Overview

This International Standard specifies methods of preparing the methyl esters of fatty acids. It includes methods for preparing fatty acid methyl esters from animal and vegetable fats and oils, fatty acids and soaps. To cover different requirements, four methylation methods are specified. Methyl esters so produced are used in various analytical procedures requiring such derivatives, such as gas-liquid chromatography (GLC), thin-layer chromatography (TLC) and infrared spectrometry (IR). Milk and milk products (or fat coming from milk and milk products) are excluded from the scope of this document. The determination of the fatty acid composition of oils and fats is one of the fundamental analyses within the fats and oils sector. For this purpose, the fatty acid components of lipids are usually converted to methyl esters followed by GC analysis. The "rapid" method does not derivatize free fatty acids (FFAs) present in oil to fatty acid methyl esters (FAMEs). If FFAs are present, the assumption is usually made that the FFAs have the same fatty acid distribution as the triglycerides. This is usually true for crude oils, but less so for fractionated or refined oils. The "general" procedure derivatizes both FFAs and glyceryl esters to FAMEs. It is up to the analyst to decide whether the use of either the "rapid" or "general" procedure is appropriate based on the nature of the oil being analysed. Alternatively, if a partially hydrolysed fat is to be converted to FAMEs, the acid-catalysed transmethylation procedure may be used. Owing to the toxicity of BF3, it is recommended that the BF3 method be used only in extremis. The International Standard has been prepared by ISO/TC 34/SC 11 "Animal and vegetable fats and oils" (secretariat: BSI, United Kingdom) of Technical Committee ISO/TC 34 "Food products" (secretariat: AFNOR, France). CEN/TC 307 "Oilseeds, vegetable and animal fats and oils and their by-products - Sampling and test methods" (secretariat: AFNOR, France) is responsible for the European Standard. On the national level, the standard is supervised by NA 057-05-05 AA "Gemeinschaftsausschuss für die Analytik von fetten, Ölen und Fettprodukten, verwandten Stoffen und Rohstoffen " (GA Fett) of the German Society for Fat Science (DGF) ("Joint committee for the analysis of fats, oils and products thereof, related and primary products") and DIN Standards Committee Food and Agricultural Products (NAL).

Document: references other documents

Responsible national committee

NA 057-05-05 AA - Joint committee of DIN and DGF for the analysis of fats, oils and products thereof, related and primary products  

Responsible european committee

CEN/TC 307 - Oilseeds, vegetable and animal fats and oils and their by-products - Methods of sampling and analysis  

Responsible international committee

ISO/TC 34/SC 11 - Animal and vegetable fats and oils