombul, Uzunmusa, Yassi Badem, and Yuvarlak Badem), grown in the Giresun province of Turkey, were compared for their differences in oil content and fatty acid profiles. The oil content in natural and roasted Hazelnut varieties ranged from 57.85% for Kargalak to 68.31% for Incekara and from 61.37% for Kargalak to 71.72% for Incekara, respectively. A total of 20 fatty acids were identified in oils extracted from different varieties of natural and roasted Hazelnuts. Among the identified fatty acids in natural Hazelnut oils, 18:1ω9 was the dominant fatty acid (ranging from 77.77 to 86.91%). Roasting had minor influence on the fatty acid profiles. These results suggest that semi-commercial Hazelnut varieties are as good source of oils and possess valuable fatty acid profiles as commercial varieties (Tombul, Cakildak, Fosa, Karafindi...
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comparison of natural and roasted turkish tombul Hazelnut corylus avellana l volatiles and flavor by dha gc ms and descriptive sensory analysis
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Cesarettin Alasalvar, Fereidoon Shahidi, Keith R CadwalladerAbstract:Natural (raw) and roasted Hazelnuts were compared for their differences in volatile components and sensory responses. A total of 79 compounds were detected in both Hazelnuts, of which 39 (27 positive, 5 tentative, and 7 unknown) were detected in natural Hazelnut and 71 (40 positive, 14 tentative, and 17 unknown) were detected in roasted Hazelnut. These included ketones, aldehydes, pyrazines, alcohols, aromatic hydrocarbons, furans, pyrroles, terpenes, and acids. Pyrazines, pyrroles, terpenes, and acids were detected in roasted Hazelnut only. Concentrations of several compounds increased as a result of roasting and these may play significant roles in the flavor of roasted Hazelnut. Pyrazines together with ketones, aldehydes, furans, and pyrroles may contribute to the characteristic roasted aroma of Hazelnut. Descriptive sensory analysis (DSA) showed that some flavor attributes such as "aftertaste", "burnt", "coffee/chocolate-like", "roasty", and "sweet" were rated significantly higher in roasted Hazelnut compared to its natural counterpart. Natural and roasted Hazelnuts can be distinguished using these attributes.
Ebru Pelvan - One of the best experts on this subject based on the ideXlab platform.
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effects of roasting on the antioxidant status and phenolic profiles of commercial turkish Hazelnut varieties corylus avellana l
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Ebru Pelvan, Cesarettin Alasalvar, Suheyla UzmanAbstract:The effect of roasting on the antioxidant status and phenolic profiles of seven commercial Turkish Hazelnut varieties (namely, Cakildak, Fosa, Karafindik, Mincane, Palaz, Sivri, and Tombul) was assessed. Samples were examined for their total phenolics, oxygen radical absorbance capacity (ORAC) values, condensed tannins, and phenolic acids (free and bound forms). Significant losses (p < 0.05) in total phenolics (~66.3%), ORAC values (~41.6%), condensed tannins (~75.2), and phenolic acids (~42.7) were noted when the Hazelnuts were roasted. Some variations both between and within natural and roasted Hazelnuts were observed (p < 0.05). Phenolic acids were mainly found in the bound form. Gallic, protocatechuic, p-coumaric, and ferulic + sinapic acids were present in all Hazelnut varieties, albeit to different extents, and the first two were dominant. Mincane, in roasted form, had the highest total phenolics, ORAC values, condensed tannins, and phenolic acids. This was due to the presence of some skin in roasted Mincane. No skin was left in all other varieties upon roasting. The present work suggests that roasting results in a significant loss in the antioxidant status and phenolic profiles because of the removal of the skin, which is a rich source of phenolics. It is highly recommended to consume natural Hazelnut instead of the roasted counterpart to take advantage of all of the functional benefits of this nut.
