Monitoring of pumpkin osmotic processing in different condition

Osmotic dehydration (OD) is the process by which there is partial removal of water from the cellular materials when these are placed in a hypertonic concentrated solution of soluble solute. Osmotic dehydration process of pumpkin was carried out at different temperature ranges 5, 25 and 50℃ with different concentrations of sodium chloride (5, 10 and 15% w/w) and constant concentration of sucrose (50% w/w). Ratio of sample to osmotic solution was chosen 1:20. Water loss and solid gain values were calculated for each temperature and concentration in different time interval. Equilibrium water loss and solid gain as well as mass transfer rate were calculated using proposed model of Azuara. The results indicated that water loss and solid gain were directly related to concentration and temperature of osmotic solution, which maximum water loss and solid gain were shown at 5℃ and 15% sodium chloride, whereas 50℃ and 15% sodium chloride didnt have a significant effect on water loss and solid gain.