16 selected at 210 nm. The column was operated at 30ºC. The sample injection was 20 µL.
Peaks were identified by comparing their retention times and UV spectra in the 190-400 nm range with standards. The standard was injected before sample for made calibration curves.
The caffeine and catechins content were calculated using their respective calibration curves.
3.9. Product Recovery Sanphakdee, 2007
Product recovery is mainly determined by powder collection efficiency. Material loss in a spray drying system is due mostly to the attachment of sprayed droplets and dry
powder to the wall of the apparatus and the cyclone’s poor efficiency in collecting fine particle. Product recovery was calculated from the total solid content that determined form
moisture content that heat in the oven at 103±2ºC for 6 hours.
Where a g is weight of powder product dry basis, b mL is volume of feed, and c total solid content of tea extract concentrated.
3.10. Energy Consumption Kamaruddin et al, 1989
Energy analysis is used to calculate the amount of energy at each stage in the production system. Analysis of this energy can be used to understand and improve how,
where and when energy that used efficiently and effectively. This analysis can be used for identify networks and processes to obtain the final product. Energy consumption especially at
spray drying stage was calculated by using the equation as following
Where P kilowatt is power of spray dryer and t hour
3.11. Statistical Analysis
Data were analyzed by one way ANOVA using the application of SPSS software. Mean value were compared using The Duncan’s Multiple Range Test.
17
IV. RESULTS AND DISCUSSIONS
A. CHEMICAL COMPOSITION OF DRIED GREEN TEA Camellia sinensis
var. Oolong No 12
Dried green tea that used in this study is shown in Figure 9. The chemical composition of dried green tea had been studied, such as moisture content, total polyphenol compound,
antioxidant activity, caffeine and catechin content as shown in Table 4. Type of polyphenols that measured are caffeine content, total catechins, and 7 single catechins Gallocatetchin,
Epigallocatechin, Catechin, Epicatechin, Epigallocatechin gallate, Gallocatechin gallate, Epigallocatechin, Catechin gallate. The sample contains moisture content 6.05 ± 0.06 ww
db, total polyphenol compound 14.98 ± 0.42 db, antioxidant activity 141.50 ± 6.8 mmol Trolox100 g db, the caffeine content 2.77 ± 0.23 g100 g db, and total catechins content about
12.04 ± 1.20 g100 g db. The highest of single catechins that contain in dried green tea is EGCG about 4.72± 0.31 g100 g db, and was followed by EGC about 3.66± 0.39 g100 g db, EC about
0.89± 0.07 g100 g db, GC about 0.77± 0.11 g100 g db, C about 0.76± 0.06 g100 g db, ECG about 0.73± 0.02 g100 g db, GCG about 0.51± 0.10 g100 g db, and CG was not detected.
In measuring chemical composition of sample, determining of dilution factor for each chemical analysis have been studied. For determining chemical compound in dried green tea,
total polyhenol compound and antioxidant activity analysis used dilution factor 25, for caffeine and catechin content used dilution factor 10. The determining of dilution factor for each
chemical analysis is important in order to get absorbance value in spectrometer or peak value in hplc well. It means that absorbance value or peak value must be in the middle of standard curve.
The dried green tea contains of moisture content about 6.05 ± 0.06 ww db, this value is similar with moisture content of crude tea standard. The moisture content of the final product
crude tea should be less than 6 Wan et al 2009. In this research, the highest of single catechins is EGCG and was followed by EGC, EC, and GC. From literature, EGCG is the most
abundant catechin and it is followed by EGC, ECG, and EC. The catechin composition depends on the location of cultivation of the tea plant, variety of plant, season of harvest, and process
conditions Shi et al, 2009
.
Figure 9. Dried green tea Camellia sinensis var. Oolong No 12
18 Table 4. The chemical compositions of dried green tea
Chemical Composition Amount
Moisture Content 6.05 ± 0.06 ww wb
Total Polyphenol 14.98 ± 0.42 db
Antioxidant activity 141.50 ± 6.8 mmol Trolox100 g db
Caffeine 2.77 ± 0.23 g100 g db
Catechins GC Gallocatechin
EGC Epigallocatechin C Catechin
EC Epicatechin EGCG Epigallocatechin gallate
GCG Gallocatechin gallate ECG Epicatechin gallate
CG Catechin gallate 12.04 ± 1.20 g100 g db
0.77± 0.11 g100 g db 3.66± 0.39 g100 g db
0.76± 0.06 g100 g db 0.89± 0.07 g100 g db
4.72± 0.31 g100 g db 0.51± 0.10 g100 g db
0.73± 0.02 g100 g db
Not detected
B. EXTRACTION
In this research, extraction method used the best condition from previous study, like temperature of the hot water: 90°C and with regarding water: 1: 20 w v, the time of extraction
60 minutes, and pH value was 5,0 Butsoongnern, 2006. The best temperature of extraction is about 80-90°C because it can defend the antioxidant of tea Fulder, 2004. The solvent that used
in this research was water because it has lower cost, available, and not contain of side-effect. Besides, polyphenols content in green tea is soluble in the water and it contains of antioxidant
Stahl, 1969.
