Some Physical Properties of Sesame Seed of Muganli-57 Cultivar

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1 Some Physical Properties of Sesame Seed of Muganli-57 Cultivar Deniz YILMAZ 1, Can ERTEKİN 1, Ibrahim AKINCI 1, M. İlhan ÇAĞIRGAN 2 1 Department of Agricultural Machinery, Faculty of Agriculture, Akdeniz University, 07070, Antalya, Turkey 2 Department of Field Crop, Faculty of Agriculture, Akdeniz University, 07070, Antalya, Turkey dyilmaz@akdeniz.edu.tr Abstract: Knowledge of the physical properties of sesame seed, which is grown widely in Turkey, is necessary for the design of equipment for harvesting, transporting, cleaning, packing, storing, processing etc. In this study, linear dimensions, mass, seed mass, volume, sphericity, surface area, true and bulk density porosity and terminal velocity of sesame seed of Muganlı-57 cultivar were determined, and the effects of four moisture contents such as 5%, 8%, 10 and 13% w.b. on the properties were investigated. At water content levels from 5% to 13% w.b., the linear dimensions increased from 3.75 to 3.41 mm in length, 1.89 to 1.99 mm in width, and 0.70 to 0.90 mm in thickness. The geometric mean diameter and sphericity increased from 1.66 to 1.88 mm and to %, respectively. The moisture contents considered the volume, surface area and mass of the sesame seed varied from 2.29 to 2.46 cm 3, 8.62 to mm 2 and to g, respectively. Terminal velocity increased from to m/s at moisture content levels. The static coefficients of friction were measured at the different moisture contents on three different surfaces, and results varied between Keywords: Sesame, Physical Properties, INTRODUCTION Sesame (Sesamum indicum L.) is known as the most ancient oil seed according to some archaeological findings. Its cultivation goes back to 2130 B.C (Weis, 1983). The more than 90% crop breeding in the world has been produced from approximately 13 different oil plants. Sesame has been substituted in 8 th or 9 th order according to situation or yield of the plants in these oil plants. After the China and India which are the biggest procedures in the world, Myanmar, Sudan, Mexico, Nigeria, Venezuela, Turkey, Uganda and Ethiopia have been came, respectively. (Oplinger et al., 1990). According to 2005 s data, ha sowing area, tone production and 535 kg/ha yield of the sesame were recorded in Turkey. When the average yield values of the Turkey were compared with the average yield values of the world, it was a few lower. Sesame oil has high quality among the vegetable oils. It is durable to including sesamol and different nutrition. Sesame oil is canary and nice smells. The pulp is a reminder to refine of the oil. The physical properties of sesame seed are important for design of equipments for processing, transportation, sorting, separating and also packing. Since currently used systems have 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 these equipments. Many studies reported on the physical properties such as orange (Topuz et al., 2005), wheat (Yıldırım, 2001), hazelnut (Ozdemir and Akinci, 2004), chickpea (Konak et al., 2002), cotton seed (Ozarslan, 2002). MATERIAL and METHOD Seed of sesame were obtained from the cultivar - Muganlı-57 grown in 2006 following regular practices and harvested manually in the experimental field of Mutation Research Group, Agriculture Faculty at Akdeniz University, Antalya, Turkey. The moisture content of the sesame seed was determined by the oven-drying method (Asae, 1982). 898

