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Physical attributes of garlic (Allium sativum L.)

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J. Agric. Sci. Technol. (2006) Vol. 8: 15-23
15
Physical Attributes of Garlic (Allium sativum L.)
A. A. Masoumi1*, A. Rajabipoor2, L. G. Tabil3 and A. A. Akram2
ABSTRACT
Some physical attributes of two common types of Iranian garlic cloves (white and pink)
were identified and compared. A machine vision system was used to determine three di-
mensions and both major and minor projected areas of garlic cloves at a moisture content
of 42.4% w. b. The geometric mean diameter and sphericity were calculated, as well as
the unit mass and volume of cloves were measured. In the moisture range from 34.9 to
56.7% w.b., the unit density, bulk density and porosity for both types were measured. Re-
sults showed that the unit density, bulk density and porosity of cloves were affected sig-
nificantly by moisture content (p<0.01). The type of garlic had a highly significant effect
on the unit density and porosity (P<0.01), and a significant effect on the bulk density
(P<0.05). The relationship between volume and dimensions of cloves was established using
regression analysis. The effect of moisture content on physical properties of cloves was
also expressed by appropriate equations.
Keywords: Garlic, Machine vision, Physical attributes.
_____________________________________________________________________________
1 Department of Agricultural Machinery, Faculty of Agriculture, Isfahan University of Technology, Isfa-
han, Islamic Republic of Iran.
2 Department of Agricultural Machinery, Faculty of Agriculture, University of Tehran, Karaj, Islamic Re-
public of Iran.
3 Department of Agricultural and Bioresource Engineering, University of Saskatchewan, 57 Campus Drive,
Saskatoon, SK, Canada S7N 5A9.
* Corresponding author.
INTRODUCTION
Garlic (Allium sativum L.) has been culti-
vated since ancient times all over the world
especially in Asia. Garlic has medicinal
properties and it is an important ingredient
in the leading cuisines around the world.
Garlic as a spice is utilized in both fresh and
dehydrated state in the food industry. It is
dehydrated into different products such as
flakes, slices, and powders (Ahmad, 1996).
Garlic does not produce seeds, so it must
be propagated vegetatively with garlic
cloves as the most common planting mate-
rial. The yield quality of garlic is affected by
planting methods and clove rates and sizes
(Nourai, 1994; Matlob and Khalel, 1986).
Lack of basic engineering properties of this
planting material is a problem identified in
the development of new methods of sowing
the garlic crop, development of new equip-
ment for processing and control strategies
for crop storage. A number of researchers
have worked on the physical properties of
garlic (Madamba et al., 1993, 1995, 1997;
Pezzutti and Crapiste, 1997; Park et al.,
1981; Bhatt et al., 1998; Sharma and Prasad,
2002).
Madamba et al., (1993) measured the
length, width, and thickness of garlic slices
by using vernier caliper. Song and Litch-
field, (1991) measured the length and width
of seed grains by using a computer imaging
system while using a caliper to measure the
third dimension. Tabil et al., (1999) used an
image analysis program to determine the
size and shape characteristics of some spe-
cialty crops such as chickpeas, lentils and
peas including the length of the longest and
shortest axes, cross section area, perimeter
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_________________________________________________Masoumi, Rajabipoor, Tabil and Akram
16
of the object, circularity and roundness of
each seed. Olaoye, (2000) used an overhead
projector to project the image of the nut
samples on a plain cardboard sheet to char-
acterize the shape.
Sizes of materials usually play a significant
role under approximately the same operating
conditions (Gupta and Das, 1997), as shown
by Marjana (1996) who investigated the ef-
fects of the size of cloves on the yield of
garlic.Gupta and Das (1997) reported a cor-
relation among various dimensions of sun-
flower seeds. The influence of moisture con-
tent on several physical properties was re-
ported by some researchers (Madamba et al.,
1994; Joshi et al., 1993).
Information on the physical attributes of
garlic cloves is not available in the literature.
The objective of this study was to determine
the physical attributes of garlic cloves in-
cluding their dimensions, unit density, bulk
density, porosity. Models were developed to
express the relationship between volume and
dimension as well as determining the mois-
ture-dependent physical attributes of garlic
cloves in the moisture range of 34.9 to 56.7
% w.b.
MATERIALS AND METHODS
Sample Preparation
Garlic bulbs (white and pink) were ob-
tained locally in the region of Marvdasht,
Fars province Iran. Freshly harvested garlic
bulbs were randomly collected from differ-
ent farms. Similar with local practice, the
bulbs were dried by spreading them in a
thin-layer inside a darkroom with open win-
dows near the farms for 15 days. Samples
were stored in a cabinet at 5oC. The sample
bulbs were randomly selected from the bulk
sample and their outer covering manually
removed and cracked before the experi-
ments.
The moisture content of the cloves was de-
termined by following the ASAE S352.2
standard method (ASAE, 1999). Each sam-
ple weighing about 10 g, was placed in a
convection oven set at 130°c for 50 minutes.
The desired sample moisture levels were
prepared. Samples with lower moisture con-
tent were dried by placing in a oven at 60°c
and spread in a thin layer. The sample cloves
with higher moisture contents were prepared
by adding distilled water. Before beginning
the experiments the required quantity of the
samples was placed in room temperature for
12 hours (Visvanathan et al., 1996).
Determination of Dimensions, Mass and
Volume
Seventy-five cloves of each type were ran-
domly selected from the bulk of the samples
with their initial moisture and packed in la-
beled bags individually for easy identifica-
tion. Size and shape characteristics were de-
termined by using a computer imaging sys-
tem. The sample cloves were placed on the
black backplate under the camera individu-
ally and the image was acquired and the im-
ages analyzed using a Sony DXC-151A
CCD color video camera (Sony Corporation,
Japan), light stand, Matrox Meteor RGB
capture card, Pentium III 700 PC, and Ma-
trox Inspector Software version 2.1 (Matrox
electronic systems, Quebec, Canada). In or-
der to increase the accuracy of measuring
the size and shape, significant contrast be-
tween the samples and background was re-
quired that was obtained by using the black
sheet under samples as background and ad-
justing the lights, camera height, brightness,
zoom and focus. Each clove was individu-
ally placed on a black sheet in its natural
position with its length parallel to the y-
coordinate and its image was taken. Then it
was rotated 90 degrees to its major axis to
take a second image. An 80-mm needle and
a 10-mm square rubber with a 5 mm thick-
ness was used to keep and rotate each clove
on its major axis. The features of both im-
ages of each clove including area, perimeter,
feret x and feret y (the dimensions of the
minimum bounding box of the clove in the
horizontal and vertical axes, respectively)
were saved in Excel Workbook format for
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Physical Attributes of Garlic __________________________________________________
17
further analysis. The average of feret y in
both images of each clove was reported as
the major dimension (mm). The longer and
shorter of feret x in both images were re-
ported as intermediate and minor dimensions
(mm) of cloves, respectively.
The bulk clove sample was classified into
three categories-namely small, medium and
large-based on the unit mass of the cloves.
