The effects of temperature and pressure on the performance of Carboxen/PDMS fibres during solid phase microextraction (SPME) of headspace volatiles from cooked and raw turkey breast

The strongly adsorptive SPME fibre Carboxen/polydimethylsiloxane (CAR/PDMS) was evaluated for its performance in the recovery of aroma-contributing co mpounds from the headspace of heated and raw homogenates of turkey breast m uscle. In heated samples, variables such as fibre and sample temperatures, sample volume, headspace: sample ratio, and the presence or absence of inte rnal headspace pressure significantly influenced the total amounts of aroma components recovered, as well as the proportions of headspace fractions, w hich differed in volatility. The versatile nature of the fibre permitted th e selection of operating parameters that substantially increased the sensit ivity of detection for minor components of both high and low volatility. He adspace sampling of weakly aromatic raw turkey breast homogenates and of aq ueous standards at ambient temperature and a pressure of approximately 5 x 10(-2) bar resulted in a 4-70-fold increase in the recovery of aldehyde and alcohol headspace components, compared to the levels detected at atmospher ic pressure. At reduced pressure the trapping ability of the CAR/PDMS fibre was found to be much superior to that of porous polymer materials such as PDMS/DVB, and the fibre has excellent potential as a simple and effective m eans of concentrating volatile components from raw foods and other matrices where the application of heat is not desired. Copyright (C) 2001 John Wile y & Sons. Ltd.