EFFECT OF PRINCIPAL INGREDIENTS ON RHEOLOGICAL BEHAVIOR OF BISCUIT DOUGH AND ON QUALITY OF BISCUITS

A specific study of the effect of three ingredients in biscuit dough ( sugar; fat and water) and of the protein content of the flour has allo wed the determination of their respective effects on mixing, on the rh eological behaviour on biscuit size after cooking and on their mechani cal properties. Addition of sugar to the formula decreases dough visco sity and relaxation time. It promotes biscuits length, and reduces the ir thickness and weight. Biscuits which are rich in sugar ave characte rized by a highly cohesive structure and a crisp texture. Addition of fat softens the dough and decreases the viscosity and relaxation rime. Fat likewise contributes to an increase in length and to a reduction in thickness and weight of biscuits, which are then characterized by a friable structure, easy to break. Increase in water leads to an signi ficant decrease in the dough viscosity and a slight reduction of the r elaxation time. The biscuits expand lengthwise, with a smaller thickne ss. Finally, varying the protein content of the flour from 14 to 20% i nduces major changes at the mixing stage in the rheological properties of the dough and in the dimensions and texture of the biscuits. (C) 1 998 Elsevier Science Limited All rights reserved.