CHANGES OF NUTRITIONAL AND PHYSICAL QUALITY CHARACTERISTICS DURING STORAGE OF OSMOTIC PRETREATED APPLE BEFORE HOT AIR DRYING AND SENSORY EVALUATION

The aim of this research was to increase the application of different osmotic dehydration solutions to decrease the drying time, and decrease the loss of quality after drying and during storage of apples. Sucrose and trehalose solutions with 20 and 50 Brix concentrations were applied. Drying experiments were performed at 50, 60 and 70C using a hot air dryer. Changes in color, water activity, vitamin C, dry matter, total phenol content and mechanical properties were determined with 3-month intervals. Trehalose pretreatments, especially with 50 Brix concentration, generally decreased the drying time. Trehalose pretreatment with 20 Brix had better effects on quality characteristics. Texture of the samples pretreated using 50 Brix sucrose and trehalose stayed more stable just after drying. Lowest change in puncture force was found in 50 Brix trehalose-treated samples even after 12 months. Samples pretreated using 20 Brix trehalose had the higher preference by the panelists.