Raw feeding 911 Part 25:HPP (High Pressure Pasteurisation) processing on raw frozen dog food

 In the previous entry titled “Raw feeding 911 Part 13: Raw diet specific policy vote on AVMA“, I wrote that AVMA had a voting for the policy against the raw meat pet food feeding; discouraging the feeding to cats and dogs any animal
protein source that has not been processed to eliminate pathogens due to
the risk of illness to cats and dogs as well as humans.

 The AVMA has approved the policy (you can read their policy on raw diet from their point of view here), and since then, many companies that offer premade raw frozen patties mix from Nature’s Variety, Stewart, Stella&Chewy, Primal pet foods etc.. have started adding the additional processing to their raw frozen food called “HPP (High Pressure Pasteurization)” to eliminate pathogen in their products, which AVMA pointed out as the reason why they vote against the raw diet for cats and dogs for the first place.

 All of those companies state this processing step is all natural and no change in product color,texture, nutrient, except change in eliminating the pathogen in the product, would that be true to their statement?

 Besides HPP treatment processing step, to eliminate pathogen in the products, authorities can look into “irradiation” processing but, to me personally, all of these extra step of choice did not sound healthy choice.

 There are some dog treats irradiated for human/dogs on the market but, would you give those to your dog? Do you think there is no health risk for dogs consuming irradiated dog treats? 

I get fresh food all da time.

Today,I will be getting sardine and a duck foot for da breakfast.

I am patiently waiting for mom to say “OK” to dig in!

  In this entry, I would like to look into what HPP is, What it does to the raw food. 

What is HPP (high pressure pasteurization)?

 HPP is the food processing step that use pressure to preserving/sterilizing food (kill the pathogen and inactivate the enzyme in the foods).

 According to wkipedia website, first, products will be sealed tight and placed into steel compartment containing a liquid,and pumps are used for the pressure.

 The pressure is applied uniformly applied, and after certain period of set time, pressure is released.

HPP effects on food…

 During this HPP process, according to PDF document written by , N. K. RASTOGI, and K. S. M. S. RAGHAVARAO
(Department of Food Engineering, Central Food Technological Research Institute), VM. BALASUBRAMANIAM
(Department of Food Science & Technology, The Ohio State University),
(School of Food Biosciences),U.K.
KNORR , it states that
the protein will be denatured when the pressure exceeds 300MPa (Page 5 out of 45 page documents).

 At 700 MPa, protein structure changes.

 At page 18, specific to animal protein that were treated with HPP, it says that pressure changes in muscle enzyme “meat proteolysis”, and “myofibriller protein”.

 Therefore, as a result, it changes its structure and texture, and it influences the tenderrization, gelatin process of the meat (color) and the extent of Lipid peroxidation,which leads to poor taste and health benefit.

 This denaturation  is due to the destruction of hydrophobic and ion pair bonds,and unfolding the molecules.

 The PDF documents here from University of Queensland in Australia shows how the raw meat can change its color with various pressure strength on page 24 out of 43 pages documents.

 If you look at cooked meat picture to compare, you can see that “cooked” meat is not effected by the pressure for the color change.

 When I looked at the pictures,I wonder if the companies that implement the process of HPP processing did not realize that it is the “cooked” meat that does not change its color with pressure.

 The HPP processing does inactivate the bacteria but bacterial spores are resistant to the pressure unless this process is done with heat close to 100 degree Celsius (212F).

 The denaturation of protein with HPP processing can be found at pmc website here as well.

 Besides denaturation in the food, according to Wiley online library article written by
 H. Simonin,
F. Duranton and
M. de Lamballerie
, HPP process accelerate lipid oxidation, color,texture change and sensory acceptability.

 In the PDF document published online at Wiley Online library and written by DianeM.Barrett , and Beate Lloyd, here, you can find the nutrient loss in the vegetables and fruits when they were treated with HPP process. Some are minor but some are more than small amount.

 Even FDA website here states HPP process will denature the protein and, even if heat was not use with HPP processing.

