Comparison and Functional Evaluation of the Allergenicity of Different Hazelnut (Corylus avellana) Protein Extracts

Abstract

This paper investigates two methodological issues of hazelnut protein extraction: the use of protease inhibitors during protein extraction and the effect of defatting hazelnuts before protein extraction. Different protein extracts from hazelnuts were analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and IgE-immunoblotting to evaluate the presence of allergens in the extract. The allergy-provoking potential of these extracts was assessed by the Basophil Activation Test. This functional test relies on in vitro stimulation of human basophils from hazelnut-allergic patients with the different extracts. SDS-PAGE and IgE-immunoblot analysis of hazelnut extracts prepared without protease inhibitors revealed partial degradation of the proteins in the extracts. This observation was confirmed by the Basophil Activation Test, as the percentage of activated basophils was lower as compared to extracts prepared with protease inhibitors. Biochemical and functional evaluation of a defatted hazelnut extract did not reveal differences in comparison with non-defatted extracts. This study is the first to report on the use of the Basophil Activation Test applying human basophils for functional evaluation of protein extracts from hazelnuts. The results demonstrate that the use of protease inhibitors during extraction is essential for the stability and functionality of a protein extract, whereas defatting does not affect the quality of the protein extract.

Natural Variation of Hazelnut Allergenicity: Is There Any Potential for Selecting Hypoallergenic Varieties?

“…In this study, this protein is recognized by more than 50% of the tested sera of hazelnut-allergic patients, thus confirming its classification as a major allergen in hazelnut. The immunoreactive profile of the different hazelnut varieties for the different sera also showed other important allergens, namely at a molecular weight slightly higher than 62 kDa (allergic patients #1, #2, #3, faint in #5/#6 and #7), and approximately at 62 kDa (allergic patients #1, #2, #3 and #7), 49 kDa (allergic patients #1, #2, #3, #6 and #7) and 28 kDa (allergic patients #1 and #7), which is in accordance with previous studies aiming at identifying common allergenic structures in hazelnut [30,31]. A few faint immunoreactive bands with molecular weights between 62 and 98 kDa were also observed in the sera of some allergic patients, namely #1 and #7, which were posteriorly tested by the 2-DE-based proteomic approach in the present work.…”

Impact of Roasting on Identification of Hazelnut (Corylus avellana L.) Origin: A Chemometric Approach

“…15,28,29 Based on molecular weights and literature data (http://www.uniprot.org), some bands can be referred to well-known hazelnut allergens. Particularly, the 60 kDa band is attributable to 11S globulin (UniProt Q8W1C2), the 50 kDa band to 7S vicilin (UniProt Q8S4P9), and the 18 kDa band to Bet v 1 omologue (UniProt Q9SWR4), the 15 kDa band can contain profilin (UniProt Q9AXH5) and oleosin (UniProt Q84T21), and the 13.5 kDa band is ascribable to a protein group including lipid transfer protein (LTP, UniProt Q9ATH2).…”

Effect of malonaldehyde cross-linking on the ability of shrimp tropomyosin to elicit the release of inflammatory mediators and cytokines from activated RBL-2H3 cells

“…Previous studies have shown that these cells are rapidly and easily obtained and are reliable models of allergic reactions . As a result, RBL‐2H3 cells have been used to evaluate the allergenicity changes in hazelnut ( Corylus avellana ) protein extracts . In this study, RBL‐2H3 cells were used to evaluate the allergenicity changes of shrimp tropomyosin after treatment with MDA at different concentrations.…”

“…12 As a result, RBL-2H3 cells have been used to evaluate the allergenicity changes in hazelnut (Corylus avellana) protein extracts. 13 In this study, RBL-2H3 cells were used to evaluate the allergenicity changes of shrimp tropomyosin after treatment with MDA at different concentrations. In addition to our previous results on IgE/IgG binding capacity, it will be helpful to understand the changes to the immune characters of shrimp tropomyosin after treatment with MDA.…”