2 The physical properties of the sesame seeds were determined as the following methods: One-hundred seeds were randomly selected from the remainder of the 3 kg sample. The three linear dimensions, namely, length L, width W and thickness T, of each of the 100 seeds were measured with a digital caliper compass reading to 0,01 mm sensitivity. The mass of seed was determined on 1000 randomly selected seed. Seed unit mass (M) and 100 seed mass (M1000) were measured by using an electronic balance of 0,001 g sensitivity. The geometric mean diameter (Dg) and sphericity of seed were (Φ) calculated by using the following equations: Dg=(LWT) 1/3 (1) φ=dg/l (2) The seed volume (V) and seed density (Pk), were determined using the liquid displacement method. Toluene (C7H8) was used in place of water because iits absorbed by seeds to a esser extent. The bulk density (Pb) was determined with a weight per hectoliter tester which has calibrated in kilogram per hectoliter. The seeds were filled into the calibrated bucket from a height of about 15 cm and excess seeds were removed by strike off stick. The seeds were not compacted in any-way. The surface area (S) of the seed was calculated by using the following equation: S= 2 πd g (3) The porosity (ε) was determined by the following equation: Terminal velocity (Vt) was measured by using an air column for each test, a sample was dropped into the air stream from the top of the air column, up which air was blown to suspend the material in the air stream. The air velocity near the location of the seed suspension was measured by an electronic anemometer having a least count of 0.1 m/s (Ozdemir and Akinci, 2004). The static coefficient of friction (μ) was determined for three different structural materials, namely, galvanized, rubber and plywood sheet. For this measurement one end of the friction surface is attached to an endless screw. The seed was placed on the surface and it was gradually raised by the screw. Vertical and horizontal height values were read from the ruler when the seed started sliding over the surface, then using the tangent value of that angle the coefficient of static friction was found. Gezer et al., (2002), Nimkar and Chattopadhyay (2001), have used similar methods. All physical properties at four different moisture content (5, 8, 10, 13 % w.b.) were studied in three replications. The variance analysis was carried out on the four moisture content, and the difference between the mean values was investigated by using the Standard Least Significant Difference (LSD) test at 1 % or 0.1 % significance levels. RESULTS and DISCUSION The dimensions and size distribution of sesame seed at different moisture levels were given in Table 1. Dimensional characteristics linearly increase from 5 to 13 % w.b. with increasing moisture content, with the exceptions of sphericity, projected area, bulk density. The relationship between the sesame seed length, width, thickness and moisture contents were given in Figure 1-3. ε=1-ρb/ρf (4) Where ρb is bulk density in kgm -3 and ρk is fruit density in kgm -3. The equations used for calculating the geometric mean diameter, sphericity, porosity and surface area were presented in the Aydın (2002), Deshpande et al. (1993), Konak et al. (2002), Ayata et al., (1997) and Mohsenin (1970), Nimkar (2001) reports. 899

3 Figure 1. The relationship between sesame seed length and moisture contents The values of the sesame seed length at different moisture levels varied between 3.41 and 3.75 mm indicated an increase in seed length with increasing in moisture content. The values of the sesame seed width at different moisture levels varied between 1.89 and 1.99 mm indicated an increase in seed width with increasing in moisture content.the values of the sesame seed thickness at different moisture levels varied between 0.70 and 0.90 mm, indicated an increase in seed thickness with increasing in moisture content. The results are similar to those reported by Ertekin et al. (2006). Figure 3. The relationship between sesame seed thickness and moisture contents The reasons for this increase probably due to the fact that the seeds have cellulose fibers and oils. The difference between the means of length and width were found to be significant levels at 0.1 % but the difference between the means of the sesame seed thickness, geometric mean diameter and sphericity were found to be significant level at 1 %. The sesame seed geometric mean diameter at different moisture levels varied between 1.66 and 1.88 mm. T The relationship between the sesame seed geometric mean diameter, sphericity and moisture contents were given in Figure 4-5. Figure 2. The relationship between sesame seed width and moisture contents Figure 4. The relationship between sesame seed geometric mean diameter and moisture contents 900

4 Table 1. Physical properties of sesame seed Properties Moisture content, %w.b Significant level Length (mm) 3.41±0.23 d 3.58±0.21 c 3.68±0.23 b 3.75±0.28 a *** Width (mm) 1.89 b ± b ± ab ± a ±0.24 *** Thickness (mm) 0.70 b ± b ± a ± a ±0.21 ** Geometric mean diameter (mm) 1.66 c ± b ± a ± a ±0.52 ** Sphericity (%) b ± b ± a ± a ±1.23 ** Volume (cm 3 ) 2.29 c ± b ± b ± a ±0.63 *** Bulk Density (g/cm 3 ) c ± c ± b ± a ±0.006 *** Surface area (mm 2 ) 8.62 d ± c ± b ± a ±0.69 *** Mass (g) c ± c ± b ± a ±0.032 ** Terminal velocity (m/s) c ± b ± b ± a ± *** Static coeff. friction Galvanized sheet 0.211± ± ± ±0.017 ns Plywood sheet 0.223± ± ± ±0.052 ns Rubber sheet 0.225± ± ± ±0.072 ns All data represent the mean of three replications; a;b;c;d indices the statistical difference in rows; **;*** significant levels at 1% and 0.1% respectively, ns: not significant. The sesame seed volume at different moisture levels in the above range varied between 2.29 and 2.46 cm 3. The difference between the means of volume was found to be significant levels at 0.1% level. A similar trend was reported Ozarslan, (2002). The relationship between the sesame seed volume and moisture contents was given in Figure 6 Figure 5. The relationship between sesame seed sphericity and moisture contents The sesame seed sphericity at different moisture levels varied between 48.68% and 50.82%. The difference between the means of volume was found to be significant levels at 1% level.. 901

