EFFECT OF OKARA ADDITION ON BREAD QUALITY

Abstract

Okara (the residue of soymilk manufacturing) was used as a protein source in the preparation of pan bread. Okara was dried at low-temperature (40-50°C) in a forced air drying oven, milled to obtain okara flour (OF) and blended with wheat flour 72% extraction at the 10, 20,30 and 40% replacement levels. The influence of this replacement on the rheological properties of dough, chemical, baking, organoleptic properties of bread was investigated. Breads were stored at room temperature for 5days and staling rate was also studied. Results showed that water absorption, dough development time and stability increased, while mixing tolerance index and dough weakening decreased by increasing the level of replacement. Extensibility and dough energy decreased but resistance to extension and the proportional number increased by increasing the level of okara flour. Protein content of bread increased by increasing the level of replacement. Maximum improvement of protein achieved was about 57% by using 40% OF. Loaf weight increased, while loaf volume and specific loaf volume decreased by increasing the level of OF. Clear reduction of bread staling rate caused by okara flour addition. Baking quality and organoleptic evaluation showed that OF can be used to supplement wheat flour in making of pan bread up to 30% replacement level.