Department of Food Engineering and Technology, Sant Longowal Institute of Engineering and Technology (SLIET), Longowal-148106, Sangrur, Punjab, India
*Corresponding author: charanjiv_cjs@yahoo.co.in
Online published on 6 August, 2015.
The effect of process conditions on the mass transfer during osmotic dehydration of coated pineapples was studied. Pineapple samples were coated with 0.5 to 5.0% (w/v) pectin solution prior to osmotic dehydration in sucrose solution. The time of dipping in the coating solution was kept at 60 and 120 s followed by oven drying time of 10 and 40 min to solidify the coating. Water loss, solid gain, performance ratio and weight reduction were measured during osmotic dehydration of both coated and uncoated samples. Water loss of coated samples was more than the uncoated samples in coating solution of 0.5 to 3% concentration whereas solid gain of coated samples was less than the uncoated samples at all the concentrations of coating solution. Increase in drying time led to decrease in both water loss and solid gain. PR values increased as the concentration of coating agent increased from 0.5 to 1% and further increase in the concentration above 1% resulted in decreased PR. The highest value of performance ratio of 5.89 was observed in samples dipped in coating solution of 1% concentration for 120 s followed by oven drying for 40 min.
Cut pineapple samples were coated with pectin at different concentrations and then osmotic dehydration was carried out.
Coating proved to be an effective method to check transfer of solid gain without affecting water removal during osmotic dehydration.
Highest performance ratio was observed at 1% concentration of pectin as compared to other concentrations.
Osmotic dehydration, coatings, pineapple, mass transfer, pectin, performance ratio
