Optimization of osmotic dehydration of orange pieces (valencia late) in sugar solution using response surface methodology

Résumé

Response surface methodology was used to determine the optimum processing conditions that yield maximum water loss and weight reduction and minimum solid gain during osmotic dehydration orange pieces (valencia late) in sugar solution using response surface. The experiments were conducted according to a Central Composite Design ‘CCD’. The independent process variables for osmotic dehydration process were temperature (40, 50, 60 °C), processing time (60, 120 et 240 min) and sugar concentrations (45, 55, 65 % w/w). The optimal conditions for maximum water loss, weight reduction and solid gain (candying) correspond to temperature of 50 °C, processing time of 240 min, sugar concentration of 65 % in order to obtain water loss 60.83 % (g/100 g fresh sample), solid gain of 46,48 % (g/100 g fresh sample) and weight reduction of 57.42 (g/100 g fresh sample). However the optimal conditions for maximum water loss and weight reduction and minimum solid gain (respectively 53.28 %, 57.88 % and 27.18 %) correspond to temperature of 40 oC, processing time of 240 min, sugar concentration of 65 %.