JOURNAL OF FOOD RESEARCH AND TECHNOLOGY
Journal homepage: www.jakraya.com/journa/jfrt
ORIGINAL ARTICLE
Studies on Physical Properties of Orange Fruit
Dhineshkumar V1 and Siddharth M2
1
2
Research Scholar, Associate Professor, College of Food and Dairy Technology, TANUVAS, Chennai-600052,
India.
Abstract
*Corresponding Author:
Dhineshkumar V
Email: [email protected]
Received: 17/10/2015
Revised: 22/12/2015
Accepted: 24/12/2015
Orange is among the popular fruits and of a high economical value.
Sizing and grading of orange is needed for the fruit to be presented to local
and foreign markets. A study of orange physical properties is therefore
essential. Some physical properties of grade one (large), two (medium) and
three (small) oranges were investigated. These properties included:
dimensions, mass, volume, surface area, porosity and coefficient of static
friction. The major, intermediate and minor diameters of the grade two
orange were, 87.4 and 76.91 mm, respectively. Volume and mass of the
grade two orange were 270.8 cm3 and 213.28 g, respectively. As for grade
two orange piles, the bulk density and fruit density were respectively
calculated as 0.36 and 1.03 g cm-3. Porosity of grade one, two and three
oranges was 44.64, 49.39 and 51.2%, with their sphericity being 0.937,
0.933 and 0.923, respectively. The static angle of friction of grade two
orange on galvanized, glass and plywood surfaces was found to be 26.4,
22.6 and 24.6, respectively. The three classes of oranges were significantly
different from each other regarding their physical properties. Orange mass
was determined through a polynomial function of third degree involving the
average diameter of the orange.
Keywords: Physical properties, Orange, Static angle of friction,
Coefficient of friction, Bulk density.
1. Introduction
Citrus is of high importance in agriculture
nowadays and a substantial source of income for the
producing countries. Among citrus fruits, orange is the
more important one economically and industrially. It is
consumed in different forms such as fresh fruit,
concentrated juice or thin dried slices. Citrus oil, as
well as essence with medicinal uses, is extracted from
its rind and seeds. Physical specifications of
agricultural products constitute the most important
parameters needed in the design of grading, transfer,
processing, and packaging systems. Physical
specifications, mechanical, electrical, thermal, light,
acoustic and chemical properties are among properties
of useful engineering applications. The determination
of physical properties of agricultural materials is
important to design machines and processes for
harvesting, handling and storage of these materials and
requires understanding for converting these materials
into food and feed. For horticultural materials (fruits,
vegetables, grapes), dimensions (length, diameter,
thickness) are widely used properties to describe them.
Fruit physical dimensions, particularly shape, are very
important in sorting and sizing, and determine how
many fruits can be placed in shipping containers or
plastic bags of a given size (Keramat Jahromi et al.,
2008). Fruit skin colour is an attribute that determines
consumer’s behavior and it is accepted as one of the
most important external quality parameters (Ercisli et
al., 2007). Fruit volume, shape and density are
important to design fluid velocities for transportation
(Mohsenin, 1986). On the other hand, knowledge of
frictional properties of fruits is needed for design of
handling equipment (Mohsenin, 1986).
The physical properties of orange fruit can be
important for design of equipments for processing,
transportation, sorting, separating and also packing.
Currently used system has been designed without
taking these criteria into consideration, the resulting
designs lead to inadequate applications. This results in
a reduction in work efficiency, an increase in product
loss. Therefore, determination and consideration of
these criteria have an important role in designing of
this equipment’s. There is not enough published work
relating to physical properties of orange. The objective
of this study was to determine the physical properties
Journal of Food Research and Technology | October-December, 2015 | Vol 3 | Issue 4 | Pages 125-130
© 2015 Jakraya Publications (P) Ltd
Dhineshkumar and Siddharth…Studies on Physical Properties of Orange Fruit
of orange fruits, so that the knowledge gained will be
used in design and development of equipments for
cleaning, grading, dehydration, storage and handling.
get the 1000 fruits weight. This was also applied by
Tavakoli et al. (2009) for barley grains and
Gharibzahedi et al. (2010) for pine nut.
2. Materials and Methods
2.1.4 Surface Area and Volume
The surface area and volume of orange fruit
were calculated based on the geometric mean diameter
(GMD) using following equations:
Fresh orange fruits from the Koyambed Market
of Chennai District were purchased to determine the
engineering properties. The physical properties
determined were size, shape, bulk density, true density,
porosity, angle of repose, surface area and coefficient
of friction. The standard methods were adopted for
estimating these engineering parameters which are
described below.
