Insoluble and soluble roasted walnut proteins retain antibody reactivity

Melanie L Downs; Angela Simpson; Adnan Custovic; Aida Semic-Jusufagic; Joan Bartra; Montserrat Fernandez-Rivas; Steve L Taylor; Joseph L Baumert; E N Clare Mills

doi:10.1016/j.foodchem.2015.08.119

Insoluble and soluble roasted walnut proteins retain antibody reactivity

Food Chem. 2016 Mar 1:194:1013-21. doi: 10.1016/j.foodchem.2015.08.119. Epub 2015 Sep 3.

Authors

Melanie L Downs¹, Angela Simpson², Adnan Custovic², Aida Semic-Jusufagic², Joan Bartra³, Montserrat Fernandez-Rivas⁴, Steve L Taylor⁵, Joseph L Baumert⁵, E N Clare Mills⁶

Affiliations

¹ Food Allergy Research and Resource Program, Department of Food Science and Technology, Food Innovation Center, 1901 North 21st Street, University of Nebraska-Lincoln, Lincoln, NE 68588-6205, USA; Institute of Inflammation and Repair, Manchester Academic Health Sciences Centre and Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK. Electronic address: mdowns2@unl.edu.
² Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, University of Manchester & Respiratory and Allergy Clinical Research Facility, Education and Research Centre, University Hospital of South Manchester NHS Foundation Trust, Wythenshawe Hospital, Southmoor Road, Manchester M23 9LT, UK.
³ Allergy Unit, Service of Pneumology and Respiratory Allergy, Hospital Clínic (ICT), Barcelona, Spain.
⁴ Allergy Department, Hospital Clínico San Carlos, IdISSC, c/ Prof. Martín Lagos s/n, 28040 Madrid, Spain.
⁵ Food Allergy Research and Resource Program, Department of Food Science and Technology, Food Innovation Center, 1901 North 21st Street, University of Nebraska-Lincoln, Lincoln, NE 68588-6205, USA.
⁶ Institute of Inflammation and Repair, Manchester Academic Health Sciences Centre and Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK; Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, University of Manchester & Respiratory and Allergy Clinical Research Facility, Education and Research Centre, University Hospital of South Manchester NHS Foundation Trust, Wythenshawe Hospital, Southmoor Road, Manchester M23 9LT, UK.

PMID: 26471647
DOI: 10.1016/j.foodchem.2015.08.119

Abstract

Thermal processing techniques commonly used during food production have the potential to impact food allergens by inducing physical and/or chemical changes to the proteins. English walnuts (Juglans regia) are among the most commonly allergenic tree nuts, but little information is available regarding how walnut allergens respond to thermal processing. This study evaluated the effects of dry roasting (132 or 180°C for 5, 10, or 20min) on the solubility and immunoreactivity of walnut proteins. A dramatic decrease in walnut protein solubility was observed following dry roasting at 180°C for 20min. However, both the soluble and insoluble protein fractions from roasted walnuts maintained substantial amounts of IgG immunoreactivity (using anti-raw and anti-roasted walnut antisera), with similar patterns of reactivity observed for human IgE from walnut-allergic individuals. Thus, walnut proteins are relatively stable under certain thermal processing conditions, and IgE reactivity remains present even when insoluble aggregates are formed.

Keywords: Food allergy; Thermal processing; Tree nut; Walnut.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Allergens / immunology
Food Hypersensitivity / immunology
Immunoglobulin E / immunology
Juglans / chemistry*
Nuts / chemistry*
Plant Proteins / chemistry*

Substances

Allergens
Plant Proteins
Immunoglobulin E