Drying Kinetics, Energy Consumption and Color Quality Evaluation of Black and White Myrtle (Myrtus communis L.) Fruits in Convective Drying

Known as the myrtle plant and locally referred to as “Hambeles” (white) and “Murt” (black), two different genotypes of Myrtus communis L. fruits were dried at different temperatures, and their energy requirements and colour changes were investigated. On a wet-basis the Hambeles and Murt fruits possessed 73% and 61% moisture, respectively. A glass-cabinet hot-air drying system was designed and, after preliminary trials, the drying experiments were conducted. Drying was carried out at three different temperatures (50, 60 and 70 °C) and with an average drying air velocity of 0.30 m s⁻¹; for each temperature three replicates were performed. Some drying parameters and colour changes of the dried Hambeles and Murt fruits are presented graphically, and discussion is given. As a result, the longest drying times for both genotypes were measured at 50 °C, while the shortest were at 70 °C. The specific energy required to dry 1 kg of product was lowest for Hambeles at 7.696 kW h kg^-1 and for Murt at 6.415 kW h kg^-1. The total drying time at 70 °C was the lowest: 11 h for Hambeles and 6.5 h for Murt.