Development of a Small Scale Processing System for Concentrated Ginger Powders

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World Applied Sciences Journal 6 (4): 488-493, 2009
ISSN 1818-4952
© IDOSI Publications, 2009
Development of a Small Scale Processing System for Concentrated Ginger Powders
S. Phoungchandang, A. Sertwasana, P. Sanchai and P. Pasuwan
Department of Food Technology, Faculty of Technology,
Khon Kaen University, 123 Mittrapab Road, Muang, Khon Kaen 40002, Thailand
Abstract: Mature ginger rhizomes with the age of 10-12 months was used in the study. Ginger juice was
extracted using a hydraulic press and evaporated in traditional pan, natural circulation and agitated vacuum
evaporators. The evaporators had no significant difference on a , solubility, water solubility index, wate
w
r
absorption index and bulk density of concentrated ginger powders (p>0.05). The natural circulation and agitated
vacuum evaporators provided higher lightness of concentrated ginger powders than traditional pan evaporator
(p#0.05). However, the evaporators had no significant difference on yellowness (a*/b*) of concentrated ginger
powders and L* and a*/b* of reconstituted ginger powders. The agitated vacuum evaporator provided the
highest 6-gingerol remaining (p#0.05).
Key words: Evaporator % Concentrated ginger powder % Ginger % 6-gingerol
INTRODUCTION
increased surface area evaporator was higher than the pan
evaporator because of lower evaporation times of 3 folds
One of the key unit operations for fluid food products
and lower steam economy of 2.1 folds. However, the pan
is evaporation, as utilized to concentrate or increase the
evaporator provided slightly higher yield than the
solid concentration of a fluid food. One of the primary
increased surface area evaporator. The results revealed
objectives of this operation is to reduce the volume of
that the increased surface area evaporator retained better
nutrient components. This reduction of volume permits
color change than the pan evaporator [3]. Concentrated
more efficient transportation of the important product
grape juices are produced during harvest and supplied
components and efficient storage of the solids. An
throughout the year to other manufactures for the
equally important objective of evaporation of moisture
production of reconstituted grape beverages. Samples
from fluid foods is to remove large amounts of moisture
of grape cultivars were obtained at each step of the
effectively and efficiently before the product enters a
industrial process which consisted hot pressing of
dehydration process. Due to the heat sensitivity of
grapes and pasteurization of must (80°C, 30s) followed by
most products, evaporation is usually accomplished
filtration and concentration of juice to 68°Brix by
under vacuum. By utilizing relatively high vacuum
evaporation (highest temperature of 98°C for 5s).[4]
(low pressures), large amounts of moisture can be
The objectives of this work were to design and
removed from liquid food products without significant
develop a simple agitated vacuum evaporator for a small
reduction in the quality of heat-sensitive components [1].
scale processing system for concentrated ginger powders
Concentrated ginger powders were made by traditional
in order to retain the highest 6-gingerol. Quality aspects
method. Ginger rhizomes were cleaned and cut into pieces.
of the ginger powders, such as moisture content, a ,
w
Ginger juice was obtained by hydraulic pressing and
solubility, water solubility index, water absorption index,
concentrated in a pan under atmospheric pressure at a
bulk density, color values and 6-gingerol were also
temperature of 100-105°C. Sugar was added to the ginger
performed.
juice and evaporated until sugar crystallization took
place. Due to the high boiling point of 100-105°C, heat
MATERIALS AND METHODS
sensitive components were destroyed.[2] Mango pulp
was evaporated in two kinds of evaporator, namely, a
Ginger Juice Preparation: Mature ginger rhizomes
pan evaporator and an increased surface area evaporator
(Zingiber officinale Roscoe) with the age of 10-12 months
which were operated under vacuum. The efficiency of the
[5] were cleaned in 5 ppm chlorinated water and
Corresponding Author:
Dr. Singhanat Phoungchandang, Department of Food Technology,
Khon Kaen University, Khon Kaen 40002, Thailand
488

World Appl. Sci. J., 6 (4): 488-493, 2009
Fig. 1: Natural circulation evaporator Form: Wicham [6]
Fig. 2: Agitated vacuum evaporator
cut into small pieces. Ginger juice was extracted
C
Traditional pan evaporator: One and a quarter of a
using a hydraulic press (Samson, Heavy Duty, Bangkok,
kilogram of refined sugar plus 1.25 kg of brown sugar
Thailand).
were added to 1 kg of ginger juice. The sugar-ginger
juice mixture was evaporated and crystallized under
Ginger Drink Powder Processing: Evaporation of ginger
atmospheric pressure at 100±5°C for 30 min.
juice was performed in three evaporators, namely
Concentrated ginger powders were dried in a cabinet
traditional pan evaporator, natural circulation evaporator
dryer (Pasteur Ltd. Partnership, Bangkok, Thailand)
and agitated vacuum evaporator.
at 60°C for 1 hour [2].
