Identification of Volatile Compounds which Enhance Odor Notes in Japanese Green Tea using the OASIS (Original Aroma Simultaneously Input to the Sniffing port) method

Abstract

We evaluated the volatile compounds of Japanese green tea using GC/O with the original aroma simultaneously input to the sni$ng port (OASIS) method in order to determine the relationship between the volatile compounds and the green tea aroma. Application of OASIS to the volatile fractions of Japanese green tea infusions revealed ++ odor-active peaks. Those of cis-+,/-Octadien---one, .-mercapto-.-methyl-,-pentanone, --methylnonane-,,.-dione, geraniol, decanal and cis---hexenol emphasized the green note of the tea. ,-Acetylpyrrole, ,-ethyl--,/-dimethylpyrazine and ,-acetyl--,/-dimethylpyrazine emphasized the roast note. Indole strengthened the overall green tea odor. b-Ionone emphasized the sweet note in the green tea. Of these odorants, ,-acetyl--,/-dimethylpyrazine was identified for the first time as a volatile compound in tea.

Characterisation of odorant compounds and their biochemical formation in green tea with a low temperature storage process

“…Potent odorants of green tea made in China and Japan were meaty, metallic, fatty, honey-like, floral, and animal-like (Guth et al, 1993;Kumazawa et al 1999, Hattori et al 2003, 2005. In this study, we confirmed the potent characters of Sencha were green and fresh green.…”

“…Indole (peak 21) highly contributed (FD f =4 5 ) to the floral aroma and strengthened the overall green tea odour (Hattori et al 2003(Hattori et al , 2005. Moreover, there was a large difference in the amount of indole between LTPGT and NTPGT.…”

“…They are rare constituents for a green tea aroma. The odour characteristic of 3-methylnonane-2,4-dione was reported to be fruity or green (Guth et al, 1993;Kumazawa et al, 1999;Hattori, Takagaki, & Fujimori, 2003, 2005, and coumarin was reported to have a cherry flower-like character (Yang et al, 2009). In addition, (5Z)-1,5-octadien-3-one (peak 2) had a high FD factor (FD f ) of 4 4 in LTPGT with a geranium-like, green, metallic smell (Guth et al, 1993;Kumazawa et al, 1999;Hattori et al, 2003Hattori et al, , 2005).…”

Strategies for the identification and sensory evaluation of volatile constituents in wine

“…Perceptual interaction approaches can also be applied when beginning to characterize unknown volatile constituents in wine. The literature on this issue is currently limited (Béno et al., 2015; Hattori et al., 2005; Thomas‐Danguin et al., 2018; Williams et al., 2009). Therefore, a few related aspects and perspectives are described here with a view to identifying unknown volatile components.…”

“…This can be easily achieved by relocating the cryogenic trap downstream the splitter prior to olfactometry. Other techniques involving GC–O in combination with olfactometers (e.g., GC–pedestal olfactometer, GC–PO; GC–O/olfactoscan) (Béno et al., 2015; Hattori et al., 2005; Thomas‐Danguin et al., 2018; Williams et al., 2009) may also be considered for the purpose of identification, although these techniques have been more focused on perceptual interactions during postidentification. With olfactometers, additional effluent pulses from the designated sample can be introduced to coincide with traditional GC–O detection, in order to investigate the perceptual interaction phenomena that occur in the odor mixture formed at sniffing port (Burseg & de Jong, 2009).…”