M.A. Thesis:

Exeter barley flour was the optimization of production and its effect on the quality and physical and chemical properties of bread containing barley

Bread as a cheap source of energy and protein plays a vital role in feeding a large part of the world's people. FAO surveys show that people in the Middle East provide about 70% of their daily energy needs of bread and other wheat products. In this study, the effects of extrusion process on barley and its bread was investigated. Barley grits with 13, 16 and 19% moisture content was extruded at 100°C In 120, 150 and 180 rpm screw speed using Box Behnken design. Moisture content, protein, bulk density, porosity, expansion ratio, hardness, toughness, water solubility index, water absorption index and color of extruded barley was determined. Results showed that best characteristics of product were achieved by extrusion barley with 14.8% moisture content at 170 rpm screw speed. Farinograph analyses showed addition of extruded barley flour increased water absorption of dough but decreased dough stability. Texture analysis showed hardness of bread increased with addition of extruded barley though sensory analysis didn’t show significant difference between texture and color of breads. Panelists reported a sweet and cooked taste in breads containing barley flour. Finally, addition of 25% extruded barley flour could be recommended for achievement of its benefits.

Keywords: Barley flour, Extruded barley flour, Optimization, Response surface, Bread