Food Freeze Dryer

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Food Freeze Dryer

Food Freeze Dryer: The Ultimate FAQ Guide

If you have questions on the food freeze dryer, then you should read this guide.

It has all the answers that will help you become an expert in the food freeze dryer industry.

Let’s get started:

What is Food Freeze Dryer?

Food freeze dryer is a machine that will dehydrate different food contents in a bid to preserve and store them.

It depends on the lyophilization process to accurately dehydrate high-quality food thus increasing the shelf-life.

Freeze food dryer

Food freeze dryer

How does Food Freeze Dryer Work?

Food freeze dryers depend on the lyophilization process to lower the temperature of food for proper preservation.

The main principle on how the machine works is sublimation under specific temperature and pressure.

You have to understand the proper working principles of the food freeze dryer before you attempt to operate it.

Here is a step by step guide on how you can operate a food freeze dryer efficiently.

· Preparation Stage

First, you have to prepare the machine well before using it and ensure it is in proper working condition.

Apart from the machine you need to have the food that you intend to prepare ready for the process.

After that, you will power the machine on and proceed with the drying process beginning with freezing.

· Freezing Process

At this point you will treat the products accordingly in an environment with very low temperatures.

You will cool the products under the normal eutectic point thus leading to sublimation of the products.

A eutectic point is the lowest temperature where any solid and liquid of different elements can coexist.

You should be careful to do it properly to avoid damaging the products.

Apart from that, you have to note that the larger the product, the more time it will take to freeze.

· Primary Drying

At this stage, you can reduce the provisional pressure at optimum heat allowing for the sublimation of the product water content.

You can calculate the amount of heat you need using the latent heat of sublimation of each molecule on the product.

You should also note that the primary drying process of food products is always slow.

You can control the pressure using a partial vacuum during the drying process.

Apart from that, the vacuum will also increase the sublimation rate hence making it a deliberate process.

· Secondary Drying

At this point, you will remove the unfrozen molecules from the food products as the primary drying process removed the ice.

You will regulate the freeze-drying process at this stage through proper adsorption of isotherm materials.

You will also increase the drying temperature at this stage to be higher than that of primary drying.

Higher temperatures breakdown physiological interactions that could form between the water and frozen molecules.

Apart from that, secondary drying will also enable desorption when you lower the temperatures.

As soon as you complete the drying process, you can break the vacuum by applying inert gas.

The amount of water in the food products at this point is very low at about 1 to 4 %.

Finally, you will seal the food products in preparation for storage for a particular amount of time.

Is it worth Investing in Food Freeze Dryer?

Yes, it is worth investing in food freeze dryer due to a number of reasons and quality of preservation it provides.

You will experience numerous benefits that come with the use of the food freeze dryer such as:

Food freeze dryer

Food freeze dryer system

· Extension of Shelf-life of the Food Products

Quick water transition and lowering of temperatures through the sublimation process assists in achieving long shelf-life.

It will preserve the food you have and maintain the high quality of the food for a very long time.

You can also increase the shelf-life of the food further through the incorporation of proper packaging from the food freeze dryer.

· Rehydration

You can use the food freeze dryer to rehydrate the food thus increasing or improving the quality of the food.

It, therefore, leaves the food in excellent quality when it comes to the consumption period.

· Maintains Sensory Quality of the Food and Nutrients

There is minimum deterioration reactions on the food as the preservation and sublimation process happens in low temperatures.

It will also ensure that food does not lose the high quality as well as the color and the nutrients.

You will still enjoy the original shape and structure as well as the texture of the food you are drying.

·  No Addition of Preservatives

You will not add any preservatives or chemicals to the food when you use the food freeze dryer.

You will simply reconstitute the food faster through the simple addition of water to the preserved food.

Is Food Freeze Drying Healthy?

Yes, food freeze-drying is a very healthy process that you can use in the preservation of food.

Your food will not lose the necessary nutrients responsible for different bodybuilding and repair activities.

