Freeze dried VS Cold pressed pet foods

New foods and their fancy processing methods are bursting onto the scene and taking the pet food world by storm! Freeze dried, air dried, cold pressed, gently cooked, high pressure pasteurized…the list goes on. But today, we focus on the two newest on the scene; freeze dried and cold pressed.

I’ve received so many questions about these two types of pet food lately so I’m here to give some insight into how these foods are made, what benefits or drawbacks they may have and what to look for when shopping for a freeze dried or cold pressed diet.

Freeze dried pet food

Freeze dried diets undergo a three step process; first the diet is frozen, a vaccumn is then applied, and then the temperature is gradually increased slightly to turn the moisture in the diet into vapour (this is called sublimation). The end product contains 2-5% moisture. This type of food is designed as a safer alternative to a raw diet; the process is designed to reduce the bacterial load of the food and make is safer for consumption. It does not, however, remove ALL bacteria but studies show that it does reduce the survivability of the bacteria so it’s unlikely to be pathogenic when the food is eventually ingested. Some freeze dried diets are designed to have water added back in when serving, which rehydrates the food making it expand – this usually results in actually feeding smaller amounts than a traditional diet.

Benefits
– Raw without the risk: Suitable for clients who wish to feed a raw diet without the risk of bacterial contamination.

– More nutrient content: these diets claim to contain more nutrient content than other processing methods, but I was unable to find studies supporting this however based on the processing method of this diet, some nutrients or vitamins may be more bioavailable than others that degrade when cooked.

– Ability to rehydrate: some pets will benefit from the addition of water to a diet and in some cases the rehydration process actually reduces the overall amount of food you need to feed, which can be beneficial for pets who need to lose weight.

– Palatable topper: using freeze dried foods as a topper is a good way to encourage intake of food when pets are not interested in eating and if the diet being used is complete and balanced, the pet won’t be missing out on any nutrients if they decide only to eat the topper.

Disadvantages
– Freeze drying doesn’t remove all bacteria: as freeze drying is actually a method of preserving bacteria in the lab, adding water as most of these types of diets recommend can potentially ‘wake up’ the bacteria and make it live, increasing the chances of the pet falling ill.

– Excessive protein levels: these diets can be very high in protein and although you may be feeding less as a result, there’s significant waste to the body as the excess protein is excreted and in some pets, excess protein can be harmful to the kidneys or cause weight gain.

– Cost: the process of freeze drying is actually very expensive and labour intensive, so this cost is then passed onto the pet owner therefore freeze dried pet food is usually quite expensive to buy.

– Nutritional content: you still need to ensure the diet is complete and balanced as not all freeze-dried foods are designed to be fed as a sole diet (some are only designed to be used as a topper, treat or occasional snack) so always check the label.

Summary
For freeze-dried pet foods, I always recommend clients investigate the companies processes; check if the company performs testing on its final products to ensure they are free from bacteria. Consider your pet’s needs and preferences too; for picky eaters, a freeze dried diet might make a good appetite stimulant when used as a topper but for a pet with a sensitive tummy it may be unsuitable to use this type of diet due to its excessive protein levels and risk of bacterial growth.

Cold pressed pet food

Diets that are ‘cold pressed’ also follow a three step process; ingredients are ground up before cold water is added, and the food is then pressed. When pressing, the food slightly heats up, gently cooking the food between 42-46°C. Food is usually then stored in a vaccumn sealed pack, or tetra pack. Cold pressed diets are a type of gently cooked food, which is designed to retain more nutrients by cooking at a lower temperature, as an alternative to kibble diets that are cooked at higher temperatures (usually between 90°C-120°C).

Benefits
– Digestibility: cold pressed foods, like all gently cooked diets have a high digestibility and with the ingredients being finely ground they are broken down slightly making them easily digested and suitable for pets with sensitive digestion.

– Palatable for all ages: cold pressed foods retain alot of their original flavours and aromas so can be beneficial for senior pets who may lose interest in food due to age-related conditions. It can make a good supplement to their current diet or as a pure diet.

– Cost: the price of a cold pressed food is significantly cheaper than freeze dried foods as the process is alot less costly so these savings are passed onto the consumer.

