Impregnation and osmotic dehydration of some fruits:: effect of the vacuum pressure and syrup concentration

Apple, mango and melon were subjected to impregnation and osmotic dehydration at vacuum pressure (VI-VOD). The effect of the vacuum pressure (135-674 mbar) and concentration of the sucrose solutions (41-60degreesBrix) on the mass transfer parameters were evaluated. The lowest final a, levels in apple and mango were achieved with 50degreesBrix syrup and vacuum pressure of 674 mbar and in melon with 57degreesBrix and 593 mbar. Water loss of similar magnitude was observed in melon and mango, and there was water gain in the case of apple. The solids gain (SG) in apple was higher than in melon and mango. Minimal values of SG were detected in mango, and a maximum SG value was observed in apple. Melon and mango presented weight losses of up to 8.9% while the weight of apple increased. Results indicated that the impregnation phenomena predominated in the combined VI-VOD process of apple and osmotic dehydration phenomena in melon and mango. (C) 2003 Elsevier Science Ltd. All rights reserved.