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Effects of Olive Harvesting Methods on Oil Quality
Available online at www.sciencedirect.com
ScienceDirect APCBEE Procedia 8 (2014) 334 – 342
2013 4th International Conference on Agriculture and Animal Science (CAAS 2013) 2013 3rd International Conference on Asia Agriculture and Animal (ICAAA 2013)
Effects of Olive Harvesting Methods on Oil Quality C. Saglama,*, Y.T.Tunaa, U.Gecgela, E.S.Atara a
N.K.U.Agricultural Faculty Tekirdag/TURKEY
Abstract Olives are traditionally hand harvested, a process that is not only tedious and laborious, but represents the major proportion of the costs of production. As it is known, harvesting method has important effect on the quality of olive especially produced for table consumption. Objective of this research is to compare effect of harvesting methods on amount of oleic acid (%) and peroxide value (meqO2/kg) which has importance for oil quality. Two different olive varieties whole olives and de-stone olives were used. Harvesting methods were harvesting by hand and harvesting by machine to collect on a platform. Amount of the oleic acid (%) and peroxide value (meqO2/kg) were measured by using titration method. According to the statistical analyzes results, differences between measured results were important (P ≤ 0,05). © Saglam. Published by Elsevier This is and/or an open peer accessreview article under CC BY-NC-NDoflicense ©2014 2013C.Published by Elsevier B.V.B.V. Selection undertheresponsibility Asia-Pacific (http://creativecommons.org/licenses/by-nc-nd/3.0/). Chemical, Biological & Environmental Engineering Society Selection and peer review under responsibility of Asia-Pacific Chemical, Biological & Environmental Engineering Society Keywords: OLIVE HARVESTING, OLIVE OIL, OIL QUALITY, ACIDITY, PEROXIDE VALUE
1. Introduction Olives are traditionally hand harvested, a process that is not only tedious and laborious, but represents the major proportion of the costs of production. Hand harvest is accomplished by three techniques: 1) collection of fallen fruit from the ground, 2) "milking", or the stripping of fruit with half open hands from limbs which falls into picking bags or onto nets below the tree, 3) beating limbs with large sticks to dislodge fruit, which is also collected on nets. Mechanical harvest of olives has been used to a limited extent in more intensive orchards.
* Corresponding author : Tel : +90 282 2502268 ; Fax : +90 282 2509929 E-mail address: [email protected]
2212-6708 © 2014 C. Saglam. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Selection and peer review under responsibility of Asia-Pacific Chemical, Biological & Environmental Engineering Society doi:10.1016/j.apcbee.2014.03.050
C. Saglam et al. / APCBEE Procedia 8 (2014) 334 – 342
As it is known, harvesting method has important effect on the quality of olive especially produced for table consumption. Some researches showed that harvesting method also has important effect on the quality of olive oil. Although a number of studies have reported effects of irrigation on yield parameters under conditions and varieties, there is shortage of the influence of harvesting method on oil quality. [1], studied on the effects of irrigation on oil quality of fruit obtained from both mechanical and hand harvesting methods. They found that when fruit was picked carefully by hand so that no injuries were inflicted, free fatty acids levels were substantially reduced, peroxide was reduced and total polyphenol content was increased. Degradation of oil quality related to increased irrigation could potentially be aggravated by damage to fruit caused during harvesting. [2] Examined extra virgin oil from whole olives and that from de-stone olives between 1999-2002 in terms of their main chemical qualities. It was asserted that the acidity of the oil from de-stone is lower or the same, and that de-stone olives are more durable in terms of oxidation. [3] The chemical combination of the oil depends on the kind of the fruit, fruit maturity degree, environmental conditions, growth area and the techniques of processing and storage. [4] Food quality and safety are attracting an increasing amount of attention for producers, researchers, and consumers. Acid value (AV) measures free fatty acids and is usually considered to be one of the main parameters to reflect the quality of oil, degree of refining, as well as the quality change during storage. 2. Materials and Methods 2.1. Harvesting Machine Tree shaking machine (Fig.1); it is combined of the motor, the body and the vibration rod. There is a hook of which mouth gap is 42 mm. The movement which comes from the motor is transmitted with its eccentric mechanism. Machine power is 2,8 HP and cylinder capacity is 52,5 cc. The number of beats per minute is 1350. However, its length can be extended up to 3 meters with telescopic extension. The total weight of the machine is 14,5 Kg.
