Working PaperPDF Available

Figures

Content may be subject to copyright.
Acta Agroph., 2017, 24(2), 217-223
DETERMINATION OF SOME PHYSICAL PROPERTIES
OF DATE PALM FRUITS (CV. KHADRAWY AND MEDJOOL)
Manoj Kumar Mahawar1, Kirti Jalgaonkar1, Mukesh Kumar2, Vijay Singh Meena1,
Bharat Bhushan1
1Horticultural Processing Division, ICAR – Central Institute of Post-Harvest Engineering & Technology
Abohar, Punjab-152116, India
2College of Agricultural Engineering and Technology, HAU Hisar, Haryana, India
e-mail: manojmahawar362@gmail.com
A b s t r a c t. The present investigation was carried out to evaluate some physical properties of date
palm fruits cv. Khadrawy and Medjool. Pulp moisture content, seed moisture content, fruit dimen-
sions (Major and minor intercept), arithmetic mean diameter, geometric mean diameter, sphericity,
colour values (L, a, b), bulk density, true density, porosity and coefcient of static friction were
determined for both the varieties. The determined properties had signicant difference in their values
which may be due to the distinctive features of both the varieties.
K e y w o r d s: date palm, physical properties, Khadrawy, Medjool
INTRODUCTION
Date palm (Phoenix dactylifera L.) is one of the oldest fruit crops of the arid regions of
Arabian Peninsula, North Africa and the Middle East. They are considered to be a major
source of income as well as staple food for the local population in the countries where
they are cultivated (Chao and Krueger, 2007). Dates contain dietary bre, pectin, tannins,
some vitamins, minerals, low quantities of organic acids, with very little or no starch, and
a number of antioxidant anti-mutagenic compounds (Biglari et al. 2008). Because of its
nutritional properties, date fruit as such can have an extensive range of applications, but
at present the processing applications are very limited (Kamal-Eldin et al. 2012).
The knowledge of some important physical properties such as spatial dimensions,
bulk density, true density, and porosity of different fruits/vegetables/grains is essential for
the design of storage structures, processing equipments, and processes (Vishwakarma et
al. 2012). Linear dimensions and colour values are required especially for the design
of equipments related to sorting and grading. Estimation of bulk density is required to
M.K. MAHAWAR et al.
218
determine the capacity of storage and transport, while the true density is useful to design
proper separation equipment. Porosity of the fruit mass determines the resistance to air-
ow during aeration and drying operations. Information about the frictional properties is
essential to understand the behaviour of the fruits during handling operations and for the
design of handling equipments (Jahromi et al. 2008). Varietal difference of fruits is also
one of the prominent reasons for having deviations in physical properties.
There are plentiful studies which include the determination of physical properties of
different fruits with varietal differences. Few among them include ve date cultivars, viz.
Gash Gaafar, Gash Habash, Shahla, Bushibal and Lulu (Al- Hooti et al. 1997), mango cv.
Dashehari (Jha et al. 2006), three sweet cherry varieties (Prunus avium L.) (Vursavus et
al. 2006), guna fruits (Aviara et al. 2007), date fruit cv. Lasht (Jahromi et al. 2007), date
fruit cv. Dairi (Jahromi et al. 2008) and wild mango cv. Irvingia gabonensis and wombo-
lu (Ehiem and Simonyan, 2012). However, information involving the determination of
physical properties of date palm fruits cv. Khadrawy and Medjool has not been reported.
Therefore, the objective was framed accordingly to investigate some physical properties
of date palm fruits cv. Khadrawy and Medjool. The properties, viz., pulp moisture con-
tent, seed moisture content, fruit linear dimensions (length, width, thickness), arithmetic
mean diameter, geometric mean diameter, sphericity, colour values (L, a, b), bulk density,
true density, porosity and coefcient of static friction were determined.
