Effect of substituting sugar with date palm pulp meal on the physicochemical, organoleptic and storage properties of bread

Abstract

The effect of substituting granulated sugar with date palm fruit pulp meal (DPFPM) in bread production was evaluated. Date palm fruit pulp was oven dried (46°C, 8 h) and milled. Granulated sugar was substituted at 0, 25, 50, 75 and 100% with DPFPM in bread recipe and bread produced using straight dough bulk fermentation method. Proofing ability of the dough, oven spring, bread loaf weight, volume and specific volume were evaluated. Proximate composition, incidence of mold growth on bread loaves and sensory properties of the loaves were also determined. On dry weight basis, crude fat, crude fiber, crude protein and ash contents significantly (p < 0.05) increased from 6.25 to 7.72, 1.52 to 4.45, 16.85 to 21.26, and 2.26 to 3.84%, respectively, whereas carbohydrate decreased from 73.12 to 62.73% with increasing substitution of sugar with DPFPM. The decrease in proofing ability of the dough (2.20 to 2.08) was insignificant (p > 0.05) while the decreases in oven spring (2.30 to 1.87 cm), loaf volume (848.3 to 762.3 cm3) and specific volume (3.15 to 2.64 cm3/g) were significant (p < 0.05). Loaf weight increased (p < 0.05) from 265.5 to 288.8 g. Visually observable colonies of mold on bread loaves during storage initially decreased but later increased with increasing DPFPM. Substituting sugar with DPFPM had no adverse overall effect on the acceptability of bread loaves; it however increased the nutritional value but decreased the physical quality of the bread loaves.   Key words: Bread, granulated sugar, date palm fruit pulp meal, substitution, physicochemical properties.