Fig. 1. Tree shaking machine
2.2. Platform Picking platform can be carried being tied to three-point hanging system and can be directed with hand in the orchard. The height of platform chassis from the floor is 400 mm. and the height of axle from the floor is 200 mm. There are seven drawers in which the olives are gathered, in the 200 mm- space left in the chassis. There is a metal frame which carries the eight-corner and 1250 mm. diameter telescopic feet made of T profile. One corner of the frame is left open for the entrance of the trees. Some telescopic fiber rods which work with a special hinge which open and close with a 90-degree-angle are put on this eight-corner frame. The diameter of the main body of the telescopic rods is 40 mm. and the diameter of the head decreases down
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C. Saglam et al. / APCBEE Procedia 8 (2014) 334 – 342
to 20 mm. The rods can open in three levels, 1000 mm each, and the length of each bar is 3000 mm. 26 telescopic rods are installed on the eight-corner frame with a 13,8-degree angle. The total bar gap, including the semi-diameter of the eight-corner frame, is 7250 mm. when the bars open, that is, the platform get into an adverse umbrella with a diameter (Fig 2.).
7,25
Fig. 2. Picking Platform
The first levels of the bars are developed with a special rubber hinge system which provides stretch automatically for the end the first levels in order for the telescopic bars to open and close easily and in order for the shelf to keep stretched (Fig. 3).
Fig. 3. Hinge
On the telescopic bars a 3 x 3 mm. porous polyethylene-based net which is called “bee veil” or “serge” is put. This stretch of the net is adjusted in a way that the olives don’t jump too high but they don’t pile up on the net. The part of the platform which catches the tree and the net in the space left for the operator entrance can open and close like a curtain and they shift from one bar to the other and fix on it. 2.3. Harvesting Methods and Obtaining the Olive Oil Samples Olive trees in the Aegean region of western part of Turkey were harvested using the 2 methods of harvesting by hand and harvesting by machine on a platform. Olive oil was obtained as soon as harvesting was finished. Olive oil samples were processed using a laboratory type system that was manufactured in the Workshop of N.K.U. Agricultural Faculty, Department of Agricultural machinery. This system was designed as similar to big scale continues olive oil production systems (Fig. 4). To obtain the olive oil using this system, production steps were as below: z Separation dirt and leaves from the leaves, z Grinding of olives and their pits into paste which goes onto the press. z Malaxation by slow mixing of the paste which allows the oil - water emulsion to coalesce in the malaxation tank that was occurred constant temperature (30 °C). Small microscopic oil droplets join
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C. Saglam et al. / APCBEE Procedia 8 (2014) 334 – 342
z
together into large drops with this process. Pressing of the paste. The press separates out the olive juice and oil using additional filter.
Fig. 4. System that was manufactured to obtain olive oil samples
2.4. Acidity and Peroxide ValueMeasurement Oil samples pressed from olive fruits were subjected to free fatty acids and peroxide value according to methods no 2.201, 2.501 (IUPAC) respectively [5]. 3. Results and Discussion Free fatty acidity (%, FFA) is usually considered to be one of the main parameters to reflect the quality of olive oils. Because this content, resulting from the hydrolysis of triacylglycerol as well as further decomposition of hydroperoxides, is one of the most important indicators of olive oil deterioration. Our results for the FFA (%) content showed that this content in the olive oils of the manufacturing from whole olives was higher significantly (P< 0.01) than that of the manufacturing from de-stone olives. For the olive oil samples of both varieties, in both harvesting methods, excepting harvesting method by hand for Gemlik variety, the FFA (%) content was high in the manufacturing from whole olives (Table 1. And Fig 5). Our findings agree with the finding by [2], [6], and [7]. Differently observations were made by [8] and [9]. These researchers reported that the manufacturing from de-stone olives wasn’t factor influencing the FFA (%) content. Table 1. Acidity and peroxide value of whole olives and de-stone olives were collected with by hand and machine plathform in Ayvalik and Gemlik
Whole olives
1,87
PEROXIDE VALUE (meqO2/kg) 5,69
De-stone olives
1,84
5,68
Whole olives
2,06
6,44
De-stone olives
2,02
6,46
Whole olives
2,09
4,52
De-stone olives
2,05
4,46
Whole olives
2,26
6,11
De-stone olives
2,23
6,07
AYVALIK
GEMLIK
ACIDITY (%) BY HAND MACHINE + PLATHFORM BY HAND MACHINE + PLATHFORM
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C. Saglam et al. / APCBEE Procedia 8 (2014) 334 – 342
7 6 5 4 3 2 1 0
By Hand
Mach + Plat.
