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Dehydration of Chamomile Flowers under Different Drying Conditions

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Volume 10 • Issue 7 • 1000803
J Food Process Technol, an open access journal
ISSN: 2157-7110
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Research Article
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ISSN: 2157-7110
Khater et al., J Food Process Technol 2019, 10:7
DOI: 10.4172/2157-7110.1000803
*Corresponding author: El-Sayed G. Khater, Agricultural and Biosystems
Engineering Department, Benha University, P.O. Box 13736, Egypt, Tel:
+20132467034, +20132467786; E-mail: alsayed.khater@fagr.bu.edu.eg
Received May 13, 2019; Accepted May 24, 2019; Published May 31, 2019
Citation: El-Sayed GK, Bahnasawy AH, Hamouda RM (2019) Dehydration of
Chamomile Flowers under Different Drying Conditions. J Food Process Technol 10:
803. doi: 10.4172/2157-7110.1000803
Copyright: © 2019 El-Sayed GK, et al. This is an open-access article distributed
under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original
author and source are credited.
Abstract
The main aim of this study is to investigate the possibility of drying chamomile plants under different conditions. The
obtained results indicated that the accumulated weight loss of chamomile owers was (86.27, 84.67, 82.70, 85.04 and
86.53)% for the sun-drying system, shadow-drying system, room-drying system, solar-drying system, and oven-drying system,
respectively. The moisture content of chamomile owers decreased from (508.59 to 14.56)%, (502.77 to 15.43)%, (470.09 to
18.19)%, (537.47 to 13.45) and (444.84 to 5.46)% d.b. for sun-drying system, shadow-drying system, room-drying system,
solar-drying system and oven-drying system, respectively. The highest value of equilibrium moisture content was 51.78% at
90% equilibrium relative humidity was found from the Henderson equation under room system. The lowest value of equilibrium
moisture contents was 1.38% at 10% equilibrium relative humidity was found for modied Oswin equation for oven system. The
chamomile oil content values were (0.66, 0.78, 0.94, 0.73 and 0.59)% for the owers dried under sun-drying, shadow-drying,
room-drying, solar-drying, and oven-drying, respectively. The highest values of Nitrogen, Phosphorus, Potassium, Calcium,
and Magnesium contents (2.62, 1.11, 4.10, 1.12 and 0.23)% were obtained when the chamomile dried at room temperature
system. The lowest value of the Nitrogen, Phosphorus, Potassium, Calcium and Magnesium content (1.50, 0.83, 3.83, 0.84 and
0.20)% were found at the oven-drying system.
Dehydration of Chamomile Flowers under Different Drying Conditions
El-Sayed G Khater*, Adel H Bahnasawy and Ramy M Hamouda
Agricultural and Biosystems Engineering Department, Benha University, Egypt
Keywords: Chamomile; Sun-drying; Solar-drying; Oven-drying;
Equilibrium moisture content; Oil content
Introduction
Medicinal and aromatic plants cultivated in all over the world
particularly in Egypt for both local consumption and export. e
chamomile is one of the most important aromatic plants in Egypt. Its
area is about 8351 feddans (12.9% of medicinal and aromatic plants),
producing about 6949.3 ton/year [1].
Drying is the most common and eective method that increases the
shelf life of spicy herbs by inhibiting the growth of microorganisms and
preventing the onset of some biochemical reactions that may alter the
organoleptic and nutritional characteristics of the dried leaf. However,
drying must be performed carefully in order to preserve the aroma,
appearance and nutritional characteristics of the raw herbs as much as
possible [2]. e drying may cause losses in volatilities or formation of new
volatilities as a result of oxidation reactions, esterication reactions [3].
Dried chamomile ower is an age-old medicinal drug that was
well known in ancient Egypt, Greece and Rome. In Egypt, chamomile
had a religious use as the plant was consecrated to the god of the
sun. Chamomile’s popularity grew throughout the middle ages when
people used it as a remedy for numerous medical complaints. e
word chamomile is derived from the Greek roots ‘chamos’ (ground)
and ‘melos’ (apple), referring to the fact that the plant grows low to the
ground, and the fresh blooms have a pleasing apple scent.