2.1 Dimensions of Orange
Orange fruit were randomly chosen for
measuring dimensions. Length, width and thickness of
each fruit were measured using Vernier caliper (least
count 0.01 cm). Hundred observations were made to
get average values of length, width and thickness of the
orange fruits.
…(4)
…(5)
2.1.5 Radius of Curvature
This is an important property needed for the
design of conveyors and chutes. It determines the
rollability of objects. The minimum radius of curvature
(Rmin) and maximum radius of curvature (Rmax) were
calculated using the followings:
2.1.1 Geometric Mean Diameter (GMD)
The geometric mean diameter for the 100 fruits
was determined using the measured geometric
dimensions of length (L), width (W) and thickness (T)
in the following equation (Mohsenin, 1986).
…(1)
2.1.2 Sphericity
Sphericity (S) is defined as the ratio of the
surface area of a sphere having the same volume as the
fruit to the surface area of the fruit. The shape of a food
material is usually expressed in terms of its sphericity.
It is an important property used in fluid flow and heat
and mass transfer calculations. Sphericity was
determined using the measured geometric dimensions
in the formula.
…(2)
In order to gather more information about the shape of
the fruit, aspect ratio (R) of the fruit was determined
from the following relationship:
…(6)
…(7)
Where, H is the average of thickness and length (mm).
2.1.6 Angle of Repose
Angle of repose is an important physical
property for the design of processing, storage, and
conveying systems of particulate materials. When the
materials are smooth and rounded, the angle of repose
is low. For sticky and fine materials the angle of repose
is high. Angle of repose therefore indicates the
cohesion amongst the individual units of the materials.
It was determined using a bottomless cylinder (10 cm
diameter, 15 cm height) which was also applied by
Taser et al. (2005). The cylinder was placed over a
smooth surface and orange fruits were filled in the
cylinder was raise slowly permitting the sample to flow
down and form a natural slope. The height (H) and
diameter (D) of the heap were measured and the
dynamic angle of repose calculated as follows.
…(8)
…(3)
2.1.3 1000 Kernel Weight (TKW)
The mass of 100 fruits were weighed on a top
loading electronic balance (EK 5350) with a resolution
of 0.01g and the resultant weight multiplied by 10 to
2.1.7 Bulk Density
Bulk density which is defined as the ratio of the
mass of the sample to its container volume was
Journal of Food Research and Technology | October-December, 2015 | Vol 3 | Issue 4 | Pages 125-130
© 2015 Jakraya Publications (P) Ltd
126
Dhineshkumar and Siddharth…Studies on Physical Properties of Orange Fruit
evaluated by weighing an orange fruit filled beaker of
known weight and volume (Baryeh, 2000).
…(9)
Where ρb (g/cm3) is bulk density, mass m (g) of
sample.
2.1.8 True Density
This is the ratio of mass of sample to its pure
volume. For orange fruit, true density was determined
by the water displacement method (Abdullah, 2011).
3
ρt = Mass of individual fruit (kg)/ Mass of individual fruit (m )
…(10)
This is the ratio of force needed to start sliding
the sample over a surface by the weight of the sample.
The coefficient of static friction was determined on
four different structural surfaces, namely plywood,
galvanized steel sheet, rubber and glass. Each fruit was
placed on the surface and raised gradually by screw
until the fruit begin to slide. The angle that the inclined
surface makes with the horizontal when sliding begins
was measured. The coefficient of static friction (μs)
was calculated using the following expression.
…(12)
Where θ = angle that the incline makes with the
horizontal when sliding begins.
