Janet Hackert, Regional Nutrition and Health Education Specialist, Harrison County, University of Missouri Extension
With food prices on the rise, many people are becoming more interested in growing and preserving their own food. More and more are canning and freezing, while others are discovering, or rediscovering, the science of drying foods. The first dehydrator was introduced in France in 1795. Ever since, people have been storing home-dried food in a cool, dry, dark place for long periods and keeping it safe to eat.
Dehydrating removes the water from food, which is how properly dried and stored foods last for so long. Molds, yeast and bacteria that make food spoil quickly need water to live and grow. With lower moisture content, these microorganisms cannot survive.
As with most processing methods, drying foods affects the nutritional value of the food. The heat and air used in dehydration destroys both vitamins A and C. Blanching vegetables before drying stops the enzyme action that causes the produce to decay. Blanching also reduces the amount of water soluble nutrients like vitamin C, B vitamins and some minerals. However, blanching helps maintain levels of vitamin A, vitamin C and thiamin during the drying process and storage. With most of their water removed, the nutrients in dried foods are more concentrated, and are higher in calories and fiber per weight compared to their fresh counterparts.
Foods can be dried in the sun or in a solar drier, but using an oven or electric dehydrator is more reliable than depending on the weather. Oven drying is a great way to try food dehydration because it involves little, if any, added equipment. It is not, however, a very efficient way to dry foods. Those wanting to do more preservation may want to invest in an electric dehydrator designed specifically for this task.
An electric dehydrator uses warm air and good air circulation to remove moisture from food. A drying temperature of 140 degrees F is recommended. Dehydrators can dry fruit, vegetables, meat and herbs. Drying times vary from a few hours to a full day. Times depend on the moisture content, amount of food, room temperature and humidity.
For a lot more information on what foods to dry and how to dry and store them, check out the full version of this article at http://missourifamilies.org/