simple glutenin turbidity test for the determination of heat damage in gluten

A quantitative test specific to heat damage in wheat gluten has been developed. The test is simple and rapid, allowing a trained operator to analyse batches of samples, and interpret the results, in under 1 h. The glutenin turbidity test measures the loss in solubility of one class of proteins, acetic acid soluble glutenin. The soluble glutenin was isolated as a finely dispersed precipitate by extraction of gluten with dilute acetic acid, followed by precipitation in alkaline 700 ml litre-1 ethanol. The absorbance of the turbid mixture was determined by a spectrophotometer and may be related to percentage heat damage by comparison with standards. The gluten turbidity test measures loss in baking quality due to heat damage only. Glutenin turbidity was found to be independent of both total protein content and overall gluten quality (as measured by bread loaf volume improvement) for the 23 sound commercial and laboratory samples of gluten tested.