Determination of the effects on product quality of microwave technology in plum drying

Within the scope of the thesis, the quality characteristics of Mürdüm plum cultivar were investigated. Before the drying process, the plums were heated to 55°C for 1 min. 1% NaOH dip treatment was applied. Samples were divided into two groups; The seeds are extracted whole and the seeds are removed without removing them and they are subjected to the experiments half-way. In the study, the plums were dried with the sun and microwave at three different power levels (450, 720 and 900 W). Drying process was continued until the moisture content of the product was reduced to 18%. In the whole and half dried plums, the total dry matter, drying time, color, water activity, rehydration ratio, bulk density, particle density, shrinkage, texture, total phenolic matter, total flavonoid matter, total monomeric anthocyanin content, Within the scope of the thesis, the quality characteristics of Mürdüm plum cultivar were investigated. Before the drying process, the plums were heated to 55°C for 1 min. 1% NaOH dip treatment was applied. Samples were divided into two groups; The seeds are extracted whole and the seeds are removed without removing them and they are subjected to the experiments half-way. In the study, the plums were dried with the sun and microwave at three different power levels (450, 720 and 900 W). Drying process was continued until the moisture content of the product was reduced to 18%. In the whole and half dried plums, the total dry matter, drying time, color, water activity, rehydration ratio, bulk density, particle density, shrinkage, texture, total phenolic matter, total flavonoid matter, total monomeric anthocyanin content, antioxidant capacity and HMF content were analyzed. According to the results of the research, it was determined that all the dried plums were dried for 17 days and 16 hours and the half-dried plums for 4 days and 14 hours in terms of drying time. Drying times of all plums dried by application of 450, 720 and 900 W microwave power levels were 48 min. 20 s, 29 min. 40 s, 28 min. 46 s and the drying times of the semi-plums dried at the same power level were 43 min. 40 s, 27 min. 7 s and 26 min. 27 s, respectively. During the drying process, the drying time of the samples decreased with increasing microwave power level. As the power level increased, the rehydration rates of plum samples were increased. When the quality characteristics of the Mürdüm plums were examined, it was seen that the total amount of phenolic and total flavonoid matter, total monomeric anthocyanin content, total antioxidant capacity of the microwave dried plum samples were higher than the sun dried plum samples. It is considered that drying with P80 power microwave application has very good chemical characteristics for the dried plums at three different power levels, and also for the drying time were a little difference between the P100 power and P80 power.