The Influence of the Time and Temperature of Heat Treatment on the Allergenicity of Egg White Proteins

Original Article  Open Access

|  | Full Text    |    Allergy Asthma Immunol Res. 2013 Mar;5(2):96-101. English. Published online 2012 November 02.  http://dx.doi.org/10.4168/aair.2013.5.2.96  Copyright © 2013 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease The Influence of the Time and Temperature of Heat Treatment on the Allergenicity of Egg White Proteins Meeyong Shin,1 Youngshin Han,2 and Kangmo Ahn3 1Department of Pediatrics, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea. 2Environmental Health Center for Atopic Dermatitis, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. 3Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.  Correspondence to: Kangmo Ahn, MD, PhD, Department of Pediatrics, Sungkyunkwan University Samsung Medical Center, 80 Irwon-ro, Gangnam-gu, Seoul 135-710, Korea. Tel: +82-2-3410-3530; Fax: +82-2-3410-3669; Email:kmaped@skku.edu  Received July 27, 2012; Revised August 24, 2012; Accepted September 17, 2012. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Purpose The present study was performed to determine the factor, either duration or the temperature of heat treatment, exerting maximal and significant influence on the composition and allergenicity of egg white (EW) proteins. Methods Raw EW and 4 kinds of heated EW (fried EW, boiled EW for 10 minutes, boiled EW for 30 minutes, and baked EW for 20 minutes at 170℃) were prepared, and subsequently protein extraction was carried out. The proteins were separated by SDS-PAGE, and then immunoglobulin E (IgE) immunoblots were performed with the sera of 7 egg-allergic patients. Furthermore, the antigenic activities of ovalbumin (OVA), ovomucoid (OM), and ovotransferrin (OT) in different EW samples were measured by inhibition enzyme-linked Immuno-sorbent assay (ELISA). Results In SDS-PAGE analysis, the intensity of the protein band at 45 kD (corresponding to OVA) decreased significantly in boiled EW (30 minutes) and baked EW, but no change was observed in the case of boiled EW for 10 minutes. In IgE immunoblots, the IgE response to 34-50 kD (OM and OVA) in boiled EW for 30 minutes decreased significantly, when compared with raw EW and other heated EWs. In inhibition ELISA, a significant decrease in the OVA antigenic activity was observed in boiled EW for 30 minutes amongst other heated EW samples. However, OM antigenic activity in all kinds of heated EW including boiled EW for 30 minutes did not reduce after heat treatment. The OT antigenic activity nearly disappeared in heated EWs except in the case of boiled EW for 10 minutes. Conclusions Amongst 4 kinds of heated EWs, the boiled EW for 30 minutes showed the most significant changes both in composition and reduction in allergenicity. Our results revealed that the duration of heat treatment had more influence on the composition and allergenicity of EW proteins than the temperature.