Osmotic Dehydration Kinetics of Elephant Foot Yam Cubes (Amorphophallus Spp.) in Sucrose Solution

Among tubers, Amorphophallus companulatus known as elephant foot yam is a highly potential tropical tuber crop containing a good amount of protein as well as starch, fiber, minerals and vitamins. Fresh yams are perishable in nature and deteriorate in quality on storage. The shelf life of Elephant foot yam can be increased if processed properly. The quality of the dehydrated product can be enhanced if the product is pretreated osmotically in sucrose or salt solution prior to convective dehydration. In the present study cubes of uniform size (1 cm x 1cm x 1cm) were osmotically pretreated in hypertonic sucrose solution having 45, 55 and 65 °Bx concentrations at 40, 50 and 60 °C osmotic solution temperature for different intervals of time. The sample to solution ratio was kept as 1:4. Mass transfer kinetics for water loss and solute gain were studied and the data was fitted to various empirical models (Magee, penetration and Peleg models). Out of the applied models, the Magee’s model was appropriate for predicting water loss and solute gain. The highest values of water loss and solute gain were 58.8 g water/100 g of fresh sample and 25.5 g solute/100 g of fresh sample, respectively for osmotic solution having 65 Bx. concentration and 60 °C osmotic solution temperature after 240 minutes. In first 60 minutes, water loss and solute gain were maximum i.e. 65.96% and 58.57% of total values and become almost constant after 180 minutes of osmotic dehydration. The osmotic solution concentration, temperature and time have most pronounced affect on water loss as compared to solute gain during osmotic dehydration. Both water loss and solid gain increased with increasing the concentration and temperature of osmotic agent solution. Sangeeta & Bahadur Singh Hathan 482