By Hand
De-stone Olives
Whole Olives
De-stone Olives
Whole Olives
De-stone Olives
Whole Olives
De-stone Olives
Whole Olives
ACIDITY (%) PEROKSIT VALUE (meqO2/kg)
Mach + Plat.
Fig. 5. Acidity and peroxide value of whole olives and de-stone olives were collected by hand and machine plathform in Ayvalik and Gemlik
ACIDITY (%)
PEROXIDE VALUE
GEMLIK
2,1 2,05 2 1,95 1,9 1,85 1,8 1,75 1,7
2,06
1,87
Whole olives
(meqO2/kg)
GEMLIK
2,02
1,84
6,6 6,4 6,2 6 BY HAND 5,8 MACHINE+PLATFORM 5,6 5,4 5,2
5,69
BY HAND
5,68
MACHINE+PLATFORM
Whole olives
De-stone olives
6,46
6,44
De -stone olives
Fig. 6. Acidity and peroxide value of whole olives and de-stone olives in Gemlik.
Table 2. Acidity and peroxide statistical analysis of whole olives and de-stone olives in Gemlik.
Mach. + Plat.
By Hand
Harvesting Method
N
Acidity (%)
Peroksit Value (meqO2/kg)
Whole olives
3
1,8733 ± 0,014
5,6933 ± 0,003
De-stone olives
3
1,8400 ± 0,006
5,6833 ± 0,009
Whole olives
3
2,0633 ± 0,009
6,4400 ± 0,023
De-stone olives
3
2,0200 ± 0,012
6,4600 ± 0,006
Statistical Analizes Summary (F Values)
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Whole olives De-stone olives ** P ≤ 0,01
Acidity (%)
Peroksit Value (meqO2/kg)
124,962** 194,400**
1024,000** 5428,900**
According to the Fig.6. and table.2 that the results derived from the samples of GEMLİK variety show that the difference between the harvesting methods with respect to acidity and peroxide values are considered to be important pertaining to both the whole and de-stone olives. ACIDITY (%)
PEROXIDE VALUE
AYVALIK 2,26
2,3 2,25 2,2 2,15 2,1 2,05 2 1,95 1,9
2,09
Whole olives
(meqO2/kg)
AYVALIK
2,23
2,05
6,11
7 6 5 4 BY HAND 3 MACHINE+PLATFORM 2 1 0
4,52
BY HAND MACHINE+PLATFORM
Whole olives
De-stone olives
6,07 4,46
De-stone olives
Fig. 7. Acidity and peroxide value of whole olives and de-stone olives in Ayvalik.
Table 3. Acidity and peroxide statistical analysis of whole olives and de-stone olives in Ayvalik
Mach. + Plat.