489

World Appl. Sci. J., 6 (4): 488-493, 2009
C
Natural circulation evaporator [6]: Ten kilograms of
[7]. Sample of 5 g was dried in an oven (U30, Memmert,
ginger juice (3°Brix) was evaporated in a natural
Germany) at 105°C for 3 h. Moisture was calculated from
circulation evaporator (Figure 1) at 85°C under
the weight difference between the original and dried
vacuum of -10 in Hg (-33.86 kPa). Steam pressure of
sample and expressed as percentage of the original
10 lb/in (68.95 kPa) at temperature of 115°C
2
was used
sample.
to evaporate ginger juice to 6°Brix for 5 min. Half of
one kilogram (equivalent to 1 kg ginger juice) of
Water Activity (a ):
w
Concentrated ginger powders of 0.5
concentrate juice was mixed with 1.25 kg refined
g were determined using a water activity meter
sugar and 1.25 kg brown sugar and crystallized in a
(AQUALAB series 3TE, Device Co., Germany) at 25°C.
pan for 15±2 min. Concentrated ginger powders were
dried in the cabinet dryer (Pasteur Ltd. Partnership,
Solubility: Solubility was determined using the method
Bangkok, Thailand) at 60°C for 1 hour.
modified by Al-Kahtani and Bakri [8]. A small sample of
C
Agitated vacuum evaporator: In this work, an
concentrated ginger powders of 0.6 g was added to 400 ml
agitated vacuum evaporator was designed for small
of water at 70°C in a 500 ml beaker. The mixture was stirred
and medium enterprises (SMEs). Three basic
using a magnetic stirrer at 7 rpm. Solubility was timed in
components
were required to accomplish
seconds used to dissolve the concentrated ginger
evaporation, as illustrate in Figure 2. The evaporator
powders completely.
utilized for fluid food products contained the
following:
Bulk Density: Bulk density was determined by
adding 20 g of concentrated ginger powders to a 50 ml
a
An evaporation vessel. The evaporation vessel
graduated cylinder and holding the cylinder on vibrator
consisted a diameter of 0.47 m, a height of 0.26 m
for 1 min. The bulk density was calculated by dividing
and capacity of 40 liters and an agitated paddle
mass of the powders by the volume occupied in the
(0.28m length) with a speed of 50 rpm.
cylinder [9].
b
A heat source using LPG burner. The LPG
consumption was 0.25 kg/h.
Water Solubility Index (WSI) and Water Absorption
c
A Condenser. Water spray designed by Wicham
Index (WAI): Water solubility index and water absorption
(1978) was used to maintain vacuum in the
index were determined using the method described by
evaporation vessel.
Gomez et al. [10]. A small sample of concentrated ginger
powders (2.5 g) was added to 30 ml of water at 30°C in a
One and a half kilogram of ginger juice (3°Brix) was
50 ml centrifuge tube, stirred intermittently for 30 min and
evaporated in the agitated vacuum evaporator at 54°C
then centrifuged for 10 min at 5,000 rpm. The supernatant
under vacuum of -26 in. Hg (-88.05 kPa). Steam was not
was carefully poured off into a petridish and oven-dried
used in this evaporator. The evaporator was maintained
overnight. The amount of solid in the dried supernatant as
under vacuum using the water spray system and
a percentage of total dry solids in original 2.5 g sample
evaporated ginger juice to 6°Brix for 25 min. Half of one
gave an indication of water solubility index. Wet solid
kilogram (equivalent to 1 kg ginger juice) of concentrated
remaining after centrifugation was dried in an oven
juice was mixed with 1.25 kg refined sugar and 1.25 kg
(U30, Memmert, Germany) overnight. WAI was calculated
brown sugar and crystallized in the pan for 15±2 min.
as the weight of dry solid divided by the amount of dry
Concentrated ginger powders were dried in the cabinet
sample.
dryer (Pasteur Ltd. Partnership, Bangkok, Thailand) for
one hour. Completely Randomized Design (CRD) was
Color Values: The color of concentrated ginger
used to study the factors affecting concentrated ginger
powders was determined using Hunter Lab (Ultra
powders. Two replications were used to determine the
Scan XE U3115, Colorglobal Co., America). The color
main factors. SPSS version 16 for Window was used to
was measured in terms of Hunter L*, a* and b* values.
calculate analysis of variance (ANOVA).
