Optimisation of a pressurised liquid extraction method for haloanisoles in cork stoppers
Cork taint is a musty off-flavour in wines mainly caused by 2,4,6-trichloroanisole, but other haloanisoles can contribute. In this work, a method for the extraction of 2,4,6-trichloroanisole, 2,4,6-tribromoanisole and 2,6-dichloroanisole has been developed. The procedure involves the extraction of the haloanisoles from cork by pressurised liquid extraction and the analysis of the extracts by both GC–μECD and GC–MS–MS. A central composite design was used to investigate the dependence of the recoveries of the analytes on the temperature, percentage pentane–diethyl ether ratio and the extraction time. Experimental data were then processed by using the multiple regression analysis in order to calculate a mathematical model representing the relationship between factors and responses and to determine the best experimental conditions for PLE method. These conditions corresponded to a temperature of 176°C, an extraction time between 2.8 and 4min and an 80:20 pentane:diethyl ether ratio.