The chemical composition of green tea extract had been studied, such as total poliphenol compound, antioxidant activity, caffeine and catechin content as shown in Table 5. For
determining chemical compound in green tea extract, total polyhenol compound and antioxidant activity analysis used dilution factor 25, and for caffeine and catechin content used dilution
factor 50. The sample contains total polyphenol content 49.91 ± 0.33µgmL, antioxidant activity 0.45 ± 0.02 mmol TroloxL , the caffeine content 27.22 ± 0.05 µgmL, and total catechins
content about 116.81 ± 0.19 µgmL. The highest of single catechins that contain in green tea extract is EGCG about 39.64 ± 0.25 µgmL, and was followed by EGC about 33.62 ± 0.11
µgmL, GC about 12.91± 0.11 µgmL, GCG about 9.88 ± 0.32 µgmL, EC about 8.47 ± 0.11 µgmL, ECG about 6.16 ± 0.22 µgmL, C about 6.15 ± 0.16 µgmL.
Table 5. The chemical compositions of green tea extract Chemical Composition
Amount Total Polyphenol
49.91 ± 0.33µgmL Antioxidant activity
0.45 ± 0.02 mmol TroloxL Caffeine
27.22 ± 0.05 µgmL Catechin
GC EGC
C EC
EGCG GCG
ECG 116.81 ± 0.19 µgmL
12.91± 0.11 µgmL 33.62 ± 0.11 µgmL
6.15 ± 0.16 µgmL 8.47 ± 0.11 µgmL
39.64 ± 0.25 µgmL 9.88 ± 0.32 µgmL
6.16 ± 0.22 µgmL
19
C. FREEZE CONCENTRATION
In this study, the ice maker machine was used to make the concentrated green tea. Ice maker machine is one of machine that using freeze concentration method and it is shown in
Figure 10. The principle of this machine, it will resulting in a slurry of ice crystals in a fluid concentrate. The ice crystals were then removed in some way, in this study it used centrifuge
machine for separating the ice crystals and a concentrated product. The total solid in fluid concentrate will increase as longer of freeze concentration time. This step will be stopped, if the
total solid reached 3, 6, and 9 of solid. For measure the total solid, it used refractometer and it will be confirmated with oven method.
Figure 10. Ice cream maker machine
Figure 11. Centrifuge machine
20 The measurement of Total Dissolved Solids TDS in this research used two kinds of
measurement, such as hand recfractometer and oven method. Hand refractometer is a equipment to measure TDS that content in fruit, food product that contain of fruit, and sucrose solution
Nielsen, 1996. Nowadays, hand refractometer is used in process of made a solution in the industry, like milk industry and beverage industry. The principle of hand refractrometer is
measure the index of refraction from the food that contain of carbohidrat. The unit of refratometer is ˚Brix that equal with percentage of sucrose solution g sucrose 100 g sample.
Because of this research used green tea extract as the sample, which it is non-sucrose sample, the calibration of hand refractometer measurement with oven method must be done.
Green tea concentrated were analyzed TDS total dissolved solids with Refractometer ˚brix and then compared the amount of ˚brix with the amount of TDS from oven method to
make sure that TDS in tea concentrated has reached 3, 6, 9 TDS. There is a relationship between of brix and Total Dissolved Solid as shown in Figure 12. The relationship is a linear
regression with equal of regression y = 0.842x + 0.142 and R
2
= 0.997. The disadvantages of freeze concentration compared to evaporation and reverse osmosis have include higher capital
cost, higher operating cost, and excessive loss of product during the ice separation Helman et al, 1992. In this study, an increase in concentration of concentrated tea, will decrease percentage
of recovery concentrated tea on freeze concentration step.
