Effect of temperature and concentration of osmotic solution on moisture loss and solid gain during osmotic dehydration of carrot

Abstract

The effect of temperature and osmotic solution concentration on solid gain and moisture loss drying characteristics of carrot were studied. The moisture loss and solid gain increased with increase in salt and sugar concentration and temperature. The moisture loss by carrot slices increased non-linearly with increase in duration of osmosis, solution concentrations and temperature. Mass transfer was faster in initial period of osmosis than the later period. Maximum moisture loss was obtained at 60 oC for osmotically dehydrated carrot (60% sugar, 3% salt) and it ranged from 13.32% to 56.93%. Solid gain increased with duration of osmosis and did not approach the equilibrium after 3hrs of osmotic dehydration. Solid gain at 60 oC solution temperature for osmotically dehydrated carrot (60% sugar, 3% salt) ranged from 2.34% to 5.86%. 60% sugar and 3% salt concentration with 60 0C solution temperature was found as an optimum process condition for osmosis with 3 h duration.