The Effect of Temperature on the Aroma of Soft Stick Oolong Black

Tea

Ling Ren

1,2 a

, Shunying Chen

, Chunhua Zhang

1,* c

and Ruifang Wang

1,* d

Pu'er University, Pu'er, Yunnan Province, 665000, China

Tea College of Yunnan Agricultural University, Kunming, Yunnan Province, 650201, China

Corresponding author

Keywords: Soft Stick Oolong, Roasting, Black Tea.

Abstract: Soft stick oolong black tea using the processing technology of Yunnan Gongfu black tea is made from

Taiwan Qingxin oolong. In this study, in order to explore the effect of roasting temperature on the aroma of

soft stick oolong black tea. Soft stick oolong black tea was roast at 100°C, 110°C, 120°C, 130°C

temperatures, and then the aroma was determined by GC-MS. Our results showed that soft stick oolong

black tea had the most volatile compounds and the highest sensory evaluation score at the baking

temperature 120°C.

1 INTRODUCTION

Tea (Camellia Sinensis (L.) O. Ktze.) belongs to

shrubs or small trees. China is the origin of tea (Lu

2013). Initially, it exerted its medicinal value.

Legend recored that, Shennong tasted tea. Tea has

been used to clear heat and quench thirst, diuresis

and strengthen the heart. Oolong tea is mainly

distributed in Fujian and Taiwan, which has a high

aroma and low bitterness. It is often used to make

black tea and green tea, and the produced tea has a

unique aroma. An important factor influencing the

quality of oolong tea is aroma, and processing

techniques have different effects on the aroma

components of oolong tea (Su 2019).

Gongfu black tea is named from its extremely

labor-intensive production process. And Gongfu

black tea is well-known in the world for its "high

fragrance, bright color and strong taste" (Mi 2013).

The production process is not complicated, but the

control of the production process is very important.

Withering is the process of losing some water,

volatilizing grass gas, and affecting enzyme activity.

The degree of withering can affect the quality of

black tea. The process of rolling is the result of the

https://orcid.org/0000-0002-1796-6261

https://orcid.org/0000-0002-6805-019X

https://orcid.org/0000-0001-9567-0987

https://orcid.org/0000-0003-4715-6240

coordination of chemical and physical interactions,

in which black tea has begun to ferment, and

different chemical reactions have occurred. It is also

the process of black tea shaping, rolling into a firmer

curled shape, increasing the rate of cell damage and

promoting oxidation reaction. The production

process of Yunnan Gongfu black tea is wilting →

rolling → fermentation → drying → fragrance,

which is also a way to stimulate the aroma after the

black tea has been dried (Fan, et al., 2020, Feng, et

al., 2017). There are baking, hot wind, far infrared,

microwave, light wave and other fragrant ways. But

in Yunnan, baking is generally used to increase

fragrance, because the boiling point of aromatic

substances is different, the temperature of baking

and fragrance will change accordingly. In recent

years, consumers have much demanding on the

quality of black tea. How to improve the aroma and

taste of black tea has always been a hot research

topic for black tea (Liu, et al., 2015).

The so-called "soft branch" refers to an oolong

species introduced from Taiwan, also known as

Qingxin Oolong. It was originally introduced to

Taiwan by a century-old mother tree of dwarf

oolong from Jian'ou City, Fujian Province. It

belongs to a small-leaf species with a small tree

shape. It is an open-type dwarf variety with small

leaves and dense branches. The buds are initially

purple and the leaves are oblong. The thick

mesophyll makes it extremely rich in nutrition and

Ren, L., Chen, S., Zhang, C. and Wang, R.

The Effect of Temperature on the Aroma of Soft Stick Oolong Black Tea.

DOI: 10.5220/0011179700003443

In Proceedings of the 4th International Conference on Biomedical Engineering and Bioinformatics (ICBEB 2022), pages 53-58

ISBN: 978-989-758-595-1

 2022 by SCITEPRESS – Science and Technology Publications, Lda. All r ights reserved

aroma substances, which are suitable for making

many different fermented teas. Soft branch black tea

is made from the fresh leaves of soft branch oolong

tea and the processing technology of Yunnan

Kungfu black tea. Because the oolong tea has a

higher aroma, making it into black tea can improve

the aroma. Therefore, soft branch black tea is very

popular nowadays.

