Why Pet Food Manufacturers Rely on Freeze Drying

Pet foods must endure various processes and environments before they are consumed. Whether it’s kibble or a dog treat, the product is created using a variety of protein sources, which may include chicken, beef, eggs, minerals, and grains. Preserving these is crucial for maintaining product quality. From extruding dough to using equipment supplied by freeze dry equipment manufacturers, pet food producers rely on many technologies. Freeze drying is most important for keeping pet foods nutritious and shelf-stable.

Overview of the Pet Food Industry

Domesticated animals flourish in the United States. The pet food industry exists to meet the nutritional needs of dogs, cats, and other animals cared for by humans. There must be a way to preserve meat, its byproducts, and the nutrients essential for good health.


There are over 3,000 different pet food products on the market, including wet and dry foods that must be freeze-dried. With over seven million tons produced each year, pet food represents one of the largest categories of packaged food. Although biscuit-style dog foods have been commercially produced since 1860,1 the freeze-drying process perfected by the mid-20th century is now often applied to food, including what you feed your dog or cat.



How Does Freeze Drying Work?

Pet food typically contains byproducts of meat, poultry, and seafood, as well as intestines, liver, kidneys, and other organs. Freeze drying is a dehydration process that requires freezing a product, lowering the pressure around it, and removing the moisture from it. Also known as lyophilization, freeze drying involves controlling the temperature such that the product’s appearance and characteristics don’t change.


The process centers on the principle of sublimation, in which ice goes directly to the vapor phase without melting into water first. A commercial freeze dryer is used to control refrigeration and vacuum. Depending on the equipment, it might be possible to track temperature and pressure in real time. Some products require a recipe for freeze drying and advanced control systems enable users to essentially program the system and monitor the entire process.


The freeze drying process consists of four stages:


  1. Ingredients such as meat byproducts are pretreated by concentrating them, changing their formula, increasing their surface area, or decreasing a high-vapor-pressure solvent.


  1. The material is frozen in a lab, using a large freezer, to the lowest temperature it can exist as a solid and liquid; since larger ice crystals are easier to freeze dry, the product is frozen slowly or the temperature is cycled up and down.


  1. The primary drying phase involves lowering the pressure to a partial vacuum and adding just enough heat for sublimation to occur; water vapor is drawn to the condenser, away from the product and vacuum pump.


  1. Unfrozen water molecules are removed during secondary drying; the temperature may be raised above the freezing point to break the bonds between water molecules and frozen material.


Once these steps are complete, the vacuum is broken and the material is sealed. Water content is typically 1% to 4% of what it was before freeze drying.



Why Is the Process So Important?

Removing the moisture from pet food by using commercial freeze dry machines facilitates its long-term preservation. It avoids cooking and losing nutrients as a result. Rehydrating pet food is quick and leaves all the nutrients intact. Freeze drying also prevents spoilage due to contamination by mold or bacteria. The product maintains oxidative stability and is sealed to prevent anything from getting inside before it is consumed. What could spoil within days can last longer than 12 months if properly freeze dried.


Preservation isn’t only important for keeping foods on shelves. To ensure a steady supply of ingredients, many are sourced from foreign countries. Vitamin C is often sourced from China, while other vitamins, minerals, and amino acids may be shipped in from other countries. Ensuring quality and safety of ingredients is, therefore, important and aided by the freeze drying process.


Quality control is another consideration. Pet food manufacturers are regulated by the Federal Trade Commission (FTC), U.S. Food and Drug Administration (FDA), and the U.S. Department of Agriculture (USDA), which oversees meat quality and determines the types of animal byproducts that can be used in pet foods. The Association of American Feed Control Officials (AAFCO) determines the minimum amounts of protein, required nutrients, and moisture content. For example, dry foods can contain up to 12% moisture to comply with AAFCO standards.2


Why It’s Needed

Pet food manufacturers need freeze drying because it increases shelf-life and preserves quality, nutrients, and flavor. Without it, a product might not look appealing or have the nutritional content pets require. Also, spoilage can occur before it gets to the consumer.


Lyophilization is essential to preserve certain nutrients. For example, the amino acid taurine is naturally found in meat, but during manufacturing it is lost. Animals that hunt for fresh food get plenty of taurine. If it’s not added post-production and preserved, pets are at risk of a deficiency which can lead to heart disease and blindness.


Pet food companies can use commercial freeze dry machines to:


  • Ensure ingredients on the label are preserved; it’s also less likely preservatives, sulfites, and other unwanted ingredients will be added, allowing a manufacturer to be totally transparent.


  • Produce freeze-dried vegetables, which contain vitamins and antioxidants that are just as good for pets as for people; manufacturers can avoid adding grain and cereal-based fillers as well.


  • Lower operating costs, since freeze-dried products are lighter, which makes it less costly to transport them. Pet foods can be ordered in bulk, well in advance of use, so they can be stored on site and shipped less frequently.


Freeze drying isn’t only used to produce dry foods. Wet pet food brands have faced challenges such as preserving the food, controlling moisture content, and ensuring a natural source of ingredients. Lyophilization benefits them as well. It can also decrease production costs in a market where production is expensive. Increased costs must be reflected in final sale prices. So, freeze drying can lower product costs and increase shelf life and quality.


Order Your Lyophilization Equipment from Parker Freeze Dry

One of the most trusted freeze dry equipment manufacturers, we provide various types and sizes of commercial freeze dry machines, from small scale to production size systems. Freeze drying is used quite often in the pet food industry. We employ a stringent quality control process, from design and manufacture of each commercial freeze dryer to meet customers’ needs, to installation and after-sales service. For reliable equipment and dependable service, contact Parker Freeze Dry at 636-429-3232 or info@parkerfreezedry.com.