MATERIAL AND METHODS
Fruits of date palm cv. Khadrawy were procured from Regional Research
Station, PAU Ludhiana, Abohar, and fruits of cv. Medjool were procured from the
farm orchard of ICAR-CIPHET, Abohar (Fig 1). The fruits were cleaned before
using for further experimentation.
Fig. 1. Pictorial view of date fruits (Khadrawy and Medjool) – date fruit: (a) cv. Khadrawy; (b) cv. Medjool
DETERMINATION OF SOME PHYSICAL PROPERTIES ... 219
Average size of the randomly selected fruits was determined by measuring three
linear dimensions specied as length (L), width (W) and thickness (T) by digital
vernier callipers (Mitutoyo Corporation, Japan) (least count 0.01mm). Some other
associated parameters like geometric mean diameter (Dp), arithmetic mean diam-
eter (Da) and sphericity (Φs) of the seeds were also calculated using the relationship
given by (Mohsenin 1970).
Dp=(L×W×T)1/
3
(1)
Da=L+W+T
3(2)
Φs=(LW T )1/3
L(3)
Surface area (S) was found by analogy with a sphere of the same geometric
mean diameter, using the following relationship as reported by Altuntases et al.
(2005). It is calculated and represented in mm2.
S=πD2
p
(4)
Bulk density was measured using a wooden box with inside dimensions of
100×100×100 mm. Fruits were poured into the box of known volume, removing
excess fruits by rolling a measuring scale on the rim of the box without compaction.
The weight of the poured box was taken and the procedure was repeated ten times
and average bulk density was calculated by dividing the weight of the poured box
by the volume of the box (Dutta et al. 1988). True density was determined using
the toluene displacement method in which the volume of toluene displaced was
estimated by immersing the weighed quantity of fruits in toluene. Porosity (ε) was
calculated using the relationship given by Vursavus et al. (2006):
ε= 100(1 ρbt)(5)
where, ε is porosity (%), ρb is bulk density (g cm–3) and ρt is true density (g cm–3).
To evaluate the test weight (100 fruits), 100 fruits were selected randomly and
weighed by means of an electronic balance (Goldtech, India) (least count of 0.01 g).
Coefcient of static friction on four different surfaces, namely plywood, mild steel,
stainless steel and cast iron, was measured by the inclined plane method (Singh
and Goswami, 1996). A single fruit was kept on an adjustable tilting plate and the
M.K. MAHAWAR et al.
220
slope was increased gradually. The angle at which the material just started to move
downward was recorded (α). Coefcient of friction was calculated from the follow-
ing relationship given by Dutta et al. (1988):
µ= tan α(6)
Table 1. Some physical properties of date palm fruits (Khadrawy and Medjool)
Parameters Variety
Khadrawy Medjool
Pulp moisture content (% d. b) 78.12 ± 2.37 69.46±1.21
Seed moisture content (% d. b) 42.47 ± 0.66 39.08±0.31
Length (L) mm 41.75 ± 2.41 48.26 ± 2.49
Width(W) mm 19.46 ± 1.08 29.05 ± 1.75
Thickness (T) mm 19.54 ± 1.09 28.80 ±1.56
AMD 26.92 ±1.19 35.37 ±1.41
GMD 1.09 ± 0.063 2.20 ± 0.062
Sphericity 0.60 ± 0.03 0.71 ± 0.024
100 fruits weight (g) 860.45 ± 4.64 2199.6± 13.30
100 fruit pulp weight (g) 685.40 ± 5.25 1717 ± 8.39
100 fruit seed weight (g) 136.60 ± 7.86 213 ± 6.97
Bulk density (g cc–1) 0.56 ± 0.017 0.59 ± 0.014
True density (g cc–1) 0.93 ± 0.02 0.85 ± 0.015
Porosity 0.40 ± 0.01 0.34 ± 0.007
Pulp: fruit 0.890 0.833
Seed: fruit 0.166 0.111
Seed : pulp 0.199 0.124
L 61.3 ± 4.08 61.56 ± 2.81
a 35.57 ± 5.95 34.79 ± 5.74
b 38.87 ± 6.90 30.22 ± 1.68
Coefcient of static friction (Plywood) 0.19 ± 0.04 0.24 ± 0.055
Coefcient of static friction (GI) 0.17 ± 0.02 0.21 ± 0.038
Coefcient of static friction (MS) 0.15 ± 0.05 0.22 ± 0.030
Coefcient of static friction (SS) 0.13 ± 0.06 0.20 ± 0.037
All values are average with 10 replications, with representation (Average value ± S.D)
RESULTS AND DISCUSSION
The moisture content of both pulp and seed of cv. Khadrawy was found to be
higher than that of cv. Medjool. In the case of Khadrawy variety, moisture content (%
d b) of pulp and seed was 78.12±2.37 and 42.47±0.66, respectively, while for Medjool
variety the values for pulp and seed were 69.46±1.21 and 39.08±0.31, respectively.