Moisture sorption isotherm denes the relation between Equilibrium
Relative Humidity (ERH) and Equilibrium Moisture Content (EMC)
[4]. is information is required for drying and storage of agricultural
and food products, for instance, to maintain the quality in the storage
period. is knowledge is also required to stop the drying process at the
aimed moisture content to avoid quality losses and to save energy [5].
EMC is dened as the moisture content of a hygroscopic material in
equilibrium with an environment in terms of temperature and relative
humidity. EMC of the product is the result of moisture exchange between
the product and the air surrounding the sample. In this condition, the
water in a product is in balance with the moisture in the surrounding
atmosphere [6]. e relative humidity in this condition is known as the
Equilibrium Relative Humidity (ERH) [4]. Moisture sorption isotherms
are either measured during desorption (starting from the wet state) or
during adsorption (starting from the dry state).
e herbal and medicinal plants are perishable. keeping their quality
and prolonging the shelf life is required by drying them, therefore,
the main aim of this study to investigate the possibility of drying the
chamomile plants under dierent conditions.
Materials and Methods
e experiment was carried out at Agricultural and Bio-Systems
Engineering Department, Faculty of Agriculture Moshtohor, Benha
University, Egypt (latitude 30° 21` N and 31° 13` E). During the period
of April and May 2017.
Materials
e fresh chamomile was brought from the private company, El-
Sharkia Government, Egypt aer harvesting for the primary analysis.
Drying systems: e basil was dried using dierent systems as
follows:-
• Sun-drying: Chamomile plants were folded into a thin sheet of
paper and placed on a at plate in direct sunlight over a tray with
a dimension of (0.8 m long, 0.6 m wide and 0.1 m high)
• Shadow-drying: Chamomile plants were folded into a thin sheet
of paper and placed on a at plate (0.8 m long, 0.6 m wide and 0.1
m high) in shadow
Citation: El-Sayed GK, Bahnasawy AH, Hamouda RM (2019) Dehydration of Chamomile Flowers under Different Drying Conditions. J Food Process
Technol 10: 803. doi: 10.4172/2157-7110.1000803
Page 2 of 7
Volume 10 • Issue 7 • 1000803
J Food Process Technol, an open access journal
ISSN: 2157-7110
• Room temperature-drying: Chamomile plants were folded into
a thin sheet of paper and placed on a at plate (0.8 m long, 0.6
m wide and 0.1 m high) in the room for air-drying at ambient
temperature
• Solar-drying: e solar dryer consists of solar collector, drying
chamber, trolley and trays and fan/blower as shown in Figure 1.
e solar collector consists of three major components, namely:
e glass cover has 12 sheets of dimensions (2.0 × 2.0) m and 5.5
mm thickness. e reason for selecting this material is due to the
structural thermal properties. e absorber plate, (corrugated
black aluminum plate). e insulation, (thermal wool with a 5.0
cm thickness). e drying chamber has a length of 2.5 m, a width
of 2.3 m and a height of 2.6 m. It is made of galvanized steel (5
mm thickness). e trolley is made from stainless steel and has
a length of 2.3 m, a width of 1.1 m and a height of 2.4 m. It is
designed in such a way that it allows easy insertion of individual
trays at a distance of 0.2 m apart and has tires for easy movement
of trays. e trays are made of stainless steel and have a length 1.1
m, width 0.74 m and a depth of 0.03 m. ey have a perforated
bottom which allows heated air to pass through products. e
air blower was used to force and re-circulate the drying air to
the drying chamber. Two air blowers (Model C.C.P. Parma-Flow
Rate 720 m3 h-1-RPM 2800-Power 1.5 hp 380V 50Hz, Italy) for
moving air in the drying chamber (Figure 1)
• Oven-drying: Chamomile plants were spread evenly on baking
sheets and placed in conventional laboratory oven (Fisher
Scientic Isotemp Oven, Model 655F Cat. No. 13-245-655, Fisher
Scientic, Toronto, Ontario, Canada)
Methods
Chamomile was cleaned by removing undesired stems and waste
materials as shown in the process through ow chart (Figure 2).
