Collagen -> Gelatin... temperature?

[infernooo]

Hi folks,

I have read many conflicting accounts of what is the "proper" temperature that collagen is converted into gelatin when cooking tough cuts of meat... can someone enlighten me on this? I have read numerous sous vide and barbecue threads all stating different temperatures.

As an example of this, lets say I want to slow roast a leg or shoulder of lamb and want it VERY tender but don't want it cooked past well done as you would a pulled pork shoulder - what temp would I set my oven/sous vide device at? (I can maintain pretty much any temperature between 40c (~100f) and 270c (~520f) in my oven with very good accuracy) I assume it would have to be at the temperature that the collagen converts to gelatin (which hopefully is somewhere between rare and medium doneness!)

Thanks!

[infernooo]

I forgot to mention the conflicting temperatures... The BBQ'ers say "75C/175F", the sous vide thread says the conversion/breakdown starts at 130F (very slowly) but also mentions 140F as the magic number...

[BryanZ]

I was under the impression that 130 is where the magic starts to happen.

BBQ'ers only say to cook your pork to around 175. The amount of time the protein spends over 130 on the way up to 170-190 or whatever you choose to stop cooking at is significant, allowing for collagen breakdown. Perhaps that's the explanation.

Edited March 6, 2007 by BryanZ (log)

[rama]

pg 111 in my copyright 1984 copy of On Food and Cooking:

... the collagen in connective tissue requires more extensive cooking in order to be converted into soft gelatin. This process is in some ways the reverse of protein coagulation in the muscle fibers: tightly wound fibers of pure collagen come apart into more vulnerable single molecules as they heat up. The "shrink temperature," the temperature at which the ordered structure of this protein collapses, is about 140F (60C) in meat (a mere 105F (41C) in fish), and it is only at temperatures higher than this that the individual molecules separate from one another into the loose association we call gelatin.

It goes on a bit more about compromises in cooking time/temp, but I've plagiarized enough.