Effects of Different Picking Seasons on Aroma Quality of Single Fermented Tea

Zheng tingsheng

1

, Zhang Lingyun

2

(1. Zhejiang Taishun 325500 Taishun Tea Monopoly Bureau) (2. Department of Tea Science, South China Agricultural University, Guangzhou, Guangdong 5 10642)

Abstract: The fermented tea and traditional single fir tea collected in spring, summer, summer and autumn were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that heavy fermentation

Compared with traditional oolong tea, single fir tea has more kinds of aroma components, and linalool oxide is much higher than traditional oolong tea. Autumn tea and spring tea are aromatic substances in single fir tea with heavy fermentation in four seasons.

There are relatively few qualitative species (4 1 species and 43 species respectively); However, there are many kinds of aromatic substances in summer tea and summer tea (45 and 48 respectively), and the proportion of total essential oil in total volatile components is higher than that in autumn tea.

The contents of linalool oxide, pyrolene and rutine in summer tea and summer tea are higher, while the contents of geranial, indole, jasmonic acid and nerolidol are much lower than those in autumn tea. summer

Linalool and its oxides account for 69.77% of the total volatile components in tea, while the corresponding proportions of spring, summer and autumn tea are 50.98%, 565, 438+0.75% and 565, 438+0.72% respectively. sensorium

The evaluation shows that the aroma quality scores of autumn tea and spring tea are higher than those of summer tea and summer tea, that is, the aroma quality of autumn tea and spring tea is better than that of summer tea and summer tea.

Key words: single fir in Lingtou; Oolong tea; Re-fermentation; Picking season; Aroma components

China Library Classification Number: TS272.59；; Document identification number: a; Article number:1673-9078 (2007) 02-0011-05.

Effects of Different Picking Seasons on Aroma Quality of Lingtou Monofir

Submerged fermented oolong tea

grow

1

, Zhang Ling-Cloud

2

(1. Zhejiang Taishun Tea Monopoly Bureau, China Taishun 325500)

2. Department of Tea Science, South China Agricultural University, Guangzhou 5 10642, China)

Abstract: The effects of different picking seasons on the aroma components of Lingtou single fir oolong tea fermentation were studied by gas chromatography.

Chromatographic and mass spectrometry analysis. The results showed that the submerged fermented Lingtou single fir tea had more kinds of aroma.

Compared with traditional fermented oolong tea. The traditional fermented Lingtou single fir oolong tea showed a high linalool content,

α-terpineol, indole and cis-jasmone, but the content of linalool oxide is lower than that of submerged fermented tea. Difference of characteristic aroma

The composition is due to the change of linalool and linalool oxide content in different harvest periods. Tea is picked in autumn and spring.

The content of linalool and linalool oxide is relatively low (50.98~5 1.72%). However, the contents of linalool and linalool in tea picked in summer are higher.

Oxide (more than 69.77%). Such as nerolidol, Jasmine, Indole, 4- (2,4,4-trimethyl-cyclohexyllactone.

1, 5- dienyl)-butyl -3- ene -2- one and α-citral have higher contents in autumn tea. Sensory evaluation results show that

Autumn tea is better than others.

Keywords: Lingtou Dan Cong; Oolong tea; Fermentation; Picking season; Aroma components

Lingtou Danzong is a key tea variety promoted in Guangdong Province, which has been widely used in various places.

Large-scale cultivation At present, in addition to a large number of planting in the mountainous areas of eastern Guangdong, there are 3

Introduced successfully in 2 1 county of 26 provinces, and achieved considerable economic benefits.

profit

〔 1〕

. Lingtou single fir is a semi-fermented tea, which is usually made by shaking.

Fermentation is completed by the process of repeatedly alternating green and static, and the fermentation degree is different.

Yes, a little lower. Because of the heavy twisting degree of single fir tea, especially summer tea,

Under normal brewing conditions, tea soup is thicker if it is added after the green process.

Adding fermentation technology can not only reduce the bitterness of summer and summer tea, but also shape it.

The characteristics of honey-scented black tea are beneficial to improve the economic benefits of single fir tea.

Date of receipt: September 9, 2006

About the author: Zheng Tingsheng, an agronomist, is mainly engaged in the research, demonstration and popularization of green tea planting and processing technology.

work

Benefit. Generally speaking, the quality of tea is excellent under the same processing technology.

The times are spring tea, autumn tea, summer tea and summer tea.

[2]

. However, regarding the production season

The research on the influence of knot scar on tea aroma mostly focuses on green tea varieties.

〔3-5〕

, and

There is little research on the aroma difference of single fir tea in different seasons. Being single

The aroma of fir tea has a great influence on the quality of finished tea, so choose it.

Choosing the right production season is an important way to produce high-quality single fir tea

Pieces. In this study, a single Chinese fir in different seasons was used as raw material to study its production season.

Effect of node position on aroma components of Lingtou single fir oolong tea.