Baking treatment is one of the important post-

treatment processes of tea, which has an important

effect on improving the quality of tea (Wen, et al.,

2018). In recent years, Yunnan Gongfu black tea

flavoring technology has been continuously

developed, and the commonly used baking flavoring

technology has also been continuously improved.

The market has increasingly higher requirements for

the aroma of black tea. Therefore, the related

research and improvement on the standards for black

tea fragrance enhancement are needed. Zheng Silin

(Zheng 2016) studied the processing technology of

the Qingxin Oolong variety Summer and Autumn

black tea introduced in Sichuan, showed that the

black tea made with Qingxin Oolong is of good

quality. Although it is different from the processing

technology of Yunnan Gongfu black tea, it also has

a guiding significance for Yunnan Oolong Gongfu

black tea. However, the current research results on

the aroma of soft-branch black tea are lacking, the

research on the fragrance standard needs to be

perfected, and there is no research specifically aimed

at the aroma of soft-branch oolong black tea. Shi

Daliang (Shi et al. 2018) studied the drying methods

of Qingxin Oolong Gongfu black tea. The results

proved that Qingxin Oolong Gongfu black tea had

the best quality under the conditions of 120 ℃ first

firing and 90 ℃ full firing. This study explored

aromatic substances in soft stick oolong black tea to

find out aroma-stimulating temperatures. Then

through the evaluation of the tea critics, we want to

find optimal time and temperature for soft stick

oolong black tea processing, which will have certain

guiding significance for the production of soft stick

oolong black tea.

2 MATERIALS AND METHODS

2.1 Materials and Instruments

Material: The soft stick oolong black tea purchased

in the market has uniform material quality and has

not been treated with fragrance after drying.

Instrument: American Agilent 6890-5973 Gas

Chromatography Mass Spectrometer (GC-MS).

Manual solid phase microextraction instrument PC-

420D, Supelco, USA; Extraction head 65μm,

PDMS/DVB, Supelco, USA.

2.2 Sample Preparation

Divide the material into 4 groups, each group is

500g and set 3 repetitions for 60 minutes. The

temperature of control group was set at 100°C; the

temperature of other three groups were set at 110°C

(Ⅰ),120°C (Ⅱ) and 130°(Ⅲ). Spread the fragrance

and cool it in the same room. The indoor

temperature is 20-23℃, and the relative humidity of

the air is 70%-80%. After spreading to room

temperature, put it in a No. 10 ziplock bag for

sealing, and the air is full of self-sealing. After the

bag is sealed, the fragrance is prevented from being

lost after the gas exchange with the outside (Luo et

al. 2016).

2.3 GC-MS Conditions

The solid phase microextraction (SPME) method is

used to collect volatile substances. Use a clean

dissecting needle to poke a small hole about 5cm

below the top of the ziplock bag, insert a 0.5mm

length of 65μm PDMS/DVB solid phase

microextraction head manual SPME sampler into the

ziplock bag, headspace extraction and adsorption for

1 hour, sampling After the end, it was transferred to

the gas chromatograph mass spectrometer for

injection (Zhang, et al., 2020).

An Agilent 7890A-5975C gas chromatography-

mass spectrometer was used to analyze plant

volatiles. Capillary column HP-5MS (30m×0.25mm,

0.25μm), the carrier gas is high-purity helium, and

the flow rate: 1.0mL·min-1. Heating program: the

initial temperature is 50°C, the temperature is raised

to 280°C in 10 minutes, and after waiting 5 minutes,

the temperature is lowered to 50°C, and the

instrument runs for 52 minutes after sample

injection. The solvent is delayed by 2 min. The ion

source temperature is 230°C, and the quadrupole

temperature is 150°C. The detector temperature is

280°C, and the inlet temperature is 220°C (Zhang, et

al., 2020, Ma, et al., 2019, Chen, et al., 2021, Xie, et

al., 2019).

2.4 Materials and Instruments

After completing the GC-MS test, take the sample to

the tea review room for sensory review and scoring.

The sensory review of black tea is carried out with

reference to GB/T23776-2018 "Tea Sensory

ICBEB 2022 - The International Conference on Biomedical Engineering and Bioinformatics

Evaluation Method" (GB/T23776-2018), and the

determination of sensory attributes refers to GB/T

14487-2017 "Tea Sensory Evaluation Terminology"

(GB/T14487-2017), which was reviewed by 5

professionals Sensory evaluation of tea leaves is

conducted, and the scores are based on the average

of the tea judges to find the group with the best taste.

