Effect of barley and barley components on rheological properties of wheat dough

The effects of addition of whole barley and barley components (starch, beta -glucans and arabinoxylans) on rheological properties of dough prepared fr om wheat flours with variable gluten quality (cv. Glenlea, extra-strong; cv . Katepwa, very strong; cv. AC Karma, strong; and cv. AC Reed, weak) were i nvestigated in these studies using Mixograph and dynamic rheological measur ements. Whole barley meal, starch and non-starch polysaccharides from hulle ss barley with variable starch characteristics (normal, high amylose, waxy, and zero amylose waxy) were tested. Upon addition of either beta -glucans or arabinoxylans, significant increases in peak dough resistance, mixing st ability, and work input were recorded in all flours. The addition of starch to various wheat flours reduced the strength of the respective flour-water doughs. The improvement of dough strength upon addition of waxy or zero am ylose waxy barley meal was associated with the high content of total and so luble beta -glucans present in barley samples. The addition of arabinoxylan s or beta -glucans increased the G' of wheat doughs; arabinoxylans had a gr eater effect than beta -glucans. Starch substantially decreased the elastic modulus of dough prepared from cv. Glenlea but waxy and high amylose starc hes increased the G' of dough prepared from cv. AC Karma. A combination of the high amounts of non-starch polysaccharides and unusual starch character istics in barley seems to balance the negative effects associated with glut en dilution brought about by addition of barley into wheat flour. (C) 2001 Academic Press.