• Drying methods: Five dierent drying methods were used to dry
chamomile. e reported data are means of three replications. In
each replicate, 5 kg of cleaned fresh chamomile was used
• Sun-drying: Chamomile plants were folded into a thin sheet of
paper and placed on a at plate in direct sunlight at an average
temperature of (34.5 ± 1.0)°C and relative humidity of (58.5 ±
2.0)%
• Shadow-drying: Chamomile plants were folded into a thin
sheet of paper and placed on a at plate in shadow at an average
temperature of (31.0 ± 1.0)°C and relative humidity of (69.5 ±
2.5)%
• Room temperature-drying: Chamomile plants were folded into
a thin sheet of paper and was placed on a at plate in the room
for air-drying at ambient temperature at an average temperature
of (29.0 ± 1.0)°C and relative humidity of (58.0 ± 4.0)%
• Solar-drying: Chamomile plants were folded into a thin sheet of
paper and placed on a at plate in the solar dryer at an average
temperature of (46.0 ± 6.0)°C and relative humidity of (40.0 ±
13.0)%
• Oven-drying: Chamomile plants were spread evenly on
baking sheets and placed in a conventional laboratory oven at a
temperature of 65°C
Measurements
e mass was measured by electric digital balance (Model HG-
5000-Range 0-5000 g ± 0.01 g, Japan) daily for sun, shadow and
ambient air-drying methods and hourly for solar and oven drying
methods. Temperature and relative humidity were recorded by using a
HOBO Data Logger (Model HOBO U12 Temp/RH/Light-Range -20°C
to 70°C and (05 to 95)% RH, USA) every hour. e total content of
macroelements was evaluated aer being digested according to [7].
Nitrogen was determined by Kjeldahl digestion apparatus [8]. Potassium,
Calcium, and magnesium were determined by Photofatometer (Model
Jenway PFP7-Range 0-160 mmol L-1, USA) and phosphorus (P) was
determined colorimetrically following the [9] method. e content of
oil was determined in basil plants according to [10].
Calculations
Moisture content: e moisture content of the fresh and dried
Figure 1: Elevation, plan and side view for the solar dryer.
799.99MMØ
0.5MØ
0.5MØ
0.5MØ
4.13m
5.00m
2.00m
4.00m
4.59m
0.5MØ
0.5MØ
0.5MØ
500MMØ 500MMØ
3300MMØ
500MMØ
500MMØ
232.32MMØ
Citation: El-Sayed GK, Bahnasawy AH, Hamouda RM (2019) Dehydration of Chamomile Flowers under Different Drying Conditions. J Food Process
Technol 10: 803. doi: 10.4172/2157-7110.1000803
Page 3 of 7
Volume 10 • Issue 7 • 1000803
J Food Process Technol, an open access journal
ISSN: 2157-7110
chamomile plants was determined using conventional laboratory
oven kept at 105°C until a constant weight was reached. Triplicate
determinations were made and the moisture content calculated as the
following equation:
wet dry
dry
M -M
MC = M
(1)
Where:
- MC is the moisture content,% d.b.
- Mwet is the wet mass of samples (g)
- Mdry is the dry mass of samples (g)
- Equilibrium moisture content
A number of equations have been suggested in the literature to
describe the relationship between equilibrium moisture content (EMC)
and equilibrium relative humidity (ERH). e modied Henderson
modied Oswin and modied Halsey, modied Chung-Pfost and
GAB equation [11] have been adopted by the American Society of
Agricultural Engineers as standard equations for describing sorption
isotherms [12]. We transformed the equations to get EMC as the
dependent variable and ERH as the independent variable.
