Food drying

Drying (food)

Drying is a method of food preservation that works by removing water from the food, which inhibits the growth of microorganisms and hinders quality decay. Drying food using sun and wind to prevent spoilage has been practised since ancient times, and was the earliest form of food curing...

 is a practice used to preserve fruit, vegetables and animal proteins after harvest since antiquity, and a food dehydrator refers to a device that removes moisture from food to aid in its preservation. A food dehydrator uses a heat source and air flow to reduce the water content

Drying (food)

Drying is a method of food preservation that works by removing water from the food, which inhibits the growth of microorganisms and hinders quality decay. Drying food using sun and wind to prevent spoilage has been practised since ancient times, and was the earliest form of food curing...

 of foods. The water content of food is usually very high, typically 80% to 95% for various fruits and vegetables and 50% to 75% for various meats. Removing moisture from food restrains various bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 from growing and spoiling food. Further, removing moisture from food dramatically reduces the weight of the food. Thus, food dehydrators are used to preserve and extend the shelf life of various foods. The first commercial food dehydrator was sold in 1920.

Devices require heat using energy sources such as solar

Solar power

Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available...

 or electric

Electricity

Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

 power, and vary in form from large-scale dehydration projects to DIY projects or commercially sold appliances for domestic use. A commercial food dehydrator's basic parts usually consist of a heating element, a fan, air vents allowing for air circulation and food trays to lay food upon. A dehydrator's heating element, fans and vents simultaneously work to remove moisture from food. A dehydrator's heating element warms the food causing its moisture to be released from its interior. The appliance's fan then blows the warm, moist air out of the appliance via the air vents. This process continues for hours until the food is dried to a substantially lower water content, usually fifteen to twenty percent or less.

Most foods are dehydrated at temperatures of 130°F, or 54°C, although meats being made into jerky

Jerky (food)

Jerky is lean meat that has been trimmed of fat, cut into strips, and then been dried to prevent spoilage. Normally, this drying includes the addition of salt, to prevent bacteria from developing on the meat before sufficient moisture has been removed. The word "jerky" is a bastardization of the...

 should be dehydrated at a higher temperature of 155°F, or 68°C, or preheated to those temperature levels, to guard against pathogens that may be in the meat. The key to successful food dehydration is the application of a constant temperature and adequate air flow. Too high a temperature can cause hardened foods: food that is hard and dry on the outside but moist, and therefore vulnerable to spoiling, on the inside.

Solar food dehydrators

Solar dryers use solar energy to create a flow of warm air through the tray. Solar food dehydrators are often cited as viable tools in the search for agricultural sustainability

Sustainability

Sustainability is the capacity to endure. For humans, sustainability is the long-term maintenance of well being, which has environmental, economic, and social dimensions, and encompasses the concept of union, an interdependent relationship and mutual responsible position with all living and non...

 and food security

Food security

Food security refers to the availability of food and one's access to it. A household is considered food-secure when its occupants do not live in hunger or fear of starvation. According to the World Resources Institute, global per capita food production has been increasing substantially for the past...

.