Three principal dimensions i.e. length, width and thickness of date palm fruits of both
cv. Khadrawy and cv. Medjool were determined. For Medjool variety, average values of L,
W and T were 48.26±2.49 mm, 29.05±1.75 mm and 28.80±1.56, while for cv. Khadrawy
the values were 41.75±2.41mm, 19.46±1.08 mm and 19.54±1.09 mm, respectively.
Arithmetic and geometric mean diameter was found to be 26.92±1.19 mm and 1.09±0.063
for Khadrawy; 35.37±1.41 mm and 2.20 ± 0.062 for Medjool variety, respectively.
DETERMINATION OF SOME PHYSICAL PROPERTIES ... 221
Sphericity of cv. Khadrawy and Medjool was 0.60±0.03 and 0.71±0.024,
respectively. Fruits of date palm cv. Medjool, being larger in size, attained more
roundness, which resulted in higher values of sphericity. 100 fruits weight was
860.45±4.64 g for cv. Khadrawy and 2199.6±13.30 g for Medjool variety. There
was an increase of around 155% in the 100 fruit weight of Medjool variety as
compared to Khadrawy variety. Hundred fruit pulp mass was 685.40±5.25 g and
1717±8.39 g for cv. Khadrawy and Medjool, respectively. This was due to the pro-
portional increase in the size of Medjool fruit as compared to Khadrawy. Hundred
fruit seed mass was 136.60 ± 7.86 g and 213± 6.97 g for cv. Khadrawy and Medjool,
respectively. This increase of about 56% corresponds to the seed mass of Medjool
variety as compared to Khadrawy variety.
Bulk density of fruits of date palm cv. Medjool (0.59±0.014) g cm–3 was slight-
ly higher than of that of cv. Khadrawy (0.56±0.017) g cm–3. True density of cv.
Khadrawy (0.93±0.002) g cm–3 was higher than of cv. Medjool (0.85±0.015) g m–3.
Porosity of date palm fruits decreased from 0.40±0.01 to 0.34±0.007 with Khadrawy
and Medjool date palm, respectively.
Overall values of the coefcient of static friction were the highest for plywood
surface, followed by galvanised iron, mild steel and stainless steel. This is because
of the resistance of that surface for particle to ow due to the roughness of the sur-
face. Values obtained were on the higher side for Medjool variety as compared to
Khadrawy variety.
CONCLUSIONS
This study dealt with measurement of physical properties of two date palm
varieties (Khadrawy and Medjool), contributing knowledge about the changing
behaviour of the determined properties with inherited varietal differences. The val-
ues for axial dimensions with respect to major and minor intercepts of Medjool
variety were substantially higher as compared to Khadrawy variety. Also, the
weight related parameters, i.e. 100 fruit weight, were observed to be higher for cv.
Medjool. Pulp and seed moisture content was higher for cv. Khadrawy as well, as it
has a higher pulp percentage and pulp: fruit ratio. Coefcient of static friction was
found to follow a decreasing trend with the plywood, galvanised iron, mild steel
and stainless steel surfaces, respectively, for both the varieties. The engineering
properties were observed to be signicantly affected by the varietal differences.
