DEHYDRATING FOODS IN FLORIDA: Best Just for Herbs By Jim Frankowiak
Dehydrating foods to preserve them is a process that is thousands of years old. “But it was developed and practiced in areas that are much, much drier than Florida,” said Hillsborough County Extension faculty member Mary Keith, who specializes in food safety, nutrition and health and holds advanced degrees in food science and nutrition as well as licensure as a dietitian. “We live on a peninsula, surrounded by water with lakes and rivers all around us. It is too humid here! “Humidity and dehydration are opposites,” said Keith. “When we dehydrate foods we try to take out enough moisture so that bacteria, molds and yeasts cannot grow. Dehydrating when there’s already a lot of moisture on the outside means that it will take longer to get the food we are attempting to preserve dry enough to be safe.” The longer it takes to get the moisture out of the food we are processing, the more it costs us, the more the color and texture of the food will be affected, and the greater the vitamin loss there will be. Some vitamins, especially C and A, are broken down when they are exposed to air, light and heat. The longer the food being dehydrated is exposed, the more vitamin loss there will be. “Yes, fruits can be treated with sulfur to preserve the vitamin A, but that destroys one of the B vitamins, thiamin,” she said. “So, there is still a loss. You can steam or blanch some things, but that puts more moisture into something you are going to then turn around and try to take the water out of.” “Often we slice or dice the food we wish to preserve since this will speed up the moisture removal. That exposes more of the surface to drying, and helps more water to get out. But all of that exposed area also means more vitamin loss and color change.” “Some things can be dried fairly easily,” said Keith. “Herbs are one. We don’t eat them for their vitamins, minerals or fiber. They are mostly thin, flat leaves that we don’t have to peel or slice. They have lots of natural pores for the moisture to use on its way out. So, we can hang herbs in a breezy location and expect that they will get dry enough to keep without changing too much.” Dehydrating small amounts of foods for backpacking might be worth it, but it’s not the way to preserve the majority of your
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food supply. “You need to realize that to dehydrate peaches or carrots, any other fruit or vegetable or even meats and fish here in our humidity, means that we have to use electricity to speed up the process. That costs money,” noted Keith. “Even little tabletop dehydrators will be less efficient here than in a drier part of the country.” “If you are trying to dehydrate foods, it is important to be sure you get enough moisture out of the pieces so they won’t mold. Dehydrated vegetables should be brittle,” said Keith. “That means hard enough that if you bend a piece, it snaps in two, or if you tap it with a hammer, it shatters.” “Fruits should be leathery. You can bend a piece and it won’t break, but it is firm. If you pinch a piece of dried fruit between your thumb and finger, you should not be able to slide the top and bottom edges of the fruit separately. If you can feel a soft or slippery middle to the piece, it is not dry enough,” said Keith. “Or, if you fold a piece of dried fruit in half, the sides should not stick to each other. Meat jerky should be very leathery. If you bend a piece of jerky, the edges should break in sharp points.” Once foods have been dried sufficiently, they should be properly stored “so that they are sealed and humidity can’t get back into them. Storing them in the dark will help preserve some color and vitamins, too,” said Keith. “If you store dehydrated food in clear plastic bags, keep the bags in a can or box that will keep them dark.” There are some things that should never be dried at home, “they are just too risky,” advised Keith. “Milk and eggs, fish and chicken or poultry are just too likely to be carrying Salmonella to be safely dried at home. If you want those for your food supply, buy them.” Keith offers a range of food, nutrition and health information resources and classes to residents of Hillsborough County. She may be reached via email: mkeith@ufl.edu or by phone: 813/744-5519, Ext. 54136. Extension is an educational service provided by both the University of Florida and Hillsborough County. Its website is: http://hillsborough.ifas.ufl.edu.
INTHEFIELD MAGAZINE
August 2014
81