Paper Title
Kinetic Modelling Studies On The Microwave-Dried Blackthorn Fruitepicarp

Abstract
Drying is one of the most important processes in preserving food[1]. During the process of drying, the food undergoes multiple biochemical, enzymatic, chemical and physical changes. Some examples to these processes are cell destruction, enzymatic activity, loss of vitamins, decreasing in nutritional value, loss of aroma, changes in color, shrinking and alteration in texture, dehydration, and changes in solubility[2]. The drying technology can vary from drying using solar energy to many other methods like kiln drying, tray drying, tunnel drying, spray drying, drum drying, freeze dehydration, osmotic dehydration, extrusion, fluidization, microwave treatment, radio-frequency, refracting window and hurdle technology[3].In the case of microwave drying, the heat is directly produced inside the material, which leads to a faster heat increase and higher heat transfer compared to the other drying methods mentioned [4]. Anthocyanin is a red-blue-purple shaded natural pigment that is found in large amounts in the epicarp of Blackthorn fruit (PrunusSpinosa L.).Anthocyanin which belong to the phenolic compounds group known to has positive effects on health issue, such as some types of cancer and cardiovascular diseases [5]. Therefore, in the present study, the drying of Blackthorn fruit (PrunusSpinosa L.) epicarp samples due to its high content of anthocyanin was carried out by using the microwave technique. The samples were obtained from the Trakya region of Turkey. The household type microwave (Arçelik MD-594) was used during the drying experiments. The effects of the microwave output power (180, 360, 540, 720 and 900W at constant sample amount of 20 g) and the sample amount (20, 40, 60, 80 and 100 g at constant microwave output power of 360 W) were investigated on the drying time, moisture content, moisture ratio and drying rate of the samples dried. For determination of the initial moisture content, three 20 g of samples were dried in an oven at 70°C for 24 h. The initial moisture content of the samples was calculated as 1.43g water/g dry base. According to the findings obtained, the increase of the microwave output power and/or the decrease of the sample amount provided the reduction on the drying time. Moreover, the mathematical modeling studies were performed on the kinetics of the drying of the blackthorn fruit epicarp. The experimental data obtained was found compatible with the Page Model equation, which having the values of a higher coefficient of correlation (R2) and a lower standard deviation (δ). Similarly, the relationship between the microwave output power/sample amount ratio and the drying time was investigated, and it was found that the data is compatible with the Power Model equation. Keywords - Blackthorn Fruit Epicarp, Drying, Microwave, Kinetics, Modeling Study