| The character-impact aroma compounds in cooked tail meat of brown shrimp (Penaeus aztecus) were studied. Volatile compounds were isolated from cooked tail meat by vacuum simultaneous steam distillation-solvent extraction (V-SDE), dynamic headspace sampling (DHS), and static headspace sampling (SHS). Extracts were analyzed by gas chromatographymass spectrometry (GC-MS) and GC-Olfactomery (GC-O). Aroma extract dilution analysis (AEDA) was used to establish a flavor dilution (FD) chromatogram of volatiles isolated by V-SDE.; A total of 34 odorants were detected by GC-O, of which 23, 14, and 17 were found by V-SDE, DHS, and SHS, respectivety. In the present study, 2-acetyl-1-pyrroline and 3-(methylthio)-propanal were regarded as necessary and important compounds of the desirable aroma of cooked brown shrimp. They were the most intense odorants isolated by all of the above three techniques, and described as having popcorn-and baked potato-like odors, respectively. Other potent aroma compounds commonly found by the three techniques included three odorants having dark chocolate odors, 2-methylpropanal, 2-methylbutanal and 3-methylbutanal, as well as octadien-3-one with a mushroom/battery-like odor. Aroma profiles revealed by both DHS and SHS were similar. Both techniques isolated some odorants which were not detected in V-SDE extracts, such as three malodorous compounds (hydrogen sulfide, trimethylamine, and methanethiol), as well as acetaldehyde (solvent-like) and dimethylsulfide (cooked corn). A tentatively identified compound 2-methyl-3-furanthiol, having a vitamin/meaty-like odor, was considered to be important in V-SDE extracts with a FD-factor of 27. Total ion chromatograms of V-SDE extracts and DHS volatiles were different with respect to levels and types of volatiles present. However, they were similar with respect to predominant odorants. Results of the three different procedures indicated that they were complementary to each other in characterizing cooked brown shrimp aroma. |