2.5 Data Analysis

Delete all compounds with matching degree <80 and

silicon-containing oxides. Query, identify and

analyze the compound components in the samples

by CAS number, and use Microsoft Excel 2019

software to carry out the data statistical analysis of

aroma components (Zhang et al. 2020, Ma et al.

2019, Liu et al. 2021, Zhou et al. 2011).

3 RESULTS AND ANALYSIS

3.1 Analysis of Aroma Components of

Soft-branch Oolong Black Tea

A total of 113 volatile compounds were identified in

the 4 treatments by GC-MS. The control group

identified 56 volatile substances, including 12

olefins, 10 alcohols, 8 alkanes, 7 aldehydes, and 6

aromatic hydrocarbons. The contents of various

volatiles were 21.4%, 17.9%, 14.3%, 12.5%, and

10.7% respectively. Group A has identified 55

volatile substances, including 17 olefins, 11 alkanes,

8 aromatic hydrocarbons, and 4 alcohols. The

contents of various volatiles were 30.9%, 20.0%,

14.6%, and 7.3%, respectively. Group B has

identified 66 volatile substances, including 21

olefins, 18 alkanes, 10 aromatic hydrocarbons, and 4

alcohols. The contents of various volatiles were

31.8%, 27.3%, 15.2%, and 6.1%, respectively.

Group C has identified 46 volatile substances,

including 18 olefins, 11 alkanes, 9 aromatic

hydrocarbons, and 2 alcohols. The contents of

various volatiles were 39.1%, 23.9%, 19.6%, and

4.3% respectively. The 4 treatments mainly include

23 kinds of alkanes, 31 kinds of olefins, 13 kinds of

aromatic hydrocarbons, 12 kinds of alcohols, 10

kinds of aldehydes, 5 kinds of ketones, 3 kinds of

esters, 4 kinds of acids, and 2 kinds of oxygen

heterocycles, 3 kinds of nitrogen heterocycles, 3

kinds of ethers, 2 kinds of sulfides and 2 kinds of

other substances (Table 1,2,3).

With the increase of flavoring temperature, the

proportion of olefins and aromatic hydrocarbons

gradually increases, and the proportion of alcohols

gradually decreases. It shows that with the increase

of the flavoring temperature, most of the volatile

substances in soft stick oolong black tea are

converted into olefins, and alcohols are decomposed

into other volatile substances.

Table 1: The total fraction of aroma substance in soft stick

oolong black tea.

Varieties

Total fraction

control Ⅰ Ⅱ Ⅲ

Alkanes 8 11 18 11

Olefins 12 17 21 18

Aromatic hydrocarbons 6 8 10 9

Alcohols 10 4 4 2

Aldehydes 7 4 6 3

Ketones 3 3 1 1

Esters 3 0 1 0

Acids 2 2 0 0

Oxygen heterocycles 1 1 1 0

Nitrogen heterocycles 2 0 1 1

Ethers 0 2 1 0

Sulfide 1 2 1 1

Other 1 1 1 0

Total 56 55 66 46

The relative content of alkanes with more than

10 carbon atoms (Dodecane, Tetradecane,

Undecane, Tridecane, 3-methyl-) decreases with the

increase of the flavoring temperature, while those

with less than 10 carbon atoms The relative content

of alkanes (Nonane, Decane) increases with the

temperature, indicating that long-chain alkanes are

decomposed into short-chain alkanes at high

temperature. Myrcene is made from linalool as the

raw material. The relative content of myrcene

gradually increases with the fragrance temperature,

while the relative content of linalool has a

downward trend with the increase of the fragrance

temperature. It shows that with the increase of

fragrance temperature, a large amount of linalool is

converted into myrcene. beta-Pinene and (1S)-L-β-

Pinene are both intermediates in the manufacture of

flavors and fragrances. As the flavoring temperature

increases, their relative content tends to increase,

indicating that as the flavoring temperature increases

Some of the elevated substances are converted into

beta-Pinene and (1S)-L-β-pinene (Table 2).

The Effect of Temperature on the Aroma of Soft Stick Oolong Black Tea

Table 2: Percentage of aroma substances in soft stick

oolong black tea.

