International Journal Agricultural, Research and

ripening treatment on properties of banana fruit. Salvador et al (2007) studied the changes in color and texture of banana during storage at 10 ºC and...

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International Journal of Agricultural Science, Research and Technology

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Some Physical Properties of Full-Ripe Banana Fruit (Cavendish variety) M, Soltani1*; R, Alimardani1; M, Omid1

Soltani et al. Some physical properties of full-ripe banana fruit (Cavendish variety). International Journal of Agricultural Science, Research and Technology, 2011; 1(1):1-5].

Keywords: Physical properties, Banana fruit, Image processing.

1. Introduction Physical properties of fruits and vegetables are necessary data to design an agricultural machine for handling, cleaning, conveying, sorting and other treatments, also the size of individual units of a product can significantly affect consumer appeal, handling practice, storage potential, and market selection. So investigation of agricultural products physical characteristics is the subject of numerous researches and studies. Many studies have been reported on the physical and mechanical properties of fruits, such as bergamot (Keramat Jahromi et al, 2007), coconut (Terdwongworakula et al, 2009), date fruit (Keramat Jahromi et al, 2008), kiwi fruit (Lorestani and Tabatabaeefar, 2006), longan fruit (Varith et al, 2008), melon (Emadi et al, 2009), orange (Khojastehnazhand et al, 2009) and citrus fruits (Omid et al, 2010). Keramat Jahromi et al (2007) modeled mass and surface area of bergamot by physical attribiutes such as dimensional characteristics and projected areas. They reported all determining coefficients for surface area modeling were higher than R2= 0.92 and the highest determining coefficient in all models was obtained as R2 =1 for some combinations of projected areas. Lorestani et al (2006) measured The physical characteristics of kiwi fruit included mass, volume,

dimensions and projected areas perpendicular to major diameters. They used these properties to predict the mass of kiwi fruit. Khojastehnazhand et al (2008) determined volume and projected area of orange by image processing technique. They assumed each orange was composed of a number of right elliptical cone. They computed the volume and surface area of each frustum by the segmentation method. They approximate the total volume and surface area of the orange by suming of all elementary frustums. Among fruits and vegetables, banana fruit has exclusive physical properties that make it different from other fruits and vegetables such as shape and curvature. Also banana is one of fruits that need to extract its physical properties as a result of its importance. Banana is a popular fruit and the fourth most important food crop in the world, after rice, wheat and maize, in terms of gross domestic product, with a world production of about 70 million tons in 2003 (Lorestani and Tabatabaeefar, 2006). Banana fruit is grown in many countries in sub-tropical areas and the big exporters are located in South East Asia, South America and the Caribbean. The Cavendish variety is widely produced by these countries. This huge volume of banana cultivation needs to design

Received: 15 April 2011, Reviewed: 18 April 2011, Revised: 23April 2011, Accepted: 24April 2011

Physical properties of fruits and vegetables are the subject of many researches because of its importance in designing of agricultural machinery. Banana fruit is one of important fruit. In this study some physical properties of banana fruit (Cavendish variety) were determined. Properties which were measured included weight of whole fruit peel and pulp weight, dimensions, surface area and projected area. The actual surface area and projected area were measured by image processing technique. The calculated attributes were geometric mean diameter, sphericity, radius of curvature, assumed ellipsoidal volume, surface area and projected area. The diameters of fruit varied as quadratic form. High correlation was observed among assumed ellipsoidal attributes and measured properties. The highest correlation was between estimated projected area and measured projected area as R2= 0.978. [Mahmoud


Department of Agricultural Machinery, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran. *Correspondence author email:[email protected]



