Improved protocols for ELISA determination of gliadin in glucose syrups

Simple modifications of existing protocols for high-sensitivity detection of gluten proteins by immunochemical methods allowed rapid and sensitive determination of residual gluten in highly viscous samples of glucose and maltose syrups obtained from processing wheat starch. Dilution of the original syrup to no less than 15-20% in solids allowed retention of gluten proteins in a soluble form so that ELISA determination of gliadin was possible without an extraction step in aqueous ethanol. An ultrafiltration step may be added to concentrate residual gluten proteins in the diluted syrup samples and allow a further increase in sensitivity. The results are relevant for quality assessment of wheat starch derived syrups as raw materials for use in gluten-free foods for celiac individuals.