Modied Henderson
3
1/C
12
1
EMC = ln(1 ERH)
C (T + C )

−−


(2)
Modied Halsey
3
1/C
12
-exp(C C T)
EMC = ln(ERH)

+


(3)
Modied Oswin
( )
3
1/C
12
ERH
EMC = C C T
1 ERH

+


(4)
Modied Chung-Pfost
(5)
GAB equation
( )
( ) ( ) ( )
123
2 2 23
C C C ERH
EMC = 1 - C ERH 1- C ERH C C ERH+
 
 
(6)
Where:
• ERH is the equilibrium relative humidity,%
• T is the temperature, °C
• C1, C2 and C3 are the constants
e parameters C2 and C3 in the GAB equation are correlated with
temperature using the following equations [13]:
6
24
a
C
C = C exp RT



(7)
7
35
a
C
C = C exp RT



(8)
Where:
• C4, C5, C6 and C7 are coecients
• Ta is the absolute temperature, K
• R is the universal gas constant, R=8.314 kJ/kmol K
Results and Discussion
Weight loss
Figures 3 and 4 show the accumulated weight loss of chamomile
plants that dried under dierent drying systems (sun-drying, shadow-
drying, room temperature-drying, solar-drying, and oven-drying)
at dierent drying air temperature and relative humidity during the
experimental period. e results indicate that the accumulated weight
loss of chamomile plants increases with increasing drying period. It
could be seen that the accumulated weight loss of chamomile plants
increased from (83.63 to 86.270)% when the drying period increased
from 1 to 5 days at drying air temperature ranged from (23.91 to
26.54)°C and relative humidity ranged from (58.16 to 61.97)% for the
sun-drying system.
For shadow-drying system, the accumulated weight loss of
chamomile plants increased from (77.12 to 84.67)%, when the drying
period increased from 1 to 8 days at drying air temperature ranged
from (22.69 to 24.67)°C and relative humidity ranged from (53.29 to
57.20)%. For room temperature-drying system, the accumulated weight
loss of chamomile plants increased from (73.95 to 82.70)%, when the
drying period increased from 1 to 12 days at drying air temperature
ranged from (20.04 to 22.67)°C and relative humidity ranged from
(49.94 to 52.58)%. For solar-drying system, the accumulated weight
loss of chamomile plants increased from (54.61 to 85.04)%, when the
Harvesting
Stem Removal
Washing
Removal of excess water by bloating paper
Weighing
Drying
Figure 2: Flow chart of chamomile processing.
Citation: El-Sayed GK, Bahnasawy AH, Hamouda RM (2019) Dehydration of Chamomile Flowers under Different Drying Conditions. J Food Process
Technol 10: 803. doi: 10.4172/2157-7110.1000803
Page 4 of 7
Volume 10 • Issue 7 • 1000803
J Food Process Technol, an open access journal
ISSN: 2157-7110
drying period increased from (1 to 41) hours at drying air temperature
ranged from (36.24 to 41.35)°C and relative humidity ranged from
(48.97 to 55.37)%. For oven-drying system, the accumulated weight
loss of chamomile plants increased from (60.14 to 86.53)%, when the
drying period increased from (1 to 8) hours at drying air temperature
was 65°C and relative humidity was 10.0%.
e results also indicate that the shorter drying period (8 hours) was
occurred under the oven-drying system due to the higher temperature
(65°C) and lower relative humidity (10%). Meanwhile, the longer drying
period (12 days) was occurred under the room temperature-drying
system due to the lower temperature (20.04 to 22.67)°C and higher
relative humidity (49.94 to 52.58)%. e results show the highest rate
of weight loss occurred on the rst day under the sun-drying, shadow-
drying and room temperature-drying systems. It could be seen that the
weight losses were (83.63, 77.12 and 73.95)% for sun-drying, shadow-
drying, and room temperature-drying systems, respectively.
