Fortification of wheat bread with 3-7% defatted soy flour improves formulation, organoleptic characteristics, and rat growth rate.

Abstract

BACKGROUND: The present study designed to test effects of defatted soy-fortified wheat bread on the organoleptic properties as well as influences on rat growth rate. METHODS: Defatted soy flour (DSF) was blended with wheat flour with extraction rate of 82-84% at 3, 7, and 7% levels plus 3% sugar. Bread produced with these blends compared with regular Taftoon bread and was tested for chemical and organoleptic characteristics. The organoleptic characteristics of blends consist of taste and flavor, crust texture, fragrance and aroma, appearance, bendability, and overall acceptability were determined through taste panel by 213 judges. Forty Sprague Dawley rats were randomly given codes and allocated to different groups via tables with random numbers to feed on three DSF-fortified bread blends and control bread for 30 days. RESULTS: The blending of wheat flour with DSF altered the organoleptic properties of breads. Addition of DSF increased significantly the protein and ash content of the bread (P < 0.05). Organoleptic test indicates that the best formulation is between 3 and 7% fortifications of DSF blends. In biological evaluation, rats fed the control diet had the lowest body weight gain and their food efficiency ratio was significantly different (P < 0.05) in compare with 7% DSF-fortified blend. CONCLUSIONS: It was concluded that overall acceptability score significantly decreased with increasing DSF substitution level. Rats fed 7% DSF-fortified blend showed privileged food efficiency ratio. Then, the best formulation is between 3 and 7% DSF bread. This formulation can nourish all human at risk of malnutrition.