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flavour of natural and roasted turkish Hazelnut varieties corylus avellana l by descriptive sensory analysis electronic nose and chemometrics
International Journal of Food Science and Technology, 2012Co-Authors: Cesarettin Alasalvar, Ebru Pelvan, Banu Bahar, Figen Korel, Hulya OlmezAbstract:Summary A total of eighteen natural and roasted Hazelnut varieties (amongst which only Tombul variety is classified as prime quality), grown in the Giresun province of Turkey, were compared for their differences in descriptive sensory analysis (DSA), electronic nose (e-nose) data and chemometrics. Differences in some descriptive of DSA between natural and roasted Hazelnuts as well as within the varieties were observed. Although Tombul Hazelnut was selected as one of the best varieties in terms of flavour attributes and received the highest intensities in general, no significant differences (P > 0.05) existed among Hazelnut varieties except in certain flavour attributes (‘after taste’ and ‘nutty’). DSA and e-nose data of natural and roasted Hazelnuts were also evaluated for discrimination using principal component analysis (PCA) and cluster analysis. Results of PCA using e-nose data showed that extracted principal components explained 99.7% and 99.8% of the total variance of the data for natural and roasted Hazelnut varieties, respectively. Both DSA and e-nose can be used for discrimination of natural and roasted Hazelnuts.
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effects of roasting on oil and fatty acid composition of turkish Hazelnut varieties corylus avellana l
International Journal of Food Sciences and Nutrition, 2010Co-Authors: Cesarettin Alasalvar, Ebru Pelvan, Bahar TopalAbstract:AbstractA total of 18 natural and roasted Hazelnut varieties (namely, Aci, Cavcava, Cakildak, Fosa, Ham, Incekara, Kalinkara, Kan, Karafindik, Kargalak, Kus, Mincane, Palaz, Sivri, Tombul, Uzunmusa, Yassi Badem, and Yuvarlak Badem), grown in the Giresun province of Turkey, were compared for their differences in oil content and fatty acid profiles. The oil content in natural and roasted Hazelnut varieties ranged from 57.85% for Kargalak to 68.31% for Incekara and from 61.37% for Kargalak to 71.72% for Incekara, respectively. A total of 20 fatty acids were identified in oils extracted from different varieties of natural and roasted Hazelnuts. Among the identified fatty acids in natural Hazelnut oils, 18:1ω9 was the dominant fatty acid (ranging from 77.77 to 86.91%). Roasting had minor influence on the fatty acid profiles. These results suggest that semi-commercial Hazelnut varieties are as good source of oils and possess valuable fatty acid profiles as commercial varieties (Tombul, Cakildak, Fosa, Karafindi...
Stefan Vieths - One of the best experts on this subject based on the ideXlab platform.
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enhancement of Hazelnut extract for ige testing by recombinant allergen spiking
Allergy, 2007Co-Authors: K Andersson, Barbara Ballmerweber, A Cisterobahima, Jeanette Ostling, Iris Lauer, Stefan Vieths, Jonas LidholmAbstract:BACKGROUND: Hazelnuts are a common cause of food allergic reactions. Most Hazelnut allergic individuals in central and northern Europe are sensitized to Cor a 1, a member of the PR-10 protein family, while the lipid transfer protein Cor a 8 acts as a major allergen in the south of Europe. Other allergens, including profilin and seed storage proteins, may be important in subgroups of patients. Reliable detection of specific IgE in the clinical diagnosis of food allergy requires allergen reagents with a sufficient representation of all relevant allergen components. Some reported observations suggest that natural Hazelnut extract may not be fully adequate in this respect. METHODS: The capacity of immobilized natural Hazelnut extract to bind Cor a 1-, Cor a 2- and Cor a 8-specific IgE and IgG antibodies was investigated by serum adsorption and extract dilution experiments and by the use of allergen specific rabbit antisera. All measurements were performed with the ImmunoCAP assay platform. RESULTS: The experimental results revealed an incomplete capacity of immobilized Hazelnut extract to capture IgE antibodies directed to the major allergen Cor a 1. Spiking of Hazelnut extract with recombinant Cor a 1.04 prior to solid phase coupling gave rise to significantly enhanced IgE antibody binding from Cor a 1 reactive sera. The spiking did not negatively affect the measurement of IgE to extract components other than Cor a 1. CONCLUSION: A Hazelnut allergen reagent with enhanced IgE detection capacity can be generated by supplementing the natural food extract with recombinant Cor a 1.04.
