When performing Bellier index tests, the vegetable oil sample is first saponified using ethanol ethanol KOH solution. The KOH solution is a potassium hydroxide solution. The dissolved fatty acids are then allowed to cool. Then the temperature at which the fatty acids begin to precipitate is determined. The Bellier index refers to the temperature at which the fatty acid salts begin to precipitate. That is, the temperature at which the precipitate occurs is considered to be the Bellier index.

The Bellier indices were first used in the early 1900s to understand how pure olive oil is.

In the Communiqué on the Mandatory Implementation of the Revised TS 2004 Edible Olive Oil Standard (Communiqué No: 341 / 2004) issued by the Undersecretariat of Foreign Trade in 21, the determination of the Bellier index process shall be performed according to the TS 5048 standard and the result shall be It is explained that it should comply with the values ​​given in the table showing the properties. According to this table olive oil production methods and production techniques, according to the classification of olive oil, natural, refined and Riviera are three classes, and natural olive oil Bellier index must be at most 17,0.

Among the physical analyzes performed within the scope of food analyzes, Bellier index tests are performed in laboratories accredited according to TS EN ISO / IEC 17025 standard from domestic and foreign accreditation organizations. In this way, the results become more objective and reliable.

These laboratories comply with the accepted test methods and test criteria, follow scientific researches and apply the standards published by local and foreign organizations in their studies. The Bellier index tests are based on the following standard:

• TS 5048 Vegetable oils - Determination of Bellier index

This standard includes a method for determining the Bellier index in vegetable oils.

Testing in laboratories is performed by using sensitive devices and under the supervision of experienced employees.