BS EN ISO 3657:2020

What is ISO 3657 about?  

ISO 3657 specifies a method for determining the saponification value of animal and vegetable fats and oils and applies to refined and crude vegetable and animal fats. 

If mineral acids are present, the results given by this method are not interpretable unless the mineral acids are determined separately. 

The saponification value can also be calculated from fatty acid data obtained by gas chromatography analysis as given in Annex B. For this calculation, it is necessary to be sure that the sample does not contain major impurities or is thermally degraded. 

Who is ISO 3657 for? 

ISO 3657 on animal and vegetable fats and oils is useful for: 

• Food technologists  
• Chemical Engineers 
• Food and safety department 

Why should you use ISO 3657?  

The saponification value is a measure of the free and esterified acids present in fats and fatty acids. 

ISO 3657 provides methods for saponification of samples by boiling them under reflux with excess ethanolic potassium hydroxide, followed by titration with a standard volumetric hydrochloric acid solution. 

ISO 3657 provides methods and standard procedures to be taken care of while examining oil samples for saponification test.  

Overall, ISO 3657 provides a set of complete guidelines for testing, calculating, methods, preparing test samples, and determining the saponification value in oils and fatty acids, which will help standardize product quality by determining standard saponification value. 

What’s changed since the last update? 

BS EN ISO 3657:2020 supersedes BS EN ISO 3657:2013. BS EN ISO 3657:2020 includes some technical changes concerning BS EN ISO 3657:2013. These include: 

• Corrects the mistake in the calculation of the C16 TAG molecular weight (B.7.3); 
• Stipulates using the preferred indicator, alkali blue, to phenolphthalein (5.4 and 5.5) for safety reasons;