Determination of Soap Number

Soap Number Analysis in Oils

Fatty acids turn into soap as a result of the treatment of oils with strong acids or heating them with water under pressure.

With the determination of soap number, sodium soap content and other basic substances reacting with hydrochloric acid are determined. The result of the analysis is calculated in terms of percent sodium soap or percent sodium hydroxide.

Determination of soap number is based on determining the amount of soap dissolved in oils as oleate. Oleate is a fatty acid ester with low viscosity and high flash point.

According to the Turkish Food Codex Communiqué on Oils with Plant Name (Communiqué no: 2012/29), it should not be found in cold and pressed natural oils. For refined oils, the limit is 0.005 (m / m).

If the oil is not washed well, the amount of soap is high. However, even if the bleaching process is done, the amount of soap will be low. For this reason, it is important to determine the amount of soap in order to have an idea about the processes performed on oils.

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