When Freezing Foods. Fresh fruits and vegetables when frozen undergo various chemical changes which can cause spoilage and deterioration of the food products. It appears as grayish-brown leathery spots.
The science of freezing foods Chemical changes during freezing. The optimum temperature range for storing fresh food is between 38 - 40 degrees Fahrenheit. Add only the amount that will freeze within 24 hours.
Freezing raw food draws water out of the cells of plant foods such as fruits vegetables and grains and meat.
Textural changes during freezing. Overloading slows down the freezing rate and foods that freeze too slowly may lose their quality according to the Food Freezing Guide. Foods freeze at temperatures lower than the freezing point of pure water which is 001C although most calculations assume 00C because the water in the foods is not pure water and when removing heat energy from the food the freezing point is depressed lowered due to the increase in solute concentration in the ice-water sections of the material. Some fruits and vegetables are blanched immersed in boiling water for a short period before freezing to inactivate enzymes and yeasts that would continue to cause food spoilage even in the freezer.
