The following nutrients are reduced by cooking at temps over 300 degrees:

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• Water-soluble vitamins: Vitamin C and the B vitamins — thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), folic acid (B7) and cobalamin (B8).

• Fat-soluble vitamins: Vitamins A, D, E and K.

• Minerals: Primarily potassium, magnesium, sodium and calcium.

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A good read: https://www.whole-dog-journal.com/issues/4_3/features/5150-1.html

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Dogs Naturally Magazine:

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From an article provided for petsumers on the Pet Food Institute website (lobby organization of Big Pet Food), the following diagram explains the process of making kibble pet food by extrusion.

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• Step one, dry and wet ingredients may be ground, and then mixed together to form pet food dough.

• Step two, the pet food dough is “preconditioned” by heat and steam.

• Step three, the extrusion process is where the dough is forced through a channel with what looks similar to a giant screw in the middle.  The pet food dough is cooked using heat and pressure. At the end of the extruder hot pet food dough passes through a shaping die and knife which produces wet pieces of kibble.

• Step four, the kibble is then dried using heat.

• Step five, a coating of flavoring and or probiotics are sprayed onto the dried kibble.

• Step six, the kibble is packaged into bags.

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Raw ingredients of pet food are treated with heat, steam, and or pressure in three steps of the manufacturing process

(imagine cooking a chicken three times before you eat it).

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 The result, as Dr. Aldrich explains, can be the destruction of essential nutrition of the pet food.

“Petfood is unique. Unlike with human foods, many of the starting ingredients used in commercial petfoods have already been extensively processed (e.g., meat and bone meal, tallow, rice bran, etc.), all of the ingredients in the diet are mixed together and then processed under fairly harsh conditions (e.g., extrusion) and the finished product is expected to be shelf-stable for more than a year under ambient conditions.”

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“Human foods are typically singular ingredients or dietary components, only a portion of which are processed, they are eaten a la carte in multiple meals throughout the day and most are refrigerated, frozen or consumed within weeks of production. Livestock feeds use a similar all-in ration approach like petfoods, but the final diet is seldom heat-processed and is commonly fed the same day it’s produced, so shelf life is of little concern. These differences have profound implications on the nutritional value of the final product.”

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“With petfood ingredients, the most prominent processing challenge is a result of the rendering process. This is important because rendered protein meals are found in nearly all dry petfoods. These protein meals, like meat and bone meal and chicken by-product meal, have undergone extensive cooking to reduce moisture and fat. While the intent of the process is to stabilize and homogenize the resulting material, significant nutritional variability exists (Pearl, 2004). The nutrients most affected by the process are essential amino acids such as lysine and the sulfur amino acids methionine and cysteine.”

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“All vitamins appear to be affected to some degree at every step of the process from production through shelf-storage (see Figure 3 under More Images). The loss in fat-soluble vitamins (A, D, E, K) is the most significant in extruded products, with rates of more than 50% lost before the kibble goes into the bag (Coelho, 2003). In wet foods, the water-soluble B-vitamin thiamine can be almost completely lost due to its reactivity with heat, moisture, sulfites, elevated pH and the thiaminase enzymes found in fish and organ meats.”

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“Today, we support nutritional adequacy by super-fortification before and nutrient analysis after the fact. Generally, this has proven effective, but occasional toxicities and deficiencies resulting in recalls occur. This would suggest that we still need more comprehensive evaluation of the nutritional effects of thermal processing of petfoods with better models to support fortification needs.”

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Dogs Naturally note:

 Because so many nutrients are lost during processing, synthetic vitamins and minerals must be added back into the food in the form of a premix.  If the premix wasn’t added, the food would not meet the minimum AAFCO standards. Most premixes are manufactured in China.

 

Next we should discuss the bodies (human or animal) ability to process synthetic vitamins & minerals

 

Unnatural vs natural, does it matter?

Let’s analyze just one mineral out of the above list of synthetic additives: sodium selenite.

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Sodium selenite contains selenium. When we eat natural, unprocessed, whole foods such as nuts, meat, mushrooms, fish or eggs, we eat selenium that is complexed and consumed along with other nutrients which help the selenium function properly in the body. “Humans and animals derive selenium primarily from foods. In plants and animals, selenium is primarily localized in the protein fraction” (Ferretti and Levandar, 1976). Brazil nuts are the richest dietary source of selenium. High levels of selenium are also found in kidney, tuna, crab, and lobster. But, these foods contain selenium, not sodium selenite.

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“Both mutagenic activity (cancer causing) and antimutagenic (cancer preventing) activity have been attributed to selenium; the concentration and the chemical form in which selenium is administered appear to be critical in determining its effects. At the trace levels normally found in biological systems (plants and animals), selenium apparently acts as an antimutagenic, oxygen-radical scavenger, but at higher concentrations selenium is capable of inducing mutations (cancer).”

Arciszewskaet al, 1982; Shamberger, 1985; Kramer and Ames, 1988

 

Where does sodium selenite come from anyway? Sodium selenite is prepared by evaporating an aqueous solution of sodium hydroxide (lye or drain cleaner) and selenous acid (Merck Index 1983). Selenous acid is produced by combining water and selenium dioxide which is produced during the industrial purification of copper.

 

A body can thrive on smaller amounts of whole food source vitamins than it can on their synthetic counterparts. If the addition of a vitamin or mineral nutrient is necessary, it should ideally be added from a whole food source.

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