Moisture content
Figure 5 shows the moisture content of chamomile plants
under dierent drying systems (sun-drying, shadow-drying, room
temperature-drying, solar-drying, and oven-drying) during the
experimental period. e results indicate that the moisture content
of chamomile plants decreases with increasing drying period for all
drying systems. It could be seen that the moisture content of chamomile
plants decreased from 508.59% to 14.56% d.b., (by 97.14%) when the
drying period increased from 1 to 5 days for the sun-drying system
[14]. For shadow-drying system, the moisture content of chamomile
plants decreased from (502.77 to 15.43)% d.b., (by 96.93%) when the
drying period increased from 1 to 8 days. For room temperature-drying
system, the moisture content of chamomile plants decreased from
(470.09 to 18.19)% (by 96.13%), when the drying period increased
Sun drying
Shadow drying
Room temperature drying
Solar drying
Oven Drying
Figure 3: The accumulated weight loss of chamomile owers at different
drying systems at different drying air temperature during experimental period.
Shadow drying
Room temperature drying
Sun Drying
Solar drying
Oven Drying
Figure 4: The accumulated weight loss of chamomile owers at different
drying systems at different relative humidity during experimental period.
Citation: El-Sayed GK, Bahnasawy AH, Hamouda RM (2019) Dehydration of Chamomile Flowers under Different Drying Conditions. J Food Process
Technol 10: 803. doi: 10.4172/2157-7110.1000803
Page 5 of 7
Volume 10 • Issue 7 • 1000803
J Food Process Technol, an open access journal
ISSN: 2157-7110
from 1 to 12 days. For solar-drying system, the moisture content of
chamomile plants decreased from (537.47 to 13.45)% d.b., (by 97.50%)
when the drying period increased from 1 to 41 hours. For the oven-
drying system, the moisture content of chamomile plants decreased
from (444.84 to 5.46)% d.b., (by 98.77%) when the drying period
increased from 1 to 8 hours. ese results agreed with those obtained
by Özcan et al. and Arafa [15,16].
e results indicate that the highest rate of the decrease moisture
content of chamomile plants (98.77%) happened under the oven-drying
system. Meanwhile, the lowest rate of the decrease moisture content of
chamomile plants (96.13%) was found at the room system.
Equilibrium moisture content
Figure 6 shows the equilibrium moisture content of chamomile
plants for dierent drying systems (sun-drying, shadow-drying, room
temperature-drying, solar-drying, and oven-drying) and dierential
equation models (modied Henderson, modied Halsey, modied
Oswin, modied Chung-Pfost and Gab models).
e results indicate that the equilibrium moisture content of
chamomile plants increases with increasing equilibrium relative
humidity for dierent drying systems. It could be seen that the
equilibrium moisture content of chamomile plants was increased from
(2.86 to 50.61, 2.89 to 51.04, 2.93 to 51.78, 2.62 to 46.27 and 2.27 to
40.11)% for sun, shadow, room temperature, solar and oven drying
systems, respectively, when the equilibrium relative humidity increased
from (10 to 90)% for modied Henderson equation. For modied
Halsey equation, the EMC of chamomile plants was increased from
(5.64 to 44.15, 5.69 to 44.50, 5.76 to 45.12, 5.15 to 40.30) and (4.36 to
34.16)% for sun, shadow, room temperature, solar and oven drying
systems, respectively, when the equilibrium relative humidity increased
from (10 to 90)%. For modied Oswin equation, the EMC of chamomile
plants was increased from (5.17 to 15.40, 4.13 to 15.41, 2.35 to 15.42,
1.70 to 15.28 and 1.38 to 15.08)% for sun, shadow, room temperature,
solar and oven drying systems, respectively, when the ERH increased
from (10 to 90)%. For modied Chung-Pfost equation, the EMC of
chamomile plants was increased from (16.13 to 39.20, 16.96 to 40.03,
18.67 to 41.74, 10.20 to 33.27)% and (5.06 to 28.12)% for sun, shadow,
room temperature, solar and oven drying systems, respectively, when
the ERH increased from (10 to 90)%. For GAB equation, the EMC of
chamomile plants was increased from (5.43 to 37.76, 5.47 to 38.12,
5.53 to 38.78, 4.95 to 34.18 and 3.93 to 29.63)% for sun, shadow, room
temperature, solar and oven drying systems, respectively, when the
ERH increased from (10 to 90)%.
Solar drying
Oven drying
Figure 5: The moisture content of chamomile owers for different drying
systems.
