Wet agglomeration of barley flour-wheat semolina blends into couscous: Effects on rheological, culinary and sensory properties

Abstract

Wheat semolina was replaced by different percentages of barley flour (25, 50, 75 and 100%) for the preparation of artisanal couscous. The rheological behavior was evaluated using a Caleva® mixer torque rheometer. The dry couscous produced were characterized by determining the water content, the agglomeration yield, the particle size, and the aerated and tapped densities. The culinary and sensory qualities were also assessed by determination of cooking losses, swelling, indices of mass and volume gain, and cooking time. The incorporation of barley flour caused weak cohesive forces between the agglomerated particles (mean torque of 0.802 N m during barley flour wet agglomeration) and increased the optimal hydration rate. The agglomeration yield of barley flour was very low (74.24%), but its mixture with wheat semolina improved yields. The incorporation of barley flour led to significant increase of swelling, weight and volume gain indexes, but decreased the cooking time and couscous becomes more sensitive to heat treatments. Apart from color and flavor, the stickiness, firmness and overall acceptability of couscous were not affected.