Agric. BioL Chem., 47 (9), 2077-2083, 1983 2077

Flavor Constituents of Longjing Michiko Kawakami and Tei Yamanishi* Ibaraki Christian Junior College, Hitachi-shi, Ibaraki 319-12, Japan *Ochanomizu University, Bunkyo-ku, Tokyo 112, Japan Received February 23, 1983

The flavor constituents of the highest quality Longjing tea parched on a pan while the leaves were turned over by hand were identified by GC-MS, and compared with those of Japanese kamairi-cha. Seventy-six components were characterized in Longjing tea. Nine compoundswere newly identified related to tea aroma; six from both Longjing and Japanese kamairi-cha, two from Longjing only and one from Japanese kamairi-cha only. The amount of pyrazines, linalool oxides, carboxylic acids, lactones, geraniol, 2-phenylethanol and ionone compoundswas larger, while the amount of cw-3-hexenol, cw-jasmone, nerolidol, indole and benzyl cyanide was muchsmaller in Longjing tea than in Japanese kamairi-cha. The former seven compoundsseemed to contribute to its characteristically strong pan-fired aroma as well as its floral and sweet aroma.

"Longjing" tea is one of the famous Chinese method as previously reported.1* Yields of aroma con- green because of its attractive pan-fired centrates from Longjing tea and Japanese tea were 18.5 mg aroma and of its high quality. This sample and 6.0 mg respectively. formed a typical flat shape because it had been Identification of the components. The componentswere parched by hand. Pan-firing was done at a identified by matching GCand MSdata with those of lower temperature and it took a longer time authentic compounds or published data.1'2'4"6* Two than that of Japanese kamairi-cha, i.e. heated aroma concentrations were analyzed directly by GC-MS, at 80°C for 15min, and then at 25°C for 20hr. the system consisting of a Hitachi 663 gas chromatograph coupled with a Hitachi M-80A+M-003mass spectrom- In the present work we analyzed and iden- eter. The GCcolumn was a 50mx0.35mmfused silica tified the characteristic flavor componentsof column coated with FFAP. Longjing tea and compared them with those of Japanese kamairi-cha. The flavor of Japanese kamairi-cha was reported previously1'2) and RESULTS AND DISCUSSION Chinese kamairi-cha manufactured by a gen- Parameters of GC-MSand gas chromato- eral process was also reported.3) grams are shown in Fig. 1. The gas chroma- togram of Longjing tea showed more than MATERIALS AND METHODS one hundred peaks, while that of Japanese kamairi-cha showed about ninety peaks. Materials. Chinese Longjing tea was got from National Native Products of . The sample was Aromapatterns of both samples were different of a yellowish green color and of the highest grade of from each other. Relative quantities of the spring tea, produced in 1982 (240 leaves/g). And it has a componentswere calculated from peak area strong sweet pan-fired aroma different from that of percentages on gas chromatograms and are Japanese kamairi-cha. Japanese kamairi-cha (cultivar. shown in Table I. Yabukita) was of the high grade produced in the Aso area, Kumamoto,in the same season in 1982 and it was of a Amongthose compounds listed in Table I, deep bluish green color and had a weak greenish aroma. four sesquiterpene alcohols, i.e. cedrol, cadinol T, torreyol and /?-eudesmol, 2,6,6-trimethyl- Preparation of aromaconcentrate. Aromaconcentrates cyclohex-2-en-l,4-dione and 3-methyl indole were prepared from 300g of individual teas by the same (skatol) were newly identified in tea aroma. to o 00

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Fig. 1. Gas Chromatograms of the Aroma Concentrates from Longjing Tea and Kamairi-Cha. Column, FFAP0.35 mmx 50m; column temp., 70->210°C, 3°C/min; ionization voltage, 20eV. Reconstructed total ion current. Flavor of Longjing Tea 2079

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Fig. 2. Mass Spectra of Newly Identified Compounds in Tea Aroma. A), cedrol; B), cadinol T; C), torreyol; D), jS-eudesmol; E), 2,6,6-trimethylcyclohex-2-en-l,4-dione; F), 3- methyl indole. 2080 M. Kawakami and T. Yamanishi

Table I. Composition of the AromaConcentrates from Longjing Tea and Kamairi-Cha Re la tiv e qu an ti ty ( %) tR P e a k (m in ) N o . C o m p o u n d C h i n e s e J a p a n e s e L o n g j i n g K a m a i r i

3. 1 4 l -Pent en-3-o l 1.8 1. 3 3.7 6 D o d ec a n e 0 . 2 0 . 4 4.2 7 P en ta n o l 0 . 9 0 . 2 5.2 8 T rid ec a n e 0 .4 5.4 9 ds-2 -Penta n ol 0 . 9 0 . 3 6.4 l l 2, 5 - Dim eth ylp yra zine 0.3 7.0 12 CLS - 3 -Hex enol 0 . 3 1 . 8 7.2 1 3 ' T e tr ad ec a n e 0. 5 7.7 14 N o n a n al 0 . 2 0 . 1 8. 1 16 Ace ti c aci d 0 . 5 1 . 2 2 -M e th y l-5 -e th y lp y ra z in e 0. 1 8.7 17 F u r fu r a l 0. 1 8.9 18 Tr ime th yl p yr azi ne 0. 1 9.3 19 l -Octe n-3-ol 0.2 9.5 2 0 L in a lo o l o x id e (c is , fu ra n o id ) 1 . 2 0 . 2 9.8 2 1 H e p ta n o l 0.5 10 .1 2 2 ds - 3- He xe ny l bu ty rat e 0. 1 0 .1 10.2 2 3 ' B e n z a ld e h y d e 0 . 1 0 . 3 10.3 2 3 2, 5-D ime thy l- 3 -et hyl pyra zin e 0.3 10.5 2 4 P en ta d ec an e 0. 2 10.7 2 5 Li na loo l o xi de (tr an s, fur an oid ) 1.8 10.9 2 6 c/s - 3 - Hexe nyl -2 -met hyl bu tyra te 0.2 l l.4 29 130 1 U n k n o w n 9 . 2 9 . 3

l l.8 3 1 L in a lo o l 3 . 6 1 . 9 12.0 3 2 O cta n o l 1 . 8 0 . 8 12.2 3 3 trans , trans-3 , 5-Octad ien-2-one 1.6 0 .1 12.6 3 5 6- Me thy l- /r aHs -3 , 5- hep ta di en- 2- on e 0 . 1 0 . 2 12.9 3 6 2 , 6 , 6 -Tr ime thy l-2 -hy dro xyc ycl ohe xano ne 1 . 9 0 . 8 13.2 3 7 l -E thy l-2 -fo rmy l p yrr ole 1. 8 1. 8 13.5 3 8 tf -C y c lo c itra l 1. 1 0 .5 13.7 3 9 H e x a d ec a n e 0 . 2 0 . 2 14.2 4 0 l -Et hyl-2 -acety l pyr role 0.5 14.3 4 1 S afranal6 0.6 14.5 4 2 A ce to p h en o n e 0. 3 14.6 4 3 U n k n o w n 0 . 3 0 . 1 14.8 4 4 5 -H ex an o lid e 0.3 15. 1 4 5 ds - 3 -H e xe ny l h ex a no at e 1.5 1. 6 15.2 4 6 F u rfu ry l alc o h o l 0.2 15.8 4 7 2,6 ,6- Trim eth ylc ycl ohex -2- en- 1 , 4-d ion ea 0.2 16.0 4 8 4- H eptan olid e 0 . 8 0 . 7 16.2 4 9 a -T erp in e o l 0 . 8 0 . 4 16.4 5 0 5 - Hepta nolide 0 . 6 0 . 8 17. 1 5 2 N a p h th a le n e 0 . 2 0 . 3 17.3 5 3 U n k n o w n 0 . 6 0 . 4 17.6 5 4 Li nal oo l o xid e (ci s, py ran oid ) 1. 1 0 .3 17.9 5 6 U n k n o w n 0 . 5 0 . 1 18.5 5 8 M eth y lsa licy la te 0.9 18.7 5 9 L in a lo o l o x id e (tra n s, p y ra n o id ) 4 . 8 1 . 8 20 .0 6 1 N e ro l 0 . 2 0 . 1 20 .8 6 2 2 -M e th y l n a p h th a len e 0. 1 0 .1 Flavor of Longjing Tea 2081

