No abstract

The main objective of this study is validation of a proposed mathematical model for the estimation of the influence of kneading arms geometries on rheological properties of dough. Two types of kneading arms are studied, both mounted on the same industrial kneader type. A tridimensional numerical simulation for dough kneading is used for obtaining the Eddy viscosity values, which were introduced in a mathematical model for calculation of the dough�s resistant torque at the kneading arms, at 15 seconds time intervals. Real time torque diagrams developed by the kneading arms, were traced using a system for data acquisition and dough kneading control (SOPF), developed by BioTechnologiCreativ Company. These diagrams were used for mathematical model validation using the comparison between the torque values measured in real time and the ones obtained using the mathematical model, in which was introduced the Eddy viscosity value obtained with the 3D simulation. The obtained results have very similar values. With this study it is possible to predict the rheological behavior of dough during kneading process. Anticipation of the kneading diagram form can be helpful in the optimization of the entire technological process and the obtaining of dough with uniform consistency and optimal development during the stages of the manufacturing process.

This study presents the analysis of multiple bread dough proving processes with the purpose of establishing a correlation between the concentration of released carbon dioxide during fermentation and the working parameters (time and temperature). The testing was performed using a standard recipe for white bread dough, a small capacity prover with air conditioning unit for temperature and relative humidity regulation, CO2 and temperature sensors with data acquisition plate. In the first part are presented the results for 11 measurements of CO2 concentration for one dough piece fermentation process at varying proving temperatures. In the second part of the paper are presented the results of 4 measurements of CO2 for 9 dough pieces proving at temperatures between 30 and 39 °C, at 3°C intervals. The obtained measurements of CO2 were correlated with the volume and dimensions of the finished products. The obtained results are considered relevant for this study and for the possibility of fermentation level evaluation using the quantity of CO2 released during proving. The presented study is part of an extensive research performed for the identification of a method for automated control of working regime in industrial bread dough provers using the measurements of released CO2.

The final proofing of wheat dough takes place in enclosed spaces called provers, in which temperature and relative humidity are controlled. The purpose of this paper is to analyse the possibility of reducing the power consumption necessary for prover air conditioning by replacing the thermal agent (heated with methane gas) with recovered energy from the burnt gases released on the evacuation tunnel during baking. In the first part of the paper the necessary power was calculated for: heating the air in the prover and the interior structure up to 33 ºC; the losses through the prover walls and the necessary power for raising the dough's temperature to 6 ºC. The second part of the paper contains real time measurements for power consumption in three stages: at the starting point; after reaching the set parameters; with load. In the last part of the paper a comparative analysis of power consumption before and after mounting an energy recovery system on the evacuation tunnel for burnt gases of a bread oven is presented. The obtained results showed less than 5 % differences between the calculated and measured values. To ensure the set parameters for a 216 m 3 prover, with an hourly capacity of 4000 dough pcs*0.36 kg, the prover consumes: 27 kW in the first hour of functioning (without load), 14 kW after reaching the set parameters and 20 kW when working fully loaded. The results obtained after using the energy recovery system showed 55 % reduction of power consumption using conventional fuel.