Preserve food to preserve nutrients
If you can't eat fresh produce within a couple of hours of harvesting, freezing or canning will help keep the nutrients. A recent University of California study found that 75% of vitamin C in fresh green beans and spinach was lost after being stored in the refrigerator for a week.
When fresh produce is exposed to the air, nutrients such as vitamin C and folic acid are destroyed rapidly. It's a good idea to either freeze or can your produce as soon as possible after pickling or harvesting. Freezing is usually considered the best method to maintain nutrients because blanching stops the enzymatic changes that destroy vitamins.
Other tips to maximize nutrient preservation include:
- Raw: Refrigerate and use as soon as possible; buy local to prevent nutrient loss during shipping and handling; cook vegetables in a small amount of water.
- Canned: Store in a cool, dark area.
- Frozen: Use good freezer packaging and minimize the freezer storage time.
- Dried: Store in a cool dark area.
Written by Deb Botzek-Linn, University of Minnesota Extension educator, 2011.