Effect of Pretreatment on Drying Properties of Golden delicious L. Apple

Apple (Malus domestica) is a cultured species from the rosaceae (Rosaceae) family, and its consumption as fresh as well as dried fruit and chips has become more popular in recent years. However, it is important to determine the appropriate drying conditions in the drying processes, taking into account the energy and quality characteristics. In this study, it was aimed to reduce the energy consumption of the drying process and to preserve the physico-chemical properties of the samples by applying some drying pretreatments (citric acid, potassium carbonate, vacuum impregnation) to apple slices of Golden delicious L. Apple slices were dried at a constant temperature of 70 oC from 3.98 +/- 0.06 to 0.06 +/- 0.019 g moisture g dry matter-1. In the study, the shortest drying time was 5.5. The longest drying time was determined as 9.5 hours. The best predictive mathematical model was determined as Wang Sing. It has been determined that the effective diffusion values of the drying processes vary between 1.03x10 -5- 6.67x10-6 m2 s-1. It was found that the effective diffusion value of the dried samples after dipping in citric acid solution was the highest. It was determined that the fresh color values were preserved best (P<0.05) for the dried samples after dipping in citric acid solution. The lowest total energy, specific energy consumption (SEC) and latent heat of evaporation values were determined in the drying process of the samples dipped in citric acid solution. These values were found as 0.766 kWh, 247.41 kWh kg-1, 2.02 kWh, respectively. The highest specific moisture absorption rate (SMER) was determined as 0.00404 kg kWh-1 in the drying of the samples dipped in citric acid solution. In line with the findings obtained Golden delicious L. variety is recommended to be dried after dipping in citric acid solution because the optimum energy parameters and physico-chemical properties of dried apple slices are determined. Since it has been determined that some color values are statistically more suitable for fresh in dried samples after vacuum impregnation pretreatment is applied, it is recommended to apply citric acid+vacuum impregnation pretreatment in the next study.