Freshness characterisation of whiting (Merlangius merlangus) using an SPME/GC/MS method and a statistical multivariate approach

BACKGROUND: The freshness of whiting was studied at five stages of ice storage by comparing the analysis of volatile compounds obtained through solid phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) with two sensory methods. RESULTS: Of the volatile compounds identified, 38 were analysed using a statistical multivariate approach and classified according to their role in the estimation of freshness during storage as markers of freshness or spoilage. Regarding the evolution of the presence or absence of individual compounds, three categories were defined. For example, the volatile compounds propanal, hexanal, 1-penten-3-ol, pentanal, 2,3-pentanedione, 1-penten-3-one, heptanal, (E)-2-pentenal, 2,3-octanedione, (Z)-2-penten-1-ol, 1-pentanol, butanal, octanal, 3,5,5-trimethyl-2-hexene, 1-hexanol and 4,4-dimethyl-1,3-dioxane appeared highly relevant, because they are found throughout storage and can be divided into several categories that are directly related to the quality of fish. CONCLUSION: SPME/GC/MS combined with a statistical multivariate approach may be a useful method to identify volatile compounds and characterise fish freshness during storage. (C) 2010 Society of Chemical Industry