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Friday, November 21, 2008

It's not just leftovers, it's GenEd science.

Wow, three weeks have passed since my last post. It may seem that I haven't learned anything in that time which may be correct. Spring registration has been particularly busy so I haven't had time to post let alone to learn much.

I am enjoying my conversations with Bill Bloemer who is teaching CHE 137 Chemistry Cooks. Bill is the Dean Emeritus of the College of Arts and Science and, like so many other retired UIS faculty, continues to teach. He was also the person who hired me so we've had a lot of cooking conversations over the years - something we both enjoy.

A couple weeks ago, his class was covering the Maillard reaction. This is chemical reaction involving an amino acid and a sugar (Bill would give you a better and more correct answer.) Maillard results in hundreds of different flavor compounds and is the basis for many artificial flavors. If you've ever made a pan gravy by scraping the brown bits off the bottom on the pan, you've tasted some of these flavor compounds.

I did the lab assignment for his class (at least the fun part that resulted in dinner) by making gumbo. I've made many a roux in my life (flour and fat used as a thickener) but I've never had the courage to make a chocolate roux, which is required for gumbo. If you know how to make a roux, imagine continuing to cook it until it goes from white to blonde to tan to chocolate. Those color changes are a sign of the Maillard reaction. It was not as difficult as I thought. By the time it got dark brown, it started smelling like burnt popcorn, but it didn't taste like it.

Last week, they were studying brining ('tis the season with Thanksgiving turkeys on the menu soon.) Common knowledge is that brining is an osmotic process in which salt, which is in higher concentration in the brine, moves through the cell walls of the turkey to create equilibrium. If you watch Alton Brown, he says this every year and has cute demonstrations of how it works. Bill likes to watch Alton, but he tells me Alton is out of his mind when it comes to brining. He says osmosis would move water from out of the turkey in an attempt to dilute the brine. Equilibrium might be the result but it would be at the cost of a shriveled up turkey that had lost its moisture.

Of course, this isn’t what happens when your brine. Your turkey gets heavier and juicier and the salt and other seasoning do get into the turkey. So if not osmosis, as Alton says, then what? Bill says it’s not a cellular process. Muscle tissue is made up of bundles of cells, muscle fibers. He thinks that the muscle tissue is simply acting like a sponge and holding water among the fibers rather than within the cells themselves.

He did an experiment with some porkchops. He weighed two porkchops. One was soaked in plain water and the other was brined. After an equal soaking time, he weighed the two porkchops again. The brined chop had absorbed more liquid than the unbrined chop. His theory is that the salty brine breaks down the connective tissues that hold the muscle fibers tightly together. This means that there is more potential space between the fiber which allows them to absorb more water.

3 comments:

Ray of Sunshine said...

Wow...I never knew that much existed from the cooking process and I've been cooking for several years now. It's amazing all the things one can learn from trial and error, other people's recipes, and by watching another cook on a television show. I will admit that your post is making a sistah r-e-a-l-l-y hungry, lol. I don't know if I can stand to wait until Thanksgiving day to enjoy turkey with all the fixings. I could really go for a big dinner plate right now, lol. Great post, Andy! I really enjoyed reading what you've learned about cooking and more. And you're absolutely right that cooking is a science. Even though I've never looked at it so much from that angle, it is definitely a science because you're cooking something over a flame and you're testing out recipes that could either turn out to be very good or really bad experiments. Thanks for sharing this with us. It sure comes right in time for Thanksgiving! Yum! :)

~Pam~

Beth C. said...

Andy, I would love to take that class. Can I still take it after I graduate? I remember learning that water follows salt. That is true in the human body as well, that is why if you receive fluids in the hospital you need 9% saline to make sure your body will maintain an electrolyte balance. If the body's salt levels are too high or too low (hypernatremia or hyponatremia), all of your cells will either swell up or be depleted of water and you will be very sick. With meats I thought I heard that you salt them after they are cooked so the juices are not drawn out of them. I am only making jello this Thanksgiving but would like to investigate this brining theory further.

Andy Egizi, Program Coordinator said...

I don't think salting meats before you cook them is a problem unless the meat is sliced very thinly. I think it's actually a good thing since it would draw some juices to the surface which would promote carmelization including Maillard reaction.

When I BBQ a turkey or brisket, I leave a salt/sugar based rub on the meat for a day or more. My thought is that the salt draws out moisture but the sugar, which is hygroscopic, absorbs and maintains the moisture which leads to a nice "bark" (that tasty black stuff on the outside of BBQ.

I do understand that you should not pepper meats before cooking on high heat since it burns. I've never paid attention to this "rule" and never noticed a problem.

Once you graduate you have to reapply to take more UIS courses. If you can on to grad school with us, you'd do a full application but you could apply non-degree seeking if you just want to take a course - you just fill out the app. Once you graduate no more grant money from FinAid and no loans unless you're degree seeking.