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Hazelnut corylus avellana vicilin cor a 11 molecular characterization of a glycoprotein and its allergenic activity
Biochemical Journal, 2004Co-Authors: Iris Lauer, Barbara Ballmerweber, Stefan Vieths, Kay Foetisch, Daniel Kolarich, Amedeo Conti, Friedrich Altmann, Stephan ScheurerAbstract:In Europe, Hazelnuts (Corylus avellana) are a frequent cause of food allergies. Several important Hazelnut allergens have been previously identified and characterized. Specific N-glycans are known to induce strong IgE responses of uncertain clinical relevance, but so far the allergenic potential of glycoproteins from Hazelnut has not been investigated. The aim of the study was the molecular characterization of the glycosylated vicilin Cor a 11 from Hazelnut and the analysis of its allergenic activity. Although MALDI–TOF (matrix-assisted laser-desorption ionization–time-of-flight) MS showed that one of two potential glycosylation sites of Cor a 11 was glycosylated, CD spectroscopy indicated that recombinant and natural Cor a 11 share similar secondary structures. Thus to analyse the impact of the glycan residues of Cor a 11 on IgE binding, the allergenic activity of natural glycosylated Cor a 11 and recombinant Cor a 11 was compared. In addition, the IgE sensitization pattern to recombinant Cor a 11, Cor a 1, Cor a 2 and Cor a 8 of 65 Hazelnut allergic patients was determined in vitro. The prevalence of IgE reactivity to Hazelnut vicilin Cor a 11 was below 50%. Basophil histamine-release assays were used to determine the allergenic activity of both natural and recombinant Cor a 11 in comparison with Cor a 1, a birch (Betula verrucosa) pollen-related major Hazelnut allergen. Both forms of Cor a 11 induced mediator release from basophils to a similar extent, indicating that the Hazelnut allergic patients had cross-linking IgE antibodies binding to the protein backbone and not to carbohydrate structures. In comparison to Cor a 1, a 10000-fold higher concentration of Cor a 11 was required to induce similar basophil mediator release. In conclusion, the Hazelnut vicilin Cor a 11 is a minor allergen both in regard to prevalence and allergenic potency, whereas its glycan does not contribute to its allergenic activity.
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roasted Hazelnuts allergenic activity evaluated by double blind placebo controlled food challenge
Allergy, 2003Co-Authors: Skamstrup K Hansen, Barbara Ballmerweber, Stefan Vieths, D Luttkopf, Per Stahl Skov, B Wuthrich, Carsten Bindslevjensen, Lars K PoulsenAbstract:Background: Allergy to Hazelnuts is a common example of birch pollen related food allergy. Symptoms upon ingestion are often confined to the mouth and throat, but severe systemic reactions have been described in some patients. The aim of the study was to evaluate the reduction in allergenicity by roasting of the nuts. Methods: Double-blind, placebo-controlled food challenges (DBPCFC) with roasted Hazelnuts (140°C, 40 min) were performed in 17 birch pollen allergic patients with DBPCFC-confirmed food allergy to raw Hazelnuts. The effect of roasting was further evaluated by skin prick test (SPT), histamine release (HR), measurement of specific IgE, and IgE-inhibition experiments. Results: In 5/17 patients the DBPCFC with the roasted nuts were positive. The symptoms were generally mild and included OAS (oral allergy syndrome) in all patients. Roasting of the nuts significantly reduced the allergenic activity evaluated by SPT, HR, specific IgE, and IgE-inhibition. Immunoblotting experiments with recombinant Hazelnut allergens showed sensitization against Cor a 1.04 in 16/17 patients and against Cor a 2 in 7/17 patients. None of the patients were sensitized to Cor a 8. Challenge-positive patients did not differ from the rest in IgE-binding pattern. Conclusions: All the applied methods indicated that roasting of Hazelnuts reduces the allergenicity, but since 5/17 birch pollen allergic patients were DBPCFC-positive to the roasted nuts, ingestion of roasted Hazelnuts or products containing roasted Hazelnuts can not be considered safe for a number of Hazelnut allergic consumers. For patients with a history of severe allergic symptoms upon ingestion of Hazelnuts, thorough and conscientious food labelling of Hazelnuts and Hazelnut residues is essential.
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quantitative sandwich elisa for determination of traces of Hazelnut corylus avellana protein in complex food matrixes
Journal of Agricultural and Food Chemistry, 1999Co-Authors: Thomas Holzhauser, Stefan ViethsAbstract:A Hazelnut-specific sandwich-type ELISA based on polyclonal antisera was developed for detection of hidden Hazelnut protein residues in complex food matrixes. In the absence of a food matrix, extractable protein from different native and toasted Hazelnuts was detected at rates of 94 ± 13 and 96 ± 7% applying standards prepared from native and toasted Hazelnuts, respectively. From complex food matrixes, 0.001−10% of Hazelnut was recovered between 67 and 132%, in average by 106 ± 17%. Depending on the food matrix, Hazelnut protein could be detected down to the ppb (ng/g) level. Intraassay precision was <6% for Hazelnut ≥ 0.001% and interassay precision was <15% for Hazelnut ≥ 0.01%. In 12 of 28 commercial food products without labeling or declaration of Hazelnut components, between 2 and 421 ppm of Hazelnut protein was detected, demonstrating a remarkable presence of potentially allergenic Hazelnut protein “hidden” in commercial food products. Keywords: Hazelnut (Corylus avellana); hidden allergens; ELISA; ...
