Optimization of the drying conditions of tarhana dough in the cabinet dryer and determination of the drying kinetics

In this thesis study, it is aimed to determine the most suitable drying conditions in terms of preserving the quality properties of tarhana by using a cabin drying method as an alternative to the traditional (sun) drying method. For this purpose, tarhana production was carried out both with the industrial drying system and the traditional method. Tarhana dough was left to ferment at 30 oC. Tarhana dough, prepared in a circle shape and 1 cm thick, was dried at 30, 40 and 50 oC temperatures, 0.5, 1 and 2 m/s air speed, and constant relative humidity (10%). In dried tarhana samples, Moisture and drying kinetics, color, β-carotene and lycopene analyses, change reaction kinetic calculations of these components, aroma profile analysis, microbiological analyzes and optimization studies were carried out to determine the most suitable production conditions. As a result of drying kinetics analyses, Page and Modified It was determined that Page models were the best models explaining the drying kinetics of tarhana samples. R2, χ2 and RMSE values Page and Modified Page models were found to be in the range of 0.9596-0.9981, 0.000042-0.00061 and 0.000764-0.003041, respectively. Diffusion coefficient values of dried tarhana samples determined for 0.5, 1.25 and 2 m/s air speeds; 6.99-14.79x10-8 for 30 oC, 15.7-32.11x10-8 for 40 oC and 26.64-44.98x10-8 m2/s for 50 oC It was detected in the range. β-carotene and lycopene during drying of tarhana samples for each temperature and air speed. It was determined that the decomposition reaction was suitable for the first order kinetic model. In addition, it was determined that the increase in drying temperature for all different air speed conditions in tarhana drying processes caused a decrease in the β-carotene and lycopene contents of tarhana samples. The β-carotene and lycopene exchange reaction rate constants during the drying process of tarhana dough were found to be in the range of 0.0001-0.007 min-1 and 0.0003-0.0014 min-1, respectively. In the drying process of tarhana samples, the optimum condition values calculated with the Central Composite Design Model for the lycopene and β- carotene change rate and drying time are among the condition values with the highest desirability value; The temperature was determined as 40.362 °C and the air speed was determined as 1.62 m/s.