The main aroma components of oolong and black tea, linalool and four diastereomers of linalool oxides (LOs), were enantioselectively isolated by capillary gas chromatography, using a column coated with an optically active liquid phase, permethylated fJ-cyclodextrin.The RIS ratio varied among linalool and LOs, and among the different types of tea, the ratio for a particular compound also being different. However, the complete patterns of RIS ratio were similar in the semi-fermented and fermented teas, respectively.Using a specific cultivar of black tea, the RIS ratio for each of the five compounds was compared in the free state in black tea with that of an aglycone of the glycoside in fresh tea leaves or in black tea. While the e.e. values of the compounds varied, those for a specific compound were similar, except for linalool, regardless of their free or combined state.These results show that LOs are not directly transformed from linalool, but are formed enzymatically from glycoside precursors.The mono terpene alcohols play an important role in semi-fermented tea (oolong tea) and in fermented tea (black tea) aroma, among which linalool and its oxides (LOs) are the main components, which in some varieties of black tea account for over 50% of the tea volatiles.1 ) Both linalool and LOs have asymmetric carbon, as shown in Fig. 1. It is known that some optical isomers have a different aroma character,2) and identification of the chirality of aroma components existing in tea is important for clarifying the formation mechanism for tea aroma in plants and during tea fermentation.A few chiral aroma compounds in tea volatiles have already been studied in our laboratory by the classical chemical approach. 3) However, the most important tea aroma components, linalool and LOs, were not included. High-resolution gas chromatography (HRGC), using an open tubular capillary column coated with a cyclodextrinbased chiral stationary phase, has recently been developed to conduct an effective enantioselective analysis of various ~", . . . O<- The optical separation and structural elucidation of linalool by using such a column coated with heptakis (2,3,6-tri-O-methyl)-fJ-cyclodextrin (CD column) have been reported by Konig et al., (R)-linalool being eluted earlier than (S)-linalool. 7) The elution order for the diastereomers of furanoid and pyranoid LOs in the CD column has been ascertained, and direct stereodifferentiation of the furanoid LOs in the CD column and their chromatographic behavior has also been clarified by Askari and Mosandl. 8) We tried to compare the ratio of the optical isomers of linalool and LOs in different varieties of tea, and the ratio of the optical isomers of free and glycosidically bound linalool and LOs to evaluate their enzymatic or non-enzymatic formation process, as well as the separation conditions for the optical isomers. Materials and MethodsMaterials. Two varieties of commercial oolong tea (Huang Jin Gui and Tie Guan Yin) were imported from China in 1993. Two varieties of black tea (Clone 2025 and Cl...

The aroma properties of fish broths prepared from 16 fish species (10 saltwater, three freshwater, two anadromous and one brackish water species) were described quantitatively by reference to 10 sensory attributes. Principal component analysis (PCA) and cluster analysis of sensory attributes classified the fish into four groups. Group 1, characterised by a strong 'green' odour, comprised all three freshwater species (loach, pond smelt and carp), two saltwater whitefish species (snapper and conger) and eel. Group 2 included migratory coastal species (sardine, banded blue-sprat and mackerel) and was distinguished by strong 'fish oil' and 'grilled fish' notes. Group 3 consisted of swordfish, sablefish and salmon, which exhibited a strong 'fried chicken' note. Group 4 included flounder, cod, tuna and goby, which were scored high for 'cooked fish', 'roasted soy sauce', 'canned tuna' and 'sweet' aromas. Partial least squares regression (PLSR) models derived from selected influential peaks in the gas chromatograms of the volatile components in the broths for each attribute were highly predictive (R 2 5 0.936). The selected peaks corresponded well to each sensory attribute.

We report X-ray spectroscopic results for four giant solar flares occurred on 2005 September 7 (X17.0), 2005 September 8 (X5.4), 2005 September 9 (X6.2), and 2006 December 5 (X9.0), obtained from Earth albedo data with the X-ray imaging spectrometer (XIS) onboard Suzaku. The good energy resolution of the XIS (FWHM∼100 eV) enables us to separate a number of line-like features and detect the underlying continuum emission. These features include Si Heα, Si Lyα, S Heα, S Lyα, Ar Heα, and Ca Heα originating from solar flares as well as fluorescent Ar Kα and Ar Kβ from the Earth atmosphere. Absolute elemental abundances (X/H) averaged over the four flares are obtained to be ∼2.0 (Ca), ∼0.7 (Si), ∼0.3 (S), and ∼0.9 (Ar) at around flare peaks. This abundance pattern is similar to those of active stars' coronae showing inverse first ionization potential (i-FIP) effects, i.e., elemental abundances decrease with decreasing FIP with a turnover at the low end of FIP. The abundances are almost constant during the flares, with an exception of Si which increases by a factor of ∼2 in the decay phase. The evolution of the Si abundance is consistent with a picture that the i-FIP plasma originates from the chromosphere evaporation and then mixes with the surrounding low-FIP biased materials. Flare-to-flare abundance varied by a factor of 2, agreeing with past observations of solar flares. Finally, we emphasize that Earth albedo data acquired by X-ray astronomy satellites like Suzaku and XRISM can significantly contribute to studies of solar physics.

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