– Safe: Given cold pressed foods are considered a gently cooked diet, the bacteria in the diet is killed and not present in the final product (unlike freeze drying where the bacteria is more or less dormant). This is another reason it is suitable for pets with sensitive tummies.

Disadvantages
– Spoilage: These diets generally do not contain any preservatives, so once the package is opened it must be consumed or discarded. As these diets are often in a moist form, they rapidly spoil when left out which results in wastage. Cold pressed kibble diets also rapidly spoil, so you’ll need to be mindful of this too.

– Wastage: as above due to the rapid spoiling of these forms of diets, the wastage may be higher than a diet that is dry or preserved in other ways. This means that although you may not be paying much for the diet itself, you likely will be purchasing more of it as you are wasting alot of food if your pet doesn’t eat it all right away. Some companies do try to overcome this with making their packaging recyclable but this obviously doesn’t help the food waste.

Summary:
Cold pressed diets are the latest craze. They certainly do provide alot of benefits and may be a good option for pets who are picky and like diets that retain alot of natural flavour and scent. It can also be a good choice for pets with sensitive digestion due to its gently cooked nature and higher digestibility. Due to the lack of preservatives (natural or otherwise) it is also important to take into account the potential food waste, so if your pet doesn’t tend to eat their entire meal in one sitting, it may not be a suitable choice for them.

As with any diet, I always recommend clients use the WSAVA Guidelines on Selecting a Pet Food as a guide in choosing a reputable company to get your food from. These guidelines apply to ALL types of diets, and if the company can’t or won’t give you an answer to these questions, they probably aren’t something you should be feeding your pet. I feel with these new processing types of pet foods popping up, it’s vital we view these foods behind the lens of science rather than getting attracted by the flashy marketing and buzzwords. And if you need a little extra help selecting a pet food, why not set up a Nutritional Consultation with me!

Do you feed a freeze dried or cold pressed diet? Have you noticed any improvement in your pet’s health on these diets? If yes, please let us know in the comments below!

If you found this post helpful and informative, please consider making a small donation via buymeacoffee. The proceeds help me continue to provide educational materials for Veterinary professionals and pet owners.

References

Kananub S, Pinniam N, Phothitheerabut S, Krajanglikit P. Contamination factors associated with surviving bacterial in Thai commercial raw pet foods. Veterinary World 2020; 13:1988-1991.

https://www.researchgate.net/publication/340429073_Beynen_AC_2020_Pressed_dog_food

One Comment Add yours

  1. mvdhaak says:

    Cold pressed kibble have no higher digestibility than extruded foods, and they aren’t better tasting, according to this study:

    Fatma, İ. N. A. L., et al. “Using of Pelleted and Extruded Foods in Dog Feeding.” Kafkas Üniversitesi Veteriner Fakültesi Dergisi 24.1 (2018).

    My experience in The Netherlands, where pelleted kibble has been on the market for a long time, is that most dogs like extruded foods better. I think pelleted foods is less tasty for most dogs, because:
    – In pelleted foods, only meals can be used, no fresh ingredients.
    – there is no fatty layer around the kibble

    The protein being less digestible is probably caused by more Maillard reaction in pelleted foods, which also causes more damage to lysine, sources:

    van Rooijen, Charlotte, et al. “Quantitation of Maillard reaction products in commercially available pet foods.” Journal of agricultural and food chemistry 62.35 (2014): 8883-8891.

    Tran, Q. D., et al. “Lysine reactivity and starch gelatinization in extruded and pelleted canine diets.” Animal feed science and technology 138.2 (2007): 162-168.

    van Rooijen, Charlotte, et al. “The effect of steam pelleting of a dry dog food on the Maillard reaction.” Animal Feed Science and Technology 198 (2014): 238-247.

    This study suggests the minerals in extruded kibble are better absorbed than the minerals in pellets kibble:

    Stroucken, Willeke PJ, et al. “Extruding vs pelleting of a feed mixture lowers apparent nitrogen digestibility in dogs.” Journal of the Science of Food and Agriculture 71.4 (1996): 520-522.

    Like

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