Apart from that, there is no addition of drying chemicals hence leaving the food in proper and safe conditions.

You will enjoy the fresh, crispy and original taste of the food you are eating as the food remains healthy for long.

Are there Disadvantages of Food Freeze Dryer?

Yes, just like any other machine, you might experience a few hitches while using the food freeze dryer.

Here are some of the challenges that you might experience while using the food freeze dryer.

 Freeze food drying system

Figure 3 Freeze food drying system

· High Cost of Equipment

The equipment that you will use for food freeze drying is more expensive in comparison to the other available options.

It makes no economic sense when the value of the dried food does not meet the high-cost expectations.

Here are the main factors that usually determine the varying cost of the food freeze dryer:

i. Nature of the product you intend to dry and preserve

ii. Capacity of the machine to process the products

iii. Type of packaging material you intend to use

You can also choose the type of energy you intend to use to determine the cost of the equipment.

· Leaking Silicon Oil

The process of drying food using a food freeze dryer involves using fluids to heat or cool shelves in freeze dryers.

Continuous process of heating and cooling often makes the silicon joints of the food freeze dryer weaker.

It melts the silicone thus leaving it in a weaker position and also exposes the product to dry to contamination.

You should, however, use a spectrometer to test the amount of silicon in the vapor to avoid contamination.

  • Complexity and sensitivity of products
  • It also leads to the destabilization of protein structure and liposome fusion after removal of hydration cell without suitable stabilizers.

You can solve this problem by maintaining an optimal amount of water in the water through the freezing and drying process.

  • Application of excess heat may alter and destroy the structure of the product during the food freeze drying process.
  • You can only apply the freeze-drying process in selected types of foods as others cannot withstand the pressure.
  • Apart from that, you may take longer than usual to dry large products owing to high moisture content.

This can lead to wastage of energy and other resources in the drying process.

  • You must store the frozen dried foods well as they might spoil even after the process of freeze drying.

What is the History of Lyophilization Process?

Lyophilization dates back to the 15th century with the Incas who were using rudimentary forms of freeze drying.

In the modern era, the process of food preservation using lyophilization started during the world war II.

It also became an important process in blood preservation from the US to Europe for wounded soldiers.

Is Freeze Food Drying better than Dehydration?

You can use both machines in the process of dying and preserving food even though they have notable differences.

Here are the main differences between the food freeze drying process and dehydration.

· Moisture Content

The level of moisture that every method eliminates from different products vary.

Food freeze dryer will eliminate about 99% of the moisture content within the food products.

On the other hand, the food dehydration machine will eliminate about 95% of the water from food products.

· Product Appearance

A food dehydration machine will squish and change the appearance of the food you intend to dry.

Food freeze dryers, on the other hand, maintain the appearance of the food that you intend to dry.

· Cost

Food that you will preserve using the dehydration process is cheaper in comparison to food from freeze dryers.

This is because food from the food freeze dryers maintains the high quality of the food for a longer period.

Generally, food freeze drying process is a better method in comparison to dehydration despite the high cost.

How does Food Freeze Dryer compare to Fluid Bed Dryer?

Food freeze dryer and the fluid bed dryer are machines that you can use to get rid of excess moisture from different products.

Fluid bed dryer uses the suspension principle in drying the products as hot air flows at a very high speed.

Food freeze dyer does not involve the suspension of products in the air.

It is because the air does not flow at high speeds.

Apart from that, food freeze dryers depend on different drying methods in comparison to the fluid bed dryer.

In terms of size, the fluid bed dryer is smaller than the food freeze dryer which has a wider capacity for different products.

What’s more, you can use a fluid bed dryer to granulate different particles which is not possible with the food freeze dryer.

Food freeze dryer employs a freezing mechanism in drying the products which is not available in the fluid bed dryer.

What is the Difference between Food Freeze Dyer and Pharma Oven?

You can use a pharma oven and the food freeze dryer to get rid of excess moisture from different products.

