Abstract: Methods for detecting heat-stressed wheat, that is, wheat that has experienced elevated temperatures during the grain filling period, and methods to assess end-use properties of wheat grain are disclosed. In the method to detect heat-stressed wheat, wheat heat stress peptide in a sample of wheat grain or flour is measured. Wheat grain or flour that has a level of wheat heat stress peptide two or more times greater that the constitutive level is determined to have experienced elevated temperatures during the grain filling period. In the method to assess an end-use property of wheat, wheat heat stress peptide in a sample of wheat grain or flour is measured, and the level is compared to a calibration curve that correlates the level of wheat heat stress peptide and the end-use property.