3. Results and Discussion
2.1.9 Porosity
Porosity is a vital physical property that
characterizes the amount of air spaces in a bulk. It is
needed in modeling and design of various heat and
mass transfer processes. It is defined as the volume
fraction of air in the bulk sample and is calculated as;
…(11)
2.1.10 Coefficient of Static Friction
3.1
Some Dimensional and
Attributes of Orange Fruit
The physical properties such as major, minor,
and intermediate diameter, mass, volume, bulk density,
true density, geometric mean, porosity, sphericity, and
rolling frictional properties of Orange fruit are given in
Table 1. The mean lengths of the grade one (large), two
(medium) and three (small) oranges were 87.4, 83.03
and 76.91 mm, and for the mean width were 82.01,
74.29 and 69.52 mm, respectively. As observed from
Table 1, the mean thickness values of grade one, two
and three oranges were 82.01, 74.29 and 69.52 mm, -
Table 1: Physical properties of Orange Fruit Properties Values
Particulars
Large
Medium
Small
87.4
82.01
82.26
54.7×102
58.2×102
60.4×102
270.24
273.56
84.64
0.937
22.1×103
0.997
0.368
43.62
26.4
26.3
24.7
83.03
74.29
75.54
47.0×102
49.2×102
51.2×102
214.72
213.28
76.26
0.933
17.2×103
1.011
0.434
48.38
22.6
20.4
24.6
76.91
69.52
69.15
37.2×102
41.6×102
43.4×102
165.13
156.74
70.94
0.923
14.2×103
1.036
0.424
50.21
21.3
17.8
24.16
Average
Number of
Observations
a (length) (mm)
b (width) (mm)
c (thickness) (mm)
Pa (mm2)
Pb (mm2)
Pc (mm2)
Fruit mass (g)
Fruit volume cm3
Geometric mean diameter (mm)
Sphericity (%)
Surface area (mm2)
Fruit density (g cm-3)
Porosity (%)
Bulk density (g cm-3)
Co efficient of static friction
Glass Galvanized steel
Plywood
100
100
100
100
25
Frictional
Journal of Food Research and Technology | October-December, 2015 | Vol 3 | Issue 4 | Pages 125-130
© 2015 Jakraya Publications (P) Ltd
127
Dhineshkumar and Siddharth…Studies on Physical Properties of Orange Fruit
Table 2: Analysis of variance as related to graded orange physical probe
Dependent variety
Source
Major diameter (mm)
Error
Total
Intermediate diameter (mm)
Error
Total
Minor diameter (mm)
Error
Total
Fruit density (g cm-3)
Error
Total
Bulk density (g cm-3)
Error
Total
Fruit volume (cm3)
Error
Total
Fruit mass (g)
Error
Total
Sum of squares
3892.85
2372.49
6265.34
5191.75
764.18
5830.04
5090.05
764.18
5854.23
0.008
0.001
0.009
0.003
0.001
0.005
80.5×104
71.9×103
87.7×104
51.1×104
41.3×103
55.3×104
respectively. Also as seen in the same table, the mean
volumes of grade one, two and three oranges were
273.56, 213.28 and 158.74 cm3, respectively.
Bulk density of grade one, two and three (0.368
0.434, 0.424 g cm-3) oranges were found to be lower
than that of varieties Alanya (0.527), Shamouti (0.526),
and Finike (0.515 g cm-3) oranges (Topuz et al., 2005).
Porosity of grade one, two and three oranges was
44.64, 49.39 and 51.2%, respectively.
The static coefficient of friction vales were 26.4,
22.6 and 21.3° for Galvanized iron, 26.3, 20.4 and
17.8° for glass surface and 24.7, 24.6 and 24.16° for
wooden surface. Packing coefficients, as indicated in
Table 1 were 0.31, 0.42, and 0.53 for the three sizes of
grade one, two and three oranges. The figures are lower
as compared with those in the case of Alanya,
Shamouti and Finike varieties with packing coefficients
of 0.62, 0.61, and 0.57 (Topuz et al., 2005). Ratio of
rind to total fruit weight for the grades of one, two and
three fruits was found to be 0.254, 0.256, and 0.251,
respectively. Means of major, intermediate and minor
diameters, specific volume of fruit and of a pile of fruit,
fruit volume and mass of the three grades of orange
were compared and are shown in Table 2. There are
significant differences among them as revealed by
multi range Duncan test at 5% level of probability.
Major, intermediate and minor diameter figures for
grade one orange are higher than those of the grade two
as well as those of the grade three oranges. These
Mean of squares
1946.43
16.14
2595.87
5.20
2545.03
5.20
0.004
0.000
0.002
0.000
40.2×104
11.9×103
25.5×104
68.8×103
F*
120.60
596.90
489.57
35.20
9.32
33.58
37.15
figures are higher for the medium size oranges as
compared with the small ones (Table 1). Density of a
pile of oranges is significantly higher for grade one
oranges in comparison with those of grade two and
three ones, but no difference was observed between the
figures for grade two and three oranges (Table 1). No
difference was observed between either grade one and
two or grade two and three oranges as far as density is
concerned, but the fruit density of grade one oranges
was found to be less than that of the grade three (Table
2). The result showed that Orange fruits were a free
flowing material. It required force to convey the
material. The results and observations are comparable
with the results reported by Owolarafe and Shotonde
(2004) for the physical properties of okro fruit. The
results on the average length, width, thickness, the
geometric mean diameter, unit mass and volume of
gumbo fruits of Sultani and Amasya variety reported
by Akar and Aydin (2005) are comparable with the
methods adopted for the present study.
