Determination of total fat content by automatic acid hydrolysis

The total fat content is one of the most important key figures in foodstuff analysis. However, in order to determine this total value, the sample has to be subjected to either acid or alkaline hydrolysis before the fat is extracted. This hydrolysis is what dissolves the fatty acids that are bound to the glycerides, sterol esters, glycol and phospholipids, breaking down the cell walls in the process and breaking up lipid emulsions and lipid-protein compounds.

There are various different AOAC reference methods for hydrolysis of different sample matrices; however, they are all very labour-intensive and their reproducibility fluctuates from matrix to matrix.

HYDROTHERM, our automated, self-contained acid hydrolysis system based on the gravimetric Weibull-Berntrop method in accordance with ISO 8262-1, can be combined with the innovative SOXTHERM rapid extraction system for fully automated fat analysis of food products with minimal effort.

In this validation study, the analysis data derived using the HYDROTHERM were compared against analysis data from the AOAC 922.06 method. The study involved manual acid digestion using the Mojonnier extraction method for acid hydrolysis The comparison showed that the HYDROTHERM method achieves greater hydrolytic effectiveness than the AOAC method. The HYDROTHERM method for automated acid hydrolysis features good reproducibility, high productivity, precise results and is universally applicable.

  • Analyt: Various foodstuffs
  • Sample parameter: Total fat
  • Method(s): Röse-Gottlieb method / Schmid-Bondzynski-Ratzlaff method.
  • Standard(s): AOAC 922.06 / ISO 8292-1

Instruments for total fat determination