HOW FREEZING PRESERVES FOOD

If frozen fruits and vegetables are properly prepared, they will be just as nutritious as their fresh counterparts. Make sure to select only the freshest, best quality produce at the peak of maturity. Fruits should be ripe but firm, avoid over ripe or spoiled produce. Freezing is a quick and easy way to preserve foods. Enzymes are responsible for changes in fruits and vegetables during ripening. These changes are desirable until the food reaches its peak of maturity, then ripening must be stopped to prevent eventual spoilage. Blanching and freezing slows enzyme activity. Blanching for certain fruits, like peaches, helps to remove the skin, while blanching for vegetables sets the colour and texture.

HOW TO MINIMIZE QUALITY LOSS IN FROZEN FOODS

1. Control Enzyme Activity: blanching to control enzyme activity in vegetables.

2. Control Ice Crystal Size: fruits and vegetables contain a high proportion of water, which will form ice crystals when frozen. Sharp edges and corners of the crystals puncture cell walls and consequently softening the texture and causing loss of juice. To minimize this, make sure to drain foods well, freeze foods quickly as possible and keep the freezer at a constant temperature of -18C (0F) or lower.

3. Control Freezer Burn: frozen foods lose moisture to the dry freezer if they are not properly packaged. This drying is called freezer burn. The burnt area should be discarded. To avoid freezer burn, use appropriate packaging. Be sure to remove as much air as possible from the packages before freezing.

SIX STEPS TO SUCCESS IN FREEZING FRUITS & VEGETABLES 

1. Prepare produce quickly and carefully. Wash in cold water using a soft brush to gently scrub produce, including melons. Drain well and blot with clean tea towel or paper towels. Remove all extra moisture to avoid formation of ice crystals on foods surface.

2. To quicken freezing and to freeze pieces individually, use the tray freezing method. To tray freeze place pieces of prepared fruit or vegetable in a single layer on a cookie sheet or shallow pan, place uncovered in freezer for 1 to 2 hours; when frozen, package accordingly. Tray freezing allows fruits and vegetables to maintain their shape and avoid sticking together.

3. Package in clean, food safe plastic packaging, using freezer tape if necessary, to protect food from freezer burn and maintain the best quality.

4. Freeze foods at -18C (0F) or lower as soon as packaged. Freezing storage time for most fruits and vegetables is 1 year. Store foods at -18C (0F) or lower with little temperature fluctuation.

5. Thaw foods carefully.

6. When cooking, be careful not to overcook frozen vegetables.