The distribution of cloves by number and
size for each category of unit mass was de-
termined.
The geometric mean diameter (Dp) of the
cloves was calculated by using the following
relationship (Mohsenin, 1986):
3
1
(LWT)
p
D= (1
where L, W and T are the length, width and
thickness in mm, respectively. The spheric-
ity (φ) of the cloves was calculated using the
following equation (Mohsenin, 1986):
L
)LWT(
=
3
1
Φ (2
The volume of each clove was measured
using the gas comparison multipycnometer
(Quanta Chrome Corporation, Boynton
Beach FL, U.S.A). The pycnometer had cell
cups of a volume of 6, 18, and 150 cm3.
Some of the sample cloves were larger than
the smallest cell and partially occupied the
large cell, so a more accurate calibration of
the system was needed. The system was
calibrated as follows. Actual and measured
volumes of different unit sizes were com-
pared by using the known volume of steel
spheres. The average diameter of each
sphere was measured by a digital caliper
(resolution of 0.01 mm), to calculate its ac-
tual volume. Combinations of spheres were
placed in different cell cups for volume de-
termination by the gas pycnometer. The
measurement was repeated three times. The
data was analyzed to find the relationship
between actual and measured volumes by
using different cells for different unit sizes.
To obtain the mass, each clove was weighed
using an electronic weighing balance (Qhaus
scale corp. G 160D, W. Germany) reading to
0.0001 g.
Physical Properties of Cloves
The bulk and unit densities as well as po-
rosity of the various garlic cloves at different
moisture contents were determined. Bulk
density, ρb, was calculated from the mass
and volume of the circular container with a
known volume that was filled by the sample
cloves. The cloves were dropped from a
hopper into the container at a height of 200
mm and excess cloves were removed by
passing a wooden stick across the top sur-
face using 5 zigzag motions (Madamba et
al., 1993).
Unit density, ρp is defined as the ratio of
the mass of the bulk of cloves to its volume
(Joshi et al., 1993). The average value of the
densities was taken from three replications
for each moisture content of each type of
garlic.
The porosity, ε of bulk cloves expressed in
a percentage was calculated from the bulk
and unit densities by using the following
relationship (Jha, 1999):
100
-
=ε
p
bp ×
ρ
ρ
ρ
(3
where ρb and ρp are the bulk density and the
unit density.
Data Processing and Analysis
All the tests were conducted on two various
garlic cloves commonly grown in Iran
(white and pink). SAS PROC MEANS,
FREQ and CORR were used to determine
the maximum, minimum, mean, standard
error, frequency distribution, and correlation
of dimensions of cloves. The relationship
between the volume and dimensions of
cloves was established using regression
analysis and the relationship between the
physical properties of cloves and levels of
moisture content was determined.
Model coefficients were determined using
the SAS routines, REG for linear models
and NLIN for non-linear models (SAS,
2001). The analysis of variance (ANOVA)
and comparison of means were performed
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_________________________________________________Masoumi, Rajabipoor, Tabil and Akram
18
using PROC ANOVA. The coefficient of
multiple determination (R2) and the mean
square error (MSE) of models and the varia-
tion of predicted values with respect to
measured values as well as the distribution
of the residuals with respect to the estimated
coefficients were used to evaluate the mod-
els for fit to the experimental data.
RESULTS AND DISCUSSION
Dimensions and Size Distribution of
Garlic Cloves
Table 1 shows the size distribution of both
the white and pink garlic clove samples at a
42.4% moisture content (w.b.). About 36%
and 38.67% of the white and pink cloves,
respectively, had a mass ranging from 3-5 g,
whereas 28% and 37.33% of the white and
pink cloves, respectively, had a mass less
than 3 g, (small). The larger (mass greater
than 5 g) white and pink cloves were 36%
and 24% of cloves, respectively.
The mean values of 75 measurements for
the major, intermediate and minor dimen-
sions as well as the major and minor pro-
jected areas of white cloves were found to
be 31.71 mm, 19.91 mm, 15.41 mm, and
473.83 mm2, 377.88 mm2, respectively. The
corresponding values for pink cloves were
30.56 mm, 18.72 mm, 15.15 mm, 427.59
mm2 and 352.76 mm2, respectively.
The unit mass and volume of white cloves
were found to be 4.28 g and 4410 mm3, re-
spectively. The values for pink cloves were
3.68 g and 3809 mm3, respectively.
Table 2 shows the Pearson correlation co-
efficients of cloves at a moisture content of
42.4% (w.b.). These values indicate a high
correlation among all the parameters of both
cloves. For both types, the major dimension
of the cloves were also closely related to the
Table 1. Size and distribution of white and pink garlic cloves at 42.4% moisture content (w. b.).
Size category
a
Type
Physical attributes
Total Small Medium Large
White
Percent of sample
By number 100 28 36 36
By mass 100 12.5 34.98 52.52
Average dimensions
Major (a), mm 31.71±0.46 27.41 ± 0.97 32.38 ± 0.41 34.40 ± 0.29
Intermediate (b), mm 19.91±0.47 14.50 ± 0.49 20.63 ± 0.41 23.39 ± 0.30
Minor (c), mm 15.41±0.45 11.06 ± 0.39 15.39 ± 0.46 18.81 ± 0.54
Major projected area (A1), mm2 473.8±16.1 303.3 ± 19.2 485.6 ± 14.8 594.6 ± 13.1
Minor projected area (A2), mm2 377.9±14.6 227 ± 13.4 377.4 ± 10.8 495.7 ± 15.8
Unit mass (M), g 4.28±0.22 1.19 ± 0.15 4.16 ± 0.11 6.25 ± 0.21
Unit volume (V), mm3 4401±213 2122 ± 212 4387 ± 129 6188 ± 260
Pink
Percentage of sample
By number 100 37.33 38.67 24
By mass 100 19.07 40.99 39.94
Average dimensions
Major (a), mm 30.56±0.54 26.10 ± 0.74 31.89 ± 0.35 35.39 ± 0.59
Intermediate (b), mm 18.72±0.46 14.73 ± 0.50 20.16 ± 0.37 22.62 ± 0.54
Minor (c), mm 15.15±0.41 12.24 ± 0.45 15.39 ± 0.33 19.29 ± 0.68
Major projected area (A1), mm2 427.6±16.6 281.3 ± 14.4 470.8 ± 13.2 585.4 ± 20.8
Minor projected area (A2), mm2 352.8±14.15 241±12.8 364.7± 8.43 507.4 ± 21.8
Unit mass (M), g 3.68±0.21 1.88 ± 0.12 3.90± 0.11 6.13 ± 0.26
Unit volume (V), mm3 3809±199 2114±132 4101±151 5974±260
a Small <3g; Meduium 3-5g; Large>5g.
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Physical Attributes of Garlic __________________________________________________
19
intermediate dimension. The geometric
mean diameter and sphericity of cloves were
calculated. Table 3 shows these values for
both white and pink cloves.
