Water Loss and Sugar Migration during the Osmotic Dehydration of Pineapple.

L. RAMALLO,; C. SCHVEZOV; R. MASCHERONI

Santa Fé - Argentina

Congreso; Jornadas Empromer 2001; 2001

Universidad Nacional del Litoral - CERIDE

Water loss, Sucrose gain and the variation in concentration of natural fruit sugars (glucose and fructose) were studied during osmotic dehydration of pineapple slices in sucrose solution (60% by weight) at three temperatures (30, 40 and 50ºC). As temperature increased from 30 to 50ºC, the apparent moisture and sucrose diffusivities(Dw and Ds) increased 3.8 and 2.8 times, respectively; therefore the dehydration efficiency  index (Dw/Ds) increased with temperature . The loss of glucose and fructose increased with temperature, too. Concentration profiles measured in the slices after 150 minutes of processing showed that the changes in concentration of water and sucrose take place in the first 2 mm of depth; concentrations remaining unchanged at inner positions.