Osmotic Concentration of Green Gram Prior to Air Drying

摘要

Green grams were osmotically concentrated in NaCl-water solution at three concentrations (5, 10 and 17% NaCl by weight) and three temperatures (20, 30 and 40℃). It was observed that the rate of water removal and salt gain was maximum at the beginning of the process. The moisture and salt content decreased gradually with length of contact time. The nature of kinetic curves indicated that moisture content of green grams approached equilibrium with bath much faster than the salt content. It also indicated that salt uptake by green grams could be regulated by controlling the length of contact time. Movement of salt and water was modeled for water loss from and salt uptake by the green grams. Green grams were contacted with 10% NaCl-water solution at 30℃ for 30 min and were processed further for air drying in fluidized bed dryer. Evaluation of colour, texture flavour and overall acceptability indicated that the dehydrated product was organoleptically acceptable.