Unit Volume
The relationship between unit volume and
dimensions of cloves for both types of garlic
were established using the following regres-
sion analyses:
)c(Ln62.0)b(Ln16.1
)a(Ln2.173.0)
Vw
(Ln
+
++=
(R2=0.96) (4
)c(Ln61.0)b(Ln67.0
)a(Ln4.136.0)
Vp
Ln(
+
+
+=
(R2=0.93) (5
where (Vw) and (Vp) are the unit volume of
white and pink cloves (mm3) and a, b , and c
are the major, intermediate and minor di-
mensions (mm), respectively. Mohsenin
(1986) reported the same model for corn
with various coefficients. As Table 2 shows
the correlation between volume and the ma-
jor and minor dimensions of white and pink
garlic cloves at 42.4% moisture content
(w.b.) was close but the corresponding val-
ues for intermediate dimensions of white
garlic cloves were larger than pink garlic
cloves. The same results can be observed
from Equations 7 and 8.
Unit Density
Type and moisture level had a significant
effect (P<0.01) on the unit density of garlic
cloves as revealed by a one-way analysis of
variance. The Duncan multiple range test
indicated that, at each moisture level, the
mean unit density for both types of cloves
was significantly different (P<0.01).
The unit density of the white and pink gar-
lic clove samples were found to decrease
from 1142 to 1106 and 1184 to 1108 kg/m3,
respectively, when the moisture content in-
creased from about 34.9 to 56.7 %w.b. (Fig-
ure 1). The relationship between unit density
and moisture content for both types of
cloves is shown as:
Table 2. Correlation of white and pink garlic cloves dimensions, volume and mass at 42.4% mois-
ture content (w. b.).
Type A2(mm2) A1(mm2) a(mm) b(mm) c(mm) V(mm3)
White
A1(mm2)
a (mm)
b (mm)
c (mm)
V (mm3)
M (g)
0.8024**
0.7701**
0.8108**
0.9680**
0.9230**
0.9411**
1
0.9007**
0.9719**
0.6763**
0.9192**
0.9164**
1
0.8305**
0.6172**
0.8187**
0.8089**
1
0.7122**
0.9232**
0.9157**
1
0.8473**
0.8756**
1
0.9793**
Pink
A1(mm2)
A (mm)
B (mm)
c (mm)
V (mm3)
M (g)
0.8497**
0.8776**
0.7966**
0.9641**
0.9308**
0.9367**
1
0.9177**
0.9633**
0.7303**
0.9020**
0.9209**
1
0.8533**
0.7524**
0.8768**
0.8762**
1
0.6933**
0.8571**
0.8785**
1
0.8577**
0.8601**
1
0.9692**
**Significant at 1% level.
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_________________________________________________Masoumi, Rajabipoor, Tabil and Akram
20
2
cc M0.1+9.1M-13607=
ρp(w)
(R2=0.93) (6
2
cc M0.18+20M-1667.8=
ρp(p)
(R2=0.94) (7
ρp(w) and ρp(p) represent the unit density of
white and pink garlic cloves (kg/m3), respec-
tively and Mc is the percentage of moisture
content ( w. b.). Madamba et al. (1994) pro-
posed the second degree polynomial model
to predict the apparent density of garlic
cloves (cv. Early California) as follows:
0.1M-2.6M1267.2=
ap
2
cc
+
ρ
(R2=0.93) (8
where ρ(ap) is the apparent density kg/m3. As
shown in Equations 6 to 8, the difference in
coefficients may be due to the garlic variety.
Bulk Density
In this study, significant differences
(P<0.01) in bulk density were found be-
tween the two types and moisture levels of
cloves. The mean bulk density for both types
of cloves were significantly different
(P<0.05).
The bulk density for white and pink garlic
cloves was found to increase from 468.8 to
612.8, and 510.2 to 672 kg/m3, respectively,
while the moisture level increased from
about 34.9 to 56.7 % w.b. (Figure 1). The
second degree polynomial model was found
to predict bulk density values for both types
of garlic, shown as:
0.25M+
c
16.1M-725.8=
ρb(w) 2
c
(R2=0.96) (9)
2
ccp(b) 0.17M+8.61M-591.8=ρ
(R2=0.94) (10)
where ρb(w) and ρb(p) are the bulk density of
white and pink garlic cloves (kg/mm3), re-
spectively. Some researchers such as (Joshi
et al. 1993) expressed the bulk density of
pumpkin seeds as a function of moisture
content using the second degree polynomial
model. Modamba et al. (1993) proposed the
linear model for bulk density of garlic slices
as a function of moisture content and slice
thickness.
Porosity
The relationship between porosity and
400
600
800
1000
1200
30 35 40 45 50 55 60
Moisture content,% w.b.
Density,kg/m
3
U-density-w B-densit y-w U-density-p B-density-p
Figure 1. Effect of moisture content on unit and bulk densities of white
and pink garlic cloves.
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Physical Attributes of Garlic __________________________________________________
21
moisture content of both cloves is given in
Figure 2. The porosity decreased from 59 to
45% and 57 to 39% for white and pink garlic
cloves, respectively, when the moisture con-
tent increased from about 34.9 to 56.7% w.b.
The results revealed a high significant effect
of both moisture content and garlic type on
the porosity (P<0.01). The variation in po-
rosity with respect to moisture can be ex-
pressed by the following equations:
)0.94=(R 0.68M-83.49=
w2
c
ε (11
0.93)=(R 0.82M-86.9=
p2
c
ε (12
where εw and εp are the porosity of white and
pink garlic cloves (%) respectively.
Madamba et al. (1993) proposed a linear
model as a function of moisture content and
of garlic slice thickness also showed de-
creasing porosity with respect to the increas-
ing moisture content of garlic slices.
CONCLUSION
The average major, intermediate and minor
dimensions as well as the major and minor
projected areas of white garlic cloves were
31.71 mm, 19.91 mm, 15.41 mm and 473.8
mm2 and 377.9 mm2 , respectively; the cor-
responding values for pink garlic were 30.56
mm, 18.72 mm, 15.15 mm and 427.6 mm2
and 352.8 mm2, respectively. The values of
average unit mass and volume were 1.19 g
and 2122.4 mm3, respectively, for white gar-
lic cloves and 1.88 g and 214.4 mm3, respec-
tively, for pink garlic.
35
40
45
50
55
60
33 35 37 39 41 43 45 47 49 51 53 55 57 59 61
M oist ur e conten t, % w .b.
Poro sity %
porosity-w Porosity-p
Figure 2. Effect of moisture content on porosity of white and pink garlic clove.
Table 3. Geometric mean diameter and sphericity of white and pink garlic cloves at 42.4%
moisture content (w. b.).
Geometric mean diameter (mm) Sphericity
Type Range Mean Range Mean
White 12.43 – 27.55 21.25 (3.74) 0.58 - 0.91 0.72 (0.08)
Pink 11.14 - 28.38 20.46 (3.77) 0.57 – 0.87 0.74 (0.07)
Each value is a mean of 75 measurements. The standard deviation is given in parentheses.
