Description
The sample is boiled in dilute hydrochloric acid in order to, among other things, liberate bound fat and convert salts of fatty acids to free acids. After filtration and gentle drying, the residue is extracted with petroleum ether or hexane. The solvent is distilled off and the mass of the residue determined. This method describes a standardised procedure for the determination of the total fat content in foods after extraction. It is a general method applicable to most solid foods with the exception of pure milk products and food fats. The results of the method performance study gave acceptable results for sausage, gruel powder, cheese, biscuits, potato chips and ice cream. For fish, oats and banana/avocado, however, the results from the study were unacceptable. See also section 12. The extracted fat may be analysed for fatty acid composition. For other normal determinations made on fat more careful extraction methods must be used.