Wheat and its Proteins

The proteins that are of most interest in baking are the proteins from wheat. The wheat that is normally used is Triticum aestivum not Triticum durum which is used to make pasta. The distinguishing property of wheat proteins is that some of them can develop into the viscoelastic mass known as gluten. The only other grain that has 

Given that some of the protein, particularly that in wheat bran, does not form gluten it is obvious that the quality of the protein is as important as the quantity. Unfortunately, measuring the quantity of protein is easier and less controversial. 

The quantity of protein present is normally measured by the Kjeldahl method. As wheat endosperm protein is around 17.5% nitrogen a factor of 5.7 is normally used to convert Kjeldahl nitrogen measurements into protein. Tkachuk suggested that 5.7 should be used for whole wheat but 5.6 should be used for flour.24 

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