Some Physical Properties of Full-Ripe Banana Fruit

related machinery. Physical properties play an important role in machine designing. For banana fruit, some researches were accomplished about its physico-mechanical properties. For example, Kachru et al (1995) investigated physical and mechanical characteristics of two varieties of green-mature banana fruit. Ahmad et al (2001) conciliated the temperature effect of ripening treatment on properties of banana fruit. Salvador et al (2007) studied the changes in color and texture of banana during storage at 10 ºC and 20 ºC. They found that during storage, the change in peel color from green to yellow was gradual in the M. Cavendish samples, whereas the M. Paradisiacal variety presented a different pattern, remaining green for the first 8 days and then changing rapidly to a yellow tone from day 12 onwards. While the flesh texture of the M. Cavendish type bananas softened quite rapidly during storage, it evolved more slowly in the M. Paradisiacal variety and there was little variation in the flesh hardness values over the storage time. This paper aims to investigate some physical properties of Cavendish variety of banana fruit include weight of pulp and peel, peel to pulp ratio, external and internal length, diameters, geometric mean diameter, sphericity, actual surface and projected area, assumed ellipsoid surface and projected area. 2. Material and Methods Banana fruits (Cavendish variety) shipped out from the Ecuador were used in this experiment. The banana fruits have been stored at 14 ºC temperature during transportation. The samples were randomly selected from banana boxes in Damirchilo warehouse located in Karaj city of Alborz province and transferred to the Physical Properties of Materials Laboratory, Department of Agricultural Machinery Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran. The external and internal length of banana (Lo, Li) was measured by a flexible ruler (Figure 1). The perpendicular diameters (Di, di) were measured to 0.01 mm accuracy by a digital caliper (Figure 2). The mass of each sample was measured by a digital balance with an accuracy of 0.01 g.

Mahmoud Soltani et al

Figure 1. Longitudinal section of banana fruit

Figure 2. Plane of cut along the longitudinal axis of the banana The average value of L is calculated from: ( L + Li) L= o 2 The difference between Lo and Li was defined as: ∆L = L o − L i Geometric mean diameter (Dg) and sphericity ( φ ) values were determined using the following equations [11]: Dg = ( L ave . D ave . d ave )0.333


Dg L

D ave =

D3 + D 4 2

d3+ d4 d ave = 2 The intermediate section of banana was assumed as a part of ring (Figure 3). So the radius of curvature was obtained from: L R = i D ave ∆L

Figure 3. The assumed intermediate part of banana The banana fruit shape was assumed as an ellipsoidal shape and thus its estimated volume (Vellip), surface area and projected area (Sellip) were estimated as: π V ellip = L ave . D ave . d ave 6× 1000

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International Journal of Agricultural Science, Research and Technology, 2011;1(1)

S = π . D 2g


L ave . D ave 6 × 100 The actual projected area and surface area were measured by image processing technique. This system consisted of the light emitting chamber utilized as to emit light from behind the fruit. The equipment was set as a whole are composed of the three different basic sections of light source, diffuser, and camera holding stand. The function of the light source (4×20W lamps) is to emit light to the bottom section of the diffuser. The diffuser task is to diffuse light at its level. The camera (model Canon Power Shut A85, Japan) was mounted on 40 cm above the diffuser. To measure the projected area, the banana fruit was laid on a flat surface and allowed to reach its natural rest position, then the image was captured, after that the banana was peeled and the peel was weighted. The rind was set between the diffuser and a vitreous brede to tabulate it and the image was acquired again. The acquired images from digital camera were transmitted to the MATLAB 7 software and then the area was computed as following procedure: A single grayscale threshold was used to determine if an image pixel belongs to the background or the object. Once the threshold was determined, the object boundary can be traced and the number of pixels can be enumerated. System calibration was performed by attaching a quadrangular card (100 cm2 area). The card was employed to provide pixel per cm2 ratio. P ellip =

3. Results and discussion The Weighting properties of banana fruit as a weight of whole fruit, weight of peel and pulp, the percent of peel and pulp and pulp-peel ratio are presented in Table 1. The average weight of whole, peel and pulp of fruit were 180.56 g, 66.02 g and 114.54 g respectively. Kachru et al [3] reported 89.69 g and126.16 g of whole fruit for Dwarf Scavendish and Nendran variety respectively. The average value of banana peel percent was 36.6, while Kachru et al (1995) reported the average value 41.9% and 30.23% for peel percent for Dwarf Scavendish and Nendran variety respectively. Also they reported 1.39 and 2.32 as pulp to peel ratio respectively, while we obtained the pulp-peel ratio as 1.74. These results show the Cavendish banana has a thicker peel than Nendran variety and has a thinner peel than Dwarf Scavendish variety.

