The best conditions for osmotic dehydration of oranges was studied, assessed by determining the physico-chemical characteristics of the fruit. The study was conducted in 2³ full factorial experimental design to evaluate the influence of time, solution concentration and fruit:solution ratio on the solid gain, water loss and mass reduction of osmotically dehydrated oranges. After dehydration, the fruits were dried in tray dryer until 20% moisture. In the product the pH, titratable acidity, vitamin C, carotenoids, phenols content and color were determined. The best results of osmotic dehydration were obtained using a sucrose solution 60 ºBrix, fruit:solution ratio 1:3 for 90 min, that resulted in 3.5 g solid 100g-1, 10.6 g water 100g-1 and 7.1 g 100g-1 of solid gain, water loss and weight reduction, respectively. The losses of phenolic content and antioxidant activity were 45.1 and 37.3% lower than in conventional drying, demonstrating the efficiency of the process for the preservation of functional properties of the product.
Citrus sinensis; drying; vitamin C; phenolic compounds; experimental design