Barbara Ballmerweber - One of the best experts on this subject based on the ideXlab platform.
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enhancement of Hazelnut extract for ige testing by recombinant allergen spiking
Allergy, 2007Co-Authors: K Andersson, Barbara Ballmerweber, A Cisterobahima, Jeanette Ostling, Iris Lauer, Stefan Vieths, Jonas LidholmAbstract:BACKGROUND: Hazelnuts are a common cause of food allergic reactions. Most Hazelnut allergic individuals in central and northern Europe are sensitized to Cor a 1, a member of the PR-10 protein family, while the lipid transfer protein Cor a 8 acts as a major allergen in the south of Europe. Other allergens, including profilin and seed storage proteins, may be important in subgroups of patients. Reliable detection of specific IgE in the clinical diagnosis of food allergy requires allergen reagents with a sufficient representation of all relevant allergen components. Some reported observations suggest that natural Hazelnut extract may not be fully adequate in this respect. METHODS: The capacity of immobilized natural Hazelnut extract to bind Cor a 1-, Cor a 2- and Cor a 8-specific IgE and IgG antibodies was investigated by serum adsorption and extract dilution experiments and by the use of allergen specific rabbit antisera. All measurements were performed with the ImmunoCAP assay platform. RESULTS: The experimental results revealed an incomplete capacity of immobilized Hazelnut extract to capture IgE antibodies directed to the major allergen Cor a 1. Spiking of Hazelnut extract with recombinant Cor a 1.04 prior to solid phase coupling gave rise to significantly enhanced IgE antibody binding from Cor a 1 reactive sera. The spiking did not negatively affect the measurement of IgE to extract components other than Cor a 1. CONCLUSION: A Hazelnut allergen reagent with enhanced IgE detection capacity can be generated by supplementing the natural food extract with recombinant Cor a 1.04.
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Hazelnut corylus avellana vicilin cor a 11 molecular characterization of a glycoprotein and its allergenic activity
Biochemical Journal, 2004Co-Authors: Iris Lauer, Barbara Ballmerweber, Stefan Vieths, Kay Foetisch, Daniel Kolarich, Amedeo Conti, Friedrich Altmann, Stephan ScheurerAbstract:In Europe, Hazelnuts (Corylus avellana) are a frequent cause of food allergies. Several important Hazelnut allergens have been previously identified and characterized. Specific N-glycans are known to induce strong IgE responses of uncertain clinical relevance, but so far the allergenic potential of glycoproteins from Hazelnut has not been investigated. The aim of the study was the molecular characterization of the glycosylated vicilin Cor a 11 from Hazelnut and the analysis of its allergenic activity. Although MALDI–TOF (matrix-assisted laser-desorption ionization–time-of-flight) MS showed that one of two potential glycosylation sites of Cor a 11 was glycosylated, CD spectroscopy indicated that recombinant and natural Cor a 11 share similar secondary structures. Thus to analyse the impact of the glycan residues of Cor a 11 on IgE binding, the allergenic activity of natural glycosylated Cor a 11 and recombinant Cor a 11 was compared. In addition, the IgE sensitization pattern to recombinant Cor a 11, Cor a 1, Cor a 2 and Cor a 8 of 65 Hazelnut allergic patients was determined in vitro. The prevalence of IgE reactivity to Hazelnut vicilin Cor a 11 was below 50%. Basophil histamine-release assays were used to determine the allergenic activity of both natural and recombinant Cor a 11 in comparison with Cor a 1, a birch (Betula verrucosa) pollen-related major Hazelnut allergen. Both forms of Cor a 11 induced mediator release from basophils to a similar extent, indicating that the Hazelnut allergic patients had cross-linking IgE antibodies binding to the protein backbone and not to carbohydrate structures. In comparison to Cor a 1, a 10000-fold higher concentration of Cor a 11 was required to induce similar basophil mediator release. In conclusion, the Hazelnut vicilin Cor a 11 is a minor allergen both in regard to prevalence and allergenic potency, whereas its glycan does not contribute to its allergenic activity.