Hunter L* represents the lightness or darkness of
the object and it is measured on a scale of 0 to 100. L*
Moisture Content: Moisture content of concentrated
values of 100 represents white and L* of 0 represents
ginger powders was determined using the oven method
black. Hunter a* represents redness (+) or greenness (-).
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World Appl. Sci. J., 6 (4): 488-493, 2009
Hunter b* represents yellowness (+) or blueness (-) [11].
increased to double the original concentration. Qualities
The samples were ground using a grinder and a sample
of concentrated ginger powders are illustrated in Table 1.
size of 5 g was used for color measurements. For each
The results indicated that the types of evaporators did
sample, three replications of color test were performed.
not affect a , solubility, water solubility index and bul
w
k
density of dried concentrated ginger powders (p>0.05).
Determination of 6-gingerol by High Performance Liquid
However, the types of evaporator influenced moisture
Chromatography: 6-Gingerol of concentrated ginger
content and lightness of the products. The natural
powders was determined using the method modified from
circulation and agitated vacuum evaporators provided
Balladin et al.[12] A sample of dry powders (1 g) was
higher moisture content than traditional pan evaporator
extracted in 10 ml methanol overnight and then
because of higher evaporation temperature of 100±5°C
centrifuged for 10 min at 5,000 rpm. The supernatant was
and longer evaporation times of 30 min of the traditional
filtered through a Whatman paper No.2 and then the
pan evaporator (p#0.05).
filtrate was filtered through a 0.45 µ nylon filter. Reverse-
Color values of concentrated ginger powders were
phase high performance liquid chromatography (HPLC)
shown in Table 2. Lightness of concentrated ginger
was used for the determination of 6-gingerol in the extract
powders obtained from the agitated vacuum evaporator
of ginger powders. Twenty µl of the extract was injected
was higher than the product obtained from the traditional
into the HPLC. The water HPLC system was used. The
pan evaporator due to also the lower evaporation
column was a reverse-phase HI5C (150 mm x 4.6 mm), i
18
d
temperature. The agitated vacuum evaporator could
5 µm (HiChrom Co.) with Nova-Pack ® C pre-colum
18
n
maintain at very low vacuum of -26 in. Hg so that the
(Water Co.). The mobile phase was methanol: double
boiling point of ginger juice during the evaporation
deionized water (70:30 v/v). The solvent flow rate was
decreased to 54°C, whereas the boiling point of ginger
1.2 ml/min. The UV detector (Water
TM 480) was monitored
juice in the traditional pan and natural circulation
at 282 nm. The correlation regression of external standard
evaporators were 100±5°C and 85°C, respectively. By
curve was 0.998. Area under a curve of a sample was
utilizing relatively high vacuum (low pressures and
determined the 6-gingerol content using the external
temperatures [1, 13, 14], large amount of moisture can
standard curve.
be removed from liquid food product without
significant reduction in the quality of heat sensitive
RESULTS AND DISCUSSION
components [1].
6-Gingerol remaining of concentrated ginger powders
Evaporation of ginger juice was performed in three
was shown in Table 3. Figure 3 illustrate chromatograms
evaporators, namely traditional pan evaporator [2], natural
(6-gingerol) of standard and concentrated ginger powders
circulation evaporator [6] (Fig.1) and agitated vacuum
from agitated vacuum evaporator. The results revealed
evaporator of this work (Fig. 2). The ginger juice was
that types of evaporation affected 6-gingerol remaining.
evaporated from 3°Brix to 6°Brix or the concentration was
The agitated vacuum evaporator provided higher
Table 1: Moisture content, water activity, solubility, water solubility index (WSI), water absorption index (WAI) and bulk density of concentrated
ginger powders
Types of evaporator
Moisture content (% d.b.)