The recovery of concentrated tea from freeze concentration method ice cream maker is
shown in figure 13. It was calculated from total solid in concentrated tea after freeze concentration dividing with total solid in extract tea before freeze concentration. The percentage
of concentrated tea recovery from ice cream maker will decrease as increase the total solid concentration of green tea. This could be explained because the ice crystal is likely to contain
sample solid at some extent. The solid present in ice crystal has the higher concentration with the longer freeze concentration process. Moreover, the solid recovery from the ice crystal by
centrifuge cannot give the 100 yield. This lead to the higher loss of recovery in the green tea concentrate obtained from the longer freeze concentration process. An increase in concentration
of tea concentrated will decrease percentage of recovery because ice separation with centrifuge more difficult and the loss of product during the ice separation increase.
y = 0.842x + 0.142 R² = 0.997
1 2
3 4
5 6
7 8
9 10
2 4
6 8
10 12
To tal so
li d
Brix
Figure 12 . The Relationship between of ˚Brix refractometer and Total
Dissolved Solid oven method
21
D. CONCENTRATED GREEN TEA
The chemical composition of concentrated of green tea had been studied, such as total poliphenol compound, antioxidant activity, caffeine and catechin content as shown in Table 6.
For determining chemical compound in concentrated green tea 3, 6, and 9 have total polyhenol compound and antioxidant activity analysis used dilution factor 200, 400, and 600,
respectively, and for caffeine and catechin content used dilution factor 50, 100, 175, respectively.
Table 6. The chemical composition of concentrated green tea
Chemical Composition Sample
Conc. Tea 3 Conc. Tea 6
Conc.Tea 9 Total Polyphenol µgmL
45.68 ± 0.15
b
52.99 ± 0.75
a
46.42 ± 2.89
b
Antioxidant activity mmol TroloxL
0.51 ± 0.00
b
0.55 ± 0.00
a
0.39 ± 0.02
c
Caffeine µgmL 33.43 ± 0.10
a
32.82 ± 0.43
a
25.31 ± 1.44
b
Catechin µgmL GC
EGC C
EC EGCG
GCG ECG
139.46 ± 0.20
a
17.74 ± 0.07
b
46.17 ± 0.11
a
10.57 ± 0.02
a
11.56 ± 0.00
a
37.41 ± 0.10
a
10.67 ± 0.17
a
5.35 ± 0.07
a,b
138.16 ± 0.90
a
20.12 ± 0.16
a
44.63 ± 0.30
b
9.69 ± 0.01
b
11.81 ± 0.16
a
35.51 ± 0.16
b
11.30 ± 0.13
a
5.11 ± 0.01
b
111.40 ± 2.00
b
12.99 ± 0.32
c
34.58 ± 0.28
c
6.01 ± 0.17
c
8.35 ± 0.31
a
35.43 ± 0.59
b
8.58 ± 0.50
b
5.48 ± 0.16
a 1
Values are mean ± SD n=2
2
Value in a column followed by different letters are significantly p0.05 different. Concentrated green tea 3, 6, and 9 contain total polyphenol content 49.91 ± 45.68 ±
0.15, 52.99 ± 0.75, 46.42 ± 2.89 µgmL, respectively. Concentrated green tea 3, 6, and 9 contain antioxidant activity 0.51 ± 0.00, 0.55 ± 0.00, 0.39 ± 0.02 mmol TroloxL , respectively.
Total polyphenol µgmL and antioxidant activity mmol TroloxL in concentrated tea 6 solid is more higher than concentrated 3 because it were concentrated. But total polyphenol and
antioxidant activity decrease when concentration in feed increase until 9, it because there are 96.91
71.15 68.36
20 40
60 80
100 120
3 6
9
Re co
v er
y
Concentrated Tea Total solid after freeze concentration
Figure 13. Recovery of concentrated tea from freeze concentration step that used ice cream maker machine solidsolid
22 some chemical compound that looses in freeze concentration method. The highest of single
catechins that contain in concentrated green tea is EGC, and it was followed by EGCG, GC, EC, GCG, C, and ECG.
E. PRODUCTION TEA POWDER BY SPRAY DRYER
There are many things that affect on spray drying process, in spray drying condition such as inlet air temperature, outlet air temperature, blower speed, inlet and outlet humidity, and in
feed condition, such as feed concentration, feed temperature, and feed flow. In this research, parameter which used feed concentration and inlet air temperature. Then, the blower speed was
adjusted at 2500 rpm and the outlet air temperature was controlled at 75˚C. To control outlet temperature at 75˚C, the pressure air and feed rate were increased or decreased. The pressure air
and feed rate were affected by inlet air temperature, an increase inlet air temperature, the pessure air and feed rate increased. To control outlet temperature at 75˚C with inlet temperature 180˚C,
the pressure air that used about 2-5 psi and feed rate about 3-5 Lhr, to control outlet temperature at 75˚C with inlet temperature 200˚C, the pressure air that used about 15-20 psi and
feed rate about 15-20 Lhr
, and to control outlet temperature at 75˚C with inlet temperature 220˚C, the pressure air that used about 17.5-25 psi and feed rate about 25-30 Lhr. This condition
will affect the time of drying. An increase inlet air temperature, will reduce the time of drying because the drying process will occur faster.
