PHYSICOCHEMICAL AND FUNCTIONAL-PROPERTIES OF RYE NONSTARCH POLYSACCHARIDES .4. THE EFFECT OF HIGH-MOLECULAR-WEIGHT WATER-SOLUBLE PENTOSANS ON WHEAT-BREAD QUALITY IN A STRAIGHT-DOUGH PROCEDURE

Addition of 2% high molecular weight rye water-soluble pentosans to Eu ropean bread wheat flour greatly changed its rheological and functiona l breadmaking properties. When the rye fractions were added as dry pow der, the changes in the mixograph curves were smaller than the changes of the fractions that were presoaked in water and then added. Under t he latter conditions, the mixograph peak height and area under the cur ve were greatly increased. Response surface methodology showed that th e loaf volume of breads obtained from wheat flour is strongly dependen t on mixing time and water addition. The addition of the rye component s as a fine powder to wheat flour increased the water-absorption level and the range of mixing times for obtaining a bread of constant loaf volume and crumb quality. At the same time, it was possible to incorpo rate more water and to mix for a longer time without impairing the dou gh-handling properties. In general, the loaf volume increased and the crumb structure was comparable to that of the control. When the high m olecular weight water solubles from rye were presoaked and added as a solution, the range of mixing times and the water-absorption level aga in were increased. Mixing time and water-absorption level strongly inf luenced loaf volume. The rye components used in this study, therefore, obviously influenced the quality of the wheat flour.