TY  - JOUR
A1  - Huschek, Gerd
A1  - Boenick, Josephine
A1  - Loewenstein, Yvonne
A1  - Sievers, Steven
A1  - Rawel, Harshadrai Manilal
T1  - Quantification of allergenic plant traces in baked products by targeted
proteomics using isotope marked peptides
JF  - LWT - food science and technology : an official journal of the Swiss Society of Food Science and Technology (SGLWT/SOSSTA) and the International Union of Food Science and Technology (IUFoST)
N2  - The right choice of analytical methods for plant allergen quantification is a deciding factor for the correct assessment and labeling of allergens in processed food in view of consumer protection. The aim of the present study was to develop a validated target peptide multi-method by LC/MS/MS providing high specificity and sensitivity for plant allergen protein detection, plant identification in vegan or vegetarian products using peptide markers for quantification. The methodical concept considers the selection of target peptides of thermostable allergenic plant proteins (Gly m6 soy, Ses i6 sesame and (beta-conglutin from white lupine) by data base research, BLAST and in silico digestion using Skyline software. Different allergenic concentration levels of these proteins were integrated into our own reference bakery products and quantified with. synthesized isotopically labeled peptides after in-solution digestion using LC/MS/MS. Recovery rates within the range of 70-113% and LOQ of 10 ppm-50 ppm (mg allergenic food/kg) could be determined. The results are independent of thermal processing applied during baking and of epitope binding site for the tested allergens. (C) 2016 Elsevier Ltd. All rights reserved.
KW  - Allergenic food
KW  - Plant allergen (soy, sesame, lupine)
KW  - LC/MS/MS;
 Quantification of allergenic plant traces
KW  - Food labeling
Y1  - 2016
U6  - https://doi.org/10.1016/j.lwt.2016.07.057
SN  - 0023-6438
SN  - 1096-1127
VL  - 74
SP  - 286
EP  - 293
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Sievers, Steven
A1  - Rawel, Harshadrai Manilal
A1  - Ringel, Karl Peter
A1  - Niggemann, Bodo
A1  - Beyer, Kirsten
T1  - Wheat protein recognition pattern in tolerant and allergic children
JF  - Pediatric Allergy and Immunology
N2  - BackgroundWheat is one of the most common food allergens in early childhood. In contrast to other food allergies, wheat-specific IgE correlates badly with clinical symptoms and relevant components have been identified mostly for wheat-depended exercise-induced anaphylaxis. Moreover, a high percentage of patients present with immediate type symptoms but wheat-specific IgE cannot be detected with commercial available systems. ObjectiveWe addressed the question whether the IgE recognition pattern between wheat allergic (WA) and clinically tolerant (WT) children differs in order to identify individual proteins useful for component-resolved diagnostics. MethodsSera of 106 children with suspected wheat allergy, of whom 44 children had clinical relevant wheat allergy and 62 were tolerant upon oral food challenge, were analyzed for wheat-specific IgE using the ImmunoCap system as well as immunoblots against water and salt soluble, and water-insoluble protein fractions. 40 randomly selected sera were analyzed for specific IgE to 5-gliadin. ResultsSixty-three percent of the WT and 86% of the WA children were sensitized to wheat with >0.35 kU(A)/l in ImmunoCAP analysis. We could confirm the role of -, ss-, -, and -gliadins, and LMW glutenin subunits as major allergens and found also IgE binding to a broad spectrum of water- and salt-soluble protein bands. It is of great importance that wheat allergic and tolerant patients showed IgE binding to the same protein bands. WT and WA did not significantly differ in levels of 5-gliadin-specific IgE. Conclusions & Clinical RelevanceChildren with challenge proven clinical relevant food allergy and tolerant ones had a similar spectrum of IgE binding to the same protein bands. These findings imply that component-resolved diagnostics might not be helpful in the diagnostic work-up of wheat allergy.
KW  - wheat
KW  - IgE
KW  - 5-gliadin
KW  - protein pattern
KW  - immunoblot
Y1  - 2016
U6  - https://doi.org/10.1111/pai.12502
SN  - 0905-6157
SN  - 1399-3038
VL  - 27
SP  - 147
EP  - 155
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -