Fatty acid methyl ester

The molecules in biodiesel are primarily FAME, usually obtained from vegetable oils by transesterification.

One reason for using FAME (fatty acid methyl esters) in biodiesel production, rather than free fatty acids, is to mitigate the potential corrosion they can cause to metals of engines, production facilities, and related infrastructure.

As an improved quality, FAMEs also usually have about 12-15 units higher cetane number than their unesterified counterparts.

Microorganisms have diverse and sometimes distinctive FAME profiles, the basis of "microbial fingerprinting".

After triglycerides, fatty acids and certain other lipids of some cultured microbes are transesterified or esterified, the resulting FAMEs can be analyzed with gas chromatography.