Main lipophilic extractives in different paper pulp types can be removed using the laccase-mediator system.
Lipophilic extractives in wood and other lignocellulosic materials exert a negative impact in pulp and paper manufacturing causing the so-called pitch problems. In this work, the appropriateness of an enzymatic treatment using the laccase-mediator system for pitch biocontrol is evaluated. With this purpose, three pulp types representative for different raw materials and pulping processes-eucalypt kraft pulping, spruce thermomechanical pulping, and flax soda-anthraquinone pulping-were treated with a high-redox-potential laccase from the basidiomycete Pycnoporus cinnabarinus in the presence of 1-hydroxybenzotriazole as a redox mediator. The gas chromatography and gas chromatography/mass spectrometry analyses of the lipophilic extractives from the enzymatically treated pulps revealed that the laccase-mediator treatment completely or greatly removed most of the pitch-causing lipophilic compounds present in the different pulps including: (1) free and conjugated sitosterol in eucalypt paper pulp; (2) resin acids, sterol esters, and triglycerides in spruce pulp; and (3) sterols and fatty alcohols in the flax pulp. Different amounts of free and conjugated 7-oxosterols were found as intermediate products in the oxidation of pulp sterols. Therefore, the laccase-mediator treatment is reported as an efficient method for removing pitch-causing lipophilic compounds from paper pulps obtained from hardwood, softwood, and nonwoody plants.
Instituto de Recursos Naturales y Agrobiología, CSIC, Reina Mercedes 10, PO Box 1052, E-41080, Seville, Spain. anagu@irnase.csic.es
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A
Gutiérrez
J C
JC
del Río
J
J
Rencoret
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D
Ibarra
A T
AT
Martínez
D002849:Chromatography, Gas; D008401:Gas Chromatography-Mass Spectrometry; D007218:Industrial Microbiology; D007220:Industrial Waste; D042845:Laccase / Q000378:metabolism*; D009930:Organic Chemicals / Q000032:analysis*; D010084:Oxidation-Reduction; D010209:Paper; D013261:Sterols / Q000378:metabolism; D014934:Wood
D007220:Industrial Waste; D009930:Organic Chemicals; D013261:Sterols; D042845:Laccase