Such information may nd applicability in adequate design and development of
equipments pertaining to post harvest technology and processing of these fruits.
M.K. MAHAWAR et al.
222
REFERENCES
Al-Hooti S., Sidhu J.S., Qabazard H., 1997. Physicochemical characteristics of ve date fruit cultivars
grown in the United Arab Emirates. Plant Food Hum. Nutr., 50, 101-113.
Altuntases E.O., Zgo Z.E. Tas-er O.F., 2005. Some physical properties of fenugreek (Trigonella foe-
num-graceum L.) seeds. J. Food Eng., 71, 37-43.
Aviara N.A., Shittu S.K., Haque M.A., 2007. Physical properties of guna fruits relevant in bulk han-
dling and mechanical processing. Int. Agrophys., 21, 7-16.
Biglari F., Al-Karkhi A.F.M., Essa A.M., 2008. Cluster analysis of antioxidant compounds in dates
(Phoenix dactilifera): effect of long-term cold storage. Food Chem., 112, 998-1001.
Chao C.C.T., Krueger R.R., 2007. The date palm (Phoenix dactylifera L.): Overview of biology, uses
and cultivation. Hort. Sci., 42, 1077-1082.
Dutta S.K., Nema V.K., Bhardwaj R.K., 1988. Physical properties of grain. J. Agric. Eng. Res., 39, 259-268.
Ehiem J.C., Simonyan K.J., 2012. Physical properties of wild mango fruit and nut. Int. Agrophys.,
26, 95-98.
Jahromi M.K., Jafari A., Raee S., Keyhani A.R., Mirasheh R., Mohtasebi S.S., 2007. Some physical
properties of date fruit (cv. Lasht). Agril. Eng. Int., Manuscript FP 07 019. Vol. IX.
Jahromi M.K., Raee S., Jafari A., Ghasemi Bousejin M.R., Mirasheh R., Mohtasebi S.S., 2008.
Some physical properties of date fruit. Int. Agrophys., 22 (3), 221-224.
Jha S.N., Kingsly A.R.P., Chopra S., 2006. Physical and mechanical properties of mango during
growth and storage for determination of maturity. J. Food Eng., 72, 73-76.
Kamal-Eldin A., Hashim I.B., Mohamed I.O., 2012. Processing and utilization of palm date fruits for
edible applications. Recent Pat Food, Nutr Agric, 4, 78-86.
Mohsenin N.N., 1970. Physical Properties of plant and animal materials. Gordon and Breach Science
Publishers, New York.
Singh K.K., Goswami K.K., 1996. Physical properties of cumin seed. J. Agric. Eng. Res., 64, 93-98.
Vishwakarma R.K., Shivhare U.S., Nanda S.K., 2012. Physical properties of guar seeds. Food
Bioprocess Technol., 5, 1364-1371.
Vursavus K., Kelebek H., Selli S., 2006. A study on some chemical and physico-mechanic properties
of three sweet cherry varieties (Prunus avium L.) in Turkey. J. Food Eng., 74, 568-575.
OKREŚLENIE NIEKTÓRYCH WŁAŚCIWOŚCI FIZYCZNYCH OWOCÓW
PALMY DAKTYLOWEJ (ODM. KHADRAWY AND MEDJOOL)
Manoj Kumar Mahawar1, Kirti Jalgaonkar1, Mukesh Kumar2, Vijay Singh Meena1,
Bharat Bhushan1
1Wydział Przetwórstwa Produktów Ogrodniczych, ICAR – Centralny Instytut Inżynierii Pożniwnej
i Technologii, Abohar, Punjab-152116, India
2Szkoła Inżynierii Rolniczej i Technologii, HAU Hisar, Haryana, India
e-mail: manojmahawar362@gmail.com
Streszczenie. Przedstawione badania zostały przeprowadzone w celu oceny niektórych właś-
ciwości zycznych owoców palmy daktylowej odmian Khadrawy and Medjool. Dla obydwu odmian
oceniano wilgotność miąższu, wilgotność nasion, wymiary owoców (wielka i mała oś), średnią
DETERMINATION OF SOME PHYSICAL PROPERTIES ... 223
arytmetyczną średnicę, średnią geometryczną średnicę, kołowość, wartości barwy (L, a, b), gęstość
usypową, gęstość rzeczywistą, porowatość i współczynnik tarcia statycznego. Wartości badanych
właściwości wykazywały znaczące różnice międzyodmianowe, które mogły wynikać z cech charak-
terystycznych obydwu odmian.
Słowa kluczowe: palma daktylowa, właściwości zyczne, Khadrawy, Medjool
... Bulk density, ρ b (g cm À3 ) was determined by weight to volume ratio, whereas true density, ρ t (g cm À3 ) using the toluene displacement technique. Using the bulk and true density values, porosity, ε (%) was calculated using the formula given as Equation (1) (Mahawar, Jalgaonkar, Kumar, Meena, & Bhushan, 2017). Geometric mean diameter, D g (mm) and sphericity, S p were determined by considering the spheroid shape of seeds, using Equations (2) and (3) by Raigar and Mishra (2015). ...
Article
Full-text available
Hempseed (Cannabis sativa L.) owing to its excellent nutritional and pharmaceutical potential has resurrected the industrial and scientific community to exploit their processing and utilize for new food products optimization. The design and development of storage, postharvest processing and quality analysis of seeds depend upon the correlation properties with their physical parameters. In this study, the mass of hempseed is predicted as a function of its linear dimensional property, projected area and bulk seed density using linear and nonlinear mathematical models. Various engineering properties of different hempseed grades were investigated at a moisture content of 6.49% (wet basis). The effect of size and density-based grading was also studied on mass modeling and was compared with ungraded hempseed. Results revealed that the mass models developed using graded seeds had more appropriate results (higher R²) than the ungraded ones. Models based on minor dimension (R² 0.939) and third projected area (R² 0.914) within a 5% level of significance were recommended from an economic standpoint to predict hempseed mass with maximum accuracy. Therefore, bulk mass modeling of hempseed based on engineering properties is strongly recommended for the design and development of grading mechanisms. Practical Application The growing demands for plant-based protein and bioactive phytochemicals have directed the agriculture-based industries towards non-traditional food sources like hempseed. However, its richer protein and a blend of sensitive bioactive components demand a critical storage and processing unit. Mass is one of the important physical aspects needed for the design of various storage and processing units. Determining the mass of small grains that are almost unique in size and structure is a challenging task. In recent years, mass modeling based on physical dimension has been increasingly used for various fruits like kinnow mandarin, pomegranate, and lime fruits; therefore, we decided to test the applicability and accuracy of the same technique, along with examining the effect of grading, for mass modeling of hempseed for the first time. Various hempseed processing operations including dehulling, require crucial information about the bulk seed behavior and their correlation with their engineering properties. The study results might be useful to formulate an automatic grading mechanism for hempseed grading based on the mutual effect of mass and size. In this study, in addition to the introduction of a mass modeling system for hempseed, some grade-specific engineering properties of hempseed have been determined, which are important for the design of equipment for harvesting, transporting, storing, cleaning, packing and processing.
... The physical properties of the fruit are determined mainly as the quality of the fruit. The knowledge of some important physical properties is essential for the design of the storage structures, processing equipment, and processes [10]. The individual physical characteristics of the sweetie and its parent fruits are presented in Table 1. ...
Article
Full-text available
In the presented study, an overall Jaffa sweetie evaluation was made to find a correlation between Citrus grandis Osbeck × Citrus paradisi Macf. and its parent fruits’ (Citrus grandis Osbeck, Citrus paradisi Macf.) properties. Based on the sensory analysis, it was found that the taste and aroma of the new hybrid fruit are close to pummelo. By the use of chromatographic analysis, the selected monoterpenes present in the fruits were quantified. α-terpineol was typed as the main monoterpene compound in the headspace of sweetie and grapefruit, with the concentrations: 20.96 and 87.9 μg/g, respectively. In turn, γ-terpinene was chosen as the most important monoterpene determining the flavor of sweetie fruit. Based on two-dimensional gas chromatography (GC × GC-TOF-MS) and principal component analysis (PCA) of the data, several volatile compounds were associated with analyzed fruits’ aroma. Jaffa Sweetie is the hybrid fruit with sensory properties similar to pummelo with a higher content of monoterpenes, which improves its health benefits compared to the parent fruit. The research presents an instrumental method for assessing the aroma properties of the fruit as a reference method for sensory analysis, commonly used in the industry.
... The density of the coconut shell powder and the date seed powder was 1.60 g/cm 3 and 0.81 g/cm 3 , respectively. The density of the coconut shell powder was about 97.53% higher than that of date seed powder (Bhaskar and Singh 2013;Mahawar and Jalgaonkar 2017). Figure 2 shows a slight decrease in density between CT and hybrid composites with CT, A and E having densities of 0.94, 0.84 and 0.85 g/cm 3 , respectively. ...
Article
Full-text available
Biodegradable hybrid composites were prepared by introducing hydrophilic organic fibres (coconut and date seed powder) into waste high-density polyethylene (WHDPE). Each hybrid polymer composite was prepared with different ratios of fibre loading of coconut shell/sweet date seed powder (5/25%, 10/25%, 15/15%, 20/10% and, 25/5%). 100% WHDPE without any filler was the control sample. The results showed that there was an increase in mechanical properties as the fibres were introduced in the WHDPE with sample 25/5% showing relatively higher superior mechanical properties due to the more crystalline densified structure of the coconut powder compared to the date seed powder. There was also a significant degree of biodegradation (de-polymerization) observed in the hybrid composites compared to WHDPE when they were exposed to the environment averaging at 1.4% per month compared to the WHDPE which averaged at 0.11% biodegradation per month. The results showed that the hybrids can be utilized for industrial and domestic applications and can also undergo biodegradation when disposed, indicating a more environmentally friendly substitute compared to WHDPE.
Article
Full-text available
Effect of harvesting and post-harvest practices on the microbiological quality of dates fruits (Phoenix dactylifera L.), Abstract In Morocco, many dates varieties are produced and marketed, including local and imported dates, mainly Deglet Nour variety. The present study aimed to evaluate microbiological contamination on ten varieties of dates from four different production areas in Morocco, from the date market of Marrakech, and from the imported Deglet Nour variety, and to show effects of harvesting and post-harvest practices on the microbiological quality of dates. 2 Physicochemical data presented that the pH of studied varieties varies between 5 and 6 and water activity from 0.28 to 0.62. Microbiological analysis displayed that samples from Tata region presented the highest microbial spoilage with Total Viable Counts (TVC) ranging from 4.2 log CFU.g-1 to 2.6 log CFU.g-1 and yeast/moulds reaching 2.99 log CFU.g-1. Deglet Nour dates imported from Algeria, and Tunisia were less contaminated (TVC <1.0 log CFU.g-1, yeasts/moulds <1.0 log CFU.g-1). Coliforms, Bacillus sp. and Staphylococcus were not found in any sample. Results revealed that some varieties produced and marketed in Morocco are affected by microbial spoilage, which can be assigned to uncontrolled dates processes of harvesting and post-harvesting practices.
