Patterns in volatile components over heated fish powders

Freeze dried powders of herring and blue whiting filets were heated for 0.5-4 h at 40 to 140 degrees C. The volatile components over the powders were analysed by solid phase micro extraction and gas chromatography-mass spectrometry. Principal component analysis was performed on the chromatographic areas. The patterns over the heated samples showed evolution with temperature exposure along one gradient, indicating that heating at high temperature over a short time interval can produce a similar pattern as heating at a lower temperature for a longer time interval. The response to heating was similar for both herring and blue whiting powders, and a common model based on partial least squares regression was developed for prediction of the temperature exposure. Chemical markers for evaluation of the temperature exposure in a heated fish powder were found. The best markers were pyridines, pyrazines, aromatic hydrocarbons, amides and selected volatile sulfur compounds. (c) 2005 Elsevier Ltd. All rights reserved.