OSMO-CONVECTIVE DEHYDRATION OF SWEET POTATO (IPOMOEA BATATAS L.)

DOI: 10.5958/0976-0563.2014.00602.2    | Article Id: DR-865 | Page : 197-203
Citation :- OSMO-CONVECTIVE DEHYDRATION OF SWEET POTATO (IPOMOEA BATATAS L.).Asian Journal Of Dairy and Food Research.2014.(33):197-203
A.K. Singh, G.K. Sidhu* and B. Singh gagandeep@pau.edu
Address : Department of Processing and Food Engineering Punjab Agricultural University Ludhiana-141 004, India

Abstract

The effect of sugar concentration and different drying temperatures on the quality of osmotically dehydrated sweet potato was determined.  Sweet potato cubes were osmotically dehydrated in sugar syrup concentrations of 50, 60 and 70oBrix for 48 hours and thereafter samples were dried using tray drier at temperatures of 55, 65 and 75 oC. The quality of the samples was determined in terms of bulk density, water activity, sugar gain, hardness, shrinkage ratio and color. The drying rate decreased with increase in drying time and became uniform for 55, 65 and 75oC drying temperature irrespective of concentration of sugar solutions, whereas at initial stage higher decrease in drying rate was found in 75oC at 50 o Brix.  Bulk density was maximum for sugar solution concentration of 60oBrix at 65oC (46.52 kg/m3). The maximum water activity was found for sample having sugar concentration of 50 o Brix and drying temperature of 55oC and the minimum value of water activity was attained for sliced sample at a drying temperature of 75oC and sugar concentrations of 60oBrix. It was observed that the sugar gain was highest in samples dipped in sugar solutions of concentration 70 oBrix and lowest in the samples of sugar solution concentration of 50oBrix.

Keywords

Drying temperature Osmotic dehydration Sugar Sweet potato.

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