The Effect of Ascorbic Acid on the Physical and Proximate Properties of Wheat-Acha Composite Bread

Abstract

This work studied the effect of different proportions of ascorbic acid on the physical and proximate properties on wheat-acha composite bread. Bread was produced from wheat (Triticum aestivum) and acha (Digitaria exilis) composite flours. The wheat: acha ratios used were 100:0, 90:10 and 80:20. The proximate, and functional properties of the flours were analysed. The dough improver, ascorbic acid was added at 80, 100 and 120ppm during the bread making process and the proximate, physical and sensory properties of the bread was analysed. Flour sample with 20% acha had the significantly highest values for bulk density (0.744g/cm3), water absorption capacity (1.5g/g), oil absorption capacity (1.564g/g), foam capacity (11.32%) and swelling index (1.24). There was no significant difference in the crude fat and ash content of all bread samples. Significant difference was observed in the volume and specific volume of the bread samples, with 100% wheat flour giving the highest values of 431.33 ml and 3.16 ml/g respectively. However, addition of ascorbic acid significantly improved these parameters with no significant difference between the 100ppm and 120ppm bread samples.  Also the bread samples produced with 100:0 and 90:10 wheat: acha flours showed no significant difference in their sensory properties. The 80:20 composite bread gave significantly lower sensory scores for all the sensory parameters.