I was wondering about the actual technical process of determining nutrients in a given portion of food.
Specifically, let’s talk about something like fried chicken with coating.
It seems to me that they would have to liquify the piece of chicken, then measure the nutrients in a sample. And that if that IS the way they figure it out, then it isn’t quite right for some things, like fried chicken, because the liquified stuff will include bits that are never eaten, or are not usually eaten, like the bones, and the coating over certain parts of the bones.
So how is it done, exactly. Anyone know?
stoid
wanting to eat more fried chicken on her low-carb diet.
If you’re talking about chicken meat, it’s muscle (100% protein). The amount of non-meat substance, such as fat and skin, can be measured. The coating material is known.
My first job out of college (BS in biochem and Mol Bio) was determining nutritional content of food. We actually did the testing on McD’s and we did a fried chicken study of various fast food chains as one of them was advertising a healthier version and a competitor wanted to see.
Anyway, we went to several locations of each chain and bought large orders over the counter (one manager actually kind of freaked out and offered me money to tell him what was going on. He had apparently called his colleagues and found out they recieved the same large order). We had a large sample prep kitchen that contained state of the art kitchens and what not for cooking food as it was supposed to be cooked per the directions. For the chicken, the techs cut the meat off the bones as specified in the study protocol under the supervision of the study director. The study called for " a sample consistent with the edible portion of the product". So, no bones or inedible portions. The meat was then placed in a “suitable sample homogenization apparatus” (i.e. a big-ass industrial blender) and homogenized, but not liquefied.
I’ll spare you the gory details of the assays for each nutrient or additive save that it is done via various analytical chemistry techniques as specified by the [url=“http://www.usp.org”]USP[/link]. These methods are rigorously controlled and monitored and in order to be licensed to “officially” perform them, your lab must jump through all sorts of QC hoops and accept random test samples from the USP for calibration and validation.
All in all, a pretty interesting job. If you’re bored some time I’ll tell you about the pesticide residue screening we did on environmental samples (that’s “homogenized” carp, frogs and sparrows to the lay person). You haven’t lived until you’ve gone to work hungover and had to extract pureed carp samples with warm acetic acid (vinegar) and alcohol!
Thanks, jk. “sample consistent with edible portion” is telling.
And barbitu8, my understanding is that the only pure naturally occurring protein is egg white. All other natural animal proteins have some degree of fat, even in what appears to be pure muscle.
Fat surrounds muscle, but the muscle itself does not have any fat. Well marbled steaks, for example, have much fat, but not inside the meat. When alive, the muscle has other stuff, such as glycogen and electrolytes. Once the animal is dead, is the glycogen still in the muscle? I don’t know. Guess it must be.
barbitu8 - Sorry, bro - “pure protein” bars are not pure protein, and neither is chicken meat.
Fat is stored in several places. The “marble” of a marbled steak, as well as the fat between muscle and skin, is called subcutaneous fat. There is also fat around the organs (mostly for shock absorbtion), called visceral fat. Then there is fat that you’re disregarding, called intramuscular fat. It’s blended into the muscle cells, and can’t be trimmed.
By the way, this stuff is why pork is called “the other white meat.”
barbitu8 - Sorry, bro - “pure protein” bars are not pure protein, and neither is chicken meat.
Fat is stored in several places. The “marble” of a marbled steak, as well as the fat between muscle and skin, is called subcutaneous fat. There is also fat around the organs (mostly for shock absorbtion), called visceral fat. Then there is fat that you’re disregarding, called intramuscular fat. It’s blended into the muscle cells, and can’t be trimmed.
By the way, this stuff is why pork is called “the other white meat.”
