A range of dietary proteins pose risks to human health. In susceptible individuals, consumption of cereals can cause coeliac disease by the autoimmune reaction to gluten proteins, wheat allergy through an IgE-mediated reaction to various types of prolamins, and non-coeliac wheat sensitivity by a reaction to non-gluten proteins such as alpha-amylase/trypsin inhibitors expressed by wheat. Importantly, the only effective treatment of these diseases is to eliminate sources of gluten from the diet.
Gluten-free (GF) bread can be made by substituting wheat flour for potato or corn starch. In some bread products, wheat flour is used wherein enzymes are proposed to degrade the gluten during fermentation. In this study, a number of GF bread varieties that are available commercially are explored with the aim to determine the GF status of these products and hence determine their safety for people with gluten intolerance.
Discovery proteomics is employed to characterise the protein components within the finished product, and to assess the degree of protein degradation during fermentation. The identities and abundance of gluten and homologous proteins are compared to a typical wheat bread. High sensitivity protein discovery was performed on a TripleTOF 6600 (SCIEX) mass spectrometer with microflow HPLC, and SWATH proteomics was used to track the global abundance of key peptides. These data informed the development of quantitative approaches targeting gluten proteins using multiple reaction monitoring on a QTRAP 6500+ (SCIEX) mass spectrometer coupled to an Exion HPLC system.
This study explores how extended microbial fermentation affects the proteome of commercial GF bread.