Make sure your freezer maintains a temperature of 0° F or less. If the temperature rises above that level, the frozen products may begin to thaw and lose some of their vitamin content. In addition, some frozen products have been found to lose vitamin content after prolonged storage of a year or more, so you should not store them for more than two or three months before use.
Vegetables should be stored unwashed in a sealed plastic bag in the vegetable crisper draw. The refrigerator should be set at 35 to 40° F. Today’s frost-free refrigerators are the worst thing for fresh vegetables because they automatically withdraw moisture from the air in the refrigerator, and water-soluble vitamins will be lost with the moisture extracted from the vegetables. Placing produce in sealed plastic bags in the crisper drawer will help to maintain the vitamin content for a few days.
Canned foods should not be stored in a very hot environment. The breakdown of vitamins is a chemical process. Like all chemical processes, this breakdown is more rapid when temperatures are higher. Therefore, maintaining your pantry in a cool place will minimise vitamin losses in canned foods.
Store milk and bread away from the sun or strong light, which can destroy their riboflavin content (and milk’s vitamin A content, too). Clear plastic milk bottles should not be used for this reason.
Orange juice will begin to lose vitamin C after it has been stored in your refrigerator for several days, regardless of the container in which it is stored. Don’t keep more than you will be able to use in a week’s time. Powdered drinks with supplementary vitamin C will hold their vitamin content for a long time and may be an acceptable alternative to fresh or frozen juice products for some people even though they have no other nutrients.
If you pick tomatoes before they are ripe, allow them to ripen in a cool (not cold), dark place. They can be easily ripened by storing them in a paper bag at room temperature, never in the refrigerator. Ripening under any other conditions will result in the loss of some of their nutrients.