Pharma oven

 Pharma oven

 Food freeze dryer

Food freeze dryer

The pharma oven uses very high temperatures to get rid of the excess moisture from the products.

This enables the machine to work faster to get rid of the excess moisture from the products.

Food freeze oven employs a moderate amount of heat in drying the products and takes longer to dry the products.

In addition to that, you have the freedom of choosing different types of food freeze drying machines.

The different drying machines come with different drying mechanisms for different products.

Pharma ovens depend on a particular drying mechanism with a limited range of machines.

Pharma ovens do not employ the freezing mechanism which is common with the food freeze dryer.

What are the Features of Food Freeze Dryer?

The food freeze dryer depends on a number of features which enables it to dry the products well.

Here are some of the features of the food freeze dryer you need to look at:

  • Typical input capacity which dictates the quantity of products you can dry in the food freeze dryer.
  • Output capacity which varies according to the size of the food freeze dryer
  • Varying sublimation capacities with a maximum and a minimum according to your choices
  • Wide effective tray area for placing the products you intend to dry.

Which Type of Freeze Food Dryers are there?

There are different types of food freeze dryers that you can use in your applications.

Here are the different types of food freeze dryers that you can choose from.

Food freeze drying system

 Food freeze drying system

1) Radiation Freeze Dryer

Radiation freeze dryers is a type of food freeze dryer that depends on infrared radiation from the radiant heater.

· Advantages of Radiation Freeze Dryer

It has a uniform heating process that dries the products within the dryer uniformly.

Apart from that, it does not use a lot of energy thus leading to proper energy conservation.

· Disadvantages of Radiation Freeze Dryer

The cost of purchasing and installing the radiation freeze dryer is high.

It is big in size thus making it very difficult to move from one place to another.

· What makes Radiation Freeze Dryer Unique

The machine depends on radiation which heats the shallow ends of the product it is drying.

It begins from the shallow end and progresses towards the inner part of the product gradually.

This ensure the machine freeze-dries the products in a more accurate manner.

2) Microwave and Dielectric Freeze Dryer

The microwave and dielectric freeze dryer depend on radio frequency dry heater in drying all the products.

· Advantages of Microwave and Dielectric Freeze Dryer

It is capable of handling a large batch of products and drying them uniformly.

It is efficient and very accurate to the points of removing excess moisture through dehydration.

· Disadvantages of Microwave and Dielectric Freeze Dryer

It uses the heater in freeze drying method even though the use is not very common.

Controlling the heater is not easy as the water gets heated faster in comparison to ice.

· What makes Microwave and Dielectric Freeze Dryer Unique

You can use the heater of the microwave in heat drying which is not common.

It is capable of drying the products without worrying about contamination from the micro-waves.

3) Irradiation Freeze Dryer

The irradiation freeze dryer depends on ionizing energy and radiation in drying the food products.

·  Advantages of Irradiation Freeze Dryer

Application of the irradiation freeze dryer process increases the shelf life of the products to dry.

It is the safest and most effective method of processing of food.

Radioactive sources that you use in this equipment do not produce gamma, beta and x-rays thus limiting product radioactivity.

· Disadvantages of Irradiation Freeze Dryer

There might be accidents that result from this drying process due to difference from radioactive fallouts.

· What makes Irradiation Freeze Dryer Unique

Operations of the machine entails exposing the product to ionizing radiation with higher energy and penetration.

It kills all the poisonous organisms within the product even though it does not heat the product.

Finally, it is capable of dehydrating the products by removing 99% of the water.

4) Contact Freeze Dryer

The contact freeze dryer uses the conduction principle in the dehydration of different products.

· Advantages of Contact Freeze Dryer

It depends on very high heat levels to dry the products thus reducing time it takes to dry products.

You can dry a large quantity of products in the freeze dryer as the machine is available in varying capacities.

· Disadvantages of Contact Freeze Dryer

You will need a bigger storage space as the products dried through this machine may not preserve original sizes.

You must invest in proper storage conditions which might increase the overall cost of production.

