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About Collagen Breakdown In Meat

http://www.sweetbabymedia.com/recipes/allbynumber3/013001.shtml
John Isenhouer asked for a thesis on collagen. It won't take a thesis to discuss the process as it relates to BBQ. Meats are made of muscle, connective tissue, fat and bone. Muscle contains proteins and glycogen. As the temperature of the meat increases, glycogen, a long chain sugar, is reduced to simple sugars. This caramelizes and is responsible for one of the flavor components. Proteins (flavorless) are denatured to amino acids which not only have flavors themselves, but undergo Maillard browning reactions which adds another flavor component. While bone adds no flavor itself, the marrow is rich in methyglobulin and other proteins. This reacts with smoke nitrites to give us the smoke ring. You may have heard that "the sweetest meat is next to the bone". The proteins are reduced to amino acids. Nutrasweet is an amino acid. Fat is very simple cells which breakdown to sugars, fatty acids, and triglycerides at low temperatures. Collagen is proteins that have lots of side chain bonds. This makes them elastic. It takes more energy to denature them than the simpler proteins of muscle tissue. Energy in the form of heat will denature these proteins into the flavorful amino acids. If the temperature is too high, the water in the muscle cells and the fat is rendered out before the collagen melts. This results in dry, tough meat. Too low and you risk bacterial activity. Tough cuts of meat like brisket and pork butts benefit from low temperature cooking as the collagen adds flavor to the meat. Less tough, more expensive cuts do not need this phase and can be cooked at high temperatures for shorter periods. That is why ribs take only a few hours and briskets take 20.

Recipegoldmine.com
Fat can only be rendered in a dry cooking environment over a long period of time and at low temperatures. Here is what happens . . . the meat must attain a temperature of 160� - 170� to start the fat rendering process. At these temps, the meat temperature will 'plateau' . . . that is, it will stay at these temps for up to 2 hours on ribs and 4 and 5 hours on butts and briskets. What is happening is, the collagen (connective tissue) starts to break down . . . this process releases water, which in turn causes a cooling of the meat. So the temps stay steady. This collagen breakdown is what makes meat so tender.
Once this collagen completely breaks down, the temps will start to rise. It is this process that allows all of the fat to be rendered from a rib.

http://www.madsci.org/posts/archives/jan2001/980785018.Cb.r.html
I will answer your question based on my knowledge of Food Science and information provided in the text "Foundations of Food Preparation" 1996. 6th edition, J. Freeland-Graves & G. Peckham, Prentice Hall, Englewood Cliffs, NJ.
As the temperature increases during cooking, enzymes in the interior of the meat that degrade muscle proteins are activated. Between 104-122 F, protein chains begin to unfold and denature (proteins lose their quaternary and tertiary structure. These changes eventually cause the structure of the myofibrils to break and shorten. As the protein molecules aggregate, immobilized water is freed, decreasing the ability of the meat to hold water. You referred to this change in your question.
Protien denaturation and water loss from the muscle contribute to increase in toughness of meat during cooking. High temperatures results in the fat melting, and this fat can be absorbed by the meat or lost as drippings. The fat that covers the surface of the meat reduces water loss, which can aid in maintaining juiciness. Heat can also tenderize meat by breaking down connective tissue (collagen). The heat can denature the collagen resulting in the hydrolysis of the protein chains. The end product of this process is the formation of gelatin. Cooking at low temperatures for long periods of time causes two changes (1) Hydrolysis of collagen and (2) Breakdown of muscle fibers by proteolytic enzymes.
These two processes result in meat that is more tender. This is why it is recommended that one use slow cooking methods for tougher cuts of meat (i.e. pot roast). The color change that occurs to meat on cooking is a results of myoglobin breakdown (pigment that causes fresh hamburger to be red - oxymyoglobin). The surface of cooked meat browns as a result of the partial breakdown of its proteins, fat, pigments and other constituents. The browning that occurs on the surface of fried meat is the result of the Maillard reaction (reaction between the carbonyl group of a reducing sugar and and amino acid or amino group (i.e. that found on lysine)of a protein or peptide.
I hope this answers you question. Sincerely, Al Bushway, Professor of Food Science

