Volatiles from sheep wool and the modification of wool odour

Compounds in the headspace of a variety of wool samples and greases have been analysed with the aid of solid phase microextraction using a carboxen-polydimethylsiloxane coated fibre. Volatiles were analysed by gas chromatography/mass spectrometry, while sulphur-containing compounds were analysed using gas chromatography/pulsed flame photometric detector. The volatile organic compounds released from scoured sheep wool and wool grease were investigated in vials under dry and humid conditions between 20 and 40 ◦C. A laboratory scale scouring apparatus was also used to investigate the emission of volatiles at different stages of the wool scouring process. A variety of volatile compounds, including sulphur-containing compounds, were emitted with their concentration increasing with temperature and humidity in most cases. There was a progressive decrease in the number of volatiles released after various stages of the wool scouring process.Wool grease emitted an assortment of volatile compounds, many of which were also detected in the headspace of scoured wool. Degradation of wool and particularly wool grease is thought to be responsible for the occurrence of the detected compounds. Use of an odour index helped identify possible contributors to the odour of wool, but unqualified proof remains elusive because of the possibility that compounds present at concentrations below detection limits may have made a contribution. A major aim of this work was to improve the odour of scoured wool. To achieve this aim two antioxidants were separately incorporated into the wool scouring process. In both cases, this resulted in a reduction of the number of headspace volatile compounds detected, and a distinct improvement in the pleasantness of the odour with an accompanying reduction in the odour intensity. © 2003 Elsevier Science B.V. All rights reserved