Quantifying Carbohydrates: I've been looking for information about how the
carbohydrate content of foods is determined. My guess is that most of the
information we see on the labels is a simple tally of the ingredients
followed by a table lookup. I know how calories are measured (in a
bomb-calorimeter), and have built and used my own equipment to do so. But
so far I've been unable to find any information describing how one
ascertains the carbohydrate content of our foods.
I want to be able to independently verify the carbohydrate content of what I
buy/get/make. And then I want to be able to measure the effects of various
food-processing steps as they undergo various chemical and natural changes
(yeast rising, bacterial activity, etc.).
I've Googled and visited dozens of libraries.and can't seem to get a hit.
Does anybody reading here know the process by which the carbohydrate content
of foods can be validated?
TIA,
Dusty

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DJ Delorie - 24 Mar 2004 02:35 GMT
> Quantifying Carbohydrates: I've been looking for information about how the
> carbohydrate content of foods is determined. My guess is that most of the
[quoted text clipped - 3 lines]
> so far I've been unable to find any information describing how one
> ascertains the carbohydrate content of our foods.
http://www.nal.usda.gov/fnic/foodcomp/Data/SR16-1/sr16-1.html
Download the "SR16 documentation" PDF (not the sr16-1 one) and view
the section titled "Proximates".
It's not something you can normally do yourself.
Roger Zoul - 24 Mar 2004 02:49 GMT
:: Quantifying Carbohydrates: I've been looking for information about
:: how the carbohydrate content of foods is determined. My guess is
[quoted text clipped - 14 lines]
:: hit. Does anybody reading here know the process by which the
:: carbohydrate content of foods can be validated?
A thread that was started on 3/21 touches on this topic. It's title is:
Opinion wanted on Mission low-carb tortillas - really low carb?
Look for the posts by "Bob (this one)". He addresses how this is done.
Bob - 24 Mar 2004 13:57 GMT
The food is blended together and then burnt to ash-like consistency then
analyed. If you want to send your food samples out to a lab, you'll probably
be broke before lunchtime.
Your guess is wrong.
> :: Quantifying Carbohydrates: I've been looking for information about
> :: how the carbohydrate content of foods is determined. My guess is
[quoted text clipped - 20 lines]
>
> Look for the posts by "Bob (this one)". He addresses how this is done.
Cubit - 24 Mar 2004 15:10 GMT
> I know how calories are measured (in a
> bomb-calorimeter), and have built and used my own equipment to do so.
What on earth is a "Bomb-Calorimeter?"
Cubit
308/263/165
The Queen of Cans and Jars - 24 Mar 2004 15:24 GMT
> > I know how calories are measured (in a
> > bomb-calorimeter), and have built and used my own equipment to do so.
>
> What on earth is a "Bomb-Calorimeter?"
http://www.google.com is your friend, you lazy thing.
DJ Delorie - 24 Mar 2004 15:32 GMT
> What on earth is a "Bomb-Calorimeter?"
It's a heavily insulated flask (with an internal water jacket) in
which a sample is burned. The temperature of the water changes and is
monitored, and based on that, the calories can be inferred.
Doug Freyburger - 24 Mar 2004 23:32 GMT
> Quantifying Carbohydrates: I've been looking for information about how the
> carbohydrate content of foods is determined. My guess is that most of the
> information we see on the labels is a simple tally of the ingredients
> followed by a table lookup. I know how calories are measured (in a
> bomb-calorimeter), and have built and used my own equipment to do so.
If you have a calorimeter you're only a quarter of the way there.
Fat has a tight legal definition and there are chemical processes to
extract all of the fat from a food. Start with one sample and put it
through this process.
Protein has a tight legal definition and there are chemical processes
to extract all of the protein from a food. Start with a sample and
put it through this process.
Calories have a tight legal definition and they are measured with a
bomb calorimeter. A sample is dried, put in the calorimeter, burnt
to ashes with an electric current, and the heat released minues the
electricity spend is the calorie count.
So subtract calories from fat and protein in the first two processes
from total calories from the calorimeter and the difference is the
total carb count.
The final quarter is some process to figure out how much of the carbs
are fiber. There much be some chemical process to do that as well.