Determining suitable drying conditions for celery leaves in terms of drying kinetic and color values

The leaves of celery, one of the medicinal and aromatic plants, were dried in two different dryers and under three different drying conditions. These; drying in an oven and drying in a vacuum oven. Drying was done at three different temperatures (40ºC, 50ºC, 60ºC), without pre-treatment and by pre-treatment in the microwave at 720 W power for 1 minute. Within the scope of the study, drying kinetics, drying performance and color analysis of dried products were examined. Midilli-Küçük, Jena-Das and Exponential Decay models were tested, and among all the models, Midilli-Küçük was the model that best explained the drying kinetics. The drying process in the oven and vacuum oven was completed in 14.5, 8.5, 5.5 and 15.5, 10.5, 5.5 hours, respectively. The drying process in the pre-treated oven and vacuum oven was completed in 9.5, 6.5, 3.5 and 10.5, 8.5, 4.5 hours, respectively. It has been observed that increasing the temperature and applying pre-treatment shortens the drying time. The least energy consumption was achieved in oven drying at 60 oC with pre-treatment. The highest energy consumption occurred in vacuum oven drying at 40 oC without pretreatment. The method that best preserved the brightness (L*) value of fresh celery leaves was found to be vacuum oven pre-treated at 60 oC. (a*) The method that best preserved the greenness value was found to be at 50 oC without oven pre-treatment. (b*) The method that best preserved the yellowness value was found at 40 oC with oven pre-treatment. (C*) The method that best preserved the chroma value was found at 40 oC with oven pre-treatment. The method that best preserved the hue angle (h°) was found to be vacuum oven pre-treated at 60 oC. The method that best preserved the Brown Value (BI) was found to be vacuum oven pre-treated at 40 oC. (ΔE) is the total color change value and the least color change occurred at 40 oC with pre-treatment in vacuum oven drying. When all color analysis values were examined in detail, the pre-treatment drying method in the oven was determined as the most suitable method.