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IV. RESULTS AND DISCUSSION
A. CHEMICAL COMPOSITION OF GREEN TEA LEAF Camellia
sinensis
Dried green tea leaf var. Oolong No. 12 was supplied by Boonrod Tea Factory Thailand. Dried green tea leaf was milled using hammer mill as shown in Figure 4.1.
There were some chemical compounds that have been observed in this research, which were moisture content, total polyphenol compound, teaine content, gallic acid, and
cathecin. Beside, volatile compound in dried green tea leaf was also analyzed. Chemical composition on green tea leafis shown in Table 4.1. and volatile compound in green tea
leaf is shown in Table 4.2.
Figure 4. 1. Dried green tea leaf milling Table 4. 1Chemical composition of dried green tea leaf
Chemical composition Amount Mean ± SD
Moisture content w.b. 6.91 ± 0.02
Total polyphenol g100g d.b. 28.80 ± 0.18
Gallic acid g100g d.b. 0.45 ± 0.02
Caffeine g100g d.b. 1.21 ± 0.02
Total catechin g100g d.b. 3.72 ± 0.08
GC g100g d.b. 0.33 ± 0.00
EGC g100g d.b. 0.97 ± 0.08
C g100g d.b. 0.40 ± 0.02
EC g100g d.b. 0.31 ± 0.01
EGCG g100g d.b. 1.24 ± 0.11
GCG g100g d.b. 0.23 ± 0.01
ECG g100g d.b. 0.23 ± 0.03
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Table 4. 2Volatile compound in dried green tea leaf
Number Volatile compound
Peak areagram 1
2-propanone 116389.20
2 2-thiapropane
26040.51 3
2-methyl-butanal 10610.79
4 Trimethyl cyclohexanone
13404.64 5
Linalool oxide 49258.85
6 4-methyl-3-oriranemethanol
21376.33 7
Azulene 12510.03
Plants, including tea leaf from Camelia sinensis Beecher 2003, produce secondary metabolites, organic compounds that are involved in the defense of the plants
against invading pathogens, including insects, bacteria, fungi, and viruses. In the case of tea leaf, these metabolites include polyphenolic catechins and theaflavins and the
alkaloids caffeine and theobromine.
Previous study by Graham 1992, Chu and Juneja 1997 said that the catechin content is up to 30 of the dry weight, whereas, the content of teaine is up to 5 of the
dry weight. But, this result show a lower amount, total catechin content is 3.72 ± 0.08 g100g db and caffeine content is 1.21 ± 0.02 g100g db. This can be explained by
several factor such us season, varieties, and agricultural practice which are known to influence the content Balentine et al. 1998 and Yao et al. 2009. Table 4.3. shows a
result from Baptista et al.1998who studied some green teas from different area.
Table. 4.3. Teaine and catechin content of green tea from different area
Type of tea Teaine ww
Total Green Tea Polyphenol ww Epicatechin Derrivate
EGCG Azorean green tea
Gorreana 8.01
74.5 47.9
Chinese green tea Fuijian
2.68 73.9
47.2 Chinese green tea
Uncles Lee’s 4.49
71.9 39.9
Japanese green tea Yamamoto
2.66 59.5
37.4 Taiwan green tea
Lung Ching 2.50
66.8 42.6
Baptista et al. 1998 Based on Table 4.2., volatile compound analysis shows the highest constituent is
2-propanone, 2-propanone is the simplest form of ketone, other ketones are trimethyl cyclohexanone. Other constituents are alcohol, which are linalool oxide and 4-methyl-3-
oriranemethanol, aldehide which is 2-methyl-butanal, hydrocarbon which is azulene, and sulfide, which is 2-thiapropane. These compounds are organic compounds that commonly
found in plants Pripdeevech and Matchan 2011. Kato and Shibamoto 2001 reported
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that generally, concentrations of linalool and hexanal seem to play an important role in the quality of green tea.
B. PRODUCTION OF CONCENTRATED GREEN TEA EXTRACT
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