The Difference Between Freeze-Dried, Dehydrated and Raw Foods

DEHYDRATION

Dehydration is one of the oldest methods of preserving food. Dehydrated dog and cat food is generally processed at low heat for a long time to draw out or evaporate any moisture out of the food. Each of the dehydrated food companies that we carry use different methods and temperatures to achieve this. I outline this below. In my research there definitely seems to be more variation and uniqueness in the processes used to dehydrate than to freeze- dry pet foods.

Foods dehydrated at higher temperatures are not considered completely raw, but very lightly cooked as the moisture is removed. Cooking denatures many of these nutrients including delicate enzymes, vitamins, minerals and amino acids, affecting the nutrition of the product.

Dehydrated dog food is usually harder than freeze-dried food and takes longer to rehydrate.

Some of the dehydrated food companies that we carry:

Canisource on their dehydration process – “This is a unique process to CaniSource. The food is dehydrated at low temperature over a period of several hours. Dehydration time allows the lethality of pathogenic bacteria as well as E. Coli and Salmonella. Instead of exposing the product to high heat, we expose it to a longer period of time at low temperature. For example, did you know that we could kill these bacteria at temperature as low as 54.4 degrees? However, the product should be exposed for a period of 112 minutes. It is for this reason that when we speak of low temperature, we must always mention the duration of exposure. CaniSource Grand Cru is dehydrated for a minimum of 14 hours. This process preserves most of the recognized benefits of raw food, serving them in handy kibbles.”

The Honest Kitchen on their dehydration process  (pictured left) – “Most of our raw ingredients are dehydrated below 104 degrees F and are therefore still considered raw and the meats and eggs in our foods are dehydrated at a high enough temperature to kill any pathogenic bacteria that may be present, and the required temperature for this (about 165 degrees F) is essentially equivalent to cooking.”

NRG Pet Products on their dehydration process– “We became the first company to offer dehydrated nutrition for pets. We built our own dehydration technology, and make diets specifically formulated for dogs from 100% edible fresh whole foods that are table grade quality, grown by North American farming families. Our dehydration process builds on this quality, locking in nutrition, intensifying flavours and controlling pathogens.”

They use 100% renewable energy, so they are not contributing to green house gasses. The dehydration temperature never above 125 degrees.

Smack Pet Food on their dehydration process– “Smack Raw Dehydrated Pet Foods are holistic raw foods with kibble convenience, handmade in Canada, and low temperature air dried.

Today’s customers demand a high standard of food safety and nutrient retention.  Smack’s air drying technology is a unique super condensation system which rapidly dries our temperature sensitive foods at 110°F and ensures maximum nutrient, enzyme, and antioxidant retention.”

Other companies that some of the stores carry are Addiction (raw dehydrated), Hurraw (low temperature), and Wellness dehydrated.

AIR-DRIED

Ziwi Peak on their air-dried process – “Hands-on, artisan approach to air-drying (no heat used). Ziwi’s air-drying process is a modern twist on the centuries-old technique of naturally preserving meats. Their slow and gentle, proprietary twin-stage process is to create a shelf stable product, remove pathogenic bacteria, such as E. coli, salmonella and listeria, deliver a complete and balanced food that is nutritionally equivalent to raw and to provide a true scoop and serve experience, with no need to freeze, thaw, refrigerate or rehydrate.

The end result of our unique air-drying process is a highly palatable food that is over 98% meat, organs, seafood and bone. Including 3% New Zealand Green Mussel for natural glucosamine and chondroitin, and 7% species-specific tripe for added palatability and digestive benefits. Ziwi air-dried recipes are 95% absorbable and resemble the texture of natural jerky without the use of gelatins, glycerins or other additives.”

Amore/ Vintage– These raw dehydrated complete diets are cool-air-dried using no heat, which maintains the benefits of raw simply by removing the water.

FREEZE-DRYING

Another term for freeze-drying is sublimation. It is the shifting of a solid directly into a gas. Freeze drying is a slow process that preserves nutrients, enzymes, and protein structures while making the food shelf stable, so it does not require refrigeration.

Orijen explains their take on freeze-drying and the process that they use: “Freeze drying does not involve cooking, it requires only two stages: solid and vapor. This means that only the water is removed, so all of the flavour and nutrients remain locked inside. We start by flash-freezing our fresh ingredients to lock in their goodness. Then using extremely low temperatures (-50C) and special pressurized chambers, our 18 hour freeze-drying process converts the frozen water in our ingredients directly into vapor, without creating any liquid. That means H20, and ONLY H20 is removed, leaving all of the goodness in the food.”

Freeze-dried food is nutritionally equal to raw food, except for the lack of moisture. The food rehydrates in minutes. It retains the taste, texture and smell of raw food. Freeze-dried foods may be better at preserving the natural taste of the food as compared to some dehydrated foods, but it seems to be agreed that the difference is very negligible.

By removing all moisture from these foods, any growth of bacteria, yeast, or mold is inhibited, which is why they have a longer shelf life.

Freeze-dried foods don’t necessarily have to be re-hydrated, though increased moisture content is always beneficial.

Primal Pet Foods Freeze Dried Food (Not Rehydrated)

Some of the freeze-dried foods that we carry:

Orijen (Canadian product)
Grandma Lucy’s
K9/Feline Naturals
Nature’s Variety
Primal (pictured above)
Sojos
Stella and Chewy’s
Open Farm (Canadian product)
Rawz

RAW FOOD

Raw feeding offers exceptional, untouched and bio-available nutrients and live enzymes. It can be messy and more labour intensive.  Some people are worried about any bacteria that may be present in raw food and it can be inconvenient when travelling. Freeze-dried and dehydrated foods offer an alternative for people with these concerns and in these circumstances.

Written by Tamara Low
Co-founder of Tail Blazers