Varieties

Precentage (%)

control Ⅰ Ⅱ Ⅲ

Alkanes 14.3% 20.0% 27.3% 23.9%

Olefins 21.4% 30.9% 31.8% 39.1%

Aromatic

hydrocarbons

10.7% 14.6% 15.2% 19.6%

Alcohols 17.9% 7.3% 6.1% 4.3%

Aldehydes 12.5% 7.3% 9.1% 6.5%

Ketones 5.4% 5.5% 1.5% 2.2%

Esters 5.4% 0 1.5% 0

Acids 3.5% 3.6% 0 0

Oxygen

heterocycles

1.8% 1.8% 1.5% 0

Nitrogen

heterocycles

3.5% 0 1.5% 2.2%

Ethers 0 3.6% 1.5% 0

Sulfide 1.8% 3.6% 1.5% 2.2%

Other 1.8% 1.8% 1.5% 0

Total 100% 100% 100% 100%

3.2 Sensory Review

Compared with the control group, different

temperatures had no effect on the cord and clarity,

but slightly affected the color, evenness, tea liquor

color, tea taste and infused leaves of the dry tea, and

had a greater impact on the flavor and height of the

tea aroma (Table 3-4).

Table 3: Sensory evaluation of shape.

Titian

treatment

Shape- Sensory evaluation (score)

Cord Color Evenness clarity

control 82.8 85.4 86.2 86.0

Ⅰ 82.8 85.4 86.2 86.0

Ⅱ 82.8 85.4 86.2 86.0

Ⅲ 82.8 84.8 83.6 86.0

Table 4: Sensory evaluation of quality.

Titian

treatment

Quality - Sensory evaluation

(score)

overall

ratings

Tea

liquor

colo

Tea

aroma

Tea

taste

infused

leaves

control 85.2 83.0 83.6 85.0 84.65

Ⅰ 85.8 84.8 83.0 85.0 84.88

Ⅱ 85.6 89.4 82.6 85.0 85.38

Ⅲ 84.0 84.0 80.8 82.6 83.58

Proper high-temperature fragrant treatment will

make the black tea liquor color red slightly, and the

tea liquor color will become turbid after over-

baking. The unflavored black tea tastes mellow, and

the flavored black tea has different degrees of high

fire flavor. Over-baked black tea will cause throat

discomfort. In the sensory evaluation, the aroma

gradually changed from rock and flower aromas to

sweet and sugary aromas. After the caramel aroma, a

burnt smell would appear.

In summary, with the increase of temperature,

soft stick oolong black tea has the most volatile

substances and compounds at 120°C, and the

sensory evaluation score is the highest.

4 DISCUSSION AND

CONCLUSIONS

The aromatic substances in tea are organic

compounds. So far, more than seven hundred aroma

substances have been separated from tea (Zhang, et

al., 2008). To date, more than 400 aroma

components have been detected in black tea (Zhang

et al. 2019, Shi 2010, Wan 2003). Alcohols, esters,

aldehydes, ketones, alkenes, alkanes, etc. are the

main aroma substances in black tea, among which

linalool, nerol, methyl salicylate, nonanal and

phenylacetaldehyde are among the aroma

components. The content of black tea is higher

(Wang, et al., 2013, Li, et al., 2021).

According to the source of aroma, it can be

divided into tea aroma and aroma produced during

production; most aromas contain unsaturated double

bonds, which are chemically active and volatile.

Aroma is not only an important factor in

determining the quality of tea, but also an important

indicator for distinguishing the quality of different

tea leaves (Ye, et al., 2018).

With the increase of fragrance temperature,

alcohols such as linalool show a downward trend.

Some previous studies have shown that alcohols are

the key aroma substances for the aroma of black tea.

For example, Li Jun (Li, et al., 2021) found that 2,6-

Octadien-1-ol, 3,7-dimethyl-, (E)-, 1,6-Octadien-3-

ol, 3,7-dimethyl-, Benzyl Alcohol, Benzaldehyde,

and Acetic acid are the key aromas compound of

Guizhou black tea. Liu Yang (Liu, et al., 2021)

found that alcohols and aldehydes are the most

important aroma components in tribute eyebrows.