By Hand
Harvesting Method
N
Acidity (%)
Peroksit Value (meqO2/kg)
Whole olives
3
2,0900 ± 0,006
4,5200 ± 0,012
De-stone olives
3
2,0500 ± 0,006
4,4633 ± 0,009
Whole olives
3
2,2633 ± 0,009
6,1100 ± 0,006
De-stone olives
3
2,2300 ± 0,006
6,0700 ± 0,006
Statistical Analizes Summary (F Values)
Whole olives De-stone olives ** P ≤ 0,01
Acidity (%)
Peroksit Value (meqO2/kg)
270,400** 486,000**
15168,600** 23232,400**
According to the Fig.7. and table 3. that the results derived from the samples of AYVALIK variety show that the difference between the harvesting methods with respect to acidity and peroxide values are considered to be important pertaining to both the whole and de-stone olives. Peroxide value (meqO2/kg, PV) is a measure of oxidative rancidity and a guide to olive oil quality. The PV is one of the most frequently determined quality indices during olive oil production, storage and marketing [10]. Our results for the PV showed that this value in the olive oils of the manufacturing from whole olives for
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C. Saglam et al. / APCBEE Procedia 8 (2014) 334 – 342
the Ayvalık variety was higher significantly (P< 0.01) than that of the manufacturing from de-stone olives. As for Gemlik variety, the olive oils of the manufacturing from whole olives were only characterized by high PV in by hand harvesting method. The results for Gemlik variety also were found to be significant (P< 0.01). As for influencing harvesting methods, there were similarly variations among their PV for Gemlik variety. Comparing the effects of the harvesting methods for the Ayvalık variety, however, the PV showed statistically significant differences. Our findings different with the finding by [6] and [8]. In contrast, several research studies showed oxidative stability increases in olive oils of the manufacturing from de-stone olives [2], [7]. Table 4. Acidity and peroxide statistical analysis of olives were collected by hand and machine plathform in Gemlik
De-stone oliv.
Wholol iv.
Harvesting Method
N
Acidity (%)
Peroksit Value (meqO2/kg)
By Hand
3
1,8733 ± 0,014
5,6933 ± 0,003
Machine + Platform
3
2,0633 ± 0,009
6,4400 ± 0,023
By Hand
3
1,8400 ± 0,006
5,6833 ± 0,009
Machine + Platform
3
2,0200 ± 0,012
6,4600 ± 0,006
Statistical Analizes Summary (F Values) Acidity (%) 4,545 8,895*
By Hand Machine + Platform *P ≤ 0,05
Peroksit Value (meqO2/kg) 1,125 0,706
ACIDITY (%) PEROXIDE VALUE (meqO2/kg)
GEMLIK 2,06
2,1
2,02
2 1,9
1,87
1,84
1,8 1,7 BY HAND
MACHINE+PLATFORM
GEMLIK
6,6 6,4 6,2 Whole Olives 6 De-stone Olives 5,8 5,6 5,4 5,2
6,44 6,46
Whole Olives
5,69 5,68
De-stone Olives
BY HAND
MACHINE+PLATFORM
Fig. 8. Acidity and peroxide value of olives were collected by hand and machine plathform in Gemli
Data presented in the above Fig. 8. and table 4. show that while acidity was significantly affected has the method of harvest only in machine + platform harvestinng, whereas both acidity and peroxide values were not affected significantly by hand harvesting which depended on the olives being de-stone or whole in the GEMLIK variety. With regards to the AYVALIK variety, while acidity was significantly affedted by hand harvest only, the peroxide value was signifikantlyaffedted in both hand harvest and machine + platform harvest (Fig. 9 and table 5). The results appearing different than those found in the GEMLIK variety. As results, for the manufacturing from de-stone olives, positive variations in the factors (concentration and activity of lipolytic enzymes etc.) which influencing hydrolytic deterioration reactions can decrease the FFA (%) content. According to numerous research studies, an increase in the enzymes activity (lipoxygenese,
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peroxidase etc.), a decrease in the total antioxidant capacity (tocopherol, phenols contents etc.) can influence on the PV in the manufacturing from whole olives. However, effects of olive variety on the PV are also important. Table 5. Acidity and peroxide statistical analysis of olives were collected by hand and machine plathform in Ayvalik
De-stone oliv.
Whololiv .
