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Ewart, John Archibald Douglas (1964) Some studies on cereal proteins with special reference to wheat. Doctoral thesis, Sir John Cass College.
Starch-gel electrophoresis has been developed for the first time as a tool for investigating the composition of cereal protein mixtures. With its aid definite varietal differences have been demonstrated among wheat gliadins though not among the albumins and globulins; the positions of these groups of proteins have been identified, and four major gliadin constituents have been recovered and shown to behave as single entities upon further electrophoresis. Marked differences were found when rye, barley, oat and maize were compared with wheat. Information upon a number of problems in cereal chemistry has been obtained, and the technique has been developed as a micro-preparative method.
Rabbit antiserum to Manitoba No.2 gluten was used to compare cereal extracts by means of double diffusion, and it appeared that four of the main wheat gluten proteins are closely related in structure in several wheat varieties; three of these were present in bye, but barley oat and maize gave only slight reactions with the serum. The immunological and electrophoretic results together suggest that the inability of barley, oat and maize to form dough is due to lack of proteins of the required structure, that the poor rheological behaviour of Durum wheat and rye comes from deficiencies in these, and the change in properties of wheat dough with variety must depend on quantitative rather than qualitative differences in composition,or in some other, as yet undetermined, factor.
Preliminary trials with a radioactive approach to test whether the speed of disulphide interchange in flours were such a factor indicated that further work might yield useful results.
Experience has been gained in "fingerprinting" proteins, although this technique gave equivocal results when studying the structural relationship of glutenin to gliadin.
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