Drying Foods National Center for Home Food 干燥食品国家食品中心.pptxVIP

Drying Foods at Home National Center for Home Food Preservation Disclaimers This slide show is a description of principles and considerations in food dehydration at home. It is not intended to be complete directions or instruction for drying specific foods. It was developed to help educators teach classes in home food dehydration. References to commercials products, services, and information is made with the understanding that no discrimination is intended and no endorsement by the University of Georgia, U.S. Department of Agriculture and supporting organizations is implied.? This information is provided for the educational information and convenience of the reader. A long, long time ago, in a far away place… One of the oldest methods of preserving food Evidence of Middle Eastern and oriental cultures drying foods in 12,000 B.C. Sun and wind- natural dryers Fire creates heat to dry in still houses Electricity Cylindrical commercial dehydrator design patented in 1980 Why dry? Simple Minimal equipment, supplies, and ingredients Reduces size and weight of food Long shelf life Requires little space Why not dry? Time- 1 (parsley) to 48 (peaches) continuous hours in dehydrator…2 to 6 days under the sun Attention – watch, stir, turn, test for dryness Preparation is same as for canning or freezing Not suitable for all foods How does drying preserve? Microorganisms (yeast, mold, bacteria) need water to grow, so removing moisture prevents spoilage from microorganisms. Concerns with jerky and foodborne illness Enzyme action is slowed (though not stopped), which means that color, texture, and quality do not degrade as rapidly once food is dried. Choosing a method of drying You must be able to control: Air circulation Moving air encourages evaporation by maintaining low humidity Temperature 140°F ideal for most foods Too slow (low temp., poor air circ.)=microorganisms could grow Too fast (high temp., rapid air circ.)=cooked food or “case hardening” “Case hardening” is when