The food drying is a process in which the food is dried at temperatures ranging from 30 to 50 degrees if you want to keep the enzymes intact (with the exception of meats, which must be dried at least at 70 degrees). Thanks to the uniform airflow of the dehydrator, moisture is slowly removed from the foods by evaporation. Generally, a food is considered “dehydrated” when 95% of the moisture is removed from the food: this greatly improves shelf life and prevents spoilage.
Domestic or home dehydrators are divided into three main groups:
- new generation infrared dehydrators
- conventional steel dehydrators
- conventional plastic dehydrators
Infrared dehydrators
The main benefits of infrared dehydrators are:
- shorter drying times
- low energy consumption
- greater retention of intensity of flavors in foods
- greater retention of intensity of colors in foods
- greater retention of active ingredients in foods
- possibility of more challenging drying (for example half plums or half apricots, while in many conventional dehydrators this is not possible and you need to cut thinner slices)
- quiet operation
Heat transfer and infrared radiation
It is the form closest to cooking in the sun. For example, Essene bread, or sun-baked bread, has very ancient origins and recalls traditions and peoples of the past. It is a raw bread, made from sprouts, prepared by drying and used by the Essene people. The Essenes are a Jewish group of uncertain origin, living around the middle of the 2nd century BC, also considered the precursors of raw foodism. For them, in fact, food could not be altered by cooking, which destroys the life of the food and alters its nutrients. They were strictly vegetarian, eating mainly bread, wild roots, and fruit. Using a dehydrator practically achieves a similar result.
“Heat transfer” is the passage of thermal energy from one body to another due to a temperature difference. In other words, if two bodies are at different temperatures, heat is transferred from the warmer body to the cooler one.
Unlike conduction or convection transfer, heat transfer by radiation does not involve direct contact between the heat source and the part to be heated and does not require a medium to propagate. It occurs by radiation: the sun’s heat propagates through the vacuum and reaches our planet as well. Physically, radiation consists of the emission of electromagnetic waves, while the heat exchanged mainly depends on the frequency of the radiation, the nature of the bodies involved in the thermal exchange, and some characteristics of their surface.
From a thermodynamic point of view, heat transfer can occur in three different ways: by conduction, convection, and radiation. In particular, infrared radiation (IR) is electromagnetic radiation characterized by frequencies between those of visible light and those of radio waves and is often associated with concepts of “heat” and “thermal radiation,” since all objects at room temperature or above spontaneously emit radiation in this band. Infrared radiation is part of the electromagnetic spectrum: it has wavelengths between 700 nm and 1 mm, with frequencies lower than visible light but higher than radio waves. It is often associated with the concepts of “heat” or “thermal radiation”: every object spontaneously emits infrared radiation, so sensors able to detect it are used for night vision or thermographic applications. Infrared is also used to transmit signals or data (remote controls, wireless mice and keyboards, etc.), or for infrared spectroscopy, very useful in material characterization (including foods): NIR (near infrared) spectroscopy is a well-known example.
There is also the use of infrared for cooking foods: compared to conventional heat use typical of a traditional oven, it has the advantage of not requiring heating of the air inside the oven as a means of heat transfer to the food. This allows cost reduction and a better qualitative result on the food, which does not tend to “dry out” as in a conventional oven. In addition, the sensory result obtained with medium infrared radiation is usually better.
Infrared can be applied to foods not only for cooking but also for surface pasteurization treatments before packaging. The application of infrared has proven effective in eliminating pathogenic microorganisms such as Listeria monocytogenes, specifically inoculated on the surface of meat-based preparations, without the need to reach temperatures that could cause qualitative damage to the product (as verified through colorimetric tests). Another special application of infrared is their combination with smoking processes (typically very long), to make them faster and obtain healthier products: in this way, smoking can occur in a few minutes rather than several hours and can be done in line rather than inside traditional discontinuous smoking ovens.
Infrared cooking has become one of the most popular features of modern kitchens. In particular, some grills are equipped with an infrared burner as an additional function of the stove. Cooking with infrared allows for gentle and simple steam cooking. The equipment browns, gratinates, and alone could replace many kitchen appliances. Infrared rays respect the structure of cells and the good taste of food. Radiation with shorter wavelengths (near and mid-infrared) penetrate the food surface more efficiently but are quickly slowed down due to the evaporative effect that consumes much of the heat and the formation of a surface “crust” that hinders further heat penetration. Compared to normal ovens, infrared also has the advantage of not heating the home environment in summer.
Best infrared dehydrators
1 Klarstein Florida Jerky – Dehydrator Device, Dryer, 500W, Infrared
2 Klarstein Florida Jerky – Dehydrator Device, Dryer, 500W, Infrared
Conventional steel dehydrators
Just like the infrared dehydrator, the steel ones are more robust than conventional plastic material dehydrators. These are normally disliked by health-conscious consumers because heated plastic produces substances such as xenoestrogens both in heat environments and in cases of contact with fats. But dehydrators operate at low temperatures that should not cause such problems, and fats are used sparingly in dehydrators.
Top 3 steel food dehydrators
1 Excalibur 9 Tray Deluxe Black Dehydrator 3900B
Great machine, one of the best even if at a high price.
