Home freeze drying

Preserve your garden produce, create the perfect dry food supply, make camping meals and healthy snacks. Unlike other methods of food preservation, freeze-drying does not shrink or toughen DEFORM the food and retains flavour, aroma, colour, and nutrition.

Because freeze-drying has good results in the pharmaceutical industry, it is now increasingly being used in the food industry.

Freeze-drying has moved from pharmaceutical industry to the food industry, but is now available also as a home process.

For heat-sensitive foods or products with high commercial value, it is used to dehydrate.

Freeze-drying operation is based on sublimation, which is the transformation from ice to vapour without passing through the liquid phase. The sublimation process makes freeze-drying operations expensive to use. However, there are several advantages of using freeze-drying instead of conventional air-drying. The main thing is the absence of heating at high temperatures. This process preserves nutrients and sensory characteristics within the food product. These advantages make freeze-drying an adequate technology among the new trends of functional and nutraceutical products in the food industry.

Freeze-drying is also known as lyophilization. It is a water removal process typically used to preserve perishable materials, with the goal of extending their shelf life and/or preparing them for transport. Freeze drying works by freezing the material, then reducing the pressure and adding heat to allow the frozen water in the material to change directly to a vapour (sublimate).

Freeze-drying maintains nearly all of the nutritional value of fresh food. Other methods of preservation, such as canning and dehydrating, use high temperatures that destroy much of the food value. So, the absence of heating elevated temperature in this process preserves nutrients and sensory characteristics within the food product.

The refrigeration system cools the (ice) condenser located inside the freeze dryer. The refrigeration system can also be employed to cool shelves in the product chamber for the freezing of the product.

The vacuum system consists of a separate vacuum pump connected to a product chamber with a condenser in between.

Control systems vary in complexity and usually include temperature and pressure sensing ability. Advanced controllers will allow the programming of a complete “recipe” for freeze-drying and will include options to monitor how the freeze-drying process is progressing. Choosing a control system for the freeze dryer depends on the application and use (i.e., lab vs. production).
We made it simple and effective for anyone to use without programming experience.

Product chambers are typically either a manifold with attached flasks or, a larger chamber with a system of shelves on which to place the product.

The purpose of the condenser is to attract the vapours being sublimed off of the product. Because the condenser is maintained at a lower energy level relative to the product ice, the vapours condense and turn back into a solid form (ice) on the condenser. The sublimated ice accumulates in the condenser and is manually removed at the end of the freeze-drying cycle (defrost step). The condenser temperature required is dictated by the freezing point and collapse temperature of the product. The refrigeration system must be able to maintain the temperature of the condenser substantially below the temperature of the product.

In shelf freeze dryers, the condenser can be located inside the product chamber (internal condenser) or in a separate chamber (external condenser) connected to the product chamber by a vapour port.

Manifold freeze dryers rely on ambient conditions to provide the heat of sublimation to the product. This heat input does not melt the product because an equivalent amount of heat is removed by vaporisation of the solvent. Advanced shelf freeze dryers can provide a heat source to control/expedite the drying process and they can also employ the refrigeration system to allow freezing of product inside the unit.

We have to understand the physical properties of materials that are freeze-dried. It is a key part of developing a successful lyophilization process. Few products are simple crystalline materials, but the vast majority of products that are lyophilized are amorphous and form glassy states when frozen.

Processing and formulation development are important steps often taken to make a product ready for freeze-drying and usable for its specific application. The choice of excipients added to a formulation can severely affect the thermal characteristics of the product and its ability to be freeze-dried in a reasonable amount of time.

Our freeze-dryer is optimised to be simple to use without programming need, while still delivering a superior freeze-drying experience to the majority of food products.