Effect of emulsifiers, fat level and type on the rheological characteristics of biscuit dough and quality of biscuits

The effect of level and type of fat as well as emulsifiers on the rheological characteristics of
biscuit dough and quality of biscuits has been studied. Increasing the level of fat from 150 to 250gkgˇ1
softened the dough, as indicated by a reduction in extrusion time from 108 to 18s and an increase in
compliance from 31.9 to 49.9%, while it reduced the development of gluten, as shown by a reduction in
elastic recovery from 0.485 to 0.365mm. Among the different types of fats used, hydrogenated fat
produced the stiffest dough. Addition of any of the emulsifiers glycerol monostearate, lecithin or
sodium stearoyl lactylate lowered the elastic recovery value, indicating their contribution to the
shortening effect on gluten, and also resulted in a reduction in consistency and hardness and made the
dough more cohesive. The maximumchange was observed with sodium stearoyl lactylate. The density,
breaking strength and compression strength of biscuits decreased, indicating an improvement in
crispness, with increasing fat level. The thickness of biscuits was significantly higher when
hydrogenated fat or oil was used in the formulation. Biscuits made with bakery shortening had better
surface characteristics and higher crispness. Glycerol monostearate and lecithin brought about a
greater improvement in the quality of biscuits when compared with sodium stearoyl lactylate. Studies
indicated that emulsifiers in general had a greater benefecial effect, particularly in the case of biscuits
made from medium hard wheat flour.