http://forums.egullet.com/index.php?showtopic=40548#ref
If the object is to raise the internal temperature of the meat to 60C/140F, then why put it in a 200C/400F oven, overcook the outside, undercook the inside and hope they even out during the resting period? They won�t. The heat changes are irreversible. All that happens is the inside cooks a bit more from the retained heat and some of the juices squeezed out from the middle migrate a bit to the outside.
A much better idea is to put the meat in a much lower oven, say 65C/150F, for a long enough time for the entire joint to come up to temperature � about 5 hours. This also has the beneficial effect of letting the collagen denature to gelatin, as we shall see later. The meat will be uniformly tender, juicy and delicious. People will marvel. There is no danger of overcooking, so timing is not critical.
Stewing, boiling, or braising uses wet heat, and another mechanism comes into play. The glue that holds the muscle together dissolves slowly. This glue is made up of different proteins, primarily collagen. Collagen consists of three strands of molecules wound around each other. The older the animal, the greater the amount of collagen. Likewise, the more active the muscle, the greater the amount of collagen.
With long, slow cooking, those strands will unwind and turn to soft, succulent gelatin, providing the juiciness to tough cuts of stewing beef like oxtail and shin This however is a comparatively slow process. If you cook it long enough for all of the collagen to turn to gelatin, and hot enough for the contraction of the meat to squeeze out the liquid, you have just the cooked meat fibers. If they have been overcooked, you are left with irretrievably dry and stringy meat. Even if it is swimming in liquid, you can�t get that juiciness back into the fibers that the curled up proteins have squeezed out.
Collagen starts to turn into gelatin and dissolve at around 60C/140F. This process (and also the fat melting) takes energy. Experienced BBQ cooks know that during the long slow smoking of brisket there is a "temperature stall" at around 72C/165F, where the internal temperature, instead of continuing to climb, stays steady for a long time before increasing again. That is the period the collagen is converting to gelatin. Once the temperature starts to climb again the conversion is complete, and the meat is tender. Any more cooking tends to dry the meat without improving tenderness.
Heston Blumenthal says that softening the collagen also improves even normally tender cuts of meat, such as the roast beef above. He suggests holding the temperature of the beef for up to 10 hours at 55C/130F (longer will start to generate �off� flavors) to make beef that is "unbelievably tender."
Wet cooking is appropriate for the tougher (but flavorful) pieces of meat that have a lot of connective tissue. The long, slow moist cooking melts the toughness into smooth unctuousness. The tougher pieces of meat can stand the long cooking and will become tender as the collagen dissolves. Even so, although they are fairly tolerant, overheat them and they too will fall apart into dry, tough shreds. These joints have much more flavour than the softer joints
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Lang
This sounds like a great thread for Jack to respond to. He really likes the scientific part of cooking. I'll let him know. I did enough scientific during my radiology training. I did enjoy reading this though, it reminded me of late nights studying. My favorite piece of meat is the beef shoulder roast with the small round bone. You can't find those here anymore, as they all sell boneless shoulder roast. So, I guess you told me the reason why I like it. It just tastes best to me.
Thanks
Peggy
2 Greyhounds....SMOKIN!!!!
lang,
thanks for the thread on this one. it reminds me of when i went to culinary school at age 40. i love the physics of cooking and there is a good book but i don't know if it is still in print. it was titled "on food and cooking" and makes alton brown look like a real dummy. dry reading though if you don't like why food does what it does while cooking. when i was teaching culinary arts i always advised my students to take physics, chemistry and economics for obvious reasons. as an aside a lot of the info in your thread is on the ACF Chefs Certification Exam.
Again thanks for your thread
jack
2 Greyhounds....SMOKIN!!!!
p.s in 1991 our team came in 4th in the nation over just a question similar to this. thank god i didn't blow it lol Big Grin


c
I agree that if you don't hit 190F or so internal, it isn't right. The long times at 165F are a necessary step on the way to finishing at 190F+.

I posted an opinion about nuoc mam for a savory salty flavor instead of other salt based additives on the Forum favorites/butt rub. If you will try this additive, you won't be sorry.....

New poster here.......I currently have a gas smoker and have enoyed this forum site a lot. I have a suggestion about any mop or wet marinade that uses salt/soy sauce/worcestershire. Try adding nuoc mam, fish sauce, instead. The best is the Vietnamese nuoc mam.

There is an unbelievable flavor explosion from using nuoc mam in almost anything. My wife can't stand it, but I always use it and just don't tell her. She loves it on all meats. Used judiciously, there is no discernable odor.