(9) Table 1. Weighting properties of full-ripe banana fruit (Cavendish). (10) Property Average Min Max Sd Weight of fruit (g) 180.56 121.10 272.50 36.25 Weight of peel (g) 66.02 47.20 99.30 13.11 Weight of pulp (g) 114.54 73.90 173.20 23.74 Peel percent (%) 36.6 32.15 40.87 1.89 Pulp percent (%) 63.38 59.13 67.86 1.89 Pulp/peel 1.74 1.45 2.11 0.14 The dimensional properties of banana fruit are presented in Table 2. The average value of external and internal length was 235.33 mm and 165.17 mm. it is because of being curvature in structure of banana fruit. Banana has a cushioned shape. Figure 4 shows the average values of D1 to D6 and d1 to d6 respectively. Changes in these perpendicular diameters were as function of their position on banana. Diameters varied as a polynomial form.

Figure 4. The average values of banana fruits. The vertical lines represent 5% confidence interval The Dave and dave were obtained 40.34 mm and 36.56mm respectively. Kachru et al (1995) obtained the maximum diameter as 30.86 mm and 23.13 mm for Dwarf Scavendish and Nendran variety respectively. The size of Cavendish variety was larger than Dwarf Scavendish and Nendran variety.

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Some Physical Properties of Full-Ripe Banana Fruit


Table 2. Dimensional properties of fruit Property (mm) Average Min Lo 235.33 202 Li 165.17 135 L 200.25 168.50 ΔL 70.16 45 D1 36.60 31.38 D2 39.89 34.18 D3 40.20 33.41 D4 39.25 32.69 D5 38.20 32.06 D6 35.48 28.34 d1 30.83 26.17 d2 35.52 30.38 d3 36.40 31.46 d4 36.20 31.17 d5 35.61 31.06 d6 33.72 22.32 D ave 40.34 34.88 d ave 36.56 31.46

full-ripe banana Max 288 220 247.50 89 42.36 48.96 49.15 48.90 47.36 45 36.36 39.56 40.90 40.70 39.37 38.60 49.15 40.90

Sd 24.24 21.95 22.29 12.28 2.49 2.66 2.84 2.89 2.73 3.22 2.66 2.32 2.38 2.23 2.14 2.95 2.64 2.30

Results of other estimated and calculated properties are presented in Table 3. The radius of curvature was 98.67 mm. it means a circle with a 98.67 mm radius is tangent to middle section of banana fruit. Average value of geometric mean diameter was 66.52 mm that varied between 56.97 mm and 78 mm. the sphericity was obtained as 0.33. Table 3. Physical properties of full-ripe banana fruit Property Average Min Max Sd R (mm) 98.67 65.52 174.4 26.46 Dg (mm) 66.52 56.97 78 4.42


Vellip (cm3) Sellip (cm2) Pellip (cm2) S (cm3) P (cm2)

0.33 156.10 139.62 63.76 181.48 75.87

0.30 96.77 101.96 46.14 141.27 54.78

Mahmoud Soltani et al

0.37 248.42 191.17 94.53 242.63 116.29

0.02 32.16 18.86 10.91 27.67 13.38

Figure 5. Estimation of ellipsoid volume of banana fruit by weight The R2 was obtained 0.96, so by measuring of weight, the ellipsoid volume can be estimated precisely. The average value of measured surface area was obtained as 181.48 cm2. Result of regression estimation shows that the measured surface area had high correlation with Sellip.

Figure 6. Correlation between measured surface area of banana fruit and estimated ellipsoid surface The measured projected area varied between 54.78 cm2 and 116.29 cm2 with average value of 75.78 cm2. Figure 7 shows that a very good correlation was found among Pellip and measured projected area. The coefficient of determination (R2) was obtained 0.978.

The sphericity of banana was low; it is acceptable, because banana is an elongated shape fruit (oblong shape). The average ellipsoid volume was calculated as 156.1 cm3. High correlation was found between the weight of fruit and ellipsoid volume of banana (Figure 5).

