Design of solar vacuum tube dryer and determination of drying performance of black mull berry (Morus nigra L.) in different conditions

It is known that there are approximately 68 types of mulberry fruit, which has a wide ecological production area. Especially mulberry fruit consumed as jam is a highly preferred product by making fruit juice. In this study, black mulberry fruit was dried semi and fully ripe. Initial moisture content of the fruits was determined as 86.74% in the semi-mature and 82.95% in the complete case. In the drying process, the first moisture values of the fruits are reduced to 10-13% moisture range in the oven, vacuum oven, precision dryer, solar dryer; It was dried at 50, 60 and 70 ºC and in the open sun. Drying time, thin layer drying patterns, effective diffusion, activation energy, specific energy consumption, color and phytochemical properties of black mulberry fruits were examined, and the maturity level and the effect of drying methods were investigated. In terms of drying time, while fully ripe fruits dried in a shorter time, effective diffusion, activation energy and specific energy consumption values were found to be higher than semi-ripe fruit. When all the color properties are evaluated together, it has been determined that the most suitable drying method for semi-ripe fruits is 60 ºC in a solar dryer, and 60 ºC in a vacuum oven and a solar dryer for fully ripe fruits. In terms of phytochemical properties, it has been determined that a temperature of 70 ºC in a sensitive oven dryer is more suitable for semi-ripe fruits. For fully ripe fruits, it was determined that the most suitable drying method is 70 ºC sıcaklık sensitive, all temperatures of vacuum oven and 50 ºC temperature in solar dryer.