Quality & Specifications
How to Read a Certificate of Analysis for Edible Oil
What each result on an edible oil Certificate of Analysis means, the international reference limits, and the red flags to look out for.
A Certificate of Analysis (COA) is the laboratory report for one lot of oil. It shows what was tested, the methods used and the results, so you can check that the oil you received matches what you ordered. Every order from us comes with one. Here is how to read it.
Check the header first
- Product and grade, for example “Refined sunflower oil” or “Extra virgin olive oil”, matching your order.
- Lot or batch code, matching the code printed on your packs.
- Production and test dates, and the best-before date.
- The laboratory that ran the tests. Our results come from our ISO/IEC 17025-accredited laboratory, which means its competence has been independently assessed.
- Test methods, usually AOCS or ISO method numbers, so results can be compared with another laboratory.
The key results and what they mean
The table shows common parameters with reference limits from the Codex General Standard for Fats and Oils. These are international benchmarks; the specification agreed for your oil may be tighter.
| Parameter | What it tells you | Codex reference limit |
|---|---|---|
| Acid value (or free fatty acids) | How much the oil has broken down into free fatty acids. Low values mean fresher, better-refined oil and longer fry life. | Refined: max 0.6 mg KOH/g. Virgin and cold-pressed: max 4.0 mg KOH/g |
| Peroxide value | Early oxidation. Rising values are a warning that the oil may soon taste rancid. | Refined: max 10 meq/kg. Virgin and cold-pressed: max 15 meq/kg |
| Moisture and volatile matter | Water and volatile substances, which shorten shelf life and can cause spitting in the fryer. | Max 0.2% |
| Insoluble impurities | Solid particles left in the oil. | Max 0.05% |
| Soap content | Residue from refining; affects taste and frying performance. | Max 0.005% |
| Iron and copper | Trace metals that speed up rancidity. | Refined: iron max 2.5 mg/kg, copper max 0.1 mg/kg |
Free fatty acids are sometimes reported as a percentage, calculated as oleic acid, instead of an acid value. To compare, the acid value is roughly twice the free fatty acid percentage.
Identity and grade results
- Fatty acid composition, measured by gas chromatography, confirms what the oil is. For example, high-oleic sunflower oil should show a high oleic acid content, and canola and mustard oil results include erucic acid.
- Iodine value measures how unsaturated the oil is and is another identity check.
- Color, often on the Lovibond scale, confirms a light refined oil or the natural color of a virgin oil.
- Oil-specific results, such as THC in hemp seed oil, thymoquinone in black seed oil or tocopherols in wheat germ oil.
How to check a COA against your order
- Match the product, grade and lot code to your invoice and packs.
- Compare each result with the specification sheet for the grade you ordered.
- Check that the test date is recent and appropriate for the lot.
- File the COA with your delivery records; you may need it for audits or your own customers.
Red flags
- No lot code, or a code that does not match the packs
- No test methods or laboratory named
- Results outside the agreed specification
- A COA that looks altered, or arrives from an unfamiliar email address
If something does not look right, keep an unopened sample from the lot and contact us within 30 days of delivery, quoting the lot code. Our Terms of Sale explain how quality claims are handled, and our How We Make It page describes our testing.
Sources
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