·  What makes Contact Freeze Dryer Unique

It is capable of drying products just by exposing the products to heat.

It is possible as the heat the machine transfers to the product dehydrates the moisture from the products.

5) Conductive Freeze Dryer

This freeze dryer depends on conduction principle in the drying of different products through dehydration.

· Advantages of Conductive Freeze Dryer

It has heat trays which have heater plates where you will place the products that you intend to dry.

It is an automatic machine and most of the operations are automatic thus limiting excess use of labor.

· Disadvantages of Conductive Freeze Dryer

The original cost of purchasing and installing the conductive freeze dryer is high.

You need to have or train special personnel to help in the handling of the drying process.

· What makes Conductive Freeze Dryer Unique

It begins the drying process through conduction and transfer of heat to one side of the products to dry.

As the heat flows from one side to the other, it dehydrates the food products by eliminating the water.

6) Accelerated Freeze Dryer

Just like the conductive freeze dryer, accelerated freeze dryers also use the conduction principle.

· Advantages of Accelerated Freeze Dryer

It has sensors and safety mechanisms that will protect you and the machine through the drying process.

It has very high levels of accuracy ensuring that it dehydrates almost 99% of the moisture content.

· Disadvantages of Accelerated Freeze Dryer

You will have to train personnel to assist in handling the machine due to its complexity.

It takes a longer period to dehydrate larger products thus wasting a lot of energy.

· What makes Accelerated Freeze Dryer Unique

It has expanded metal mesh layers which hold the food or the products that you intend to dry.

It also subjects the products to pressure from both sides.

The mesh enables faster transfer of heat to the food or products making it better than the plates.

This is because the mesh has spaces in between them through which vapor can escape easily.

What are the Main Parts of a Freeze Food Dryer?

Food freeze dryers have different parts that perform different functions to enable the drying of different products.

Here are the main parts that coordinate to make the freeze-drying process a success.

 Food freeze dryer parts

 Food freeze dryer

· Freeze- Drying Chamber

This is a stainless steel and polished part of the machine with numerous shelves for holding products to dry.

The machine has a hydraulic or electric motor that will ensure the chamber remains a vacuum after closing the door.

· Process Condenser

It consists of refrigerated coils on the exterior and interior for trapping water during the process of drying.

You have to ensure that the temperature of the product is higher than that of the condenser during primary drying process.

It will increase efficiency and ensure that the right amount of water condenses.

· Shelf Fluid

You can use shelf fluids such as silicone oil during the primary and secondary phases of drying different products.

· Vacuum System

The machine depends on the 50 – 100 bars vacuum system in the drying process to eradicate solvents from the products.

It uses a two-stage rotary vacuum pump to enable the vacuum system of the food freeze dryer.

Larger chambers require you to use multiple vacuum pumps for increased efficiency.

· Refrigeration System

The system depends on compressors as well as liquid nitrogen to cool off the shelves and supply energy for freezing purposes.

·   Control System

You will use the control panel to program the machine by determining values such as temperature and time.

You will also control all the other processes of the food freeze dryer from the control panel

Which are the Key Methods in Food Freeze Drying Equipment?

There are three main methods that you can apply in the food freeze-drying equipment.

Here are the details on the main methods that you can use in the process of food freeze-drying.

 Food freeze drying system

Food freeze drying system

1. Manifold Freeze-Drying Method

In this freeze-drying process, every flask ampule has an attachment to different ports of the drying chamber.

You can either use a freezer different product in temperature baths through freezing or submersion.

This will also depend on the nature and volume of the product you intend to use.

You will attach the product to the manifold to prevent warming.

Additionally, you will avoid low temperatures in the entire system by making a vacuum in the container of the products.

This is also the best method that you can use for small volume products which have collapse temperatures.

Advantages of Manifold Freeze-Drying Method

This method has every vial with a direct path to a connector as the vessels have individual connections to the manifold.

It limits any form of competition on the molecular space that is within the batch system.

