R. J. Hamer, Food Chemistry Department, Wageningen University, Wageningen, the Netherlands and also TI Food and Nutrition, Wageningen, the Netherlands. Phone +31-317-485380, e-mail email@example.com; T. W. J. M. van Herpen, Plant Research International, Wageningen, the Netherlands
The Science of Gluten-Free Foods and Beverages
The discovery of specific T-cell binding epitopes in gluten has formed a major breakthrough in both understanding the etiology of celiac disease (CD) and identifying so-called toxic peptides in gluten. Initially, only reports pointing at the toxicity of alpha-gliadin protein or peptides were published. Then, the discovery was made that T-cells cloned from CD intestinal biopsies could be activated by specific gliadin sequences (Arentz-Hansen et al., 2000). This technology helped identify numerous sequences, even in previously unsuspected proteins like low molecular weight (LMW) and high molecular weight (HMW) glutenin subunits (Jensen et al., 1995; Vader et al., 2002b). Today's count is over 30 identified sequences and it is expected that more will follow in time. The discovery that deamidation by tissue-type transglutaminase (TG2) strongly increases binding to T-cells led Vader et al. to develop a search algorithm that was based on both T-cell recognition and tissue-transglutaminase specificity (Vader et al., 2002a).
The number of so-called CD-toxic sequences and the fact that they are found in the majority of wheat storage proteins impacts the possibility of developing a non-CD-toxic or low CD-toxic wheat. This will be discussed in this paper.