Peng Yun (Peng, et al., 2021) showed that 1,6-

Octadien-3-ol, 3,7-dimethyl- and its oxides are

characteristic aroma components in Yunnan black

tea. In order to explore the reasons for the formation

of the special aroma and flavor of Sichuan Qingxin

Oolong black tea, Luo Xueping used SPME-GC-MS

ICBEB 2022 - The International Conference on Biomedical Engineering and Bioinformatics

combined technology and found that the main

aroma-contributing components of Sichuan Qingxin

Oolong black tea were alcohol compounds, with a

content of 58.20% (Luo, et al., 2021). Lin Yanping

(Lin, et al., 2021) found that the aroma components

of Wuyi black tea "Jinjunmei" were mainly alcohols,

hydrocarbons, esters, aldehydes and ketones. Zhou

Senjie (Zhou, et al., 2021) research found that the

aroma components among the tender, fresh and

high-grade Longjing tea types are alcohols,

aldehydes, terpenes, ketones, alkanes, alkenes,

heterocycles and esters and other compounds. There

are differences in species and relative content. 3-

methylpentane, 3-ethylpentane, myrcene, linalool,

nerol, trans-2-hexene and α-terpinene are the key

aroma compounds of Dianhong (Shu, et al., 2022).

Xu Yuanjun (Ge, et al., 2015) research shows that

the content of alcohols, alkanes, lipids and ketones

in floral black tea is higher

In summary, with the increase of the flavoring

temperature, alcohols will be decomposed and

converted into other substances. It is not that the

higher the flavoring temperature, the better quality

of tea. The soft stick oolong black tea has an

extremely rich aroma and overall best quality after

60 minutes flavoring at 120°C. The aroma

substances of tea have a great relationship with the

production process. Consumers’ demand for the

aroma of tea is still increasing. Detecting the aroma

of different production processes is conducive to the

standardization and improvement of the tea

production process. Soft branch oolong is made into

black tea. It is an innovation. Different Titians will

produce different aromas or different aroma ratios.

There is still a lot of research space for the aroma of

soft branch oolong black tea.

ACKNOWLEDGEMENTS

This work was supported by the Outstanding Young

Teacher program (2020GGJS006).

REFERENCES

Can Chen, Xiaoli Zhang, Bailong Liu, et al. Analysis of

rice volatiles induced by rice planthopper[J]. Southern

Agricultural News, (2021)52: 37-44.

Chen Li, Cuinan Yue, Puxiang Yang, et al. Research

progress on characteristic aroma of Gongfu black

tea[J]. Journal of Food Safety and Quality Inspection.

(2021),12(22):8834-8842.

Daliang Shi, Jizhong Yu, Minming Guo, et al. The effect

of drying methods on the quality of Qingxin Oolong

Gongfu black tea[J]. Hangzhou Agriculture and

Technology. (2018)06: 32-34.

Fei Lu. Research on the origin theory of Chinese tea [J].

Tokyo Gakugei University. (2013) 06: 131-134.

Fan Zhang, Changqing Xu, Jun Chen, et al.

Electrophysiological and behavioral responses of Red

Gall Midge from Lycium barbarum to host plant

volatiles[J]. Chinese Journal of Applied Ecology,

(2020)31: 2299-2306.

General Administration of Quality Supervision, Inspection

and Quarantine of the People's Republic of China,

National Standardization Administration of China. Tea

sensory evaluation method: GB/T23776-2018[S].

Beijing: China Standards Press, (2018): 1-24.

General Administration of Quality Supervision, Inspection

and Quarantine of the People's Republic of China,

National Standardization Administration of China. Tea

sensory terminology: GB/T14487-2017[S]. Beijing:

China Standards Press, (2017): 27-29

Jun Li, Yuan Zhu, Shuting Fang, et al. Study on the aroma

components of Guizhou black tea based on solid phase

microextraction and GC/MS[J]. Food Industrial

Technology. (2021),42:304-316.

Jie Fan, Qiushuang Wang, Dandan Qin, et al. Research

progress on the quality of black tea and its related

biochemical factors [J]. Food Science.

(2020),41(03):246-253.

Lan Feng, Xiaoyan Mo, Guangzhi Liang, et al. Effects of

Different Processes on the Quality of Black Tea[J].

Chinese tropical agriculture. (2017):58-59+73.

Lixiang Wen, Fen Zhang, Chaomin Xie, et al. The effect

of different flavoring treatments on the quality of

Jinxiu wild black tea[J]. Agricultural Research and

Application. (2018)31: 30-33.

Qiushuang Wang, Dong Chen, Yongquan Xu, et al. Study

on the Aroma Components in Chinese Famous Black

Tea[J]. Journal of Chinese Institute of Food Science

and Technology, (2013),13(1): 195-200.

Suqiang Liu, Juan Yang, Linying Yuan, et al. The effects

of baking and flavoring conditions on the sensory

quality and main biochemical components of black

tea[J]. Journal of Food Safety and Quality Inspection.

