Review of methods for the determination
of fat and oil

Identify the most appropriate method of fat and oil analysis for your ingredients and products to obtain reliable results cost-effectively.

The determination of fat and oil content of foods is an important aspect of nutritional analysis. Not only do fats and oils contribute significantly to the energy content of foods but their level is used in the calculation of other food components (e.g. carbohydrate) by "difference". Fat content is also important in certain health claims, in ensuring that ingredients are suitable for purpose (e.g. milk for yoghurt production) and in determining the sensory characteristics of the food.

The ideal method for the determination of fat would be rapid, accurate and repeatable, would distinguish free and bound fat, would not involve hazardous solvents, would allow the further analysis of the sample if necessary, and would require little skilled labour. Rarely does a single method fulfil all these requirements, and it is important, therefore, to select the most appropriate methods for particular circumstances.

This review explains the basic chemistry of fats and oils (including terms such as cis, trans and omega fatty acids), outlines the EU regulatory requirements on labelling with regards to fat and oil, and discusses the advantages and disadvantages of each of the main approaches in turn.

Contents

• Introduction
• What is fat and oil?
• Legal aspects and labelling requirements
• Health aspects of fats and oils
• Which method to use?
• Methods:
  - Soxhlett & Bailey-Walker method
  - Bligh and Dyer method
  - Weibull-Stoldt method (Weibull-Berntrop)
  - Werner-Schmid method
  - Rose-Gottlieb method
  - Gerber method
  - Accelerated solvent extraction method
  - Supercritical fluid extraction method
  - Caviezel method
  - Foss-let technique
  - Volatile oil determination
  - Determination of fat in butter
  - NMR
  - Other methods