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roasted Hazelnuts allergenic activity evaluated by double blind placebo controlled food challenge
Allergy, 2003Co-Authors: Skamstrup K Hansen, Barbara Ballmerweber, Stefan Vieths, D Luttkopf, Per Stahl Skov, B Wuthrich, Carsten Bindslevjensen, Lars K PoulsenAbstract:Background: Allergy to Hazelnuts is a common example of birch pollen related food allergy. Symptoms upon ingestion are often confined to the mouth and throat, but severe systemic reactions have been described in some patients. The aim of the study was to evaluate the reduction in allergenicity by roasting of the nuts. Methods: Double-blind, placebo-controlled food challenges (DBPCFC) with roasted Hazelnuts (140°C, 40 min) were performed in 17 birch pollen allergic patients with DBPCFC-confirmed food allergy to raw Hazelnuts. The effect of roasting was further evaluated by skin prick test (SPT), histamine release (HR), measurement of specific IgE, and IgE-inhibition experiments. Results: In 5/17 patients the DBPCFC with the roasted nuts were positive. The symptoms were generally mild and included OAS (oral allergy syndrome) in all patients. Roasting of the nuts significantly reduced the allergenic activity evaluated by SPT, HR, specific IgE, and IgE-inhibition. Immunoblotting experiments with recombinant Hazelnut allergens showed sensitization against Cor a 1.04 in 16/17 patients and against Cor a 2 in 7/17 patients. None of the patients were sensitized to Cor a 8. Challenge-positive patients did not differ from the rest in IgE-binding pattern. Conclusions: All the applied methods indicated that roasting of Hazelnuts reduces the allergenicity, but since 5/17 birch pollen allergic patients were DBPCFC-positive to the roasted nuts, ingestion of roasted Hazelnuts or products containing roasted Hazelnuts can not be considered safe for a number of Hazelnut allergic consumers. For patients with a history of severe allergic symptoms upon ingestion of Hazelnuts, thorough and conscientious food labelling of Hazelnuts and Hazelnut residues is essential.
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Hazelnut allergy a double blind placebo controlled food challenge multicenter study
The Journal of Allergy and Clinical Immunology, 2000Co-Authors: C Ortolani, Barbara Ballmerweber, B Wuthrich, Carsten Bindslevjensen, Kirsten Hansen, M Ispano, Raffaella Ansaloni, Luciana Vannucci, Valerio Pravettoni, Joseph ScibiliaAbstract:Abstract Background: Tree nuts are a common cause of food allergy in Europe. However, few studies deal with real food allergy to Hazelnuts in subjects believed to be allergic to this food. Objective: We sought to select subjects with a history of allergic reactions on ingestion of Hazelnut and determine how many of these have true allergy by means of the double-blind, placebo-controlled food challenge (DBPCFC). Methods: Eighty-six subjects with a history of symptoms after Hazelnut ingestion were recruited from 3 allergy centers (Milan, Zurich, and Copenhagen). All subjects underwent skin prick tests (SPTs) with aeroallergens and Hazelnut, as well as having their specific Hazelnut IgE levels determined. Diagnosis of clinical relevant food allergy was made on the basis of the DBPCFC. Results: Sixty-seven (77.9%) of 86 subjects had a positive DBPCFC result; 8 were placebo responders, and 11 were nonresponders. Of the 11 nonresponders, 4 had positive open-challenge test results. Of the DBPCFC-positive subjects, 87% also had positive skin test responses to birch pollen extract. Specific IgE determination for Hazelnut (positive CAP response ≥0.7 kU/L [ie, class 2]) showed a sensitivity of 0.75, a positive predictive value (PPV) of 0.92, a specificity of 0.16, and a negative predictive value (NPV) of 0.05. Skin tests with commercial Hazelnut extract produced a sensitivity of 0.89, a PPV of 0.92, a specificity of 0.05, and an NPV of 0.05. Skin tests with natural food produced a sensitivity of 0.88, a PPV of 0.94, a specificity of 0.27, and an NPV of 0.15. Conclusion: This study shows that Hazelnut is an allergenic source that can cause real food allergy, as confirmed by DBPCFC. Skin and IgE tests demonstrated reasonable sensitivity and PPV but a very low specificity and NPV, thus implying that these should not be used to validate the diagnosis of food allergy to Hazelnut. (J Allergy Clin Immunol 2000;105:577-81.)
