Evaluation of Japanese Green Tea Extract Using GC/O with Original Aroma Simultaneously Input to the Sniffing Port Method (OASIS)

Abstract

Recent studies of natural aromas have focused on only the lowest odor threshold compounds. In this study, we evaluated the volatile compounds of Japanese green tea, comparing the original aroma simultaneously input to the sniffing port method (OASIS) with the aroma extract dilution analysis method (AEDA). Geraniol, indole and linalool were classified in the low odor threshold by AEDA. Using OASIS, geraniol showed enhancement of the green character and indole showed strengthening the overall green tea odor, but linalool gave the same result as AEDA. On the other hand cis-3-hexenol, decanal and ␤-ionone were classified in the high odor threshold by AEDA, OASIS showed enhancement of the green, tea-leafy, and sweet characters respectively. We added these compounds to a Japanese green tea infusion and evaluated it. The results showed great similarity to the OASIS results. In conclusion, OASIS is an effective technique by which to evaluate mixtures of volatile compounds with original aromas.

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).…”

The Aroma Profiles of Thai Green Teas Derived from Two Varieties, Chinese and Assam

“…Many researchers have studied the aroma characteristics of teas, and to date more than 600 volatile compounds have been identified [1]. Recently, it was reported that the green note, but not the floral note, of tea is emphasized by the addition of a specific concentration (from 1 ppb to 10 ppb) of geraniol (floral odor) to green tea infusion [2]. The intricate mechanism of odorant reception [3,4] suggests that complex odors such as tea odor are created by the interaction of individual compounds.…”

Improvement of the Bitterness and Astringency of Green Tea by Sub-Critical Water Extraction

“…In this study, we compared SWE to conventional heated water extraction and pressurized extraction. In addition, we simultaneously evaluated differences in the taste and flavor of green tea extracts from each extraction method (Hattori et al, 2003). Sensory evaluation results suggested that the strong unpleasant taste peculiar to catechins was decreased by SWE.…”