PROTEIN-COMPOSITION AND AGGLOMERATION TENDENCY OF GLUTEN ISOLATED FROM EUROPEAN WHEATS (TRITICUM-AESTIVUM L.) IN A BATTER SYSTEM

Pilot scale isolation of gluten (with recovery of gluten on 400, 250, and 125 mu sieves) from flour prepared from six European wheat varieti es (Apollo, Slejpner, Sperber, Camp Remy, Minaret, and Soissons) resul ted in, on average, gluten yields of 9.6% (4.7-13.2% range). Gluten pr otein recoveries averaged 63.0% (34.5-85.7% range). Gluten yields and gluten protein recoveries were linearly related and increased when mix ing times and baking absorptions required for optimal dough developmen t of the parent flours increased, indicating that there is a relations hip between the agglomeration properties of gluten proteins in a batte r system and the optimal technological conditions necessary for proces sing the flours in breadmaking. The Osborne protein fractions in the g luten fractions were determined. The 0.05 M acetic acid soluble (glute nin) fraction was quantitatively the most important fraction (40-46% o f gluten Kjeldahl nitrogen) while comparable levels of 70% ethanol sol uble (gliadins) and 0.05 M acetic acid insoluble (residue protein) wer e found (17.9-22.3% of gluten Kjeldahl nitrogen and 22.0-29.0% of glut en Kjeldahl nitrogen for gliadins and residue protein, respectively). With decreasing pore size of the sieves, the level of glutenin in the gluten decreased while the level of gliadins increased. This indicates that, in gluten with good agglomeration properties, the level of glut enins is high and that the agglomeration properties of such proteins ( i.e. their tendency to aggregate) strongly determines the agglomeratio n behavior of the gluten as a whole.