 When the pressure is applied, the temperature rises (rise larger especially if the food was high in fat). In average, 3 degree Celsius (37F)  per 100 MPa , and its temperature backs down when it got decompressed.
 Answers Raw Pet Food company here has a good document on HPP processing as their Word document file as well.
 In conclusion, HPP does change some things in the food; structure, text,color,and in some cases, nutrient content even though all the raw frozen pet food companies say they would not change its texture, color, nutrient except inactivating the bacterias in the food.

 Even if they do not use the heat when they do the processing of HPP treatment, if the protein source was high fat content items, from what I read through all of these studies and documentations, it looks like it should raises more temperature when they were applied pressure.

 I wonder if it is the reason why HPP treated vegetables loses its nutrient; because of the heat coming through from pressure even if the temperature gets back down when pressure is released.

 With common sense, if vegetables does lose some nutrient content, I would think that meat also lose its nutrient content to some extent and would not be zero changes. I also think that HPP processing would effect more on especially the one with high fat content overall.

HPP processing at 3rd party facility..

 I was curious whether the raw frozen dog food company does the HPP processing on their own at their facility so they can overseen the whole process from the start to the finish.

 Therefore, I have picked Stella&Chewy company and asked about it.

 Nature’s variety does say their food gets treated with HPP by 3rd party company, and Stella & Chewy also responded me that all of their products that include frozen dinner, freeze dried treats, everything they offer undergo the HPP processing at 3rd party facility place.

 To prevent contamination by surface or air-born pathogen, during the processing, they use series of devices that omits low level of pathogen fighting gasses such as ozone and hydrogen peroxide.

 Do you think that the raw frozen dog food that are HPP treated this way vs untreated raw meat are still exactly the same except pathogen level and still good raw meat to feed your dog?

 To me personally, I feel that they are the unnecessary processing step with more product cost added with less quality of raw meat as a finished products.

 Would this application of HPP processing is for the authorities like AVMA to make the cost of frozen raw diet cost to increase and hoping that someone would change their mind and start purchasing kibbles again because of the cost difference?

 Dogs eat poop, which I think has lots of bacterias in it, but they do not get sick.

 Tiger and Lion (big cat) eats raw meat and they do not get sick.

 I have seen cats catches the mice and eat them raw and he did not get sick.

 Otter enjoys raw fish and they do not get sick.

 We human also enjoy sashimi, steak tartar, tuna tartar and we are fine.

 Dogs have different digestive system and,their intestine is much shorter than ours. This is why, dogs can digest the raw meat without getting sick from salmonella.

 When it comes to raw meat, humans are more susceptible to salmonella than to dogs because of our long intestine.

 Of course, whether you are
preparing raw meat that are not treated with HPP for family,friends or for your dogs/cats, or whether you are handling HPP treated raw meat dog food or not, we should take the
same precaution and we should wash hands well before and after handling
meats so we would not cross contaminate the food.

 To me, it also sounds like this processing step is more for human than dog’s.

 For me, for our dog’s health, I would still believe that pure raw meat menu is better than HPP treated raw meat even if pathogen is inactivated. Pressure does not kill all of the bacteria and it denature the protein structure.

 Besides, the processing is done at the 3rd party facility, not at the maker’s facility.

 If I had to choose the HPP treated food for us human or for pets, I would be more comfortable having it done at the same facility,rather than at the 3rd part facility for the reasons of re-contamination possibility and the maker of the products being blindfolded and not observing how their products are handled at the 3rd party facility.

 If you feed raw frozen dog food, you should be informed that some frozen dog food is HPP treated, and some aren’t.

 If you would like to have more information on the products you feed, contact the maker of the products.

 HPP treated raw frozen dog food vs non HPP treated raw frozen dog food, which would you feed to your dog?

 Would you feel more comfortable if the food you feed to your dogs are HPP treated?

 Share your opinion in the comments below.

Apr 23, 2014 | 0 | Dog Diet

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