Abstract: The invention relates to the use of mediator-enzyme system, which is characterised in that the enzyme comprises a laccase-type enzyme and the mediator comprises a chemical compound which acts as a redox intermediate in the enzymatic oxidation, for the elimination of lipophilic compounds (including, among others, sterols that are free and conjugated in the form of esters and glycosides, triglycerides, fatty alcohols and resin acids) which cause deposits in the product, the machinery and the circuits during the production of pulp and paper (both from hardwood and softwood and non-woody plants). The treatment eliminates up to 100% of the aforementioned lipophilic compounds, depending on the material treated, and, in this way, improves the quality of the pulp obtained, the operation of the industrial installations and the characteristics of the end product.