Oleic acidity determination

Oleic acidity represents the free fatty acid content in an oil, expressed as oleic acid equivalent (C18:1). This parameter is a key quality criterion in the food, nutrition, and plant-based product sectors. It allows for the detection of triglyceride hydrolysis, generally caused by improper storage, inadequate processing conditions, or enzymatic degradation.

A high acidity level indicates fat deterioration, which can affect:

• The taste and stability of the product;
• Nutritional value (lipid oxidation);
• Regulatory compliance, particularly in virgin olive oil according to EC standard no. 2568/91.

Why measure acidity in oleic acid equivalent?

Oleic acidity analysis is used in various industrial contexts:

• Classification of edible oils (virgin, refined, extra virgin);
• Assessment of rancidity or aging of fats;
• Quality control of products extracted from oilseed plants;
• Standardization of oils for cosmetics or animal nutrition;
• Compliance with ISO, AOCS, Codex Alimentarius or EFSA standards.

This measurement is often coupled with other oxidation parameters such as the peroxide value, iodine value or acid value.

Analytical method: titrimetry according to ISO/AOCS

The analysis is based on a standardized titrimetric method, consisting of measuring the free fatty acids present in the sample using a basic solution (sodium or potassium hydroxide). The acidity is then expressed as a percentage of oleic acid or in mg KOH/g.

Reference methods include:

• ISO 660: applicable to all animal or vegetable oils and fats;
• AOCS Cd 3d-63: used routinely in the oil industry.

Affected matrices

Oleic acidity testing is applicable to a wide variety of products:

• Vegetable oils: olive, sunflower, rapeseed, peanut, sesame…
• Food products: margarines, sauces, canned goods in oil…
• Oils intended for animal feed (plant by-products, supplements)
• Nutraceutical supplements based on lipids (omega-3, functional oils)
• Cosmetic products containing fatty extracts or virgin oils

Useful additional analyses

For a complete characterization of your oils, YesWeLab recommends combining this test with other analyses available in our analysis catalog :

• Fatty acid profile : detailed identification of fatty acids (saturated, monounsaturated and polyunsaturated)
• Peroxide value : a measure of primary oxidation
• Iodine index : degree of fat unsaturation
• Saponification value : average molar mass of fatty acids

Why use YesWeLab?

Since 2020, YesWeLab has been supporting professionals in the agri-food, plant, cosmetic and nutraceutical sectors in managing their analyses.

Our platform gives you access to:

• A network of accredited laboratories (ISO 17025, COFRAC…)
• Digital tracking of your analyses (ordering, traceability, results)
• Technical support from our scientific team
• A multi-matrix management system adapted to your raw or finished products

Our services are designed for manufacturers, processors, formulators and distributors, concerned with ensuring regulatory compliance, the quality of their raw materials, or the safety of their finished products.

Add this analysis to your quote now

To guarantee the quality and conformity of your oils or lipid extracts, request a quote for oleic acidity testing on our platform now.

Our team is available to assist you with any specific requests (type of method, complex matrix, limit of quantification, etc.).