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_________________________________________________Masoumi, Rajabipoor, Tabil and Akram
22
The mean values of geometric mean di-
ameter and sphericity of white garlic cloves
were 21.25 mm and 0.72, respectively, while
corresponding values for pink garlic were
20.46 mm and 0.74, respectively.
The unit density, bulk density and porosity
of cloves were found to be dependent on
moisture content. The unit density and po-
rosity decreased when the moisture content
increased, while bulk density increased with
increasing of moisture content. The type of
garlic also significantly affected the above
named physical properties.
ACKNOWLEDGMENTS
The authors would like to acknowledge the
Department of Agricultural and Bioresource
Engineering, University of Saskatchewan for
technical support; we also appreciate the
help extended by Mr. Bill Crerar during the
experimental work.
REFERENCES
1. Ahmad, J. I. 1996. Garlic-apanacea for
Health and Good Taste. Nutrition and Food
Science, 96(1): 32-35.
2. ASAE. 1999. Moisture Measurement un-
ground Grain and Seeds. ASAE S352.2
DEC97. In: “ASAE Standards” 1999, 567.
St. Joseph, MI: ASAE.
3. Bhatt, R. P., Biswas, V. R. and Kumar N. A.,
1998. Note on the Physico-chemical Charac-
teristics of some Geno-types of Garlic. Veg.
Sci, 25(1): 95-96.
4. Gupta, R. K. and Das, S. K. 1997. Physical
Properties of Sunflower Seeds. J. agric.
Engng Res. 66:1-8.
5. Jha, N. S. 1999. Physical and Hygroscopic
Properties of Makhana. J. agric. Engng Res.
72:145-150.
6. Joshi, D. C., Das K. S. and Mukherjee, R. K.
1993. Physical Properties of Pumkin Seeds.
J. agric. Engng Res. 54: 219-229.
7. Madamba, P. S. 1997. Optimization of the
Drying Process: an Application to the Dry-
ing of Garlic. Drying Technology. 15(1):
117-136.
8. Madamba, P. S., Driscoll R. H. and Buckle,
K. A. 1993. Bulk Density, Porosity and Re-
sistance to Airflow of Garlic Slices. Drying
Technology. 11(7): 1837-1854.
9. Madamba, P. S., Driscoll R. H. and Buckle,
K. A. 1994. Shrinkage, Density and Porosity
of Garlic during Drying. Journal of Food
Engineering, 23: 309-319.
10. Madamba, P. S., Driscoll R. H. and Buckle,
K. A. 1995. Models for the Specific Heat
and Thermal Conductivity of Garlic. Drying
Technology. 13(1&2): 295-317.
11. Marijana, J. 1996. Effects of the Size of
Planting Material and Soil Preparation on the
Yield of Garlic (Allium sativum L.). Res.
Reports Biotechnical Faculty. 67: 203-207.
Jamnikarjeva, University of Ljubljana. Slo-
venia.
12. Matlob, A. N. and Khalel, A. M. 1986. Ef-
fect of Planting Dates, Plant Spacing and
Clove Size on Vegetative Growth and Bul-
bing of Garlic (Allium sativum L.). Iraqi
Journal of Agricultural Science zanco. 4(3):
35-50.
13. Mohsenin, N. N. 1986. Physical Properties
of Plant and Animal Materials, 2nd edition.
Gordon and Breach Science Publishers.
14. Nourai, A. H. 1994. Effect of Planting
Methods and Seed Rates on Yield, Yield
Components and Quality of Garlic (Allium
sativum L.) in the Sudan. Acta Horticulture.
358: 359-364.
15. Olaoye, J. O. 2000. Some Physical Proper-
ties of Castor Nut Relevant to the Design of
Processing Equipment. J. agric. Engng Res.
77(1): 113-118.
16. Park, M. H., Koh, H. Y., Shin D. H. and Suh,
K. B. 1981. Study on the Long Term Storage
of Garlic Bulbs. J. korean Agricultural
Chemical Society. 24(4): 218-223.
17. Pezzutti, A. and Crapiste, G. H. 1997. Sorp-
tional Equilibrium and Drying Characteris-
tics of Garlic Content. Journal of food Engi-
neering. 31(1): 113-123.
18. SAS 2001. SAS Users’ Guide: Statistics.
Version 8.2 Statistical Analysis System, Ink.,
Raleigh, NC.
19. Sharma, G. P. and Prasad, S. 2002. Dielec-
tric Properties of Garlic (Allium sativum L.)
at 2450 MHz as Function of Temperature
and Moisture Content. Journal of food Engi-
neering. 52: 343-348.
20. Song, H. and Litchfield, J. B. 1991. Predict-
ing Method of Terminal Velocity for Grains.
Transactions of the ASAE. 34(1): 225 -230.
21. Tabil, G. L., Qi, H., Chawla, K. K., Kien-
holz, J. Crossman, V. and White R. 1999.
www.SID.ir
Archive of SID
Physical Attributes of Garlic __________________________________________________
23
Physical Properties of Selected Special
Crops Grown in Alberta. ASAE/CSAE An-
nual International Meeting. Paper No.
996049.
22. Visvanathan, R., Palanisamy, P. T., Gothan-
dapani, L. and Sreenarayanan, V. V. 1996.
Physical Properties of Chickpea. J. agric.
Engng Res. 63:19-26.
