Slow freezing of fruit and vegetables causes formation of large water crystals. These crystals damage the cell wall resulting to water released when thawed. A slow frozen dragon fruit turns to liquid when thawed. Slow frozen meat might developed freezer burn. A brown discoloration on meat surface due to migration of water to meat surface. Freeze damaged is not a health hazard, it only degrades appearance and might affect flavors.
Quick freezing does not allow formation of large water crystals. It keep the food free from damaged. It is the standard freezing procedure of food industry. Quick freezing can be done through blast freezing, submersion in liquid nitrogen and use of dry ice (solid carbon dioxide) with ethanol.
Frozen commodities is good as long as it is frozen but we still want it of good quality when unfrozen. Equipment and materials for quick freezing are expensive and not readily accessible but good freezing results can be accomplished at home using home freezers. This method is not applicable to large fruits and vegetables. Quick heat transfer to this commodities is not possible unless you can cut it to small pieces prior to storage.
1. Set the freezer thermostat knob to highest possible setting. Wait until the coldest temperature is reached before freezing your food. Use a freezer thermometer in monitoring.
2. Cut meat to small pieces. Small portions freezes rapidly. The cut depends on how you want to use it later. Do the same for large fruits and vegetables.
3. Arrange them loosely in trays. Air spaces in between will allow faster heat transfer thus freezing your commodity quickly. Freezing time is dependent on size of goods and freezing capacity.
4. Wrap in plastic or aluminum foil when frozen and arrange closely. Loose arrangement is not needed when the food is already frozen. Then adjust the thermostat setting just enough to maintain the frozen state of food.
You may not succeed in quick freezing your foods due to the following reasons:
1. The freezer has low freezing capacity.
2.The commodity size is not small enough.
3. Improper way of arrangement during freezing.