Food Freeze Drying: The Process and Benefits
Industrial freeze drying has many applications, but industrial lyophilizers used by laboratories and pharmaceutical companies aren’t the only equipment of their kind. Commercial freeze drying is often used to prolong the shelf-life of fruits, vegetables, meats, and many other foods. It effectively preserves food quality over the long term.
The Process of Freeze Drying
During the process, temperature, pressure, and length of time vary, depending on the food type. First, each item is tested for purity and contamination by bacteria and other pathogens. Meat and seafood are cooked prior to freezing. Most fruits and vegetables have already been cut, peeled, and pitted and only require a water spray cleaning.
Food is then:
- Pretreated: Food may be concentrated; treated with compounds to increase stability, improve processing, or preserve appearance; or be made free-flowing. Its surface area may be increased as well.
- Frozen: Food products are laid out on metal trays, which are pre-chilled in the case of pre-cooked items, and quickly frozen at extremely cold temperatures. Aside from maintaining quality, this helps retain nutritional value as well.
- Dried: In another chamber, the pressure is lowered so frozen water droplets sublimate. The temperature is raised until ice crystals turn to water vapor, leaving behind voids that reabsorb water when food is later prepared to eat. Any unfrozen water molecules are removed during a secondary drying process.
Freeze dried food is then tested for moisture content and may be ground up or screened by size. It is then sealed in airtight packages.
Benefits of Freeze Drying Food
The advantages of freeze drying foods and liquids include:
- No damage to the physical structure.
- No need to refrigerate items.
- No need to use preservative chemicals.
- No shrinkage or toughening of material.
- Preservation of flavor, smell, and nutrients.
- Protection against spoilage for years.
- Fast preparation for consumption by adding water.
Foods That Can Be Freeze Dried
Freeze drying is often used for:
- Fruits: Color and taste are preserved so fresh fruit is available year-round, while powdered freeze-dried fruit can add color and antioxidants to other foods.
- Coffee: The quality and flavor of coffee are typically well-preserved with freeze drying.
- Vegetables: These include leafy greens, tomatoes, peas, corn, avocados, asparagus, etc.
- Meat: Steak, pork, chicken, ground turkey, hamburger patties, roast beef, and more can be safely freeze dried.
- Fish and seafood: The process is especially useful for preserving shrimp, squid, octopus, clams, scallops, cod, and many different types of fish
- Dairy: Raw or cooked eggs are well-preserved, as are cheese slices, shredded cheese, yogurt, cream cheese, sour cream, and cottage cheese.
Food freeze drying is often used for baby foods but also applied to full meals, such as stir-fry, soup, pasta dishes, and chili. It is effective for desserts as well, with freeze-dried ice cream, cheesecake, and pudding being among the most common.
Contact Parker Freeze Dry for Your Commercial and Industrial Freeze Drying Needs Today
We offer cost-effective machines for production and R&D requirements. If you are looking for custom freeze-drying equipment scaled to your application, learn more on our website, contact us online, or call 636-387-7703.