Freeze drying is a specialized preservation method that was initially industrialized to preserve pharmaceuticals for battlefield applications. It is now broadly applied to enable the long-term stability of various fast-moving consumer goods, including medicines and food products. Traditional preservation methods involve dehydrating materials by gradually heating them to remove moisture, but this practice has a distinct lack of specificity. Nutrients and flavors can be removed from the material as a result, making it unsuitable for the preservation of composition-sensitive products.
What is a freeze dryer?
Freeze dryer, also known as lyophilizer or liofilizador, they are synonymous. A freeze dryer is the equipment execute dehydrate process that typically used to preserve perishable materials, to extend shelf life, or make the material more convenient for storage or transport. Freeze dryer works by freezing the material, then reducing the surround to allow the frozen water(ice) to sublimate.
Freeze Dryer Working Steps
- Freezing: In order to lock the structural form, the food product is first frozen solid by keeping into a deep freezer. This freezes the water in the food product and provides necessary condition for low temperature (typically less than -30°C) drying.
- Vacuum: A vacuum pump is used to lower the pressure enabling the frozen water in the product to vaporize without passing through the liquid phase. The vacuum causes over 95% of the water to sublime leading to deliberate drying of the frozen food product.
- Heat: The heat gives the water molecules in the frozen food product enough energy to break free and become gas particles, thereby accelerating the sublimation process.
- Condensation: Condensation is primarily used for separating the water in gaseous state from the frozen food product. Low-temperature condensation removes the vaporized solvent by converting it back to a solid.
What Are The Benefits Of Freeze-Dried Products?
Since the freeze drying process works by removing water from the product and rendering the food product shelf stable, these items can be kept safe from spoilage for many years. In addition to the time extension, freeze-dried products have many other benefits such as:
- Untouched Nutrients: Freeze dried foods retain nearly 100% of the health benefits of the original food product. Active enzymes, nutrients, antioxidants, amino acids, and more remain “locked in”. When frozen, vital molecules remain in place and so the overall integrity of the nutritional composition remains intact. The freeze dried food is still considered a “raw food” that remains vibrant and alive in a dormant state just waiting for moisture to reactivate.
- Taste & Appearance: Freeze-fried products retain their original color, shape, size, form, taste, texture, and structure. When placed in water, they can reconstitute to their original state quickly.
- Long Shelf Life: Cold storage is not required for freeze-dried products. They can be stored at room temperature for many years without spoilage. It is important to keep them in a dry place to avoid absorption of environmental moisture.
- Light Weight: Freeze-dried food products weigh less than fresh as over 98% of water is removed. This makes it easier to handle them and less costly to transport.