(2015)04: 1301-1306.

Silin Zheng. Research on the processing technology of

summer and autumn black tea introduced from

Sichuan Qingxin Oolong variety [D]. Sichuan:

Sichuan Agricultural University. (2016):10-14.

Senjie Zhou, Chuangsheng Huang, Chunlin Li, et al.

Comparison of Aroma Composition and Related

Components of Longjing Tea with Different Aroma

Types[J]. Journal of Zhejiang University (Agriculture

and Life Sciences Edition). (2021),47(02):203-211.

Weisheng Ye, Jianliang Hu. Research progress of tea

aroma components and detection technology[J].

Agriculture and Technology. (2018): 34-35.

Wengang Xie, Shisheng Fan, Yan Liu, et al. Analysis of

aroma components of Guizhou high-quality

The Effect of Temperature on the Aroma of Soft Stick Oolong Black Tea

“Wuniuzao” green tea byHS-SPME/GC-MS[J]. Tea

Communication, (2019),46(4): 448-454.

Xiaochun Wan. Tea biochemistry [M]. Beijing: China

Agricultural Press. (2003): 39

Xuan Mi. Research on the processing technology and

quality characteristics of Anyuan Gongfu black tea

[D]. Beijing: Chinese Academy of Agricultural

Sciences: (2013): 17-20.

Xueping Luo, Lixia Li, Chaolong Ma, et al. SPME-GC-

MS Analysis of Aroma Components in Black Tea

from Mainly Planted Tea Plants in Sichuan[J]. Food

Science. (2016)37(16):173-178.

Xueping Luo, Lixia Li, Xueyan Lian, et al. Analysis of

Aroma Components in Sichuan Qingxin Oolong Black

Tea by SPME-GC-MS[J]. Southern Agriculture.

(2021),15(16):7-11.

Xuefang Zhou, Hong Tang, Qian Lei, et al. Analysis of

Aroma Components in Sichuan Gongfu Black Tea[J].

Journal of Southwest Normal University (Natural

Science Edition). (2011)36(3): 178-182.

Xin Shu, Yanxiang Gao. Research progress on extraction

of volatile components from tea and analysis of aroma

characteristics[J/OL]. Food Industry Technology: 1-

19[2022-02-14] DOI:10.13386/j.issn1002-

0306.2021080311.

Yan Ma, Liyang Shi, Yi Zhao, et al. Antennae potential

and behavioral responses of L-onghorn beetle to the

volatile components of hickory under different

conditions[J]. Journal of Zhejiang Agriculture and

Forestry University, (2019)36: 437- 443.

Yan Ma, Liyang Shi, Yi Zhao, et al. GC-EAD and

behavioral responses of volatile com-ponents of

hickory nut under different infestation states of A.

longiflora[J]. Acta Applied Entomology, (2019)56:

530-538.

Yang Liu, Yafang Liu, Zhi Lin, et al. Analysis of aroma

composition and key aroma components of white tea

tribute eyebrow[J]. Food Science. (2021),42:183-190.

Yun Peng, Guo Li, Xueyan Liu, et al. SPME/GC-MS

analysis of aroma quality of black tea from different

origins[J]. Food Industry Science and Technology,

(2021)42: 237-244.

Yanping Lin, Bo Zhang, Jianming Zhang et al. Effects of

different withering methods on the quality of Wuyi

black tea "Jinjunmei" [J]. Food Research and

Development. (2021),42(19):78-85.

Yanan Zhang, Yiling Ou, Li Qin, et al. Research progress

on the formation of aroma substances and its influence

of processes in black tea[J]. Science and Technology

of Food Industry, (2019),40(11): 351-357.

Yuanjun Xu, Liang He, Lingyan Jia, et al. Differentiation

of aroma compositions in different regions and special

varieties of black tea[J]. Journal of Zhejiang

University (Agriculture & Life Sciences),

(2015),41(3): 323-330.

Zhongping Su. The influence of different processing

techniques on the aroma components of Oolong tea[J].

Quanzhou Manyi Tea Industry., Fujian Province.

(2019): 254-255.

Zhenxian Zhang. The effect of UV-B on the formation of

volatile compounds in tea [D]. Zhejiang: Zhejiang

University. (2008) 05: 19-20.

Zhaopeng Shi.

Tea review and inspection [M]. Beijing:

China Agricultural Press.

(2010): 6-57.

ICBEB 2022 - The International Conference on Biomedical Engineering and Bioinformatics