Harvesting Method
N
Acidity (%)
Peroksit Value (meqO2/kg)
By Hand
3
2,0900 ± 0,006
4,5200 ± 0,012
Machine + Platform
3
2,2633 ± 0,009
6,1100 ± 0,006
By Hand
3
2,0500 ± 0,006
4,4633 ± 0,009
Machine + Platform
3
2,2300 ± 0,006
6,0700 ± 0,006
By Hand Machine + Platform ** P ≤ 0,01 * P ≤ 0,05
Statistical Analizes Summary (F Values) Acidity (%) Peroksit Value (meqO2/kg) 24,000** 15,211* 10,000 24,000**
ACIDITY (%)
PEROXIDE VALUE
AYVALIK
2,3 2,25 2,2 2,15 2,1 2,05 2 1,95 1,9
2,26
2,09
2,23
2,05
BY HAND
MACHINE+PLATFORM
(meqO2/kg)
AYVALIK
7 6 5 Whole Olives 4 De-stone Olives 3 2 1 0
6,11 4,52
6,07
4,46 Whole Olives De-stone Olives
BY HAND
MACHINE+PLATFORM
Fig. 9. Acidity and peroxide value of olives were collected by hand and machine plathform in Ayvalik
4. Conclusions In conclusion, the values derived from the implementation of the platform we have developed shows that there are not big differences from the average values, despite the minor differences from picking with hand. Hence, it can be recommended that this platform can help to avoid olive harm which leads to decrease in the quality of the olive oil and it can provide labor and time saving so that this platform can be used especially in small businesses as an alternative harvesting method. References [1] Dag, A.; Ben-Gal, a.; Yermiyahu,u.; Basheer, l.; Nir, Y. and Kerem, Z., 2008. The effect of irrigation level and harvest mechanization on virgin olive oil quality in a traditional rain-fed ‘Souri’ olive orchard converted to irrigation. J Sci Food Agric 88:1524– 1528.
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[2] Mulinacci, N., Giaccherini, C., Innocenti, M., Romani, A., Vincieri, F.F., Marotta, F., Mattei, A., 2005. Analysis of extra virgin olive oils from stoned olives. J. Sci. Of Food and Agric., 85, 662-670. [3] Sievers, G.P., Hynninen, H., 1977. J. Chromatogr. 134, 359-366. [4] Yulan, R., Bingren, X., Xiaohua, Z., Zhimei, W., Shaofei, X., and Jianping, X., 2009. Quantitative and qualitative determination of acidvalue of peanut oil using near-infrared spectrometry. Journal of Food Engineering Volume: 93 Issue: 2 P: 249-252 JUL 2009. [5] IUPAC. Standard Methods for the Analysis of Oils, Fats and Derivatives. International Union Pure and Applied Chemistry Division Commission on Oils, Fats and Derivatives, 7th ed., Blackwell Jevent Publishers, 1987, Oxford. [6] A. Del Caro, V. Vacca, M. Poiana, P. Fenu, A. Piga. 2006. Influence of technology, storage and exposure on components of extra virgin olive oil (Bosana cv) from whole and de-stoned fruits, Food Chemistry, 98 (2) 311–316. [7] Tekin, A., Yorulmaz, A. veTuran, S. (2008). Çekirdeksizüretiminveazotaltındamalaksiyonunzeytinyağınınoksidatifstabilitesi, yağasidive sterol kompozisyonunaetkisi, I.National Olive Congres, 17-18 May 2008, Edremit, Balıkesir. [8] Amirante P., Clodoveo ML., Dugo G., Leone A., Tamborrino A. 2006. Advance technology in virgin olive oil production from traditional and de-stoned pastes: Influence of the introduction of a heat exchanger on oil quality. Food Chemistry 98 (4) 797-805 [9] Ranalli, A., Benzi, M. Gomes, T., Delcuratolo, D., Marchegiani, D., Lucera, L. 2007. Concentration of natural pigments and other bioactive components in pulp oils from de-stoned olives. Innovative Food Science and Emerging Technologies, 8 (3) 437-442. [10] Nouros G.P., Constantinos A.G., Moschos G.P. (1999). Direct paralel flow injection multichannel spectrophotometric determination of olive oil peroxide value. AnalyticaChimicaActa 389,239-245
ScienceDirect APCBEE Procedia 8 (2014) 334 – 342
2013 4th International Conference on Agriculture and Animal Science (CAAS 2013) 2013 3rd International Conference on Asia Agriculture and Animal (ICAAA 2013)
Effects of Olive Harvesting Methods on Oil Quality C. Saglama,*, Y.T.Tunaa, U.Gecgela, E.S.Atara a
N.K.U.Agricultural Faculty Tekirdag/TURKEY
