scholarly journals Effect of Moisture Content on Selected Physical and Mechanical Properties of Two Varieties of Tigernut (Cyperus spp)

2013 ◽  
Vol 2 (6) ◽  
pp. 24
Author(s):  
A. S. Oyerinde ◽  
A. P. Olalusi

<p>The effect of moisture content on some physical and mechanical properties of two varieties of tigernuts (<em>Cyperus esculentus</em>) was investigated. These properties include: geometric dimensions, linear dimensions, 1000 tuber weight, bulk density, tuber size, sphericity, angle of repose, porosity, coefficient of static friction and compressive strength. The moisture content levels used were 20, 25, 30, 35 and 40% wet basis (wb), and the two tigernut varieties used were yellow and brown types. The linear dimension, geometric diameter, sphericity, 1000- tuber weight, bulk density and angle of repose in both varieties increased with increasing moisture content. The average length, width and thickness of the yellow variety increases more than the brown variety at the determined moisture contents. True density of the yellow variety increased while the brown variety decreased with increase in moisture content. The porosity of the yellow variety reduces with increase in moisture content from 45.95 at 20% mc to 42.4 at 40% mc, while the brown variety decreased from 42.72 at 20% mc to 30.77 at 40% moisture content. The yellow variety had bigger size tubers than the brown variety and this has serious implications in packing, handling and transportation issues.</p>

2016 ◽  
Vol 12 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Mohammad Hossein Nadian ◽  
Mohammad Hossein Abbaspour-fard

Abstract The effect of moisture content on some properties of two varieties (Meymeh and Maragheh) of Russian olives was studied. The physical and mechanical properties including: dimensions, geometric mean diameter, thousand mass, volume, sphericity, surface area, true and bulk densities, porosity, angle of repose, coefficient of friction, rupture force, and rupture energy. The changes of moisture content levels from 17% to 25% (w.b.) indicated a statistically significant effect on all studied physical properties, except bulk density for Russian olive fruits. Shearing force was applied to the fruit using a testing machine in double shear mode. Shear strength and shearing energy increased with increase of loading rate; however, they were higher in Meymeh variety than Maragheh variety. Therefore, the lowest loading rate, with up to about 10 mm/min is desirable to design a suitable pulverizing mill in the herbal medicine industries.


Author(s):  
P. C. Vengaiah ◽  
S. Kaleemullah ◽  
M. Madhava ◽  
A. Mani ◽  
B. Sreekanth

Some physical properties of palmyrah fruit were investigated in this study. The average values of major, medium, minor and geometric mean diameters of fresh whole palmyrah fruit were 11.54,10.45, 9.85 and 10.64 cm respectively at 47.34 % (w.b) moisture content whereas that of palmyrah nut were 8.59, 7.35, 4.99 and 6.79 cm respectively at 8% (w.b) moisture content. Sphericity, surface area and aspect ratio were found to be 91.94%, 359.17 cm2 and 0.90 for fruit and whereas that of nut were 79.19%, 145.16 cm2 and 0.86 respectively. The average mass of the individual palmyrah fruit and nut was 927.78 and 248.10 g whereas bulk density was 525.92 and 693.0 kg/m3 respectively. The coefficient of static friction on mild steel, glass and plywood surfaces were 0.27, 0.21 and 0.25 for palmyrah fruit and 0.36, 0.28 and 0.27 for nut respectively. The angle of repose of palmyrah fruit and nut were 30.77 and 44.03 respectively.


2014 ◽  
Vol 4 (1) ◽  
pp. 21-30
Author(s):  
Yuwana Yuwana ◽  
Evanila Silvia ◽  
Bosman Sidebang

This research aimed to determine relationships between weight and several physic-mechanical properties of coffee grains. Grains having 12.2% (wet basis) moisture content in average, originated from cherries of different ripening levels identified by green, yellow, red and deep red in colors were used for experiment. Research used regresi linear analysis. Results of experiment indicated that weight of grains positively correlated to length, width, thickness and frontal area with very high values of determination coefficient. Weight of grains correlated positively to sphericity and negatively to porosity. Weight of grains originated from green and red cherries had positive correlation with density whereas weight of grains originated from yellow and deep red cherries possessed no correlation with density. Weight of grains from yellow, red and deep red cherries had negative correlation with true density in contrast weight of grains from green cherries had positive correlation with true density. There were no reliable trend concerning the relationships between weight of grains and coefficient of static friction and angle of repose.


