7 Mar 2016

Testing chocolate for contaminants

If you haven't bitten into a chunk of plastic when you last ate a Mars Bar or Snickers, you may think there's no chance of eating any contaminants with your elevensee's. But not all foreign objects in food can be seen with human eyes.

FTIR spectroscopy is an ideal method for the characterization of chocolate samples, detecting more than the eye could ever find.


Straight-forward chocolate generally consists of coca butter, egg white, organic acids, cellulose, polyphenols, water, minerals, salts, theobromine, sugar and some caffeine. White chocolate contains the most calories. 

It's a straight-forward recipe that is fairly easy to check. 

Things become complicated when other ingredients are added to achieve something like a Lion Bar, Snickers or Aero.

According to Sainsbury's a 51g Mars Bar contains sugar, glucose syrup, skimmed milk powder, coca butter, coca mass, sunflower oil, milk fat, lactose, whey protein (from milk), palm fat, fat reduced coca, barley malt extract, emulsifier (soya lecithin), salt, egg white powder, hydrolysed milk protein, natural vanilla extract, milk chocolate milk solids 14% minimum and vegetable fats. 

Quite a large margin for error here. So quality checks are as important as ever for today's sweet snacks, especially when you consider the global reach of a company like Mars, that has recently recalled products from 55 countries.

FTIR wouldn't have helped Mars find a chunk of plastic, but it could help other companies spot the following contaminant examples:

  • Nut. Most foods warn of possible traces of nut, but if a snack claims to be completely nut free, these traces must be detected.
  • Lead. According to enviro-social not-to-profit group As You Sow, exposure to this metal impairs learning development and IQ levels in children. And has been found in numerous well-known chocolate manufacturers.
  • Cadmium is thought to cause kidney, liver and bone damage. As You Sow has also claimed to have found this metal present in chocolate.

FTIR and ATR spectroscopy are two great ways of analyzing liquid or solid samples for contaminants.

Specac's Pearl FTIR transmission spectrometer accessory and Quest ATR spectrometer accessory both allow users to easily and accurately test anything without damaging the sample through preparation (e.g. grinding, pellet pressing). Check out our new application notes on each of their product pages.

The Quest ATR can also be used to test paintleather and soil.

Check out #SpectroscopySolutions for more.