4. Conclusion
The three classes of oranges vary significantly
from each other regarding their physical properties.
Highest coefficient of friction was on glass surface and
lowest value was on wood surface for orange fruit.
These data will facilitate design equipment and
machinery for this production and damage to products
will be less than before.
Journal of Food Research and Technology | October-December, 2015 | Vol 3 | Issue 4 | Pages 125-130
© 2015 Jakraya Publications (P) Ltd
128
Dhineshkumar and Siddharth…Studies on Physical Properties of Orange Fruit
Acknowledgement
The authors are very grateful to the staff of both
the Food Engineering and Food Science Laboratory of
the College of Food and Dairy Technology, Chennai,
Tamilnadu Veterinary and Animal Sciences University
for their assistance while the experiments lasted.
References
Abdullah MR, Chng PE and Lim TH (2011). Some physical
properties of Parkia speciosa Seeds. International
Conference on Food Engineering and Biotechnology,
IPCBEE, IACSIT Press, Singapore.
Al-Maiman SA and Ahmad D (2002). Changes in physical
and che-mical properties during orange (Punica
granatum L.) fruit maturation. Food Chemistry, 76:
437-441.
Aydin C (2002). Physical properties of hazelnuts. Biosystem
Engineering, 82: 297-303.
Aydin C (2003). Physical properties of almond nut and
kernel. Journal of Food Engineering, 60: 315-320.
Bart-Plange A and Baryeh EA (2003). The physical properties
of Category B cocoa beans. Journal of Food
Engineering, 60: 219-227.
Celik A and Ercisli S (2008). Persimmon cv. Hachiya
(Diospyroskaki Thunb.) fruit: some physical, chemical
and nutritionalproperties. International Journal of Food
Science and Nutrition, 59(7): 599-606.
Celik A, Ercisli S and Turgut N (2007). Some physical,
pomo-logical and nutritional properties of kiwifruit cv.
Hayward. International Journal of Food Science and
Nutrition, 58: 411-418.
Dursun E and Dursun I (2005). Some physical properties of
caper seed. Biosystem Engineering, 92(2): 237-245.
Ercan N, Ozvardar S, Gonulsen N, Baldiran E, Onal K and
Karabiyik N (1992). Determination of suitable
Orangecultivars for Aegean region (in Turkish).
Proceedings of 1st National Horticulture Congress,
October 13-16, Izmir, Turkey.
Ercisli S (2004). A short review of the fruit germplasm
resources of Turkey. Genetic Resources and Crop
Evolution, 51: 419-435.
Ercisli S, Orhan E, Ozdemir O and Sengul M (2007). The
genotypic effects on the chemical composition and
antioxi-dant activity of sea buckthorn (Hippophae
rhamnoides L.) berries grown in Turkey. Scientia
Hoticulturae, 115(1): 27-33.
Fadavi A, Barzegar M, Azizi MH and Bayat M (2005).
Physicochemical composition of ten Orange cultivars
(Punica granatum L.) grown in Iran. Food Science and
Technology International, 11: 113-119.
Fathollahzadeh H and Rajabipour A (2008). Some mechanical
properties of barberry. International Agrophysics, 22:
299-302.
Ghasemi Varnamkhasti M, Mobli H, Jafari A, Keyhani AR,
Heidari Soltanabadi M, Rafiee S and Kheiralipour K
(2008). Some physical properties of rough rice (Oryza
Sativa L.) grain. Journal of Cereal Science, 47: 496501.
Jain RK and Bal S (1997). Properties of pearl millet. Journal
of Agricultural Engineering Research, 66: 85-91.
Kabas O, Ozmerzi A and Akinci I (2006). Physical properties
of cactus pear (Opuntia ficusindica L.). Journal of Food
Engineering, 73: 198-202.
Kazankaya A, Gundogdu M, Askin MA and Muradoglu F
(2003). Fruit attributes of local oranges grown in
Pervari (in Turkish). Proceedings of 4th National
Horticulture Congress, September 8-12, Antalya,
Turkey.