2016 ◽  
Vol 44 (2) ◽  
Author(s):  
Shrikant Baslingappa Swami ◽  
N.J. Thakor A.M. Gawai

<p>The physical properties, viz., geometric diameter, surface area, sphericity, volume, bulk density, true density and angle of repose was measured for  four  cashew varieties <em>viz</em>., <em>Vengurle 1, Vengurle 3, Vengurle 4</em>  and <em>Vengurle 7</em> at different moisture content (15 to 87% db). For <em>Vengurle</em> 1 as the moisture content increased, the physical properties i.e., geometric mean diameter, volume, surface area, true density and angle of repose increased from 20.8 to 22.1 mm, 3485 to 4416 mm<sup>3</sup>, 1355 to 1540 mm<sup>2</sup>, 984 to 1030 kg m<sup>-3</sup> and 32 to 37˚, respectively. The sphericity and bulk density decreased from 74.2 to 71.4 per cent and 490 to 418 kg m<sup>-3</sup> respectively. For <em>Vengurle 3</em> geometric mean diameter, volume, surface area, true density and angle of repose increased from 27.2 to 28.6 mm, 7912 to 9169 mm<sup>3</sup>, 2320 to 2567 mm<sup>2</sup>, 1020 to 1048 kg m<sup>-3</sup> and 33 to 35.5˚, respectively. The sphericity and bulk density decreased from 75.5 to 75.2 per cent and 531 to 470 kg m<sup>-3</sup> respectively. For <em>Vengurle 4</em> the geometric mean diameter, volume, surface area, true density and angle of repose increased from 21.0 to 24.1mm, 3362 to 5113 mm<sup>3</sup>, 1391 to 1828 mm<sup>2</sup>, 970 to 1030 kg m<sup>-3</sup> and 32.5 to 38˚,  respectively. The sphericity and bulk density decreased from 65.8 to 66.8 per cent, 517 to 462 kg m<sup>-3</sup>, respectively. For <em>Vengurle 7</em> the geometric mean diameter, volume, surface area, true density and angle of repose increased from 24.2 to 24.9 mm, 5102 to 5547 mm<sup>3</sup>, 1840 to 1941 mm<sup>2</sup>, 998 to 1045 kg m<sup>-3</sup> and 33 to 38˚, respectively. The sphericity and bulk density decreased from 65.4 to 65.8 per cent, 518 to 438 kg m<sup>-3</sup>, respectively.</p>


2003 ◽  
Vol 9 (6) ◽  
pp. 435-442 ◽  
Author(s):  
E. M. Santalla ◽  
R. H. Mascheroni

High oleic sunflower seeds evaluated at 5.6% moisture content (dry basis) showed a surface area of approximately 102.41 mm2 with an average length, width, thickness and unit mass of 11.526, 5.008 and 2.809 mm and 0.055 g, respectively. Corresponding values for the kernel were 8.802, 3.897 and 1.907 mm and 0.036 g. The mean equivalent diameter and sphericity of the seeds were 5.49 mm and 0.46, respectively, while corresponding values for the kernels were 4.01 mm and 0.44. True density increased, within a moisture range of 4-26% d.b., between 652 and 708 kg/m3 for the seed, between 1015 and 1057 kg/m3 for the kernel and between 636 and 760 kg/m3 for the hull. The bulk density decreased from 386 to 373 kg/m3 for seeds and from 260 to 220 kg/m3 for hulls and increased from 535 to 553 kg/m3 for the kernels. Porosity increased from 41.2 to 47.1% in seeds, from 47.2 to 47.7% in kernels and from 59.2 to 70.1% in hull. Terminal velocity of seeds increased with moisture content between 2.8 and 5.5 m/s for seed, between 1.8 and 3.8 m/s for kernel and between 1.1 and 1.9 m/s for hull. Drag coefficient decreased when moisture content increased and varied between 4.7 and 1.4 in seed and between 12.5 and 3.1 in kernel. Angle of repose increased with moisture content between 25 and 46 in seeds, between 35 and 55 in kernels and between 49 and 66 in hull on different surfaces and resulted higher for hull and kernel than for seed. The coefficient of static friction was higher for kernel than that for seed and hull and also was higher on wood (with grain perpendicular to the direction of the motion) and lower on acrylic and galvanised iron. This coefficient increased with moisture content from 0.23 to 0.50 for seed, from 0.37 to 0.69 for kernel and from 0.31 to 0.60 for hull. All engineering properties evaluated showed a linear dependence with moisture content, leading to simple and accurate formulae, adequate to predict their variation in the range of moisture considered.


2012 ◽  
Vol 8 (1) ◽  
pp. 17-36
Author(s):  
R. ElGamal ◽  
G. ElMasry ◽  
F. Firtha

This study was carried out to evaluate some physical and mechanical properties of three Hungarian rice varieties named Dáma, Janka and M488 under different moisture levels to be a useful data for modelling the moisture changes in rough rice storage bins. Rough rice grains were conditioned to moisture contents of 12, 18, 24, and 30% (w.b.). Five mechanical expressions named rupture force (Fr), maximum stress (σmax), grain deformation (D), energy (E) and toughness (T) were extracted from stress–strain curve for all tested varieties as a function of moisture content. Also, some physical properties such as bulk density, true density, porosity and some morphological features of grain were determined as a function of moisture content for tested rough rice grain. The results revealed that the measured physical and mechanical properties are significantly effected by moisture contents for the three tested rice varieties. In general, when the moisture content increased, the rupture force and maximum stress decreased for all investigated grains. However, the deformation, energy and toughness firstly decreased with moisture content increase and after that increased with further increase of moisture content for all rice varieties. On the other hand, the bulk density, true density and porosity do not have a specific trend with increasing moisture content. Moreover, there was a significant difference among the selected rice varieties in terms of their bulk density and porosity at the same moisture content range.


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