Anotace:
The present work investigated the mass transfer process during osmotic dehydration of carambola fruit slice using binary solution of salt and sugar. The dehydration performance was improved by optimizing the time and temperature of dehydration, salt concentration and fruit to syrup ratio. Response Surface Methodology (RSM) was used to infer about the effects of these parameters on the rate of mass transfer such as water loss, solute gain, weight reduction and water activity of dehydrated carambola slice. A four factorial central composite rotatable design (CCD)adopting multiple regression technique was used to develop polynomial models of response variables and the adequacy of fit was ascertained by observing the correlation coefficients (R2 values). All the independent variables significantly affected the response parameters within the selected range. Adopting desirability function, the optimized values of process variables were, salt concentration 15g/100ml, temperature 45.08oC, time 240 min and fruit to syrup ratio 1:10. The validation of the optimised parameters confirms invariability between the predicted and experimental results.