Gluten quality

Pelshenke, P., pp. 334-7. The Raj)id Determination of Gluten Quality in Wheat and Flour by Means of Fermentation. 

SMS, Stable Micro Systems, TA-XT2 Application study. Extensibility of dough and measure of gluten quality. Texture expert guide contents, 1995. 

Zeleny, Y. 1947. A simple sedimentation test for estimating the bread-baking and gluten qualities of wheat flour. Cereal Chem. 24, 465 475. 

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. 

It appears that dried gluten produced from English non-bread making flour is just as good as gluten produced from the best quality Canadian flour. Unsurprisingly, dried gluten is normally made from the cheapest possible source. 

Peraaho, M., Kaukinen, K., Mustalahti, K., Vuolteenaho, N., Maki, M., Laippala, P., and Collin, P. (2004b). Effect of an oats-containing gluten-free diet on symptoms and quality of life in coeliac disease. A randomized study. Scand. ]. Gastroenterol. 39, 27-31. 

PER is a method to metabolize or determine the quality of protein in foods. Quality is measured by the amount of usable protein and the growth resulting from it through an animal assay. Formerly, this method was used as the standard method for all protein quality analysis. However, there is some question as to whether or not it is a valid measurement. This is because PER does not account for the differences in amino acid requirements between humans and rats (Seligson and Mackey, 1984), nor does PER account for the protein needed for cell maintenance. Therefore, PER results often overestimate the requirements for some amino acids and underestimate others. Specifically, PER tends to underestimate the protein quality of lysine-deficient proteins such as wheat gluten (Hackler, 1977). 

The external characters (colour, odour, elasticity and tenacity) of the gluten indicate its quality and so the behaviour of the flour as regards bread-making. 

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