Tall oil, a mixture of fatty and resin acids obtained as a byproduct of woo
d alkaline delignification, was subjected to purification in the form of a
sulphate soap. A procedure has been developed, involving extraction of tall
oil from an aqueous solution of sulphate soap with ethylacetate. The optim
ized working conditions (volumes of water and ethylacetate, number of extra
ctions, temperature and duration of the process) resulted in a separation e
fficiency of unsaponifiable matter up to 80%. The procedure yielded targe a
mounts of unsaponifiable matter, mainly composed of phytosterols. Methods o
f phytosterols isolation and identification have also been proposed.