Abstract Olives are traditionally hand harvested, a process that is not only tedious and laborious, but represents the major proportion of the costs of production. As it is known, harvesting method has important effect on the quality of olive especially produced for table consumption. Objective of this research is to compare effect of harvesting methods on amount of oleic acid (%) and peroxide value (meqO2/kg) which has importance for oil quality. Two different olive varieties whole olives and de-stone olives were used. Harvesting methods were harvesting by hand and harvesting by machine to collect on a platform. Amount of the oleic acid (%) and peroxide value (meqO2/kg) were measured by using titration method. According to the statistical analyzes results, differences between measured results were important (P ≤ 0,05). © Saglam. Published by Elsevier This is and/or an open peer accessreview article under CC BY-NC-NDoflicense ©2014 2013C.Published by Elsevier B.V.B.V. Selection undertheresponsibility Asia-Pacific (http://creativecommons.org/licenses/by-nc-nd/3.0/). Chemical, Biological & Environmental Engineering Society Selection and peer review under responsibility of Asia-Pacific Chemical, Biological & Environmental Engineering Society Keywords: OLIVE HARVESTING, OLIVE OIL, OIL QUALITY, ACIDITY, PEROXIDE VALUE
1. Introduction Olives are traditionally hand harvested, a process that is not only tedious and laborious, but represents the major proportion of the costs of production. Hand harvest is accomplished by three techniques: 1) collection of fallen fruit from the ground, 2) "milking", or the stripping of fruit with half open hands from limbs which falls into picking bags or onto nets below the tree, 3) beating limbs with large sticks to dislodge fruit, which is also collected on nets. Mechanical harvest of olives has been used to a limited extent in more intensive orchards.
* Corresponding author : Tel : +90 282 2502268 ; Fax : +90 282 2509929 E-mail address: [email protected]
2212-6708 © 2014 C. Saglam. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Selection and peer review under responsibility of Asia-Pacific Chemical, Biological & Environmental Engineering Society doi:10.1016/j.apcbee.2014.03.050
C. Saglam et al. / APCBEE Procedia 8 (2014) 334 – 342
As it is known, harvesting method has important effect on the quality of olive especially produced for table consumption. Some researches showed that harvesting method also has important effect on the quality of olive oil. Although a number of studies have reported effects of irrigation on yield parameters under conditions and varieties, there is shortage of the influence of harvesting method on oil quality. [1], studied on the effects of irrigation on oil quality of fruit obtained from both mechanical and hand harvesting methods. They found that when fruit was picked carefully by hand so that no injuries were inflicted, free fatty acids levels were substantially reduced, peroxide was reduced and total polyphenol content was increased. Degradation of oil quality related to increased irrigation could potentially be aggravated by damage to fruit caused during harvesting. [2] Examined extra virgin oil from whole olives and that from de-stone olives between 1999-2002 in terms of their main chemical qualities. It was asserted that the acidity of the oil from de-stone is lower or the same, and that de-stone olives are more durable in terms of oxidation. [3] The chemical combination of the oil depends on the kind of the fruit, fruit maturity degree, environmental conditions, growth area and the techniques of processing and storage. [4] Food quality and safety are attracting an increasing amount of attention for producers, researchers, and consumers. Acid value (AV) measures free fatty acids and is usually considered to be one of the main parameters to reflect the quality of oil, degree of refining, as well as the quality change during storage. 2. Materials and Methods 2.1. Harvesting Machine Tree shaking machine (Fig.1); it is combined of the motor, the body and the vibration rod. There is a hook of which mouth gap is 42 mm. The movement which comes from the motor is transmitted with its eccentric mechanism. Machine power is 2,8 HP and cylinder capacity is 52,5 cc. The number of beats per minute is 1350. However, its length can be extended up to 3 meters with telescopic extension. The total weight of the machine is 14,5 Kg.
