In Vitro Digestion and Characterization of 2S Albumin and Digestion-Resistant Peptides in Pecan

Authors

Jelena Spiric, University of Nebraska-Lincoln and Paul-Ehrlich-InstitutFollow
Stef J. Koppelman, University of Nebraska-LincolnFollow
Andre Knulst, UMC Utrecht, the NetherlandsFollow
Julie A. Nordlee, University of Nebraska-LincolnFollow
Steve L. Taylor, University of Nebraska-LincolnFollow
Joseph L. Baumert, University of Nebraska-LincolnFollow

Date of this Version

2018

Citation

International Journal of Food Science and Technology 53 (2018), pp. 1566–1578.

doi:10.1111/ijfs.13739

Comments

Copyright © 2018 Institute of Food Science and Technology. Published by Wiley. Used by permission.

Abstract

The 2S albumins are one of the major protein families involved in severe food allergic reactions to nuts, seeds, and legumes, thus potentially making these proteins clinically relevant for allergic sensitization and potential diagnostic markers. In this study, we sought to purify native 2S albumin protein from pecan to further characterize this putative allergen. The purified 2S albumin, Car i 1, from pecan was found to be resistant to digestion by pepsin in simulated gastric fluid (SGF) and comparatively stable to proteolysis by trypsin and pancreatin in simulated intestinal fluid (SIF). Digestion of purified Car i 1 in SGF and SIF resulted in formation of different digestion-resistant peptides that were capable of binding IgE antibodies from allergic individuals. Digestion stability of Car i 1 and formation of digestion-resistant antigenic peptides may explain why it is a potent sensitizing protein in pecan for susceptible individuals. The observation that digestion-resistant peptides are able to bind IgE implies that pecan can trigger systemic allergic reactions even after digestion in the stomach and small intestine.