ﻲﻜﻳﺰﻴﻓ تﺎﻴﺻﻮﺼﺧﺮﻴﺳ )Allium sativum L. (
ا. ﻲﻣﻮﺼﻌﻣ ل ، . ج . ،ﻞﻴﺒﺗع.رﻮﭘ ﻲﺒﺟر و ا.مﺮﻛا
هﺪﻴﻜﭼ
ﻪــﺒﺣ ﻲــﻜﻳﺰﻴﻓ تﺎﻴــﺻﻮﺼﺧو تﺎــﺼﺨﺸﻣ زا ﻲــﻀﻌﺑ ﺮﻴــﺳ يﺎــﻫﻲﻣﻮــﺑناﺮــﻳا رد رد و ﺪﻴﻔــﺳ عﻮــﻧ ود
و ﻦﻴــﻴﻌﺗ ﻲﺗرﻮــﺻ ﺪﻧﺪــﺷ ﻪــﺴﻳﺎﻘﻣ ﺮﮕﻳﺪــﻜﻳ ﺎــﺑ.ﻦﻴــﺷﺎﻣ ﻢﺘــﺴﻴﺳ زا ﻲﺋﺎــﻨﻴﺑ ﺢﻄــﺳ ،ﻲﻠــﺻا دﺎــﻌﺑا ﻦﻴــﻴﻌﺗ ياﺮــﺑ
و ﻪــﻨﻴﻤﻛ هﺪــﺷ ﺮﻳﻮــﺼ ﻪﭼﺮﻴــﺳ ﻪﻨﻴــﺸﻴﺑ ﻲﺘﺑﻮــﻃر ياﻮــﺘﺤﻣ ﺎــﺑ ﻲــﺸﻳﺎﻣزآ يﺎــﻫ4/42) %ﺮــﺑ ﺮــﺗ نزو سﺎــﺳا (
ﺪــﻳدﺮﮔ هدﺎﻔﺘــﺳا . و ﻪﺒــﺳﺎﺤﻣ ﺎــﻬﻧآ ﺖــﻳوﺮﻛ و ﻲــﺳﺪﻨﻫ ﻦﻴﮕﻧﺎــﻴﻣ ﺮــﻄﻗﻦﻴــﻨﭽﻤﻫ ﺎــﻫ ﻪﭼﺮﻴــﺳ ﻢــﺠﺣ و مﺮــﺟ
ﺪﻧﺪـــﺷ يﺮـــﻴﮔ هزاﺪـــﻧا. مﺮـــﺟ ،ﻪﭼﺮﻴـــﺳ صﻮـــﺼﺨﻣ مﺮـــﺟ ﻞﻣﺎـــﺷ ﻲـــﻜﻳﺰﻴﻓ تﺎﻴـــﺻﻮﺼﺧ زا ﻲـــﺧﺮﺑ
و ﻞــﻠﺧو هدﻮــﺗ صﻮــﺼﺨﻣ ﺮــﻫ جﺮــﻓ دو ﻲﺘﺑﻮــﻃر هدوﺪــﺤﻣ رد ﺮﻴــﺳ يﺎــﻫ ﻪــﺒﺣ عﻮــﻧ 9/ 34 % ﻲــﻟا
7/56) %ﺮــﺑ ﺮــﺗ نزو سﺎــﺳا ( ﺪﻧﺪــﺷ يﺮــﻴﮔ هزاﺪــﻧا. ﺲﻧﺎــﻳراو ﻞــﻴﻠﺤﺗو ﻪــﻳﺰﺠﺗ)ANOVA ( ﺎــﻫ هداد
يراد ﻲــﻨﻌﻣ رﺎﻴــﺴﺑ ﺮﻴﺛﺄــﺗ ﺎــﻫ ﻪﭼﺮﻴــﺳ ﻲﺘﺑﻮــﻃر ياﻮــﺘﺤﻣ ﻪــﻛ داد نﺎــﺸﻧ)1 ./.P < ( مﺮــﺟ ﺮﻳدﺎــﻘﻣ ﺮــﺑ
و ﻞــﻠﺧ ناﺰــﻴﻣ و هدﻮــﺗ صﻮــﺼﺨﻣ مﺮــﺟ ،ﺎــﻫ ﻪﭼﺮﻴــﺳ صﻮــﺼﺨﻣ جﺮــﻓ ﺖــﺷاد ﺎــﻬﻧآ . ﺶﻳﺎــﻣزآ ﻦــﻳا رد
و ﻞــﻠﺧ و ﻪﭼﺮﻴــﺳ صﻮــﺼﺨﻣ مﺮــﺟ ﻦﻴــﺑ يراد ﻲــﻨﻌﻣ رﺎﻴــﺴﺑ توﺎــﻔﺗ هﺪــﺷ هدﺎﻔﺘــﺳا يﺎﻫﺮﻴــﺳ عاﻮــﻧا جﺮــﻓ
ﺪــﻳدﺮﮔ هﺪﻫﺎــﺸﻣ)1./.P<( ود هدﻮــﺗ صﻮــﺼﺨﻣ مﺮــﺟ ﻦﻴــﻨﭼ ﻢــﻫ ، ﻲــﻨﻌﻣ توﺎــﻔﺗ ﻲــﺸﻳﺎﻣزآ ﻪﭼﺮﻴــﺳ عﻮــﻧ
ﺪﻨﺘــﺷاد يراد)5 ./.
P<.( دﺎــﻌﺑاو ﻢــﺠﺣ ﻦﻴــﺑ ﻪــﻄﺑار ﻪﭼﺮﻴــﺳ ر شور زا هدﺎﻔﺘــﺳا ﺎــﺑ ﺎــﻫ ﺖــﺳﺪﺑ نﻮﻴــﺳﺮﮔ
ﺪــﻧﺪﻣآ. ﻲــﺿﺎﻳر ﻂــﺑاور ﻂــﺳﻮﺗ ﺎــﻬﻧآ ﻲــﻜﻳﺰﻴﻓ صاﻮــﺧ ﺮــﺑ ﺎــﻫ ﻪﭼﺮﻴــﺳ ﻲﺘﺑﻮــﻃر ياﻮــﺘﺤﻣ ﺮــﺛا ﻦﻴــﻨﭼ ﻢــﻫ
ﺪﻧﺪﺷ نﺎﻴﺑ ،ﺪﻧدﻮﺑ هﺪﺷ ﻲﺑﺎﻳزرا ﺲﻧﺎﻳراو ﺰﻴﻟﺎﻧآ زا هدﺎﻔﺘﺳا ﺎﺑ ﻪﻛ ﻲﺒﺳﺎﻨﻣ.
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... G arlic (Allium Sativum, L.) is one of the most important root vegetable and spice all over the world (Bakhtiari and Ahmad, 2015). Garlic cloves are the economic part of plants and are used as planting material for the vegetative propagation of garlic (Masoumi, 2006;Seelothu et al., 2024). It belongs to the Alliaceae family and has been widely used to treat different diseases since ancient times (Kaur et al., 2019). ...
... The study revealed that the true density increased and terminal velocity decreased with an increasing moisture content within the obtained range. Rai et al. (2022) studied the different engineering properties of garlic cloves including linear dimension, geometric mean diameter, sphericity, angle of repose, bulk density, true density and porosity, etc. Masoumi et al. (2006) determined and compared the physical attributes of two types of Iranian garlic cloves. The results show the significant effect of moisture content (p<0.01) on the unit density, bulk density and porosity of the cloves. ...
... In the present investigation, the average weight of the whole garlic bulb was 11.41±2.77 g which is lower than values obtained by Masoumi et al., 2006. The physiological loss of weight in garlic bulbs was initiated from the second month of its storage (Kaur et al., 2019). ...
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The present experiment was conducted from February, 2024 to March, 2024 at the Department of Agricultural Process Engineering, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra, India to investigate the various engineering properties of garlic bulbs and garlic cloves. The engineering properties viz., physical, gravimetric and frictional properties, were studied for whole garlic bulbs and garlic cloves by considering their importance in developing different agricultural and post-harvest processing machinery. The weight 11.41 g, length (polar diameter) 33.69 mm, width (equatorial diameter) 29.51 mm, thickness 27.58 mm, arithmetic mean diameter 30.26 mm, geometric mean diameter 30.10 mm, shape index 0.88, sphericity 0.90, surface area 63.05 cm2, cross-sectional area 53.75 cm2, bulk density 449.50 kg m-3, true density 930.45 kg m-3, porosity 51.69%, moisture content 56.70% and angle of repose of garlic bulb 50.54° were obtained. Similar properties were determined for garlic cloves. The L, a and b values for garlic bulb and garlic cloves were 82.95, 0.23, 10.66 and 74.42, 0.28, 12.48, respectively. The water activity of garlic was found to be 0.98±0.02. The coefficient of friction of the garlic bulb and garlic cloves was measured for the selected testing surfaces such as mild steel (MS), stainless steel (SS), wood, glass and fiberglass which was considered in hopper design. The compression force required to loosen the cloves from the garlic bulb was calculated as 61 N. By integrating these engineering properties into the design process, manufacturers can develop equipments or machineries that are more efficient, durable and capable of producing high-quality garlic products.
