Solubility of proteins from non-gluten cereals : a comparative study on combinations of solubilising agents

Development of high quality gluten-free (GF) cereal products relies on understanding the properties of the GF flour components, in particular proteins. Extraction of proteins from GF cereals is a challenging task for the cereal technologist. In this work, we present a rapid and efficient method for the extraction of total proteins from GF-flours. Proteins from the GF-flours brown rice, maize and teff were extracted using four buffer systems, all containing urea and DTT, but differing for the presence/absence of SDS and/or thiourea. Extracted proteins were characterised by SDS–PAGE, capillary gel electrophoresis, and by SE-HPLC. Addition of thiourea or SDS increased both the amount of protein and the number of individual proteins in most extracts. As a consequence of the peculiar properties of proteins in each cereal species, a specific buffer was found to ensure the most effective extraction of proteins from a given flour.