Additionally, its proximity to a collector usually creates a particular environment maximizing efficiency of drying.

Disadvantages of Manifold Freeze-Drying Method

When you expose the vessel to ambient temperature, you might affect the heat input.

You cannot use this method on products which have precise temperature controls.

2. Batch Freeze-Drying Method

Using the batch-freeze dryer, you will place all the similar materials in the tray dryer.

You will perform pre-freezing of the said products on the shelves of the tray dryer.

You will ensure that you maintain the temperature as well as quantity of products during the drying process.

You might, however, experience slight variations in the input of the heat at various points of the drying process.

The method also depends on radiantly heating the vial which is located next to it through the clear door.

This will create a small variation in residual moisture as a result of variation in the entire system.

You will be able to close all the vials at the same time under the same atmospheric conditions.

You must also ensure that you maintain a uniform environment as well as uniform stability of products during storage.

You can easily achieve this by stopping the vials within the vacuum at the same time.

It is the best method that you can employ in preparation of large amounts of vials and single product ampules.

3. Bulk Freeze Drying Method

In this method, you will dry all the products on a tray dryer just like batch drying method.

The difference, however, is the drying of the products in one unit after pouring the products into bulk pans.

After that, you will spread the products over the entire surface area of the shell.

You can do it in similar sizes as that of the products that you will dry in vials.

It is possible to have alterations of the heat inputs since there are limited empty spaces within the mass.

The method requires a limitation of the input heat to the heat of the shell as a result of products contact.

In this method, the sealing of the products is not possible in comparison to the sealing in batch and manifold methods.

Apart from that, before removing the products from the freezer, products are packaged in airtight containers.

This is the most suitable method that you will use for products that are not sensitive to oxygen or moisture.

How Can you Optimize the Efficiency of Food Freeze Dryer?

You can optimize the efficiency of the food freeze dryer by looking at the factors that affect food freeze drying.

You can begin by increasing the surface area of the product and reducing the thickness of the products.

The wider the surface area of the product the better the efficiency and the thinner the product the better the efficiency.

Thickness of the product will reduce the ability of the product transfer and absorb heat through the sublimation process.

Here are the main factors that you should pay close attention to in the optimization of the efficiency.

Freeze drying system

Freeze drying system

· Reducing the Eutectic Temperature

Lower eutectic temperatures reduce the drying time of the product thus leading to better efficiency of the food freeze dryer.

· Adjusting Condenser Temperature

You can optimize the function of the food freeze dryer through proper adjustments of the condenser temperature.

You can depend on the collapse temperature as well as the freeze temperature to adjust the proper condense temperature.

· Vacuum

You should place all the products in a deep vacuum for proper optimization of the food freeze dryer.

How Do Conventional Dryers Compare to Freeze Dryers?

You can compare conventional dryers to freeze dryers based on hoe they perform.

Here is a comparison between the two types of machines.

i. Working Principle

Freeze dryers work by lowering temperature and pressure thus freezing the products you intend to dry.

On the other hand, conventional dryers depend on heating the products to eliminate the moisture content in the products.

What’s more, conventional drying method uses a product belt and passes air inside dryer and eliminates moisture from the product.

In the freeze dryer, you will place the products inside the drying equipment and then apply lower energy to the food.

This leads to the vaporization of the moisture content in the products. s

ii. End Products Quality

Apart from that, convectional dryers depend on conductive as well as convective methods thus reducing quality of products.

You might also experience very high chances of contamination through conventional drying process.

On the other hand, freeze dryers do not affect the quality of the products as it preserves the nutrients of the products.

Additionally, you can also be sure of the safety of the products.

How do you Extend the Life of Vacuum Pump Oil in Food Freeze Dryer?

You can extend the life of vacuum pump oil in the food freeze dryer by adhering to specific factors.

As the vacuum pump runs, small amounts of water will trickle into the vacuum.

You can remove the water before the starting the process of drying the next batch of drying food.

As you remove the water, you will notice a small amount of oil draining out with the water.