... Odebunmi et al. 2010 andKimura et al. 2017 also reported 65 and 58.6% moisture content in garlic, respectively. Masoumi et al. (2006) compared some physical properties of two common types of Iranian garlic cloves (white and pink), their study results showed that at different moisture levels ranging from 34.9% to 56.7% w.b. Channabasamma (2014) reported the dimensions of the garlic bulb, such as the pole diameter; The diameter and thickness of the equator are 61.25, ...
... Bakhtiari and Ahmad (2015) calculated that the average bulk density of garlic cloves increased from 476.3 to 567.4 kg/m 3 . Masoumi et al. (2006) reported 468.8 to 612.8, and 510.2 to 672 kg/m 3 for white and pink garlic cloves, respectively. The angle of repose of garlic bulbs reported by Bahnasawy (2007) and Dress (2011) was 41.52 to 45.04o and 26 to 30.5 o , respectively. ...
... The values were in agreement with the 476.3 to 567.4 kg/m 3 reported by Bakhtiari and Ahmad (2015) for garlic cloves. The values were less than the 468.8 to 612.8, and 510.2 to 672 kg/m 3 reported by Masoumi et al. (2006) for white and pink cloves of garlic, respectively. The angle of repose of bulb and cloves of broken garlic were 49.7 and 37.56o, respectively. ...
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Garlic (Allium Sativum L.) is an important root vegetable that can be used as a spice in meals and has historically been used as a remedy for various ailments in Ethiopia. The physical properties of the garlic bulbs and cloves were determined for use in the prototype design. The result showed that the equatorial diameter, polar diameter, thickness, geometric mean diameter, arithmetic mean diameter, sphericity, shape index, surface area, moisture content, hundred garlic bulb weight, bulk density, and angle of repose of the garlic bulbs were 45.89, 42.86, 30.43, 39.08 and 39.71 mm, 0.86, 1.34, 17.08 cm2, 66%, 2530 g, 596.70 kg/m3, and 49.7o for garlic bulbs, respectively. Similarly, the result of the width, length, thickness, geometric mean diameter, arithmetic mean diameter, sphericity, shape index, surface area, hundred garlic cloves weight, bulk density, and angle of repose of the garlic bulbs were 14.44, 31.02, 11.63, 17.15, and 20.07 mm, 0.57, 1.27, 4.06 cm2, 239.4 g, 468.4 kg/m3, and 37.56o for garlic cloves, respectively. Therefore, these physical and mechanical properties of garlic bulbs and cloves were used in designing machine parts.
... The image analysis technique has been used to measure the dimensions and projected area. Further, mass, volume, density, and porosity of white and pink garlic cloves have been explored (Masoumi et al., 2006). Dimensions, shape index, surface area, volume, density, frictional angle, crushing load, and coefficient of static friction have also been determined for the Egyptian Baladi garlic variety (Bahnasawy, 2007). ...
... The increase in the volume of fine solids after inserting the garlic bulbs was indicated as true volume (TV). The bulk density (BD) of garlic bulbs was estimated using the relationship mentioned (Masoumi et al., 2006). The porosity of garlic bulbs was measured using Eq. ...
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Physicochemical properties, pungency, anti-nutritional factors, cutting strength, and colour attributes of seven promising garlic varieties were assessed for their potential application. The garlic varieties were found to be slightly acidic (pH 6.08-6.77), and contained varying amounts of crude protein, carbohydrate, crude fat, ash, crude fibre, acidity, and total soluble solids (TSS). The pungency factor as pyruvic acid was found to be in the range of 34.84-86.69 μmol/mL, whereas anti-nutritional factors such as saponin (6.63-13.98 g), phytic acid (0.03-0.6 g), and tannin (0.18-0.39 gCE) per 100 g on a fresh weight basis were present. The Bhima purple (BP) variety with a purple tinge showed higher saponin content than the other varieties with a whitish tinge. The cutting strength of garlic cloves varied between 17.20 and 104.61 N. Physical and gravimetric properties were estimated and found to be variety-dependent (p ≤ 0.05). Colour attributes like L* (lightness), a* (redness), b* (yellowness), chroma, hue, and browning index were significantly different (p ≤ 0.05) for all the garlic varieties. The minimum hue value, and maximum a* and b* values, browning index (BI), and chroma were found in the BP variety. Principal component analysis as a significant multivariate analysis tool was applied to assess the existence of correlation among the estimated parameters. It was found to be 75.41% of the total variance when considering the first three principals. Haryana garlic-17 (HG-17) variety showed significant quality as it yielded positive correlation with the maximum number of quality attributes.
... It is defined as the percentage of voids of an unconsolidated mass of materials. It is often needed in airflow and heat flow studies as well as other applications (Masoumi et al., 2006) [16] . The porosity ranged 62.81-70.99% for a blanched sample and ranged% for the unblanched sample. ...
... It is defined as the percentage of voids of an unconsolidated mass of materials. It is often needed in airflow and heat flow studies as well as other applications (Masoumi et al., 2006) [16] . The porosity ranged 62.81-70.99% for a blanched sample and ranged% for the unblanched sample. ...
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The paper aims to develop a dryer that never subjects the food product to shear force and damaging temperature. The study showed that dehydrated potato products obtained using hot air dryers have a pronounced tendency to discolor to a grayish brown. Therefore, the present study aims to develop and evaluate a pilot-scale refractance based system for dehydration of potato. The prototype was developed in Pilot plant, Department of Processing and Food Engineering, PAU and evaluated by drying potato puree. The minimally processed potatoes were unblanched and hot water blanched for different blanching times (3, 4, and 5min) and immersed in a 0.2% potassium metabisuphate (KMS) solution for 15 min. After pretreatment, the potatoes were processed into a puree and a known amount of distilled water was added to the puree to achieve desired Total soluble solid (TSS) levels i.e. 8, 10, and 12ºBrix. The drying experiments were carried out at varying temperatures 70, 80, and 90 ºC. It was observed that the physical properties of potato flakes were significantly affected by TSS, blanching time, and drying temperature (p<0.05). It was observed that the developed prototype when used for drying potato puree maintained better quality potato flakes.
... Manjunatha et al. (2008) [10] determined engineering properties of garlic to design specific crop production and processing equipment like planting, handling, storing, aeration, drying, bulb breaking, peeling of garlic. Masoumi et al. (2006) [11] also studied physical attributes of garlic for development of new methods of sowing, new equipment for processing and control strategies for crop storage. Knowledge of frictional properties of rhizomes is needed for the design of handling equipment. ...
... Manjunatha et al. (2008) [10] determined engineering properties of garlic to design specific crop production and processing equipment like planting, handling, storing, aeration, drying, bulb breaking, peeling of garlic. Masoumi et al. (2006) [11] also studied physical attributes of garlic for development of new methods of sowing, new equipment for processing and control strategies for crop storage. Knowledge of frictional properties of rhizomes is needed for the design of handling equipment. ...