1 materials and methods

1. 1 test material

The tested tea raw materials were collected from 5-year-old Lingtou single fir tea varieties. Modern Food Science and Technology Volume 23 No.2 (Total 92)

12

The criteria for picking the third and fourth leaves of flower buds are spring (May 4th, 2005) and summer respectively.

Season (July 2005 10), summer (August 2005 15) and autumn (2005

September 24, 2008) Fresh tea.

1.2 tea-making technology

After the fresh leaves were harvested, the traditional single fir control sample followed the traditional single fir oolong tea.

Practice of production process. Compound fermented single fir tea refers to the traditional Lingtou single.

Processing technology of fir:

Fresh leaves → spreading → drying (30 ~ 40 minutes) → cooling → shaking? Cool green (shake green,

Cool for 3~6 times) → wither with hot air at 25 ~ 30℃ for 3 ~ 4 hours (it takes 4 ~ 5h)→ hours for spring tea) → knead.

40 minutes → fermentation for 5-6 hours (spring tea fermentation for 8 hours) → burning for 20 minutes → redrying and drying for 80 minutes.

Primary tea products.

The primary tea was baked at 100℃ for 5 hours and cooled.

The finished tea was sealed and stored for testing.

1.3 extraction of tea essential oil

See the literature for the extraction of tea essential oil.

〔6〕

.

1.4 gas chromatography-mass spectrometry analysis conditions

The aroma components were analyzed by finnigan micro gas chromatography-mass spectrometry,

Chromatographic column: DB- 1, 30m×0.25mm；; ; The carrier gas is helium with a flow rate of

1.0mL/min, no shunt. Chromatographic conditions: 5min, 5.

Heating to 65438 000℃ at the rate of℃/min, and keeping it for 65438 0 min, and then heating to 250℃ at the rate of 65438 0℃/min.

℃, the inlet temperature is 250℃, and the connection temperature is 250℃. The injection volume is 0.3 μ l.

Mass spectrometry conditions: EI ion source, bombardment voltage 70eV, multiplication voltage 350V.

The scanning quality is 35~390amu.

2 Results and analysis

2. 1 General characteristics of the essential oil components of single fir tea (see table 1)

From the table 1, it can be seen that the aroma components of heavy fermented single fir tea are better than traditional tea.

Tong Dan fir oolong tea is complicated. Among the 65 aromatic components detected, it

There are 43 kinds of spring tea, 45 kinds of summer tea, 48 kinds of summer tea and 4 1 species of autumn tea.

The traditional control is 3 1 species. The total amount of essential oil in traditional single fir oolong tea also

The lowest, only 88.93%. However, compared with the single heavy fermented Chinese fir, the traditional method is

Linalool, terpineol, indole, jasmonate, echinone,

The content of 3,7, 1 1, 15- tetramethyl -2- hexadecene-1- alcohol should be specific gravity fermentation.

The content of single fir is high, especially the content of linalool, which can almost be higher than that in summer heat.

Tea 1 time. While linalool oxide, phenylacetaldehyde, methyl salicylate, incense

The content of leaf alcohol is obviously lower than that of fermented single fir. This is consistent with previous research results.

Consistent, that is, less fermented tea contains more orange blossom tertiary orange,

Indole and linalool, but tea with high fermentation contains more linalool.

Alcohol oxide, geraniol, etc. , but contains less nerolidol orange and indole.

And linalool.

〔7〕

.

Proportion of aroma components in re-fermented single fir tea in different seasons.

Examples are linalool oxide, linalool,

Geraniol+geranial, Spinocene, farnesene, 2,6-bis (1, 1 dimethyl)

4- methylphenol, nerolidol, coniferene, 3,7, 1 1, 15- tetramethyl.

10 -2- hexadecene-1- alcohol and palmitic acid. As shown in Table 2, this

These components account for the total amount of essential oil in different seasons and traditional process samples respectively.

76.67%, 80. 17%, 73.38%, 72.20% and 8 1.64% of the total amount.

Among them, linalool accounts for the highest proportion in the traditional process, while linalool is oxidized.

The content of organic matter in heavy fermented tea is high, and all samples can reach their sum.

To more than 50%. It shows that the above 10 aroma components constitute Lingtou Dan.

Characteristic aroma components of Abies oolong tea. Especially linalool and its oxidation.

The content of these substances is closely related to the quality of Lingtou single fir oolong tea.

2.2 The influence of different picking seasons on the essential oil composition of heavy fermented single fir tea.

From the table 1, it can also be seen that the aroma components of heavy fermented single fir spring tea

Characterized by linalool, geraniol, 3,7, 1 1, 15- tetramethyl -2- hexadecene.

-1- alcohol, palmitic acid, 1.4 phthalic acid -[4- (methoxycarbonylation) benzene]

Methyl methyl ester, myrcene, benzothiazole, cedrol, caryophyllene,

The content of methyl linolenate is higher than that of single fir tea in other seasons.

