Thiolomics of the Gluten Protein Network of Wheat Dough

The thiol moiety on protein cysteines may occur in free form and as intraprotein or interprotein disulfides. In all cases, these moieties play a key role in the formation of the gluten protein network and in the sensory properties of wheat-based products. The occurrence and location of cysteine thiols in gliadins and glutelins are discussed on the basis of current sequence information, as is their relevance to the characteristics of the products. Methods for assessing the accessibility of thiols are presented as a way of estimating the mutual relationships among wheat proteins and their rearrangements upon processing. The combination of protein composition studies (in terms of the occurrence and abundance of individual protein species, using standard 'proteomics' approaches) and the labeling of accessible thiols in specific protein components is defined as 'thiolomics.' This novel approach is discussed in terms of its capacity of providing additional information - of possible practical relevance - about protein-protein interactions in wheat-based systems and about some of the structural and compositional determinants of the technological behavior of grain proteins.