The HotmixPRO Dehydrator (475x605x576 mm) is the professional solution for drying.
It offers you the possibility to make this process simple and convenient.
It can work for 150 hours without pauses and with no worries.  

  • HotmixPRO DRY gives you the opportunity to dry your foods evenly, thanks to two independent heating mechanisms and with a capacity of 9 trays (530x325x16mm).
  • The horizontal airflow managed by two independent fans allows a perfect and uniform aeration of the product in order to obtain a complete dehydration.

  • You can adjust the air flow which has ten different speeds depending on the temperature of the room and on the the product you want to dehydrated.
  • You can monitor the dehydratio by controlling the temperature degree by degree, managing and adapting it to each stage of the process.

    The efficiency and adaptability of HotmixPRO Dry can help you to to continue your travel to a better health and nutrition.

FEATURES OF DEHYDRATION AND WATER COMPOSITION 

Most fresh foods are basically composed of water, which represent from a 60% to a 90% or more of their mass.

Some of the oldest forms of cooking, such as the oven, have evolved into a form of conservation of foods, through dehydration.

However, the drying technique is known not only for its ability to retain, but also for the particular texture that foods acquire.

Hot air has a dual role: to transmit the heat, causing the evaporation of water and to remove the steam from the surface of the food and from the surrounding area.


THE PROCESS

The dehydration starts from the surface. Water evaporates and turns into a gas.
When the water evaporates, it attracts the other one from the inner part towards the surface through the food porosity.

The dehydration starts from the surface. Water evaporates and turns into a gas.
When the water evaporates, it attracts the other one from the inner part towards the surface through the food porosity.

This phenomenon slows down until the water deeper in the food is unable to reach the surface fast enough to replace the one that evaporates.
In fact, when the big channels are dry, the residual water spreads out slowly through the micro pores.

During the whole process, the dehydrated part increases and the food will be soon dehydrated with a percentage of remaining water close to 10%.

At the end of the process the food will tend to thermo-hygrometric balance with the surrounding area.
It is important to remember that the dehydration is an extremely slow process and if it is accelerated, you cannot obtain the complete elimination of water.

WARNING! Accelerating the evaporation on the surface does not help: if the evaporation removes the water faster than its movement from the inside, the surface will harden and dry up, trapping the moisture inside the food.

This phenomenon is known as “surface hardening”.

However, there is a part of the water in each food which cannot evaporate freely because it’s linked to food molecules: this water is called “bound water” and it’s different from free water that spreads and evaporates quickly.

You have to reach a higher temperature if you want to break chemical bonds. Only in this way it is possible to remove the bound water. 

DEHYDRATION INDICATORS

An important indicator of the dehydration is the amount of free water in the food, which gets its name from a property called “water activity”.
Pure water has an activity of 1, while for dry powders such as milk and instant coffee it is 0.2.

It is necessary to maintain the room without moisture (RH 10-20%), because to dehydrate means maintaining the level of air moisture around the food below the value of water activity, so that water will go out and evaporate in the air.

It is also important to remember that the decrease of water activity eliminates many enzymatic reactions which can deteriorate the food.

The dehydration protects the food from spoilage and pathogens since most of the bacteria stops growing in an activity of 0.91 or less

THE STAGES OF DEHYDRATION

The food goes through several stages. Iit’s important to know them to understand if the process is too fast or too slow.

  • The first stage is called settlement. The surface is heated up to the temperature of the wet bulb.

    The moisture inside the food starts moving towards the outside and it evaporates.

  • The following stage is called constant velocity. The product must be brilliant, slightly sticky and wet to the touch.

    WARNING: If dehydration is too fast, the surface of the food become too dry; for this reason, it is essential to lower the temperature (the food is going to be cooked rather than dried).

    On the contrary, if the surface remains wet, it means that the food is going to be dehydrated too slowly and you must increase the temperature.

  • During the final stage of dehydration, the process will seem stagnant, because most of the water is evaporated. This is due to the fact that the temperature is not high enough to evaporate the remaining bound water.
    The food will tend to remain sticky and have a hard texture (it also depends on the type of food you want to dehydrate).

    If you want to extract the bound water, it is necessary to greatly increase the air temperature even higher than those of boiling water.

    However, it is important to remember that high temperatures alter the texture and flavour of food, so you have to pay close attention during each stage of the process to avoid an incomplete dehydration.

BASIC RULES

There are some general rules for any kind of food, which must be followed to achieve a perfect dehydration.

Low temperatures almost always allow to obtain the best results; this ensures that the volatile aromas don’t evaporate together with water.

A fast dehydration at high temperature may deteriorate the food texture and causing the decay of the surface.

So it is absolutely not recommended to speed up the process, but you have to respect the time in relation to the type of food you want to dehydrate, so that your expectations will not be betrayed!

The dehydration with HotmixPRO DRY also allows you to ensure food safety.
The dehydration process eliminates the water which is fundamental for the action of decomposing microorganisms and blocks their activity. The lack of water inhibits the growth of microbes and prevents degradation and oxidation of the food.

The food should remain inside the machine at a temperature of 52 ° C or 126 F.
It’s easier to ensure food safety by cutting the food of a thickness less than 1 cm, or 3/8 in. and by dehydrating it at a temperature higher than 40 ° C or 105F.
This is sufficient to minimize the bacterial proliferation.

Although these methods, it will be necessary to dehydrate the decontaminated food quickly enough or at a high temperature to avoid that the bacteria will return to colonize and proliferate on the surface to the food.

THE TEMPERATURE

In general, the food temperature is about 20 degrees colder than air. This is due to evaporation, because the moisture on the food surface evaporates and cool it.

Thanks to HotmixPRO DRY and its horizontal airflow managed by two independent fans, you will be able to obtain a perfect dehydration with a homogeneous aeration of the product.

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