Chapter
The date is one of the most important crops cultivated in Egypt as a result of the suitable conditions to its cultivation, so there is a large area was cultivated by dates. The exported dates of Egypt were less than 1% of the total production, the Egyptian dates divided into three types (soft date, semi dry date, and dry date). North Sinai region is one of the most important date cultivated areas in Egypt, where the cultivated date varieties are Hayany date (soft dates) which spread in El-Arish city and Amry dates (semi dry dates) which spread in Beir El-Abed city. The soft date was the highest moisture content so it decays quickly so that it could be preserved by using different methods of drying such as solar, sun and greenhouse drying, to produce some products such as dry date and date pastes. Date fruit has a high content of sugar, while its content of protein and fat is very low, so we try to support date fruit by different sources of protein (dried skim milk, sesame, peanut, and soybean) to improve the nutritional and caloric values of date either Hayany or Amry date. In the same time, coconut and cinnamon were added to each variety product as flavors to produce date cubes.
Article
Full-text available
Physical properties of two wild mango varieties were studied at 81.9 and 24.5% moisture (w.b.) for the fruits and nuts, respectively. The shape and size of the fruit are the same while that of nuts differs at P = 0.05. The mass, density and bulk density of the fruits are statistically different at P = 0.05 but the volume is the same. The shape and size, volume and bulk density of the nuts are statistically the same at P = 0.05. The nuts of both varieties are also the same at P = 0.05 in terms of mass and density. The packing factor for both fruits and nut of the two varieties are the same at 0.95. The relevant data obtained for the two varieties would be useful for design and development of machines and equipment for processing and handling operations.
Article
Full-text available
A study on the guar seeds (Cyamopsis tetragonoloba) was performed to investigate the effect of moisture content on the selected physical properties. Moisture contents of seeds were varied from 5.2% to 25.0%, dry basis (d.b.). Seed geometric parameters, such as average length, width, thickness, geometric-mean diameter, surface area, volume, increased but sphericity decreased with increase in moisture content. The 1,000-seed mass increased linearly with moisture content. Bulk density of guar seeds decreased linearly when moisture content was raised from 5.2% to 25.0% d.b. On the other hand, true density decreased till moisture content was increased up to 20%. Further increase in seed moisture resulted in increased true density, which has not been observed in other food grains. The porosity decreased till seed 15.3% moisture and then increased with further addition of moisture. Angle of repose, coefficients of static friction on three different surfaces (plywood, mild steel, and galvanized iron), and terminal velocity increased linearly with seed moisture content. KeywordsFrictional properties–Geometric dimensions–Guar seeds–Physical properties
Article
Both soft (SD, Bam) and dry (DD, Kharak) date varieties were stored at 4°C for six months followed by an additional one week storage at 18°C. Antioxidant compounds (total phenolic content (TPC) and total flavonoid content (TFC)) of the dates increased following storage. Cluster analysis applied on TPC and TFC data before and after storage obtained two statistically significant clusters of SD and DD indicating that TPC and TFC had different behaviors according to the types of dates. As antioxidant concentration in dates was dependent on type of dates, selection of variety with high antioxidant compounds may be recommended. Further cold storage of up to six months followed by one week storage at 18°C may further improve the level of antioxidant compounds.
Article
The coefficients of linear expansion and thermal conductivity, the specific electrical resistance, the Lorentz number, the heat capacity, density, normal elasticity modulus and internal friction of vanadium were determined experimentally in a broad temperature range. The measurements were made on specimens of vanadium fused by an electron beam in vacuum from pressed powder.
Article
The physical properties of cumin seed were evaluated as a function of moisture content. The average length, breadth and thickness were 5·61, 1·77 and 1·55 mm respectively. In the moisture range from 7 to 22% d.b., studies on dried or rewetted cumin seed showed that bulk density initially increased from 477 to 502 kg/m3then decreased from 502 to 410 kg/m3, true density increased from 1047 to 1134 kg/m3, and porosity increased from 54 to 64%. The 1000 seed weight and terminal velocity increased linearly from 4·13 to 4·80 g and 2·6 to 4·8 m/s respectively. The angle of repose increased linearly from 36·5 to 51·3 ° and the static coefficient of friction also increased linearly on four metal surfaces, namely, mild steel (0·54 to 0·70), galvanized iron (0·48 to 0·65), stainless steel (0·37 to 0·62) and aluminium (0·43 to 0·63) with the increase in moisture content from 7 to 22% d.b.
