FOOD STORAGE SHELF LIFE

See also our related article New Tips for Old Food

The question is regularly asked, “What is the shelf life of my food storage?”

1 First, it is important to first identify what is meant by “food storage” and “shelf life.” “Food storage” that is intended to be held long-term is generally considered to be low moisture food packed in either #10 cans or in metalized bags placed within large buckets. “Shelf life” can be defined in the following two ways:
“Best if used by” shelf life - Length of time food retains most of its original taste and nutrition.
“Life sustaining” shelf life - Length of time food preserves life, without becoming inedible.

There can be a wide time gap between these two definitions. For example, most foods available in the grocery store that are dated have a “Best if used by” date that ranges from a few weeks to a few years. On the other hand, scientific studies have determined that when properly stored, powdered milk has a “Life sustaining” shelf life of 20 years. That is, the stored powdered milk may not taste as good as fresh powdered milk, but it is still edible.

2 Second, understand food constituents. Food is composed of the following:

• Calories: A unit of measurement of energy derived from fats, carbohydrates and protein.
• Fats: A wide group of compounds that are generally soluble in organic solvents and largely insoluble in water.
• Carbohydrates: Simple sugars as well as larger molecules including starch and dietary fiber.
• Proteins: Large organic compounds that are essential to living organisms.
• Vitamins: A nutrient required for essential metabolic reactions in a living organism.
• Minerals: The chemical elements required by living organisms, other than carbon, hydrogen, nitrogen, and oxygen.

Minerals and carbohydrates do not change much during storage. But proteins can denature and deteriorate in quality. Fats can acquire off odors and off flavors known as rancidity. Vitamins are susceptible to destruction by heat, light, and oxidation. Importantly, even if some components deteriorate, the fat, carbohydrates and proteins still contribute calories. To prevent starvation, the most important component is calories.

3 Third, recognize that the shelf life is extremely dependent on the following storage conditions:

• Temperature: Excessive temperature is damaging to food storage. With increased temperature, proteins breakdown and some vitamins will be destroyed. The color, flavor and odor of some products may also be affected. To enhance shelf life, store food at room temperature or below; never store food in an attic or garage.
• Moisture: Excessive moisture can result in product deterioration and spoilage by creating an environment in which microorganisms may grow and chemical reactions can take place.
• Oxygen: The oxygen in air can have deteriorative effects on fats, food colors, vitamins, flavors, and other food constituents. It can cause conditions that will enhance the growth of microorganisms.
• Light: The exposure of foods to light can result in the deterioration of specific food constituents, such as fats, proteins, and vitamins, resulting in discoloration, off-flavors, and vitamin loss.

EXAMPLES OF SHELF LIFE

CONCLUSION

Instant Nonfat Dry Milk

Freeze-Dried Strawberries

Freeze-Dried Apricots

Freeze-Dried Super Sweet Corn

Freeze-Dried Italian Meatballs