Effect of Milling and Particle Size on Development of Bread from Cassava (Manihot esculenta) Flour Combined with Wheat Flour

Abstract

Bread is made mainly using wheat, substituting cassava for wheat is challenging due to lack of a gluten network. Further the reduction of particle size affects the physicochemical properties of flour, providing specific product features. Currently bread is made incorporating only up to 30% of cassava. Hence, this study aimed to increase the cassava substitution level by decreasing particle size. To reduce the particle size, cassava was milled two (F2) and three times (F3) and their granular morphology, particle size distribution, color, and functional properties, were determined. 30% of cassava substituted bread was made using F2 and F3 and their characteristics were compared. Using the best flour, treatment composites made as 30%, 40% and 50% of cassava substitution levels, while 100% wheat bread was the control. Granular of F2 and F3 were not damaged. Mean particle size of F2 and F3 was 150-180 µm. Particle size of F3 greater than 180 µm was only 12.3%. In F2 it was 27.8%. There were no significant differences (p > 0.05) in color, dispersibility, water and oil absorption capacities of both flours. Swelling power, solubility index, bulk, and tapped densities were higher in F3 (5.83±0.20ab, 25.19±3.07a%, 0.4±0.00ab g/cm, 0.63±0.00ab g/cm) than F2 (5.46±0.30b, 13.81±2.77b%, 0.38±0.02b g/cm, 0.60±0.20b g/cm). Specific volume was higher in bread made with F3 (2.41±0.07a ml/g) than F2 (2.22±0.06b ml/g). Crust color (L*) was increased with F3 and specific volume was decreased. Hardness of dough was increased with F3 and no significant difference in bread. Moisture, protein, fat, fiber, ash and carbohydrate content of best product were 35.46±0.15a%, 7.00±0.00b%, 3.86±0.26a%, 0.78±0.03a%, 3.08±0.16a% and 53.10±0.38a% respectively. F3 was selected as the best flour for bread making, and 40% of cassava substituted bread was selected as the best product from seven-point hedonic tests. Particle size reduction helped to increase the binding ability of cassava and increased substitution level up to 40%.