Article
The measurement of maturity is of paramount importance to harvest good quality mango. Changes in size, sphericity, total soluble solids (TSS) content, surface color and firmness of mango were studied during growth and storage at ambient temperature. Size and sphericity were measured using the standard methods. Surface color was determined using a HunterLab colorimeter and the firmness by texture analyzer. The size of the fruits increased gradually during growth and the sphericity remained in the range of 0.67–0.70. Size and sphericity decreased due to shrinkage during storage. The firmness of the fruits remained almost constant over the period of growth and it decreased after attaining the maturity, whereas yellowness of fruits increased during both growth and storage. Maturity of mango could be predicted by measuring size, color and firmness.
Article
Some physical properties of fenugreek seeds were evaluated as a function of moisture content. The average length, width, thick-ness, geometric mean diameter and unit mass of the seed ranged from 4.01 to 4.19 mm, 2.35 to 2.61 mm, 1.49 to 1.74 mm, 2.40 to 2.66 mm and 0.0157 to 0.0164 g as the moisture content increased from 8.9% to 20.1% d.b. respectively. In the moisture content range, studies on rewetted fenugreek seed showed that the sphericity increased from 60.79% to 64.06%, the seed volume from 12.58 to 13.83 mm 3 , 1000 seed mass from 15.48 to 16.39 g and surface area from 18.09 to 22.18 mm 2 . As the moisture content increased from 8.9% to 20.1% d.b., the bulk density, kernel density were found to decrease from 701.16 to 645.81 kg/m 3 and 1240.36 to 1165.25 kg/m 3 , whereas angle of repose and porosity were found to increase from 14.34° to 16.88° and 43.47% to 44.58%, respectively. The static and dynamic coefficients of friction on various surfaces, namely, plywood, mild steel and galvanized metal also increased linearly with increase in moisture content. The plywood surface offered the maximum friction followed by mild metal and galvanized metal.
Article
The dependence of physical properties of gram on moisture content was determined. The best approximate shape was found to be a prolate spheroid. At 10·9% moisture content d.b., the measurements yielded an average 1000 grain weight of 0·173 kg, a mean surface area of 133·4 mm2, and sphericity and roundness of 74% and 70% respectively. In the moisture range from 9·64 to 31·0% d.b., studies on rewetted gram showed that the bulk density changed from 780 to 708 kg/m3, kernel density from 1311 to 1257 kg/m3; porosity from 40·5 to 43·7% and static coefficient of friction from 0·384 to 0·651 over surfaces of different materials. The angle of repose was observed to change from 25·5° to 30·4° in the moisture range from 8·62 to 17·6% d.b.
Article
Several physical, mechanical and chemical properties of three sweet cherry varieties (Van, Noir De Guben and 0-900 Ziraat) were determined and compared in terms of linear dimensions, length, width, thickness, volume, surface area, geometric mean diameter, fruit mass, sphericity, length of pit, width of pit, weight of pit, flesh/pit ratio, fruit density, bulk density, porosity, failure parameters (force, stress, strain and modulus of elasticity), coefficient of static friction, terminal velocity and apparent colour of sweet cherry varieties, and yield of fruit juice, titratable acidity, pH, total soluble solid, total phenolic compounds, anthocyanins, ascorbic acid, extract, total sugar, ash, and TSS/acid ratio. Further, multi linear models for three sweet cherry varieties were developed and presented to predict the fruit mass. All the properties of three sweet cherry varieties that provide useful data to engineers in equipment design and post-harvest technology for the sweet cherry varieties were generally found to be statistically different. These differences could be due to the individual characteristics of these varieties, environmental and growth conditions.