Features:
- Dimensions in cm: 48.26 x 43.18 x 31.75 cm;
- Weight: 9.98 Kg
- Motor power: 600 Watts
- Voltage: 120
- Number of trays: 9
- Warranty: 2 years
- 9-tray dehydrator, square meters of space to lay out
- Built-in on/off switch
- Ideal for large families and gardens
- Includes adjustable thermostat
- Easy to clean Polyscreen tray inserts
- Automatic shutoff: no
2 Excalibur RES10 10 Tray Dehydrator with Digital Controller
Features:
- Dimensions in cm: 40.64 x 30.48 x 40.64 cm;
- Weight: 11.79 Kg
- Motor power: 550 Watt
- Voltage: 110
- Number of trays: 10
- Material: steel alloy
- Large drying capacity
- Dual Chamber, two timer and temperature settings
- Smooth, front panel with touch controls and backlit LCD
- Transparent double-opening door
- Hyper Wave Technology temperature oscillates for precise drying
3 Vita5 Nobel Pro 7 Dehydrator – Automatic Drying Device in Stainless Steel with 7 Trays
5 Best dehydrators made of plastic
1 Tauro Dehydrators, Domus B5 Food Dehydrator with horizontal airflow and 5 plastic trays
For those looking for a compact home dehydrator, sufficiently efficient and affordable. Motor with 7 automatic programs and 5 temperature levels for good quality drying and a silent aluminum fan with ball bearings for longer life, allowing from 2 to 48 hours of operation and/or the keep-warm function.
- drying tunnel made of 100% MADE IN ITALY food-grade plastic with non-slip handle and DrySet Pro motor lock
- 5 BPA Free certified food-grade plastic trays, size 24x36x4 cm, conveniently dishwasher safe
- maximum power 550W to ensure perfect performance under the most extreme conditions, consumption control through specific programs and dedicated technology
- external dimensions 27x27x45 cm, rectangular shape optimized to make the most of the internal space
- motor with electronic Dryset Pro system featuring 12 automatic programs, timer, keep-warm
- drying tunnel made of plastic material
- motor with electronic Dryset Pro control
- indicative capacity 2/3 kg
2 Food dehydrator, 400W food dehydrators
Features:
- Powerful Drying Capacity: Equipped with 400W drying power, the Bellelife food dehydrator removes moisture and preserves the original flavors of your favorite foods. Excellent craftsmanship means excellent performance with a 97% retention rate of vitamins and minerals. This is definitely the best way to preserve food.
- Adjustable Time and Temperature: The fruit and vegetable dehydrator features adjustable temperature and time functions; the drying temperature can be set between 35℃ – 70℃, while the time can be set between 0-24 hours. Choose the optimal time and temperature with the LCD Display, the heating element ensures constant 360° air circulation for even drying.
- Large Capacity with 6 Trays: This food dehydrator is designed with 6 large-capacity drying racks, sufficient to hold most foods and create even drying; the 6 trays offer maximum convenience to categorize different foods and increase productivity.
- High-Quality Material: Made with a stainless steel base and food-grade plastic trays, all materials are BPA-free. The dehydrator can dry any variety of fruit, vegetables, herbs, mushrooms, and even fish and meat. All trays are dishwasher safe for easier cleaning and storage.
- 365 Days Warranty
3 Melchioni Babele, Multipurpose Food Dehydrator, 5 Stackable and Removable Trays
- The electric Babele dehydrator is ideal for preparing delicious and healthy snacks based on meat, fish, fruit, or vegetables, without adding fats and sugars.
- The dehydrator’s trays are height adjustable and thus allow dehydrating different foods on multiple levels for uniform results.
- The 5 trays can be used individually or stacked depending on the quantity of food to be dried; their perforation allows an even heat distribution and easy control of the drying process.
- Easy to clean The individual components of the dehydrator can be easily removed and washed separately thanks to the disassemblable structure.
- The temperature is adjustable from 40-70℃, the dehydrator allows drying not only fruit and vegetables but also herbs, bread, mushrooms, meat, and fish.
4 Hopekings Fruit and Vegetable Dehydrator
Powerful Drying Capacity: Equipped with 400W drying power, the Bellelife food dehydrator removes moisture and preserves the original flavors of your favorite foods. Excellent craftsmanship means excellent performance with a 97% retention rate of vitamins and minerals. This is definitely the best way to preserve food.
- Adjustable Time and Temperature: The fruit and vegetable dehydrator features adjustable temperature and time functions; the drying temperature can be set between 35℃ – 70℃, while the time can be set between 0-24 hours. Choose the optimal time and temperature with the LCD Display, the heating element ensures constant 360° air circulation for even drying.
- Large Capacity with 6 Trays: This food dehydrator is designed with 6 large-capacity drying racks, sufficient to hold most foods and create even drying; the 6 trays offer maximum convenience to categorize different foods and increase productivity.
- High-Quality Material: Made with a stainless steel base and food-grade plastic trays, all materials are BPA-free. The dehydrator can dry any variety of fruit, vegetables, herbs, mushrooms, and even fish and meat. All trays are dishwasher safe for easier cleaning and storage.
- 365 Days Warranty.
5 Concept Appliances SO1020 Fruit Dehydrator
Concept Appliances SO1020 Fruit Dehydrator, 9 compartments, 245 W, 46 Decibels, Plastic, White [Energy Efficiency Class A].
- Practical dehydrator with 9 transparent compartments measuring 32 cm in surface, featuring a modern white design.
- The temperature adjustment from 35°C to 70°C allows you to dry any food exactly the way you like it.
- Perfectly uniform drying – the built-in fan and the special shape of the racks ensure a perfect result.
- Very quiet operation – only 46 dB (A), 245 W.
- Product dimensions: 39 x 33 x 33 cm; 3.76 Kg
- Noise level: 46 dB
- Energy label efficiency class: A
- Wattage: 245 watt
- Material: plastic
- Diameter: 32 cm
- Weight: 3.76 kg
