Karl Fischer titration can be used to determine this critical paramete, which is important not only in production but also in the end taste of the product
The water content of many types of food can be determined quickly and accurately by Karl Fischer titration.
An example of this is the determination of water in liquorice, which in the past has been a difficult application to obtain fast and reproducible results.
Using a Metrohm 784 KFP Titrino in conjunction with a 703 pump/stirrer unit the sample (approximately 0.2g) is added to the titration cell and is broken down rapidly by a high frequency mixer (Polytron PT1200 Disintegrator) which inturn acts as a stirring device.
The high frequency mixer can be attached to a timer which will turn off the mixer after the preset time has been reached.
The 703 stirrer unit then continues to stir the contents of the cell.
An extraction time of two minutes is set in the method to allow all the moisture into the cell prior to titrating with Hydranal Composite 5 reagent.
The solvent used is 80% methanol with 20% formamide.Typically only 30ml of solvent is used per determination.
The solvent is contained in a completely sealed bottle at the back of the 703 pump/stirrer where it is effortlessly transferred into the titration cell by one button press.
The waste is also removed in the same way, thus the operator does not come into contact with the solvents whatsoever. The determination of water on other food products can be successfully analysed using a similar setup.
Examples include; nuts, icing sugar, and marzipan.