I use 1:1 nuoc mam to cider vinegar plus lots of garlic, pepper, cayenne, etc. It is a great wet brine and works fabulously as a jerky marinade--cross between biltong and jerky flavor. I believe this is a secret ingredient in Slim Jim's!
nuoc mam!!!!! dude you are a guy after my own heart. and this gives me an idea. wonder how it would turn out if pork was marinaded in coconut milk and nuoc mam with a little lemongrass and cilantro and of course some thai holy basil and a few nice bird peppers? for smoke use kafir lime leaves. man i just got to try it!!!!! by the way wasabi powder makes a nice rub on chicken and instead of using beer drink it and 1/2 fill the empty can with sake
scored a few brownie points with 2 greyhounds last week with that one
jack
Nuoc Mam is also good as a sauce over pulled pork. Buttermilk is very good for marinating chicken pieces. It tenderizes without making it mushy like vinager will. I use habernero peppers for heat and flavor in my nuoc mam sauce.

There is no limitation for using a good nuoc mam recipe. Try it with jerky.
Nuoc Mam is also good as a sauce over pulled pork. Buttermilk is very good for marinating chicken pieces. It tenderizes without making it mushy like vinager will. I use habernero peppers for heat and flavor in my nuoc mam sauce.

There is no limitation for using a good nuoc mam recipe. Try it with jerky.
well lang
it is 9.49am here
pork has been on for about 30 mins now.
here's what i marinaded it in for 24 hours
12 oz coconut milk
1/2 hand ginger, thin sliced
3 Tbs homemade habanero paste (similar to melinda's from belize)
1/2 bunch of cilantro, ruff chopped
1 lime thin sliced
1 Tbs fish sauce

meat was a boston butt which i boned out.
used 2 gallon glad bag to hold everything
around noon i plan to start mopping with the leftover marinade

will let you know how it comes out

jack
2 Greyhounds....SMOKIN!!!!!
I can't wait to hear about about your caribbean pork! Use more fish sauce next time...

I just did two whole chickens that I brines for 5 hours. They were wonderful.

I have a 10lb.load of beef top round slices about 1/2" x 1" that I marinated in 1c cider vinegar, 1c fish sauce, lots of pressed garlic and juice from a lemon. Soaked it for 6 hours and racked it to drip dry. I will smoke it at about 130-140F over night. It should be ready by early afternoon tomorrow.

You should see how attentive the dogs get when I make jerky!

All the best--
lang
you were right
next time will double the fish sauce and will add lemongrass and thai basil.
other than that for a 1st time try it was killer.
took it off at 2.30p.m. and let rest 30 mins.
sliced like a dream.
peg had me add it to our recipe journal for catering.
today i have fine diced some pork and added more 5 spice powder and a little oyster sauce.
making spring rolls but sure wish i had rice paper instead.
serving with coconut rice.
thanks for reminding me of fish sauce and you are right the best is vietnamese but i still like thai cooking cause that was where r & r was lol
jack
You guys are hilarious.

...here I am, checking the thread for a collagen discussion updaate and you're speaking about vietnamese spices...

just a suggestion, but don't hesitate to start new threads. The reason I suggest that is good suggestions, like nuoc mam get lost when I archive these. I haven't figure where to archive this one...

but you guys crack me up, and hey it IS a great idea

Big Grin

Smokin'
SO & PC313.......

Speaking of COLLAGEN, I took about 10lbs of top round roast, trimmed it for jerky and threw all the trimmings--nasty tough fiberous COLLAGEN-laden stuff with some meat and fat--into a crockpot with a little Morton's Seasoning Blend. 8 hrs on high and it was was tender and gelatinous which confirms that COLLAGEN BREAKDOWN and the general process of denaturation of protein compounds generally found in meat is a direct function of time and temperature.

I have also been succesful grilling thick nasty fibrous cuts, chuck, etc, until they are well charcoaled on each side but still raw on the inside. 6-8 hrs in a moist 200F cooker makes a tough steak fall apart. Use the right amount of spices. It doesn't need any water, although a luttle chicken stock does wonders for gravy. Currently using it for birria tacos and shredded beef caesar salad.

This was a test of the COLLAGEN BREAKDOWN theory. There was no way that these trimmings would be good for anything-even hamburger. Time and temp really make the conversion to a succulent pile of flavored beef tissue.

It would seem that the magic temperatures of 160-190F for 6-8hrs is what transforms trash into treasure. Looks bad, tastes good.

Don't forget the nuoc mam.......I am convinced it helps denature the COLLAGEN!!!!!

I will create a nuoc mam thread somewhere more appropriate so we can continue this discussion. I also have today's catch--smoked salmon--as a .jpg to post.

All the best--Lang

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