Article
Full-text available
The biometric and engineering properties which are relevant to the study were measured for turmeric rhizome (Curcuma longa Linn.). The biometric properties viz., number of leaves, height of pant, depth of rhizome, plant density, spacing, soil rhizome composite, rhizome weight, rhizome fingers per hill and weight of rhizome with plant and engineering properties which include both physical and frictional properties of turmeric viz., size (length, width and thickness), shape, geometric mean, sphericity, rhizome index, surface area, bulk volume. bulk density, the angle of repose, coefficient of friction, angle of repose and texture (firmness). The mean values observed for biometric properties such as number of leaves, height of pant, depth of rhizome, plant density, spacing, soil rhizome composite, rhizome weight, rhizome fingers per hill and weight of rhizome with plant were 9.20, 39.50 cm, 18.15 cm, 10.60, 23.90 cm, 18.60 cm, 0.61 kg, 8.20 and 1.39 kg, respectively. The mean values for obtained for engineering properties of size (length, width and thickness), geometric mean, sphericity, rhizome index, surface area, bulk volume, bulk density, the angle of repose, coefficient of friction, angle of repose and texture (firmness) were (13.83, 10.12, 3.56 cm), 7.83 cm, 0.57, 39.95, 195.20 cm 2 , 194.20 m 3 , 481.63 kg m-3 , 31.69 deg, 0.57 (stainless steel), 0.75 (plywood), 0.60 (GI) and 67.83 N, respectively. These properties were which plays an important role in the selection of the proper design components of the root crop harvester and are essential in the design and development of the digging unit and soil separator unit of the root crop harvester.
... United States developed a garlic clove planter allowed garlic to be planted upright with its blunt root part pointing down toward the ground giving effective germination after planting. A roller-type metering system containing a seed hopper, an electric motor-driven vertical roller-type seed plate, and a seed counter also effectively reducing the cost of sowing [6]. The performance of a developed garlic planter evaluated in Uttar Pradesh, India, whose field capacity and field efficiency at forward speed of 1.8 km/h were 0.018 ha/h and 78%, respectively [7]. ...
Article
The study focuses on the development and performance assessment of a garlic planter, conducted at the Swami Vivekanand College of Agricultural Engineering and Technology & Research Station, Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh. The evaluation considered various parameters, including miss index, multiple index, quality of feed index, field capacity, emergence rate index, percentage emergence, and yield attributing characteristics etc. The findings contribute to enhancing garlic cultivation practices, potentially boosting productivity and efficiency in the field.
... The moisture content affects the design of storage systems to prevent mold and decay. Masoumi et al., [2] compared some physical properties of two common types of Iranian garlic cloves (white and pink) and it was observed that at different moisture range from 34.9% to 56.7% (wet basis), the bulk density, true density and porosity of cloves were significantly affected by moisture content (p < 0.01). Bakhtiari [3] observed that increasing moisture content from 35.8% to 60.5% w.b. ...
Article
Garlic, a globally cherished spice from the Allium Sativum L. family, holds immense importance in Indian agriculture as the second-largest producer worldwide. With India contributing 10.4% to the global garlic production, totaling 3.27 million metric tons in 2022, the physical properties of garlic become integral in engineering design. This research navigates through experiments on garlic clove bulk density, considering moisture levels, and explores the mechanical aspects affecting agricultural and machinery applications. Moisture content considerations for storage, odor/flavor impact, and even the friction coefficient concerning bulb size underscore the complexity of garlic's engineering dynamics. By unraveling these properties, this study aims to fuel advancements in cultivation practices, machinery design, and processing technologies, enhancing efficiency and product quality in the agricultural and food engineering sectors.
... The capacity of man power is very low about 0.05 ha/man/day, and the cost for manpower planting is 11.9% of total cost of production. Masoumi et al. (2006) compared some physical properties of two common types of Iranian garlic cloves (white and pink). Results of their study showed that at different moisture range from 34.9% to 56.7% wb, the bulk density, true density and porosity of cloves were significantly affected by moisture content (p < 0.01). ...
Article
This study was conducted to investigate the physical and mechanical properties of garlic cloves (Allium sativum L.). Garlic variety of G-282 was selected for the study to develop cup type clove metering mechanism for battery operated garlic clove planter. Knowledge of physical properties of garlic clove are very important for development of machinery. Hence, study was conducted to determine physical properties of garlic variety of G-282. The average length, width, thickness, geometric and arithmetic mean diameter of garlic cloves were 27.80, 12.73, 9.45, 14.96 mm and 16.66 mm2, respectively. The average of the bulk density, sphericity, aspect ratio and surface area of garlic cloves were 481.74 kg/m3, 0.52, 0.46 and 702.71 mm2, respectively. The average moisture content (wb), angle of repose and coefficient of static friction were 49.03%, 41.37° and 0.32, respectively. These physical and mechanical properties of garlic are very essential for designing a garlic clove metering mechanism as well as garlic planter.
... (Table 1). [4,7] for the whole garlic segments. Design and Development of small scale garlic peeler Based on the above calculated engineering properties, a small scale garlic peeler was designed using AutoCAD software and later on fabricated in the departmental laboratory using low cost and easily available material in the market. ...
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Background Garlic is an important condiment and cash crop in Ethiopia. Low yield and productivity of the crop are the major characteristics of the crop in the country. Many factors affect the productivity of the crop in the country, however poor agronomic practices, especially the use of low-yielding varieties and inappropriate spacing, are the major ones. Objective The aim of this study is to evaluate the growth and yield response of garlic to intra-row spacing and variety, and to identify the optimum intra-row spacing and high-yielding variety. Methods The field experiment was composed of three garlic varieties vis-a-vis Tsedey 92, Bishoftu Netch and Local and four levels of intra-row spacing with 5cm, 7.5cm, 10cm and 12.5 cm laid out in a Randomized Complete Block Design replicated three times. Data pertaining growth, yield and yield-related parameters were collected and analyzed using Genstat software. Results Main effects of variety and intra-row spacing significantly(p≤0.05) affected days to maturity, plant height, leaf number, leaf length, leaf width, bulb length, bulb diameter, clove number per bulb, mean bulb weight, and clove diameter. Interaction effects of variety and intra-row spacing significantly (p≤0.05) influenced clove length, fresh biomass yield, dry biomass yield, marketable cloves per bulb, marketable, unmarketable and total bulb yield. The highest total bulb yield of 8.98 tha ⁻¹ was obtained from treatment combination of variety Tsedey 92 and 5cm intra-row spacing although at par with treatment combinations of Bishoftu Netch variety and 5cm intra-row spacing which gave 8.70 tha ⁻¹ while the lowest (5.37 tha ⁻¹ ) was obtained at treatment combinations of local variety and intra-spacing of 12.5cm. The highest (8.05 tha ⁻¹ ) and lowest (4.94 tha ⁻¹ ) marketable bulb yield of garlic were obtained at treatment combinations of variety Tsedey 92 planted with 5cm intra-row spacing and local variety planted with 12.5cm, respectively. Conclusion Tsedey 92 variety together with an intra-row spacing of 5cm could be suggested for high total and marketable bulb yield in the study area.
