Designed, constructed and performance tests of the freeze drying system

In this study, freeze-drying system was designed, constructed and performance tests were carried out. In the constructed system, 5 and 7 mm slice strawberry samples were dried. At the end of the performance tests the moisture content ratio of the strawberries were decreased from 91,2% to 9,1%. The water activity values of 5 mm and 7 mm slice strawberries were decreased from 0,918 to 0,340 in 9,5 hour and 0,915 to 0,390 in 13 hour respectively. To determine the moisture ratio at any drying time during the drying process, experimentally obtained results were compared with Newton, Page, Modified Page I, Modified Page II, Henderson and Pabis, Logaritmic, Two term, Two-term exponential, Wang and Singh, and Diffusion approach model results. By using the root means square error (RMSE), reduced chi-square (?2) and coefficient of determination (R2), the error of fhe results of the models were analyzed. According to the comparison it is determined that the page model results are in good agreement with the experimental results. The statistical eror values R2, ?2 and RMSE for the tested samples are found 0,998458066, 2,6882x10-4, 0,015491 and 0,99769943, 4,66903x10-6, 0,002076, respectively.