Dehydrofreezing of Packham´s pears. Mass transfer and quality indexes

M. BIANCHI; P. MILISENDA; A. GUARNASCHELLI; R.H. MASCHERONI

Montreal

Conferencia; 4th Inter-American Drying Conference IADC 2009; 2009

Asociación Internacional de INgenieros Químicos

The quality of Packham´s dehydrofrozen pears was studied by means of colour, exudate and texture measurement in each of the combined processes, i.e. after osmotic dehydration for different periods of time and after freezing in an air-blast tunnel (-35°C). The experimental results were compared with those obtained from the fresh product. The effect of the osmotic solution over the whole process was also evaluated using sucrose at 40 and 60 °Brix, respectively. The evolution of mass transfer was measured according to the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. dehydration for different periods of time and after freezing in an air-blast tunnel (-35°C). The experimental results were compared with those obtained from the fresh product. The effect of the osmotic solution over the whole process was also evaluated using sucrose at 40 and 60 °Brix, respectively. The evolution of mass transfer was measured according to the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. dehydration for different periods of time and after freezing in an air-blast tunnel (-35°C). The experimental results were compared with those obtained from the fresh product. The effect of the osmotic solution over the whole process was also evaluated using sucrose at 40 and 60 °Brix, respectively. The evolution of mass transfer was measured according to the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. dehydration for different periods of time and after freezing in an air-blast tunnel (-35°C). The experimental results were compared with those obtained from the fresh product. The effect of the osmotic solution over the whole process was also evaluated using sucrose at 40 and 60 °Brix, respectively. The evolution of mass transfer was measured according to the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. . after osmotic dehydration for different periods of time and after freezing in an air-blast tunnel (-35°C). The experimental results were compared with those obtained from the fresh product. The effect of the osmotic solution over the whole process was also evaluated using sucrose at 40 and 60 °Brix, respectively. The evolution of mass transfer was measured according to the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit. . The evolution of mass transfer was measured according to the variation of water loss and solids gain in time; and the freezing progress was monitored through thermal histories until they reached -18°C in the centre of the fruit.