14A-1

E. S. LAZOS, Departement of Food Technology, Technological Education Institution of Athens, Agiou Spiridonos str., Egaleo, Athens, 122 10, Greece and A. LABROPOULOS, Departement of Food Technology, Technologiacal Educational Institution of Athens, Ag Spyridon St., Athens, 122 10, Greece.

Batter-type doughs are viscoelastic with explicit, nonlinear shear thinning behavior. The commonly used empirical and descriptive rheological methods determined the consistency and extensibility of doughs by applying large deformation forces in a single-point measurement. They were therefore not suitable to describe dough flow properties. Flow properties were determined by basic rheological methods using a rotational viscometer. Flow behavior and consistency indices can be described by the power law model.

Both the flow and consistency indices were affected by the flour:water ratio of doughs and the addition of egg and milk in the pancakes. The range of consistency index vaues for the three types of flour for the various flour:water ratios at 10° C was from 47,798 to 1,577 mPas. At 20° C, 37,573 to 1,438; at 30° C, 24,120 to 1,341; at 40° C, 20,596 to 1,161; at 50 °C, 15,156 to 769.2; and at 55° C, 68,446 to 5,031 mPas. The viscosity was increased by the addition of egg, while it was decreased when milk was incorporated in the recipe.

The effect of temperature was the same for all the mixtures. Any increase from 10 °C to 50 °C resulted in a decrease in viscosity while at 55 °C to 60 °C the viscosity was inceased.

The pancake mixture showed a shear-thickening dilatant behavior with an average flow index of 1.623 compared with that of a commercial recipe of 0.779.