Table I. (continued)

tR Peak _ , Relative quantity (%) / à" \ xt Compound _,. (mm) No. ^ Chinese Japanese Longj ing Kamairi 21.2 63 a-Ionone 0.5 21.5 64 Hexanoic acid 1.2 2.9 22.0 66 Geraniol 5.2 1.0 22.2 67 Geranyl acetone 0.2 22.4 68 Benzyl alcohol 5.5 5.2 23. 5 7 1 2-Phenylethanol 4.2 1. 3 23.8 72 Benzyl cyanide 0.2 1.4 24.6 74 jff-Ionone 3. 5 2.2 ds-Jasmone 1.2 3. 8 25.2 75 Heptanoic acid 1.0 0.9 25. 5 76 2-Acetylpyrrole 3.0 1. 1 26. 1 77 5,6-Epoxy-£-ionone 2.2 2. 1 26.6 79 Phenol 0.2 27. 1 80 4-Nonanolide 0. 5 0.2 28.5 82 Nerolidol 2.3 6. 1 28.8 84 Octanoic acid 1.2 0.3 29.2 85 /7-Cresol 0. 1 30.0 87 Cedrolfl 1. 5 30.3 89 Unknown 1.3 2. 1 30.6 90 cw-3-Hexenyl benzoate 0.2 1.0 31.3 91 Unknown 1.3 1.2 3 1.5 9 1 ' 6, 10, 14-Trimethylpentadecanone 1. 1 3 1.7 92 Theaspirone 0. 5 32. 1 94 Unknown (sesquiterpene alcohol) 0.6 0,7 32.4 95 Nonanoic acid 3.5 3.3 32.7 96 Cadinol T0 0.7 1.9 33.0 98 Torreyola 0.7 0.9 33.7 99 jS-Eudesmolfl 0. 7 0.6 34.0 100 a-Cadinol 1.9 4. 1 34.3 1 01 Methyl palmitate" 0.8 5.3 35.5 104 Ethyl palmitatea 0.2 2.3 35.6 105 Decanoic acid 0.2 36.4 1 06 Dihydroactinidiolide 1. 7 1.4 36.7 108 Methyl jasmonate* 0.3 1. 1 37.4 1 09 Tricosane 0.9 38.7 1 1 1 4-Vinyl phenol 0.4 1.1 39.6 1 13 Coumarin 1.1 1.0 39.8 1 14 Indole 3.0 6.1 40.5 1 1 5 Tetracosane 1.2 40.6 1 16 Methyl stearatea 0.3 41.2 1 17 3-Methyl indolea 0.3 41.6 1 18 Ethyl stearatea 0. 1 0.2

Newlyidentified compoundas a constituent of tea flavor. Newly identified compoundas a constituent of flavor. Peak 73 is ionol (B.H.T.).

Mass spectra of these compounds are shown /^-carotene, because this compoundwaspro- in Fig. 2. duced from jS-carotene by thermal degradation 2,6,6-Trimethylcyclohex-2-en- l ,4-dione was in aqueous mediumbut remained unidentified considered to be a degradation product from in the previous study.7) 2082 M. Kawakami and T. Yamanishi