5 Figure 6. The relationship between sesame seed volume and moisture contents The values of the bulk density for sesame seed at different moisture levels varied between and gm -3 and indicated an increase in bulk density with increasing in moisture content. The difference between the means of bulk density was found to be significant at 0.01% level. Gezer at al. (2002) found similar results for Hacıhaliloğlu apricot pit. The relationship between the bulk density and moisture contents for sesame seed was given in Figure 7. Figure 8. The relationship between sesame seed surface and moisture contents The difference between the means of seed mass was found to be significant at 0. 1% level. The seed mass is closely related to volume of sesame seed. The relationship between the mass and moisture content for sesame seed was given in Figure 9. Figure 9. The relationship between sesame seed mass and moisture contents Figure 7. The relationship between sesame seed bulk density and moisture contents The surface area was found to be increase linearly with increasing moisture content. The difference between the means of surface area was found to be significant at 0.01% level. The surface area is closely related to diameter of sesame seed. The results are similar to those reported by Yıldırım, (2001). The relationship between the surface area and moisture contents for sesame seed was given in Figure 8. The difference between the means of terminal velocity of the sesame mass was found to be significant at 0.1% level. The terminal velocity of the sesame seed is closely related to mass and bulk density of sesame seed. The relationship between the terminal velocity of sesame seed and moisture contents was given in Figure 10. Figure 10. The relationship between sesame seed terminal velocity and moisture contents 902

6 The static coefficients of friction exponentially decrease with decreases in the moisture levels. The static coefficients of friction ranged from 0,211 and 0,220 for galvanized, 0,223 and 0,229 for plywood and 0225 and 0,230 for at all moisture levels, the coefficients of friction were the highest for sesame seed with rubber and the lowest with galvanized iron steel. This is due to the properties of friction surfaces. The adhesion forces between the seeds and surface materials increase when using rough materials such as rubber. CONCLUSION 1) The average length, width, thickness, geometric diameter, unit mass, volume of seed, sphericity and surface area of sesame seed were increased with increasing the moisture contents. 2) The bulk density increased from to gm -3, while the moisture content increased from 5 to 13% (w.b). 3) At all moisture levels, the coefficients of friction were the highest for sesame seed with rubber and the lowest with galvanized iron sheet. 4) Some physical properties of the sesame seed were described in order to design a specific machine for harvesting, threshing, conveying, cleaning, separating, storing and the other. For sesame seeds, many parameters were found to be significantly different. Therefore, the differences between the physical properties of sesame seed should be considered in sesame mechanization and its processing. (Prinus Domestica L.). Journal of Food Engineering, 75, Gezer İ., H. Hacıseferoğulları, F. Demir Some physical properties of Hacıhaliloğlu apricot pit and its kernel. Journal of Food Engineering, 56, Konak, M., K. Carman, C. Aydın, Physical properties of chick pea seeds. Biosystem Engineering, 82(1), Mohsenin N.N Physical Properties of Plant and seeds. Agricultural Engineers years book. American Society of Agricultural Engineers. St. Joseph Michigan, Nimkar M.P., K. P. Chattopadhyay, Some physical properties of green gram. Journal of Agricultural Engineering Research, 80, Oplinger, E.S., D. H. Putnam, A.R. Kaminski, C.V. Hanson, E.A. Oelke, E.E. Schulte, J.D. Doll, Sesame alternative field crops manuel. same.html. Ozarslan, C., Physical properties of cotton seed. Biosystems Engineering, 83 (2), Ozdemir, F., I. Akinci, Physical and nutritional properties of four major commercial Turkish hazelnut varieties. Journal of Food Engineering, 63, Topuz, A., M. Topakci, M. Canakci, I. Akinci, F. Ozdemir, Physical and nutritional properties of four orange varieties. Journal of Food Engineering, 66, Yıldırım, Ş., Determination of the terminal velocity the some grained material (in Turkish), Selçuk University, Msc Thesis. Konya Weis, E.A., Oilseed crops. Longman, New York, pp REFERENCES ASAE Standard Moisture measurement*grains and Animal Materials. Gordon and Breach Science Publisher, NewYork Ayata, M., M. Yalçın, V. Kirişci, Evaluation of Soiltine Interaction by Using Image Processing System. In National Symposium on Mechanisation in Agriculture(pp ). Tokat, Turkey. Aydın, C Physical properties of hazel nuts. Biosystem Engineering, 82, 3, Deshpande, S. D., S. Bal, T. P. Ojha, Physical properties of soybean. Journal of Agricultural Engineering Research, 56, Ertekin, C., Ş. Gözlekci, O. Kabaş, S.Sönmez, İ. Akıncı, Some physical, pomological and nutritional properties of two plum cultivars 903