a
3
w
Solubility (s)
WSI(%)
WAI(%)
Bulk density (kg/m )
Pan evaporator
1.00±0.18b
0.63±0.02
14.62±0.09
96.34±0.29
1.516±0.00
860.40±0.00
Natural circulation evaporator
1.26±0.03a
0.65±0.00
14.76±0.07
96.53±0.40
1.517±0.00
866.1040±0.00
Agitated vacuum evaporator
1.25±0.02a
0.64±0.00
14.74±0.15
96.43±0.33
1.516±0.00
866.50±0.00
a, b superscripts are significantly different (p#0.05)
Table 2: Color valves of concentrated ginger powders
Concentrated ginger powders
Reconstituted ginger powders
-----------------------------------------------------------
---------------------------------------------------------
Type of evaporator
L*
a*/b*
L*
a*/b*
Pan evaporator
77.04±0.41b
0.141±0.00
33.50±0.06
-0.47±0.04
Natural circulation evaporator
77.26±0.35ab
0.144±0.00
33.49±0.02
-0.42±0.13
Agitated vacuum evaporator
77.62±0.16a
0.146±0.00
33.59±0.02
-0.50±0.02
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World Appl. Sci. J., 6 (4): 488-493, 2009
(a)

(b)
Fig. 3: Chromatograms (6-gingerol) (a) standard (b) concentrated ginger powders from agitated vacuum evaporator
Table 3: 6-Gingeral content of concentrated ginger powders
products, evaporation is usually accomplished under
Types of evaporator
6-gingerol (ppm)
vacuum to decrease the boiling point of the products
Pan evaporator
286.96±4.94bc
without significant reduction in the quality of heat
Natural circulation evaporator
306.43±26.18b
sensitive components [1].
Agitated vacuum evaporator
675.65±35.22a
SME
220.51±27.53c
CONCLUSIONS
a, b superscripts are significantly different (p#0.05)
Ginger juice was evaporated in traditional pan,
6-gingerol remaining than natural circulation
natural circulation and agitated vacuum evaporators.
evaporator, traditional pan evaporator and commercial
The natural circulation and agitated vacuum
product because of the lowest evaporation temperature
evaporators provided higher lightness of concentrated
at 54°C. According to the heat sensitive of moist
ginger powders than traditional pan evaporator
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World Appl. Sci. J., 6 (4): 488-493, 2009
(p#0.05). The agitated vacuum evaporator provided
6.
Wicham, G., 1978. Vacuum evaporator. Massey
the highest 6-gingerol remaining (p#0.05).
University, New Zealands.
7.
AOAC., 2000. Official method of analysis.
ACKNOWLEDGEMENT
Association of Official Analytical Chemists,
Arlington, V.A., pp: 1298.
The
authors would like to acknowledge
8.
Al-Kahtani, H.A. and H. Bakri, 1990. Spray
Postharvest Technology Innovation Center, Khon
drying of Hibiscus sabdariffa L. extract. J.
Kaen University and Khon Kaen University for their
Food Sci., 55: 1073-1076.
financial support throughout this research.
9.
Goula, A., K. Adamopoulos and N. Kazakis,
2004. Influence of spray drying conditions on
REFERENCES
tomato powder properties. Drying Technol.,
22(55): 1129-1151.
1.
Heldman, D.R. and R.P. Singh, 1981. Food Process
10. Gomez, M.H.A., 1984. A physicochemical model for
Engineering 2 ed., AVI. Publishing Co., INC.
nd
,
extrusion of corn starch. J, Food Sci., 49: 40-43, 63.
Westport, Connecticut. pp: 415.
11. Francis, F.J. and F.M. Clydesdale, 1975. Food
2.
Subsomboon Farmer Group., 2001. Ginger drink
colorimetry theory and applications.The AVI
powder processing. Pupaman district, Khon Kaen,
Publishing Co., INC., Westport, Connecticut,
Thailand.
pp: 477.
3.
Phoungchandang, S., P. Sanchai, T. Ngarmsak,
12. Balladin, D.A., O. Headley, I. Chang-yen and
A. Prommakool and M.Ngarmsak, 2002. The
D.R. McGaw, 1998. High pressure liquid
comparative study of concentrated mango juices
chromatographic analysis of the main pungent
from varius varieties using pan and increased
principles of solar dried West Indian ginger
surface area evaporators. 1 National Technica
st
l
(Zingiber officinale Roscoe). Renewable Energy,
Seminar on Postharvest/Post Production
13(4): 531-536.
Technology. 22-23 Aug, 2002; Chaingmai,
13. Chegini, G.R. and B. Ghobadian, 2007. Spray dryer
Thailand.
parameters for fruit juice drying. World J. Agric.
4.
Gollucke, A.P.B., R.R. Catharino, J.C. Souza,
Sci., 3(2): 230-236.
M.N. Eberlin and D.Q. Tavarez, 2009. Evolution
14. Phoungchandang, S., L. Tochip and V. Srijesdaruk,
of major phenolic components and radical
2008. White mulberry leaf drying by tray and heat
scavenging activity of grape juices through
pump dehumidified dryers. World J. Agric. Sci.,
concentration process and storage. Food
4(S): 844-851.
Chemistry, 112: 868-873.
5.
Phoungchandang, S. and A. Sertwasana. Spray
drying of ginger juice and physicochemical
properties of powders. Science Asia, In press.
493