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Terminal velocities in air of corn, soybeans, wheat, oats, and barley were measured. The actual terminal velocities of the grains were found to be related to the theoretical terminal velocities of the grains by one of two dimensionless geometric shape factors. Based on the shape factors and the theoretical values, the terminal velocity of the five seed grains can be predicted. The maximum error of prediction was 15.7%.
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Physical dproperties of sunflower seeds and kernels were evaluated as a function of moisture content. At 6·2% m.c.d.b., the average length, width, thickness and unit mass of the seed were 9·52mm, 5·12mm, 3·27mm and 0·049g respectively. Corresponding values for the kernel were 8·28mm, 4·09mm, 2·43mm and 0·034g. The mean equivalent diameter and sphericity of the seed were 5·39mm and 0·57 respectively, while corresponding values for the kernel were 4·32mm and 0·53. In the moisture range from 4-20% d.b., the bulk density of the rewetted seed decreased from 462 to 434 kg/m3, true density increased from 706 to 765kg/m3, porosity increased from 34·3 to 43·3% and terminal velocity increased from 5·8 to 7·6m /s. For the kernel the corresponding values changed from 574 to 628kg/m3, 1050 to 1250kg/m3, 45·4 to 50·2% and 3·5-5·8 m/s. In the same moisture range the static coefficient of friction varied from 0·40 to 0·58 for seed and from 0·43 to 0·81 for kernel on different surfaces, while the angle of respose varied from 34 to 41° for seed and 27 to 38° for kernel.
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Dielectric properties of garlic were measured at 2450 MHz at moisture contents varying from 6% to 185% (dry basis) and at temperatures ranging between 35°C and 75°C, using the Resonant cavity perturbation technique. Both dielectric constant and loss factor were found to be directly proportional to the moisture content. The relationship of the dielectric constant as well as loss factor was found to be linear with temperature. Predictive models of the dielectric properties as functions of moisture content and temperature were developed using response surface methodology. Moisture content affected the penetration depth of microwaves significantly.
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The response surface methodology (RSM) was used to derive an optimum drying condition for garlic drying. The responses analyzed were L* value and Optical Index (OI) as a measure of color and rehydration ratio (RR) as well as final moisture content (Mf) which are important quality attributes of dehydrated products. L*, OI, RR and Mf varied from 70.6 to 85.0, 72.0 to 191.1, 2.2 to 3.2 and 5.4 to 10.2 % MC, respectively. An analysis of variance (ANOVA) revealed that drying temperature and slice thickness significantly (90% confidence level) affected L*, OI and RR while no effect was observed for airflow rate and relative humidity (RH). An optimum drying temperature of 70°C for drying 2 mm garlic slices is recommended.
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Drying characteristics of garlic including moisture sorption equilibrium, drying kinetics and pungency losses were investigated. Adsorption and desorption isotherms at 25, 45 and 65 °C were determined and correlated with a four parameter equation. The influence of temperature on adsorption was negligible and some hysteresis effect was observed. Air drying experiments and a diffusive model taking into account the internal and external resistances to mass transfer were used to evaluate effective diffusivity and energy of activation for diffusion. The effective diffusivity increased with temperature, ranging from 1.54 to 3.45 10−10 m2/s in the wet zone and from 0.34 to 0.58 10−10 m2/s in the dry zone. The effect of air velocity, air relative humidity and sample thickness on drying kinetics was also studied. Changes in garlic flavor or pungency during dehydration as a function of temperature, based on determination of pyruvic acid, was measured and modeled as a first-order reaction. At higher temperatures the enzymatic pyruvic acid decreased faster than the total pyruvic acid.
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Garlic (Allium sativum L) is becoming increasingly popular as an important component in the culinary vocabulary of the cooks in this country. Humans are known to have consumed garlic for many millennia as a cure for a wide variety of different conditions. Its volatile components are reputed to have antithrombotic, antimicrobial, free radical scavenger activity associated with them. Its mythical medicinal properties are now being studied scientifically and some of the claims have been proven to be correct. Ten years ago garlic would have been difficult to obtain except in the speciality health shops or ethnic supermarkets: now it is freely available everywhere.
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The proximate composition of garlic (cv. Early Californian) was determined and compared to values reported in the literature. The specific heat and thermal conductivity were determined using the method of mixtures and a modified Fitch apparatus, respectively and both approaches proved sufficiently accurate for such purposes. An analysis of variance revealed that moisture content had a highly significant effect on both specific heat and thermal conductivity of garlic. A linear empirical model was developed to characterise the specific heat as a function of moisture content. The model predictions were very close to values predicted on the basis of the proximate analysis. The measured thermal conductivity data were fitted to parallel, perpendicular and random structural models as weU as empirical mathematical expressions. The parallel and exponential models gave satisfactory agreement with the data.
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The bulk density of garlic slices at different moisture levels (ranging from approximately 3 to 65% MC wet basis) was determined by weighing the contents of a container of known volume. The porosity was calculated using its relationship with bulk and apparent densities. An analysis of variance (ANOVA) revealed that bulk density and porosity were affected significantly by moisture and slice thickness as well as the interaction of these variables. Bulk density varied in a positive linear fashion with moisture and thickness while a negative linear correlation was found for the calculated bulk porosity. The linear model met the adequacy criterion for characterising the behaviour of garlic. Using a laboratory unit, the vertical resistance to airflow through the product and the effect of misture and slice thickness were investigated for an airflow rates of 0.09 to 1.2 m3/s-m2. A higher resistance to airflow was noted for the wet product with the experimental data fitting to Shedd's model when the aifflow range was divided into two sub-flow rates and to a modified Ergun's equation for the full range.
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Makhana is the popped expanded kernel of the gorgon nut (Euryale ferox) and is used as a delicious food in India. Presently, it is sorted, graded and used as an ingredient of various ready-to-eat products. High volumetric expansion of makhana increases transport cost and makes it too expensive in distant places. Makhana thus requires further processing to get some value-added products of minimum volume. To develop any kind of product and mechanized system for their production, physical properties are required. Furthermore, since makhana is a seasonal and regional crop its storage conditions are also needed for keeping it appropriately at processing centres. Physical properties of makhana at moisture contents ranging from 5 to 20% (dry basis) and equilibrium moisture content at relative humidities ranging from 11·2 to 88% at temperature 30°C were determined using standard techniques. Physical properties were found to be: test weight (weight of 1000 makhana) 286 to 384 g; bulk density 56·5–84·6 kg/m3; particle density 105–240·6 kg/m3; porosity 29·4–48·9%; angle of repose 33–35·6°; and static coefficient of friction 0·596–0·82 and 0·493–0·684 on galvanized iron and stainless steel, respectively. The equilibrium moisture content of makhana was found to be between 11·5 and 58·9% (dry basis) within the ranges of variables studied.