Studies on Osmatic Dehydration Characteristics of Potato under Tray Dryer

Singh Anuj Pratap; Singh Sweta; Singh Papu; Singh B.R

Volume : III, Issue : X, October - 2014

Studies on Osmatic Dehydration Characteristics of Potato under Tray Dryer

Singh Anuj Pratap, Singh Sweta, Singh Papu, Singh B. R,

Abstract :

To investigate mass transfer kinetics, osmosis was carried out in binary sugar and salt solution of varying concentrations using a solution to sample ratio of 1:5. Osmosis was conducted at 30�C temperature. At each experimental condition osmotic dehydration was carried out for different time periods. At each designated osmotic time level, the samples were analyzed for moisture content and moisture loss, and the solid gain was calculated based on mass balance. To develop osmo–hot air drying process, potatoes were first osmosed in selected osmotic solutions for selected osmotic time based on the kinetics results. The binary solutions were: 20% sugar – 10% salt, 20% sugar– 15% salt, 30% sugar – 5% salt and 30% sugar – 10% salt. Osmotic time was taken to be 1 h. During this period, most of the osmotic water loss potential was achieved and the solid gain remained low so as not to presumably affect the organoleptic characteristics adversely. Osmosed potatoes were then dried in tray dryer at 60, 70, 800C till moisture content reached ≤6 % d. b. Non osmosed potato dices were also dried by conventional hot air drying method–blanching and drying at 60oC for comparison. The organoleptic quality of the dried potatoes was determined and statistically analyzed. The moisture loss from and the solid gain by potato increased nonlinearly with duration of osmosis at all solution concentrations and both were higher in the initial period of osmosis than the later period. Further, both moisture loss from and the solid gain by potato dices increased with the increasing salt as well as with the increasing sugar in the osmosis solution.