In an investigation of roasted shrimp odour adsorbed by Tenax TA during the roasting of sun-dried sakuraebi (Sergia lucens Hansen), 31 odour-active compounds were detected by application of an aroma extract dilution analysis and subsequently identified by GC-MS analysis. Among these odorants, the following six contributed to roasted shrimp aroma, with high flavour dilution (FD) factors: methanethiol (sulphury); 1-pyrroline (shrimp meat-like); N-(2′-methylbutyl)pyrrolidine (roasted seafood-like); N-(3′-methylbutyl)pyrrolidine (roasted seafood-like); methyl isopropyl disulphide (roasted shrimp meat-like); 3-methylpyridine (fishy, green).

All possible stereoisomers of imine derivatives 1 ± 4, which have the characteristic roast odor of seafood, were synthesized. As a result of odor evaluation of all isomers, we found that each isomer has a different and characteristic odor of roasted seafood.Introduction. ± Imine derivatives 1 ± 4 have the characteristic roast odor of seafood.

The SPACE™ (solid-phase aroma concentrate extraction) method is a modified version of the SPME (solid-phase micro extraction) technique for headspace analysis, with increased area of the adsorbent to enable more sensitive analysis of volatiles. The SPACE™ rod used in the technique is fabricated from stainless steel coated with an adsorbent mixture, consisting mainly of a graphite carbon. Initially, the SPACE™ rod is fixed in the head of a closed flask, where it adsorbs the aroma. Next, the rod is thermally desorbed on-line with a high-resolution gas chromatography-mass spectrometer (HRGC-MS). In the present experiments, SPACE™ sampling reproducibility was determined by analysing a standard mixture and roasted coffee beans. The SPACE™ rod collected the analytes with good reproducibility, with the exception of high polar compounds. Similar analyses of coffee powder were performed by SPME and other methods for comparison with the SPACE™ method. The SPACE™ method proved to have superior capabilities with high concentrations, and it produced a well-balanced chromatogram.

The flower scent of the damask rose (Rosa damascena) was studied. Two ultratrace components exhibiting high flavor dilution factors were detected as odor-active compounds via aroma extract dilution analysis (AEDA). One of these had a woody note and was identified as rotundone using multidimensional gas chromatography-mass spectrometry-olfactometry (MD-GC-MS-O), while the other had a citrus note and was identified as 4-(4-methylpent-3-en-1-yl)-2(5H)-furanone (MPF) by fractionation of a commercial rose absolute from R. damascena. To the best of our knowledge, this is the first study addressing the organoleptic importance of these two compounds in the rose scent. Sensory analysis was conducted to evaluate the effects of rotundone and MPF. Adding 50 μg/kg rotundone and 5 μg/kg MPF to the aroma reconstitute of R. damascena provided it with blooming and natural characteristics. Additionally, the existence of rotundone and MPF in five types of fragrant roses was investigated.

This is a report of the detection of 13-ethoxy-8α α α α α,13-epoxy-14,15,16-trinorlabdane (1) and 12-ethoxy-8α α α α α,12-epoxy-13,14,15,16-tetranorlabdane (2), hitherto unidentified and considered as degradation products of ambrein, among 31 constituents found by analysis of ambergris tincture. Copyright © 2004 John Wiley & Sons, Ltd.KEY WORDS: ambergris; tincture; 13-ethoxy-8α,13-epoxy-14,15,16-trinorlabdane; 12-ethoxy-8α,12-epoxy-13,14,15,16tetranorlabdane * Correspondence to: K. Awano, Technical Research Centre, T. Hasegawa Co. Ltd, 335-Kariyado, Nakahara-ku, Kawasaki-shi 211, Japan. E-mail: Ken-ichi_Awano@t-hasegawa.co.jp Distillation of tinctureAfter removing ethanol from the extract under atmospheric pressure to concentrate it to 200 ml, the ethanol was again distilled off carefully under 30 mmHg, to give 81 g extract. Since the residual tincture contained a considerable amount of compounds with high boiling points, it was distilled at 120°C/0.1 mmHg, to give 0.65 g (yield of 0.65% from the starting ambergris) of distillate. The distillate, exhibiting a strong aroma, was separated into several fractions by silica gel column chromatography, which were then analysed by GC, GC-MS and GC-IR. GC ConditionsAnalyses were done using a Hewlett-Packard 5890II gas chromatograph with a 0.25 mm i.d. × 60 m capillary column coated with PEG-20M. Column temperature, 70°C to 220°C at a rate of 3°C/min; carrier gas, nitrogen at a flow rate of 1 ml/min; injector and detector temperature, 250°C. GC-MS, GC-IR ConditionsA Hewlett-Packard 5970 mass spectrometer and HewlettPackard 5965B infrared spectrometer were used. The column conditions were the same as those described for GC. Carrier gas, helium at a flow rate of 1 ml/min; ionization voltage, 70 eV. NMR ConditionsThe NMR spectra were recorded on a JEOL LA400 spectrometer, using tetramethylsilane as an internal standard.