In this research, it used JMC spray dryer as shown in Figure 14 .Green tea powder was produced by JMC-minilab spray dryer as shown in Figure 15. The results of physical and
chemical analyses shown in Tables 7 and 8.
Figure 14. JMC-minilab Spray Dryer
23
1. Physical Analysis Results
The physical analysis results of green tea powder shown in Table 7. The physical results were found variated and the significant differences were found among the samples of each
physical analysis.
Table 7. The physical analysis results of green tea powder Conc
Inlet Temp.
˚C Bulk Density
gmL L
a b
Solubility db
Hygroscopicity
3 180 0.4511 ± 0.0050
b
71.95 ± 0.03
d
3.50 ± 0.07
f
30.08 ± 0.24
f
79.67 ± 0.85
c
17.84 ± 1.16
a
200 0.4278 ± 0.0011
c
70.89 ± 0.22
e
4.15 ± 0.03
d
33.56 ± 0.45
b
78.64 ± 0.04
c
15.75 ± 0.45
b
220 0.4262 ± 0.0011
c
71.14 ± 0.29
e
3.86 ± 0.09
e
31.97 ± 0.62
c
80.03 ± 0.04
c
8.84 ± 0.33
e
6 180 0.4069 ± 0.0017
d
68.07 ± 0.23
f
4.91 ± 0.04
c
34.05 ± 0.47
b
77.65 ± 0.17
c.d
15.94 ± 0.22
d
200 0.4000 ± 0.0003
e
72.42 ± 0.68
d
4.14 ± 0.12
d
31.20 ± 0.69
d
75.56 ± 1.02
d
12.69 ± 1.02
c
220 0.3972 ± 0.0004
e
73.05 ± 0.31
c
4.13 ± 0.01
d
30.65 ± 0.06
d
75.56 ± 0.34
d
10.87 ± 0.52
b
9 180 0.5014 ± 0.0008
a
70.38 ± 0.15
e
5.79 ± 0.08
a
37.37 ± 0.08
a
89.54 ± 0.22
a.b
16.56 ± 0.56
a.b
200 0.4522 ± 0.0010
b
74.41 ± 0.08
a
5.42 ± 0.15
b
37.31 ± 0.51
a
87.96 ± 0.54
b
12.37 ± 1.29
c
220 0.3933 ± 0.0007
f
73.81 ± 0.1
b
4.87 ± 0.02
c
34.31 ± 0.30
b
91.17 ± 1.12
a
12.52 ± 0.32
c 1
Values are mean ± SD n=3
2
Value in a column followed by different letters are significantly p0.05 different. Figure 15. Green Tea Powder
24
1.1 Bulk Density of Green Tea Powder
Bulk density is defined as the mass of particles occupied by a unit volume of bed. Bulk density of the powder variated between 0.3933-0.5014 gmL, the powder with treatment 9
solid concentration in feed and inlet air temperature 180˚C is sample that has the highest bulk
density and the powder with treatment 9 solid concentration in feed and inlet air temperature 220˚C has the lowest one. Significant differences were found among the samples. Bulk density
values were found in this research to be in range of bulk density values of instant tea produced by using similar technology about 0.298-0,450 gmL Nadeem et al, 2011.
Table 7 shows powder bulk density decreases as inlet air temperature increases. This is caused by evaporation rates are faster when inlet temperature increase and the products dry to
more porous of fragmented structure. Walton 2000 reported that increasing the drying air temperature generally produces a decrease in bulk and particle to be hollow. Besides, bulk
density value also depend on moisture content of the powder, as a product of the higher moisture would tend to have a higher bulking weight caused by the presence of water Chegini and
Ghobadian, 2005.
Increasing the solid concentration of the feed from 3 to 6 however which be related to increased total solid content, can reduce the moisture content and it causes bulk density value
decrease. The highest bulk density value was grained by concentration 9 and inlet air tempe
rature 180˚C because of the sample are sticky on the chamber wall, the more stick nature of a powder is associated with a high bulk density, as the particles that tend sticky together leave
less interspaces between them and consequently result in a smaller bulk volume Goula Adamopoulos, 2008.
1.2 Color of Green Tea Powder
