The sample of cheese (4.5 g) was accurately weighted, ground in a mortar and extracted by sonication with 8 g of a mixture of diethyl ether/n-hexane (1:1) for 15 min. Samples were extracted two more times with the mixture of solvents and the combined extracts were transferred to the rotary-evaporator for removal of the
solvent traces from the extracted fat. The fat amount was obtained
by weighting. The fat was then re-dissolved with 25 ml of n-hexane.