K a m a i r i - c h a L o n g ii n g t e a ' ' h o. : k w Linalool and linalool oxides, oxidative J 'O. ci s - 3 - H e x e n o l L i n a l o o l products of linalool, were much more abun- dant in Longjing tea than in Japanese tea. L i n a l o o l o x i d e The difference in amount of linalool seemed to be due to the variety of tea plant,n) but the O e r a n i o l ¥ * ^ - - ^ B m a ^ m m i ^ m ^ ^ ^ ^ m differences in amount of linalool oxides to the 2 - P h e n y l e t h a n o l 2 , 6 ,6 - T r i m et h y l - 2 - mild parching process because these com- h yC dy rc pl xo Yc ri ct yr ca l o h e x a n o n eJ- pounds were produced by mild withering, S a f r a n a l ^ 6 , 6 - T r i m e t;h y l c y c l o h e x2 -e n-lrolling. Zf -d io nande fermentating.12) The amount of tf - I o n o n e geraniol and 2-phenylethanol with a floral - 1 o n o n e aroma was greater in Longjing tea than in 5 , 6 - E p o x y ~ (S - i o n o n e Di h y d r o a c t i n i d i o l i d e Japanese tea, while the amount of cis-3- c i s - J a s m o n e hexenol, ds-jasmone, nerolidol, indole and N e r o l i d o l benzyl cyanide was smaller. Longjing tea I n d o l e contained several varieties of ionone series B e n z y l c y a n i d e compounds, 2,6, 6-trimethylcyclohex-2-en- Fig. 3. Composition Differences of Major Aroma 1,4-dione was newly identified in tea aroma Compounds between Longjing Tea and Kamairi-Cha. and safranal was reported as a constituent of flavor.13) Methyl jasmonate was 3-Methyl indole is well known as a fecal odor reported only for fermented teas such as compound like indole but this compound black tea and pouchong tea,14) nonfermented seemed to be an important factor for the teas such as kamairi-cha and Longjing tea, tea flavor the same as indole was. however, contained a small amount of this Longjing tea contained pyrazines such component.The present results showthat the as: 2, 5-dimethylpyrazine, 2-methyl-5-ethylpyr- characteristic flavor of Longjing tea is due to azine, trimethylpyrazine and 2,5-dimethyl-3- the original parching method and the variety ethylpyrazine. These are knownas heat prod- of tea plant. ucts from amino acids and sugars.8) The pan- fired aroma of Longjing tea seemed to arise Acknowledgments.Mass spectra were obtained with from these pyrazines. Naphthalene and 2- the help of Mr. T. Nakada and Mr. K. Shizukuishi of methylnaphthalene are also thermal products Naka Works, Hitachi Ltd. Standard MSspectra of ses- of fiber9} and have already been identified in quiterpene alcohols were kindly given by Dr. S. Muraki of . 10) Takasago Perfumery Co. Ltd. The authors wish to express Longjing tea contained a large amount of their thanks to them; without their cooperation these experiments could not have been made. carboxylic acids and somelactones, but esters such as methyl- and ethyl palmitates, and REFERENCES methyl- and ethyl stearates were not so abun- dant as in kamairi-cha. Except for methyl 1) T. Yamanishi, M. Nose and Y. Nakatani, Agric. Biol. Chem., 34, 599 (1970). palmitate, these were also newly identified but 2) M. Nose, Y. Nakatani and T. Yamanishi, Agric. these esters do not have aromas but have Biol. Chem., 35, 261 (1971). aromafixing ability. Large peaks, peaks 29 3) M. Kosuge, H. Aisaka and T. Yamanishi, /. Nutr. and 30, having a sweet sour aroma, seemed to Food Sci. Jpn., 34, 545 (1981). be complex peaks containing at least two 4) T. Yamanishi, S. Shimojo, M. Ukita, K. Kawashima and Y. Nakatani, Agric. Biol. Chem., 37, 2147 (1973). components, but they remained unidentified. 5) T. Yamanishi, M. Kawatsu, T. Yokoyama and Y. In order to clarify the aroma characteristics Nakatani, Agric. Biol. Chem., 37, 1075 (1973). of Longjing tea, the compositions of the major 6) M. Kawakami and T. Yamanishi, Nippon Nogei- aroma compoundswere compared by a bar- kagaku Kaishi, 55, 117 (1981). graph as shown in Fig. 3. 7) M. Kawakami, Nippon Nogeikagaku Kaishi, 56, 917 Flavor of Longjing Tea 2083

(1982). ll) T. Takeo, Phytochemistry, 20, 2149 (1981). E. Kubota and T. Hara, Chagyo Gijitsu Kenkyu 12) T. Takeo, Nippon Nogeikagaku Kaishi, 56, 799 (National Research Institute of Tea, Tokyo, Japan), (1982). 45, 23 (1973). 13) W. Renold, R. Naf-Miiller, U. Keller, B. Willhalm H. Sakuma, T. Osumi and S. Sugawara, Agric. Biol. and G. Ohloff, Helv. Chim. Ada, 57, 1301 (1974). Chem., 44, 555 (1980). 14) T. Yamanishi, M. Kosuge, Y. Tokitomo and R. K. Yamaguchi and T. Shibamoto, J. Agric. Food Maeda, Agric. Biol Chem., 44, 2139 (1980). Chem., 29, 366 (1981).