| Pasta mainly contains milled wheat, water, eggs
(for egg noodles) and sometimes optional ingredients
as salt.
Prior to analysis, some pasta has to be finely ground
in a laboratory cross-beater mill with a cooling jacket.
The content of chloride and cooking salt in pasta
is determined by titration using the electrode Ag
Titrode with an Ag2S coating. The
analysis is a so called precipitation titration with
potentiometric detection. The chloride ions in the sample
solution are titrated with a silver nitrate solution
(titrant), leading to precipitation of silver chloride
due to its low solubility product. As soon as there
are no more chloride ions present in the sample solution,
adding more titrant results in free silver ions and
hence a rapid change in the measured potential at the
Ag-Titrode. The amount of chloride/cooking salt in pasta
is determined from the first endpoint of the titration
curve.
|
Food
Analysis 
