Wheat allergies: a peptidomic approach

This thesis deals with the characterization of the peptides obtained after simulated gastrointestinal digestion of wheat proteins, with specific focus on those known to be involved in celiac disease. This autoimmune entheropathy, besides the genetic predisposition, is triggered by gluten ingestion. Several studies correlated the increased prevalence of celiac disease with different factors, including the amount and quality of dietary gluten. In this thesis, different in vitro digestion models were applied to wheat samples and the resulting peptides where identified and quantified. The results highlighted that different wheat varieties, even with similar total gluten content, can lead to huge differences in terms of immunotoxic peptides generated after digestion. The genotypic variability of wheat gluten could thus be used in varietal selections aimed to reduce people exposure to immunotoxic peptides. Other allergenic wheat proteins, such as α-amylase/trypsin inhibitors, instead, were found to be more affected by environmental factors (such as growing area). Beside the immunological point of view, in this thesis several analytical methods applied to wheat proteins were also developed using LC-MS and LC-MS/MS techniques. In particular, methods for detection and quantification of an α-amylase/trypsin inhibitor and gluten were developed, , as well as a method to detect common wheat adulteration in durum wheat samples.