Figure 7. Correlation between ellipsoid projected area and measured projected area

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4. Conclusions Some physical properties of banana fruit (Cavenish variety) were investigated. From the difference between perpendicular diameters is concluded the section shape of banana is near to ellipse. It is concluded from ΔL that there is a curvature in the shape of banana fruit. The diameters (Di and di) were varied in quadratic form. The actual values of surface and projected areas of banana were measured by image processing technique. Ellipsoidal estimation of banana fruit volume, surface area and projected area highly correlated with measured attributes. The highest correlation was obtained between ellipsoid projected areas and measured projected area. Image processing is a time consuming and complicated method. Also water displacement method is time consuming, besides water can be absorbed by fruit and influences chemical properties of sample. By ellipsoidal estimation the volume, surface and projected areas is calculated easily and reliably. Volume and surface area are beneficial in proper prediction of drying rates and hence the drying time in the dryer. Also, surface and projected areas are important to indicate physical properties such as water loss, gas permeability, heat transfer, quantity of pesticide applications and respiration rates, so ellipsoidal estimation is a useful method. References 1. Ahmad, S., Thompson, A. K., Hafiz, I. A and ASI, A. S. (2001). Effect of temperature on the ripening behavior and quality of banana fruit. International journal of agriculture & biology, 3(2): 224-227. 2. Emadi, B., Abbaspour-Fard, M. H and Yarlagadda, P. (2009). Mechanical properties of melon measured by compression, shear, and cutting modes. International Journal of Food Properties, 12(4): 780-790. 3. Kachru, R. P., Kotwaliwale, N and Balasubramanian, D. (1995). Physical and mechanical properties of green banana (Muss paradisiaca) fruit. Journal of Food Engineering, 26: 369-378. 4. Keramat Jahromi, M., Rafiee, S., Mirasheh, R., Jafari, A., Mohtasebi, S. S and Ghasemi Varnamkhasti, M. (2007). Mass and Surface Area Modeling of Bergamot (Citrus medica) Fruit with Some Physical Attributes. Agricultural Engineering International: the CIGR Ejournal, 4: 1-11. 5. Keramat Jahromi, M., Rafiee, S., Jafari, A., Ghasemi, B. M. R., Mirasheh, R and Mohtasebi, S. S. (2008). Some physical properties of date fruit (cv. Dairi). Int. Agrophysics, 22: 221-224.

6. Khojastehnazhand, M., Omid, M and Tabatabaeefar, A. (2009). Determination of orange volume and surface area using image processing technique. Int. Agrophysics, 23: 237-24. 7. Lorestani, A. N and Tabatabaeefar, A. (2006). Modeling the mass of kiwi fruit by geometrical attributes. Int. Agrophysics, 20: 135-139. 8. Mohsenin, N. N. (1996). Physical Properties of Plant and Animal Materials. 2nd Edn. Gordon and Breach Publishers, New York. 9. Omid, M., Khojastehnazhand, M and Tabatabaeefar, A. (2010). Estimating volume and mass of citrus fruits by image processing technique. Journal of Food Engineering, 100(2): 315-321. 10. Salvador, A., Sanz, T and Fiszman, S. M. (2007). Changes in color and texture and their relationship with eating quality during storage of two different dessert bananas. Postharvest Biology and Technology, 43: 319–325. 11. Sharifi, M., Rafiee, S., Keyhani, A., Jafari, A., Mobli, H., Rajabipour, A and Akram, A. (2007). Some physical properties of orange (var. Tompson). Int. Agrophysics, 21: 391-397 12. Terdwongworakula, A., Chaiyapong, S., Jarimopasa, B and Meeklangsaenc, W. (2009). Physical properties of fresh young Thai coconut for maturity sorting. Biosystems engineering, 103: 208216. 13. Varith, J., Noochuay, C., Khamdang, T and Ponpai, A. (2008).Changes in viscoelastic properties of longan during hot-air drying in relation to its indentation. Mj. Int. J. Sci. Tech, 2(2): 320-330.

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Some Physical Properties of Full-Ripe Banana Fruit

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