The Naked Scientists

The Naked Scientists Forum

Author Topic: How does anyone know the actual vitamin content of food?  (Read 5777 times)

Tina Bull

  • Guest
Tina Bull asked the Naked Scientists:
   
I wonder how nutritional information is determined on packages of food.  Are companies required to do testing or is there independent testing?

How does anyone know the actual vitamin content of food, and how much is guessing? If it's processed food, is it tested after processing? Or, is it derived from food values of the ingredients prior to being cooked? I'm often skeptical about these listings.

What do you think?


 

Offline lancenti

  • Full Member
  • ***
  • Posts: 96
    • View Profile
How does anyone know the actual vitamin content of food?
« Reply #1 on: 16/02/2009 02:44:23 »
I would say...

They do testing after it's been packaged, or right before it's been packaged but after it's been processed since cooking does affect the content.

There are a lot of ways to do it, but I'm going to go with NMR + Chromatography (HPLC and Gas) and Mass Spectroscopy to identify and quantify the substances present.

Asking the local FDA how they do it would probably be the best option though. Or maybe someone on this forum does work for the FDA and knows the process.
 

Offline Madidus_Scientia

  • Neilep Level Member
  • ******
  • Posts: 1451
    • View Profile
How does anyone know the actual vitamin content of food?
« Reply #2 on: 16/02/2009 19:29:00 »
I remember a story on an NS podcast about some high school students trying to test for the amount of vitamin C in some orange juice they bought, but their value kept coming up different from what was on the label. Turns out the juice company was wrong!

That reminds me, i've sometimes wondered how exactly do they calculate how many joules (or calories) are in a product? I forget if i've asked this before somewhere
 

Offline lancenti

  • Full Member
  • ***
  • Posts: 96
    • View Profile
How does anyone know the actual vitamin content of food?
« Reply #3 on: 18/02/2009 03:10:24 »
They use a bomb calorimeter. Sounds so dangerous.
 

Offline Chemistry4me

  • Neilep Level Member
  • ******
  • Posts: 7709
    • View Profile
How does anyone know the actual vitamin content of food?
« Reply #4 on: 18/02/2009 03:32:43 »
I remember a story on an NS podcast about some high school students trying to test for the amount of vitamin C in some orange juice they bought, but their value kept coming up different from what was on the label. Turns out the juice company was wrong!
It was 2 NZ students, they were using Ribena and yes, their results did not match what it said on the label!!! [:0][:0] The company gave them a life time supply of Ribena....just joking.
 

Offline chris

  • Neilep Level Member
  • ******
  • Posts: 5336
  • Thanked: 65 times
  • The Naked Scientist
    • View Profile
    • The Naked Scientists
How does anyone know the actual vitamin content of food?
« Reply #5 on: 03/03/2009 09:07:25 »
I was driving around in NZ when that story broke and Ribena were forced to alter their claim relating the vitamin C.

Chris
 

Offline Chemistry4me

  • Neilep Level Member
  • ******
  • Posts: 7709
    • View Profile
How does anyone know the actual vitamin content of food?
« Reply #6 on: 03/03/2009 09:10:29 »
Oh really?
What were you doing in little old NZ?
 

Offline Bored chemist

  • Neilep Level Member
  • ******
  • Posts: 8655
  • Thanked: 42 times
    • View Profile
How does anyone know the actual vitamin content of food?
« Reply #7 on: 03/03/2009 20:10:31 »
Hint
I was driving around in NZ
 

Offline Chemistry4me

  • Neilep Level Member
  • ******
  • Posts: 7709
    • View Profile
How does anyone know the actual vitamin content of food?
« Reply #8 on: 06/03/2009 03:10:30 »
Alright, thank you for the hint.
 

The Naked Scientists Forum

How does anyone know the actual vitamin content of food?
« Reply #8 on: 06/03/2009 03:10:30 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums
 
Login
Login with username, password and session length