The Selection of Volatile Extraction Methods and Identification of Fishy Off-Odor from Fish By-Products

Abstract

This study attempted to analyze volatile odor compounds and key odor active substances in fish soup using fish scarp and bone. Five extraction methods, solid-phase microextraction (SPME), dynamic headspace sampling (DHS), solvent-assisted flavor evaporation (SAFE), stir bar sorptive extraction (SBSE), liquid-liquid extraction (LLE), were compared, and SPME was finally selected as the best extraction method for the study. The volatile odor components were analyzed by gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and comprehensive two-dimensional gas chromatography-olfactometry-mass spectrometry (GC×GC-O-MS) techniques, and the key odor-active compounds were picked out together with aroma extract dilution analysis (AEDA) and relative odor activity value (r-OAV) calculation. A total of 38 volatile compounds were identified by GC-O-MS, of which 10 were odor-active compounds. While, 39 volatile compounds were identified by GC×GC-O-MS, of which 12 were odor-active. The results of this analysis showed that 1-octen-3-one, 2-pentylfuran, ( E )-2-octenal, 1-octen-3-one, hexanal, 1-octen-3-ol, 6-methylhept-5-en-2-one, ( E , Z )-2,6-nondienal and 2-ethyl-3,5-dimethylpyrazine were the key odor-active compounds in the fish soup.

Keywords: Fish scraps, fish soup, GC-O-MS, GC × GC-O-MS, AEDA, r-OAV