Keramat Jahromi M, Rafiee S, Jafari A, Ghasemi BMR,
Mirasheh R and Mohtasebi SS (2008). Some physical
proper-ties of date fruit (cv. Dairi). International Agro
Physics, 22: 221-224.
Kingsly ARP, Singh DB, Manikantan MR and Jain RK
(2006). Moisture dependent physical properties of dried
pome-granate seeds (Anardana). Journal Food
Engineering, 75: 492-496.
Lorestani AN and Tabatabaeefar A (2006). Modeling the
mass of Kiwi fruit by geometrical attributes.
International AgroPhysics, 20: 135-139.
Mars M (1996). Orange genetic resources in the Meditaerranean region. Proceedings of 1st MESFIN Plant
Genetic Resources Meet, October 2-4, 1995, Tenerife,
Spain.
Marvin JP, Hyde GM and Cavalieri RP (1987). Modeling
potato tuber mass with tuber dimensions. Transactions
of ASAE, 30: 1154-1159.
Meisami-asl E, Rafiee S, Keyhani A and Tabatabaeefar A
(2009). Some physical properties of apple cv. ‘Golab’.
Agricultural Engineering International: the CIGR
Ejournal, Volume XI.
Mirzaee E, Rafiee S, Keyhani AR, Emamjomeh Z and
Kheiralipour K (2008). Mass modeling of two varieties
of apricot (Prunus armenaica L.) with some physical
Characteristics. Journal of Plant Omics, 1: 37-43.
Mohsenin NN (1986). Physical properties of plant and animal
materials. Gorden and Breach Science Publishers, New
York, USA.
Nimkar MP and Chattopadhyay KP (2001). Some
physicalproperties of green gram. Journal of
Agricultural Engineering Research, 80: 183-189.
Ozguven F and Vursavus K (2005). Some physical,
mechanical and aerodynamic properties of pine (Pinus
pinea) nuts. Journal of Food Engineering, 68: 191-196.
Ozkan Y (2005). Investigations on physical and chemical
characteristics of some Orange genotypes (Punica
granatum L.) of Tokat province in Turkey. Asian
Journal of Chemistry, 17: 939-942.
Paksoy M and Aydin C (2004). Some physical properties of
edible squash seeds. Journal of Food Engineering, 65:
225-231.
Perkins-Veazie P (1992). Physiological changes during
ripeningof raspberry fruit. Horticulture Science, 27:
331-333.
Poyrazoglu E, Gokmen V and Artik N (2002). Organic
acidsand phenolic compounds in Oranges (Punica
granatum L.) grown in Turkey. Journal of Food
Composition and Analysis, 15: 567-575.
Tavakoli M, Tavakoli H and Ahmadi H (2009). Moisturedependent physical properties of barley grains.
Journal of Food Research and Technology | October-December, 2015 | Vol 3 | Issue 4 | Pages 125-130
© 2015 Jakraya Publications (P) Ltd
129
Dhineshkumar and Siddharth…Studies on Physical Properties of Orange Fruit
International Journal of Agricultural and Biological
Engineering, 2: 341-350.
Taser OF, Altuntas E and Ozgoz E (2005). Physical properties
of hungarian and common vetch seeds. Journal of
Applied Science, 5: 323-326.
Gharibzahedi S, Etemad V and Foshat M (2010). Moisture
dependent engineering properties of black cumin seed.
Agricultural Engineering International: the CIGR
Ejournal.
Tibet H and Onur C (1999). Adaptation of Orange (Punica
granatum L.) cultivars in Antalya region (in Turkish).
Proceedings of 3rd National Horticulture Congress,
September 14-17, Ankara, Turkey.
Topuz A, Topakci M, Canakci M, Akinci I and Ozdemir F
(2005). Physical and nutritional properties of four
orange varieties. Journal of Food Engineering, 66: 519523.
Vursavus K, Kelebek H and Selli S (2006). A study on some
chemi-cal and physico-mechanic properties of three
sweet cherry va-rieties (Prunu savium L.) in Turkey.
Journal of Food Engineering, 74: 568-575.
Yilmaz H, Sen B and Yildiz A (1992). Regional adaptation
ofOranges selected from Mediterranean region (in
Turkish). Proceedings of 1st National Horticultural
Congress, October 13-16, Izmir, Turkey.
Journal of Food Research and Technology | October-December, 2015 | Vol 3 | Issue 4 | Pages 125-130
© 2015 Jakraya Publications (P) Ltd
130