EFFECT OF PARTIAL REPLACEMENT OF WHEAT FLOUR BY BARLEY AND OAT FLOUR ON THE CHEMICAL AND RHEOLOGICAL PROPERTIES OF TOAST BREAD DOUGH

Document Type : Original Article

Authors

Food Sci. Dept., Fac. Agric., Zagazig Univ., Egypt

Abstract

The aim of this study was to investigate the effect of replacement of wheat flour by barley or oat flour and the both together on the rheological properties of the toast bread dough. Wheat flour was substituted by six levels of barley and oat flour at a ratio of (5, 10 and 15% oat flour, 5, 10 and 15% barley flour) and were used in manufacture toast bread. The results showed that the bread containing 10% barley flour or 5% oat flour or both at ratio of 15 % gave the highest scores of sensory properties than the other treatments as well as the control. Therefore, these treatments (replacement of wheat flour by 10% barley flour or 5% oat flour or both by 15%) and their effect on rheological properties of toast dough were studied. The results obtained from farinograph showed that toast dough containing 10% barley increased the rate of absorption and duration of kneading dough and consistently for maximum strength and the weakness of the dough. However, the addition of 5% oats lowered the rate of absorption, while the access time and the stability of the dough and the dough weakness were increased. In the case of adding, both of barley and oat together as a replacement of wheat flour at a ratio of 15%, the results obtained of farinograph led to low rate of water absorption, while the arrival time, dough development, the dough stability and dough weakness were increased. Also, results of extensograph showed that adding barley at 10% led to a decline in rubber dough, flatten the resistance, the relative number and energy resulting dough. Moreover, addition of oats at 5% declined the rubber dough; figure the relative energy and the resulting dough while increasing resistance to flatten. Also in the case of mixing barley and oats together at ratio of 15% led to a decline in rubber dough. From the results, it can concluded that addition of barley at rate of 10% and oats at rate of 5% in the case of mixing barley and oats were the best ratio of 15% and replacement of water dough by sweet whey improved the rheological properties of dough.

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