Freeze-dried kibbles are a type of pet food processed through freeze-drying technology. The principle of this technology is to first freeze the liquid raw materials into solid form, and then in a vacuum environment, the solid water directly sublimates into gas, achieving the purpose of drying. Specifically, the freeze-drying process undergoes liquid → solid → gas phase transitions. During this process, the "liquid bridges" between the solute particles are frozen into "solid bridges," fixing the relative positions between the particles, and there is no surface tension at the gas-liquid interface. As the solvent continues to sublimate, the "solid bridges" gradually decrease, but the relative positions between the particles remain unchanged until the "solid bridges" completely disappear.
Compared with traditional drying methods such as sun drying, baking, boiling, spray drying, and vacuum drying, freeze-drying technology has significant advantages:
Low-temperature drying, preserving nutrition: The freeze-drying process occurs at low temperatures, preventing protein denaturation while deactivating microorganisms. This means that freeze-dried granules can retain the nutritional components and bioactive substances in the raw materials to the greatest extent.
Retaining flavor and aromatic components: Since freeze-drying occurs at low temperatures, the loss of volatile components and heat-denatured nutritional and aromatic components is minimal. This makes freeze-dried granules not only rich in nutrients but also retain their flavor and aroma, making them more acceptable and appealing to pets.
Inhibiting microbial and enzyme activity: During the low-temperature drying process, the growth of microorganisms and enzymatic actions are almost halted, which helps maintain the original properties and freshness of the material. Therefore, freeze-dried granules have a longer shelf life and higher safety.
Maintaining shape and good rehydration: The volume and shape of the granules remain essentially unchanged after freeze-drying, with good rehydration properties. Simply adding water can restore them to a state close to their original form, providing more feeding options for pet owners.
Protecting easily oxidizable substances: Since the freeze-drying process is generally conducted under vacuum, the oxygen content is minimal, protecting easily oxidizable substances effectively. Therefore, freeze-dried granules have high stability and a long shelf life.
Efficient dehydration: Freeze-drying technology can remove 95-99.9% of the water content in the material, greatly extending the product's shelf life. This is particularly important for pet food because low moisture content prevents the growth and reproduction of microorganisms, ensuring the safety of the food.
Freeze-drying technology is widely used not only in the field of pet food but also in many other areas where it demonstrates its unique advantages:
Biological products and pharmaceuticals: Freeze-drying technology is extensively used in the preservation of antibiotics, antitoxins, diagnostic products, and vaccines. Through freeze-drying treatment, these biological products and pharmaceuticals can be stored for long periods without losing their activity and efficacy.
Microorganisms and algae: Various bacteria, yeast, enzymes, protozoa, and microalgae can also be preserved for long periods through freeze-drying technology. This is significant for scientific research and industrial production because freeze-drying treatment can maintain the bioactivity and function of these microorganisms and algae.
In summary, as a high-quality pet food, freeze-dried granules are increasingly favored by pet owners due to their rich nutrition, unique flavor, and long shelf life. By understanding the principles and process of freeze-drying technology, we can better appreciate the advantages of this food and make more informed choices in daily feeding.
