Oleic acidity determination

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

A high acidity value indicates deterioration of the fat, 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?

The determination of oleic acidity is used in different industrial contexts:

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

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

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 in % 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: routinely used in the oil industry.

Affected matrices

The oleic acidity test applies to a wide variety of products:

• Vegetable oils: olive, sunflower, rapeseed, peanut, sesame, etc.
• Food products: margarines, sauces, oil-based preserves, etc.
• Oils intended for animal feed (plant co-products, supplements)
• Lipid-based nutraceutical supplements (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 dosage with other analyses available in our analysis catalog :

• Fatty acid profile : detailed identification of fatty acids (saturated, mono- and polyunsaturated)
• Peroxide value : measure of primary oxidation
• Iodine index : degree of unsaturation of fats
• Saponification index : 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, etc.)
• Digitalized monitoring of your analyses (order, traceability, results)
• Technical support from our scientific team
• Multi-matrix management 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 compliance of your oils or lipid extracts, request a quote now for oleic acidity testing on our platform.

Our team is at your disposal for any specific request (type of method, complex matrix, limit of quantification, etc.).