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: