Effect of temperature of the baking chamber media and process duration on rusk crust color

Introduction.The aim of research is to determine the effect of temperature of the baking chamber and duration of the baking process on the color of rusk loaf crust.Materials and methods.Rusk loafs were produced from wheat pastry dough, baked in an oven with radiation-convection heating in the temperature range of 120-200 C.The baking and drying processes of rusk loafs were combined in one baking chamber.The color of the crust was determined on a universal photometer.The temperature along the thickness of the rusk was determined using a set of thermocouples.Results and discussion.With an increase in the duration of the baking process from 20 to 140 min and an increase in the temperature of the baking chamber from 120 to 190 C, the reflective capacity of rusks crust surface decreases from 43-53 to 12-30% according to a logarithmic dependence.The permissible value of reflective capacity is 20-30%.With a decrease in this value, the crust surface will be excessively dark.The maximum duration of heat treatment, during which the required surface quality is ensured, decreases according to an exponential dependence from 8 h at a temperature of 120 C to 33 minutes at 200 C.It is proposed to determine the defining size of a rusk loaf as the ratio of the loaf volume to its surface area, taking into account the coefficient of the ratio of product sizes.It allows to take into account the shape and dimensions of the product to determine rational modes of combined baking and drying processes.When the air temperature increases from 120 to 190 C and the value of the defining size decreases from 0.02 to 0.01 m, the duration of the drying process is reduced from 180 to 33 minutes.With an increase in the defining size of the product from 0.005 to 0.03, the rational operating temperature of the baking chamber decreases from 240 to 140 .Exceeding the temperature leads to low crust quality.Conclusions.The use of the obtained results will ensure high intensity of drying and proper reflectivity of the crust surface of the rusk loaf.The rational temperature of the baking chamber is 160-200 C.