Henderson
Halsey
Oswin
Chung-Pfost
GAB
Figure 6: The equilibrium moisture content of chamomile owers.
Citation: El-Sayed GK, Bahnasawy AH, Hamouda RM (2019) Dehydration of Chamomile Flowers under Different Drying Conditions. J Food Process
Technol 10: 803. doi: 10.4172/2157-7110.1000803
Page 6 of 7
Volume 10 • Issue 7 • 1000803
J Food Process Technol, an open access journal
ISSN: 2157-7110
e results indicated that the highest value of equilibrium moisture
content was found from the Henderson equation under room system.
It could be seen that the equilibrium moisture content was 51.78%
at 90% equilibrium relative humidity for room temperature system.
Meanwhile, the lowest value of equilibrium moisture content was found
for the modied Oswin equation for oven system. It could be seen that
the equilibrium moisture content was 1.38% at 10% equilibrium relative
humidity for oven system (Table 1).
Content of oil
Figure 7 shows the chamomile oil content for dierent drying
systems (sun-drying, shadow-drying, room temperature-drying, solar-
drying, and oven-drying) at the end of the experiment. It could be seen
that the basil oil content values were (0.66, 0.78, 0.94, 0.73 and 0.59)%
for the sun-drying, shadow-drying, room temperature-drying, solar-
drying, and oven-drying, respectively. e results indicate that the
highest value of the basil oil content (0.94%) was obtained when the
chamomile dried at room temperature system. Meanwhile, the lowest
value of the basil oil content (0.59%) was found at the oven-drying
system.
e total content of macro elements
Figure 8 shows the total content of macro elements (Nitrogen,
Phosphorus, Potassium, Calcium, and Magnesium) for dierent drying
systems (sun-drying, shadow-drying, room temperature-drying, solar-
drying, and oven-drying) at the end of the experiment. It could be seen
that the highest values of Nitrogen, Phosphorus, Potassium, Calcium,
and Magnesium content were (2.62, 1.11, 4.10, 1.12 and 0.23)% were
obtained when the chamomile dried at room temperature system.
Meanwhile, the lowest value of the Nitrogen, Phosphorus, Potassium,
Calcium, and Magnesium content was (1.50, 0.83, 3.83, 0.84 and 0.20)%
were found at the oven-drying system.
Conclusion
e experiment was carried out to study was conducted to
investigate the possibility of drying the chamomile plants under
dierent conditions. e obtained results can be summarized as follows:
e accumulated weight loss of chamomile plants increased from
(83.63 to 86.27, 77.12 to 84.67, 73.95 to 82.70, 54.61 to 85.04 and 60.14
to 86.53)% for the sun-drying system, shadow-drying system, room
temperature-drying system, solar-drying system, and oven-drying
system respectively.
e moisture content of chamomile plants decreased from (508.59
to 14.56, 502.77 to 15.43, 470.09 to 18.19, 537.47 to 13.45 and 444.84
to 5.46)% d.b. for the sun-drying system, shadow-drying system, room
temperature-drying system, solar-drying system, and oven-drying
system respectively.
e highest value of equilibrium moisture contents were 51.78%
at 90% equilibrium relative humidity was found from Henderson
equation under room temperature system.
e lowest value of equilibrium moisture contents were 1.38%
at 10% equilibrium relative humidity was found for modied Oswin
equation for oven system.
e chamomile oil content values were (0.66, 0.78, 0.94, 0.73 and
0.59)% for the sun-drying, shadow-drying, room temperature-drying,
solar-drying, and oven-drying respectively.
e highest values of Nitrogen, Phosphorus, Potassium, Calcium,
and Magnesium content were (2.62, 1.11, 4.10, 1.12 and 0.23)% were
obtained when the chamomile dried at room temperature system.
e lowest value of the Nitrogen, Phosphorus, Potassium, Calcium,
and Magnesium content were (1.50, 0.83, 3.83, 0.84 and 0.20)% were
found at the oven-drying system.
Acknowledgment
This work is fully sponsored by the utilization of solar energy in herbal plants
drying funded by the Support and Development of Scientic Research Center,
Benha University.