As soon as you close the drain valve, you should add new amounts of pump oil in the vacuum pump.

You will be replacing the oil that you will lose through the draining of the water from the pump.

This will increase the durability of the pump and it will serve you for a longer period.

You should, however, change the pump oil on a regular basis especially after the following:

  • When processing of the food batch takes longer than usual
  • When oil looks milky and amber in color and has visible particulates
  • When oil spurts from oil pump

You should also not that the oil begins to spurt from the machine due to the following reasons.

  • Substantial leakage within the system of the food freeze dryer due to dirty door and open drain valve.
  • Rise in oil levels due to additional moisture from the vacuum hose.
  • Additional trapped oil within the cartridge of the pump especially after shutting off the vacuum pump.

Which Industries use Food Freeze Dryer?

You can use the food freeze dryer in different industries for different purposes.

Here are the main industries where you can use the food feed dryer.

Food freeze drying system

Food freeze drying system

·  Biotechnology and Pharmaceutical Industry

You will use the food freeze dryer to increase the shelf life of pharmaceutical products such as medicine.

You will seal the pharmaceutical materials in vials after drying process for easy shipment to different locations.

Implying that you must have the best pharmaceutical packaging and sealing solution for your pharmaceutical products.

This will ensure that the pharmaceutical products you dry using food freeze dryers remain free of contamination.

·         Food Industry

You can use the machine in the food preparation industry to dry and preserve the food.

Apart from that, you will also use it to reduce the weight of the food making them lighter for transportation.

For example, you can use the food freeze dryer to dry and preserve cream ice.

·         Technological Industry

You can use the food freeze dryer to synthesize different chemicals by lyophilization of products for proper stability.

The process also makes the chemicals easier to dissolve in water for other subsequent applications.

You can also use it in bio-separation in the late stages of purification as it removes solvents effectively.

What are the Quality Standards for Food Freeze Dryer?

When purchasing food freeze dryers, you have to ensure that it is of very high quality.

You can confirm this through proper adherence to international quality standards.

Here are the international quality standards that the food freeze dryer should adhere to.

  • International Standards Organization (ISO) certification for high quality food freeze dryers
  • Current Good manufacturing Practices (cGMP) for high quality machines.
  • Food and Drug Administration (FDA) quality standards of the United States of America
  • CE quality standards for the electrical system of the machine

What is the Future of Food Freeze Drying Technology?

At the moment, the high cost of freeze drying remains one of the greatest challenges in drying technology.

In future, the main issue is will focus on reducing the high cost of freeze drying of different products.

One of the approaches that you can use to reduce the high cost of freeze drying is proper pretreatments.

You can use different pretreatment options such as:

  • Osmotic Dehydration
  • Ultrasound Treatment
  • Infrared Heating

Apart from that, you can increase the quality of the final product through infrared pretreatments.

Additionally, there are other options that you can use in improvement of product quality such as:

  • Replacing heating source with
  • Using spray nozzle in the drying chamber

Future advances in the areas above offers a promising support for better future of freeze-drying process.

Which Safety Features do Food Freeze Dryer come with?

One of the safety features of the food freeze dryer is the ability to maintain the quality and color of the food.

It is capable of maintaining the nutrients in the food and does not contaminate the food in any way.

Apart from that, the safety of the machine begins with systems that are in place to monitor breaches in production cycle.

The systems of the machine are also in compliance with sanitation requirements and allergen programs thus making it safer.

The safety of the food begins with proper and tight management of the process chain.

This includes proper and hygienic handling of food before it reaches the lyophilization stage of the food freeze drying process.

Additionally, the machine comes with sensors that will detect any form of malfunction in the food freeze dryer system.

The sensors will automatically send a signal to the control panel to inform of any malfunction.

In case of impending danger, the sensors will trigger the machine to automatically shut down its operations.

Clearly, there are many aspects about the food freeze dryer that you have learnt here.

Still, you could be having more specific questions on freeze drying technology.

You can contact SaintyCo technical team today for help.