Unique aromatic folic acid, damascenone, 5,6-epoxionone, 1 1, 14, 17-

Eicosatrienoic acid methyl ester, etc. ; However, linalool oxide, terpineol, Du

The terpineol content is low.

Chlorophyll aldehyde, phenylacetaldehyde, terpineol and methyl salicylate in autumn tea of single fir tree.

Ester, geranial, 3- cyclohexyl-1- ene -2- enal, indole, jasmonic acid ester and France.

Nepentene, nerolidol, citronellol, 4- (2,4,4-trimethyl-1, 5- cyclohexyl.

The content of dienyl) -2- butene -4- one and methyl palmitate is higher than its content.

Its seasonal products, especially 1- ethyl-1H- pyrrole -2- formaldehyde,

It was not detected in tea in spring, summer and summer. Because when drinking tea in autumn,

It contains higher aldehydes and alcohols, but less olefins, especially

Contents of caryophyllene, rutine, juniper, etc. It smells like grass, which is relatively high.

Low or lower. This is also the main reason why autumn tea is more fragrant than other teas.

One of the reasons.

2.3 Effects of different picking seasons on sensory quality of heavy fermented single fir tea

Sensory evaluation of single fir tea fermented in different seasons showed that autumn tea

The sensory score of fermented tea is higher than that of traditional control, which highlights the taste of fermented tea.

The quality of officials is slightly lower than the traditional practice. Among them, the nectar of autumn tea is more mellow

Durable, mellow and sweet, with the highest comprehensive score (as shown in Table 3), so

The quality is very good. Summer tea Summer tea has low floral fragrance, good aroma and good taste.

The score is lower than autumn tea, control tea and spring tea. Explain the feeling of tea in summer and summer.

The quality is not as good as that of traditional light fermentation, but the quality of spring tea is the same as that of traditional processing.

The method is closer. The sensory quality of heavy fermented autumn tea is the best.

3 Summary and discussion

The aroma of tea is composed of different kinds of aromatic substances in proportion and concentration.

Therefore, as long as the kind or relative content of aromatic substances changes.

Will affect the aroma components of tea.

〔8〕

. Effects of environmental conditions on tea trees

The synthesis of aromatic substances is directly related. Studies have shown that tea glycosides

The seasonal variation of aroma-like precursors content is obvious. In terms of the total amount of aroma precursors,

The content is higher in spring and autumn and lower in summer. Different kinds of glycoside aroma precursors have obvious differences with the seasons.

〔3〕

. it is reported (that)

way

〔9〕

Spring tea contains substances such as Shulun alcohol and hexenol, and has a high aroma.

Summer tea is low, and autumn tea contains phenylethanol and phenylacetaldehyde, which has a floral fragrance.

Materials; According to Wang Huafu, etc.

〔 10〕

It is reported that the total amount of bonded monoterpene alcohol is spring tea.

Higher than summer tea; Winter tea (snow flakes) and autumn tea in oolong tea are highly aromatic and rich.

And summer tea is low and light. Seasonal difference is mainly the difference of meteorological elements, namely

Light, temperature, humidity and other different factors.

This study shows that compared with traditional single fir tea, single fir tea leaves are fermented again.

The types of aroma components in midsummer tea and summer tea are more complicated, but not in Chaze in Spring and Autumn.

Yes, it's simple. Keywords linalool oxide, linalool, geraniol+geranial,

2,6-bis (1, 1 dimethyl ethyl) 4- methylphenol,

Nerolidol, coniferene, 3,7, 1 1, 15- tetramethyl -2- hexadecene-1- alcohol,

Palmitic acid and other 10 aroma components are the characteristics of Lingtou single fir oolong tea.

Characteristic aroma components. Especially linalool and its oxide content.

The aroma quality of Lingtou Danzong oolong tea is closely related.

Re-fermentation of chlorophyllin, phenylacetaldehyde, terpineol and water in Danzong autumn tea

Methyl salicylate, geranial, 3- cyclohexyl-1- ene -2- enal, indole, jasmine.

Ketone, farnesene, nerolidol, citronellol, 4- (2,4,4-trimethyl-1, 5-

The content of cyclohexadienyl) -2- butene -4- one and methyl palmitate is high.

Products from other seasons. Because autumn tea contains higher aldehydes and alcohols.

Class, but the content of olefinic substances is less, so autumn camellia is more fragrant than other seasons.

Tea is more obvious. High olefin content, aldehydes, ketones, alcohols

The low content may be the reason for the low aroma of single fir tea in summer and summer. different

The results of seasonal aroma analysis of single fir tea are consistent with sensory evaluation, that is, autumn tea.

Nectar fragrance is more mellow and lasting, full of alcohol, sweet aftertaste, and has excellent single fir

Quality characteristics. According to the research results, the heavy fermentation type was selected in autumn.

Single fir tea can obtain better quality.

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