What Is Total Fatty Acids Analysis?
The most common question we are asked, answered properly — and why total fatty acids is not the same number as total fat.
Total fatty acids is not the same number as total fat, and the difference catches people out on labels more often than any other lipid measurement.
What the method does
Fatty acids are converted to methyl esters — FAME — and separated by gas chromatography. Each peak is a specific fatty acid, identified by retention time against a known standard and quantified against an internal standard.
Total fat is a regulatory construct. Total fatty acids is what is actually in the sample.
Why the two differ
Total fat as declared on a label is generally calculated as triglyceride equivalent, which applies a conversion factor to the fatty acid result. The gap between the two figures is real, expected, and worth understanding before you argue with a supplier about it.
- Ask which figure a certificate is reporting.
- Check the conversion factor if triglyceride equivalent is used.
- Keep the basis consistent across suppliers before comparing them.
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