Changes in volatile compounds were monitored in whiting (Merlangius merlangus), cod (Gadus morhua) and mackerel (Scomber scombrus) and related to spoilage. Data are presented from headspace/mass spectrometric (HS/MS) analysis and solid-phase microextraction/gas chromatographic/mass spectrometric (SPME/GC/MS) analysis at two time points (day 0 and day 10) during storage at 4 • C. HS/MS revealed 24 ions that could be used as markers of spoilage. SPME/GC/MS identified 86 compounds, 20 of which could perhaps be used to characterize freshness: principally alcohols, ketones, aldehydes and C 2 -C 11 esters. Compounds common to the three species studied appear to be generated by microbial degradation.

A method using headspace-solid-phase microextraction-gas chromatography-mass spectrometry to extract volatile compounds from whiting is developed. Several parameters such as sorption time, desorption time, fiber type, and matrix form are optimized to achieve better sensitivity in minimal analysis time. The efficiency of the method is determined by the linear range and repeatability; a mean relative standard deviation of approximately 7% is measured. It was possible to identify and quantitate 30 volatile compounds of interest present in spoiled whiting.