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Coecient Equation
Henderson Halsey Oswin Chung-Pfo GAB
C10.034 -2.606 0.185 9.155 0.058
C2115.67 -7.76 × 10-3 -8.89 × 10-4 42.03
C31.074 1.300 1.713 305.44
C40.626
C52.23 × 10-3
C61010
C725000
Table 1: Shows the coefcients for Henderson, Halsey, Oswin, Chung-Pfost and
GAB equations of chamomile leaves for different drying systems.
Figure 7: The chamomile oil content for different drying systems.
Figure 8: The total content of elements for different drying systems.
Citation: El-Sayed GK, Bahnasawy AH, Hamouda RM (2019) Dehydration of Chamomile Flowers under Different Drying Conditions. J Food Process
Technol 10: 803. doi: 10.4172/2157-7110.1000803
Page 7 of 7
Volume 10 • Issue 7 • 1000803
J Food Process Technol, an open access journal
ISSN: 2157-7110
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... Values of the coefficient of determination (R 2 ) ranges from 0.967 to 0.99, which suggests high goodness of fit of the curves. The results corroborate with findings of El-Sayed et al., [22] in their studies with dehydration of chamomile flowers using different drying methods. ...
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Aims: To optimize drying technique for the popular Dutch rose cultivar, Taj Mahal, by evaluating different drying methods and appraising the physical, biochemical and sensory quality of the product. Study Design: Completely Randomized Design. Place and Duration of Study: Department of Floriculture, Medicinal and Aromatic Plants, Faculty of Horticulture, Uttar Banga Krishi Viswavidyalaya, during 2019-2020 Methodology: Flowers of rose cultivar 'Taj Mahal', at their prime beauty i.e., half-opened bud stage, were subjected to embedded drying in silica gel at six different conditions viz. at room temperature (T 1), in hot air oven at 45°C, (T 2) and at 60°C, (T 3) in microwave oven at 100% power level (T 4), 80% power level (T 5) and at 60% power level (T 6). The quality of the ensuing dehydrated flowers was judged with respect to colour, weight, volume shrinkage and anthocyanin and carotenoid contents. Temperature during drying and time to reach optimum dehydrated condition Original Research Article Narjinary et al.; IJPSS, 33(17): 173-182, 2021; Article no.IJPSS.72157 174 under different drying techniques were recorded. Sensory evaluation for the quality of the products was done after six months of storage. Results: The time taken for optimum drying ranged from 120 hours in case of room temperature drying (25.1°C) to 3 minutes in microwave oven on high power i.e., 100% (130.4°C). Significant variation in final weight of the product was recorded between 18.34% to 28% of the fresh weight. Minimum shrinkage (42.85%) was noted in room drying (T 1) and hot air oven drying at 60°C (43.53%). Maximum anthocyanin concentration (3.528 mg/g) was recorded in flowers dried at room temperature, whereas, minimum among the dried flowers, was recorded in microwave oven drying at 100% power level (1.439 mg/g). Maximum Carotenoid content (16.780 µg/g) was recorded in flowers dried in hot air oven at 45°C. Out of six treatments in the present study, maximum sensory score (30.38 out of 36) was gathered by T 2 , which was at par with T 1 and T 5. Conclusion: Dehydrating 'Taj Mahal' rose flowers by embedding in silica gel and drying under room temperature (25°C) for 120 hours or hot air oven at 45°C for 27.5 hours or microwave oven at 80% power level for 3.5 minutes can be recommended for commercial dry flower production.
... Drying is the most common and effective method that increases the shelf life of herbs which inhibit the microorganisms growth and preventing some biochemical reactions that may alter the organoleptic and nutritional characteristics of the dried leaf. However, drying must be performed carefully in order to preserve the aroma, appearance and nutritional characteristics of the raw herbs (Crivelli et al., 2002 andKhater et al., 2019). The drying may cause losses in volatilities or formation of new volatilities as a result of oxidation reactions, esterification reactions (Diaz-Maroto et al., 2002). ...
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