Best diet for cats?

[mschauer]

I find this interesting...

Originally Posted by LDG

http://www.beyondveg.com/tu-j-l/raw-...ooked-2h.shtml
Amount of nutrients in a food (the potential "benefit"). First, virtually all foods contain more nutrients in the raw state. On the other hand, the differences are not very great: ranging from approximately 10-25% in the case of most vitamins, while the difference is negligible (almost zero) with respect to minerals.

... in view of my earlier comment:

Originally Posted by mschauer

I think most people would agree that deriving nutrients from a natural source (food) is better than getting them from some sort of supplement. And cooking certainly destroys *some* nutrients. But cooked food is far from devoid of nutritional value. For some nutrients the amount destroyed may not even matter. There may still be enough left that the benefit of deriving the nutrient from a natural source remains intact. Even if it is necessary to provide some nutrients in a less natural way I would think that amount would be far less than what would be necessary with a processed diet.

I'd love to see an authoritative reference on approximately how much each vitamin and mineral is affected by cooking and at what temps.

 

[ldg]

Originally Posted by mschauer

I'd love to see an authoritative reference on approximately how much each vitamin and mineral is affected by cooking and at what temps.

Information on that site is referenced:

Cobalt is a metal, hence a mineral by definition (1) above, but not necessarily by definition (2) above. Cobalt is an essential part of cobalamin, a compound better known as vitamin B-12. Herbert et al. [1984] reports that vitamin B-12 was heated to 200°C (392°F) for 6 days, with only 15% loss.

The reference is Herbert V, Drivas G, Manusselis C, Mackler B, Eng J, Schwartz E (1984) "Are colon bacteria a major source of cobalamin analogues in human tissues?..." Trans Assoc of Amer Physicians, vol. 97, pp. 161-171.

Copper: For an example from the plant world, Neumann et al. [1995] discuss how the plant Armeria maritima binds a heavy metal (copper, from natural copper in the soil near a copper mine) into heat-stress proteins within the plant, which are stable and extracted for analysis at 95°C.

The reference is Neumann D, Nieden U, Lichtenberger O, Leopold I (1995) "How does Armeria maritima tolerate high heavy metal concentrations?" J Plant Physiol, vol. 146, pp. 704-717.

Sulfur: Two important sulfur-containing amino acids, methionine and cysteine (both found in many plant foods, see Giovanelli [1987]) survive--to a large extent--after cooking. See Clemente et al. [1998] and Chau et al. [1997] for two research papers reporting the survival of these amino acids with cooking.

The references:

Giovanelli J (1987) "Sulfur amino acids of plants: an overview." In: "Sulfur and Sulfur Amino Acids," Methods in Enzymology, vol. 143; eds. Jakoby W, Griffith O; Academic Press, Orlando, Florida; pp. 419-426.

Clemente A, Sanchez-Vioque R, Vioque J, Bautista J, Millan F (1998) "Effect of cooking on protein quality of chickpea (Cicer arietinum) seeds." Food Chemistry, vol. 62, pp. 1-6. http://www.sciencedirect.com/science...08814697001805

Abstract

Heat treatment produced a decrease of methionine, cysteine, lysine, arginine, tyrosine and leucine, the highest reductions being in cysteine (15%) and lysine (13.2%).

Chau C-F, Cheung P C-K, Wong Y-S (1997) "Effects of cooking on content of amino acids and antinutrients in three Chinese indigenous legume seeds." Journal of the Science of Food and Agriculture, vol. 75, pp. 447-452. http://www.esaim-ps.org/action/displ...=03&aid=799840 or http://agris.fao.org/agris-search/se...l;GB1997039037

From this page "Does cooked food contain less nutrition?" http://www.beyondveg.com/tu-j-l/raw-...ooked-2a.shtml (which mostly discusses starches and grains)

From Oste [1996], heating (above 100°C, or 212°F) decreases meat protein digestibility (although this is covered at length in the more recent review piece by Carmody and Wrangham, 2009, in my earlier post).

Oste RE (1996) "Digestibility of processed food protein." Adv Exp Med Biol, vol. 289, pp. 371-388. Review. http://www.mendeley.com/research/dig...-food-protein/

Seidler [1987] studied the effects of heating on the digestibility of the protein in hake, a type of fish. Fish meat heated for 10 minutes at 130°C (266°F), showed a 1.5% decrease in protein digestibility. Similar heating of hake meat in the presence of potato starch, soy oil, and salt caused a 6% decrease in amino acid content.

Seidler T (1987) "Effects of additives and thermal treatment on the content of nitrogen compounds and the nutritive value of hake meat." Die Nahrung, vol. 31, no. 10, pp. 959-970. http://www.ncbi.nlm.nih.gov/pubmed/3437919

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And while this doesn't have as much detail as you requested, it does have information on the impact of various factors (including cooking) on vitamins:

Effects of cooking on vitamins (tables): http://www.beyondveg.com/tu-j-l/raw-...ooked-2e.shtml

And here are tables that indicate the comparison of vitamin levels in raw vs cooked food, either not corrected for water loss OR corrected for water loss: http://www.beyondveg.com/tu-j-l/raw-...ooked-2f.shtml

 

[mschauer]

Originally Posted by LDG

Information on that site is referenced:

Yeah I did notice the references. There are tons of them!

Thanks for pulling out some of the relevant ones. When I get a chance I'm going to spend some time going over some of the others. I'm currently working on a project to identify exactly, well as closely as possible without use of a lab, what nutrients are contained in a homemade diet. Some of those references might help.