Abstract

This study evaluated the rheological characteristics and baking qualities of flours from five different Nigerian grown wheat grains namely Atilla (ATL), Cettia (CET), Reyna 28 (REY), Seri MSH (SER) and Norman (NOR) along with a market brand of imported wheat flour which served as the control (CON). Rheological characteristics of the improved flour samples were studied using the Mixolab and a standard Chopin + protocol. The maximum torque during mixing (C1), the protein weakening due to mechanical work and temperature (C2), starch gelatinization (C3), stability of the starch gel formed (C4), starch retrogradation during the cooling stage (C5) were all determined. Results showed that water absorption of the improved flour samples ranged from 57.4 to 67.4% with the least value in CET and the highest in NOR. The lower water absorption of CET dough seemed to affect its stability and development. Dough development time (DDT) ranged from 0.63 to 2.17 min, with REY recording the highest value and CET the least. The physical characteristics of the bread in terms of loaf weight, volume and specific volume were also determined using standard analytical procedures.The specific volume, which is an important index of loaf quality ranged from 3.41 cm³/g in CON to 3.85 cm³/g in REY. The study revealed that though there were variations in the rheological characteristics of the Nigerian grown wheat varieties compared with the imported control, nonetheless, bread loaves of good and acceptable quality can be produced from the Nigerian local wheat flours.

Key words: Rheological characteristics, baking quality, Nigerian grown wheat, Mixolab, physical characteristics.