Fig. 1. Tree shaking machine
2.2. Platform Picking platform can be carried being tied to three-point hanging system and can be directed with hand in the orchard. The height of platform chassis from the floor is 400 mm. and the height of axle from the floor is 200 mm. There are seven drawers in which the olives are gathered, in the 200 mm- space left in the chassis. There is a metal frame which carries the eight-corner and 1250 mm. diameter telescopic feet made of T profile. One corner of the frame is left open for the entrance of the trees. Some telescopic fiber rods which work with a special hinge which open and close with a 90-degree-angle are put on this eight-corner frame. The diameter of the main body of the telescopic rods is 40 mm. and the diameter of the head decreases down
335
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C. Saglam et al. / APCBEE Procedia 8 (2014) 334 – 342
to 20 mm. The rods can open in three levels, 1000 mm each, and the length of each bar is 3000 mm. 26 telescopic rods are installed on the eight-corner frame with a 13,8-degree angle. The total bar gap, including the semi-diameter of the eight-corner frame, is 7250 mm. when the bars open, that is, the platform get into an adverse umbrella with a diameter (Fig 2.).
7,25
Fig. 2. Picking Platform
The first levels of the bars are developed with a special rubber hinge system which provides stretch automatically for the end the first levels in order for the telescopic bars to open and close easily and in order for the shelf to keep stretched (Fig. 3).
Fig. 3. Hinge
On the telescopic bars a 3 x 3 mm. porous polyethylene-based net which is called “bee veil” or “serge” is put. This stretch of the net is adjusted in a way that the olives don’t jump too high but they don’t pile up on the net. The part of the platform which catches the tree and the net in the space left for the operator entrance can open and close like a curtain and they shift from one bar to the other and fix on it. 2.3. Harvesting Methods and Obtaining the Olive Oil Samples Olive trees in the Aegean region of western part of Turkey were harvested using the 2 methods of harvesting by hand and harvesting by machine on a platform. Olive oil was obtained as soon as harvesting was finished. Olive oil samples were processed using a laboratory type system that was manufactured in the Workshop of N.K.U. Agricultural Faculty, Department of Agricultural machinery. This system was designed as similar to big scale continues olive oil production systems (Fig. 4). To obtain the olive oil using this system, production steps were as below: z Separation dirt and leaves from the leaves, z Grinding of olives and their pits into paste which goes onto the press. z Malaxation by slow mixing of the paste which allows the oil - water emulsion to coalesce in the malaxation tank that was occurred constant temperature (30 °C). Small microscopic oil droplets join
337
C. Saglam et al. / APCBEE Procedia 8 (2014) 334 – 342
z
together into large drops with this process. Pressing of the paste. The press separates out the olive juice and oil using additional filter.
Fig. 4. System that was manufactured to obtain olive oil samples
2.4. Acidity and Peroxide ValueMeasurement Oil samples pressed from olive fruits were subjected to free fatty acids and peroxide value according to methods no 2.201, 2.501 (IUPAC) respectively [5]. 3. Results and Discussion Free fatty acidity (%, FFA) is usually considered to be one of the main parameters to reflect the quality of olive oils. Because this content, resulting from the hydrolysis of triacylglycerol as well as further decomposition of hydroperoxides, is one of the most important indicators of olive oil deterioration. Our results for the FFA (%) content showed that this content in the olive oils of the manufacturing from whole olives was higher significantly (P< 0.01) than that of the manufacturing from de-stone olives. For the olive oil samples of both varieties, in both harvesting methods, excepting harvesting method by hand for Gemlik variety, the FFA (%) content was high in the manufacturing from whole olives (Table 1. And Fig 5). Our findings agree with the finding by [2], [6], and [7]. Differently observations were made by [8] and [9]. These researchers reported that the manufacturing from de-stone olives wasn’t factor influencing the FFA (%) content. Table 1. Acidity and peroxide value of whole olives and de-stone olives were collected with by hand and machine plathform in Ayvalik and Gemlik
Whole olives
1,87
PEROXIDE VALUE (meqO2/kg) 5,69
De-stone olives
1,84
5,68
Whole olives
2,06
6,44
De-stone olives
2,02
6,46
Whole olives
2,09
4,52
De-stone olives
2,05
4,46
Whole olives
2,26
6,11
De-stone olives
2,23
6,07
AYVALIK
GEMLIK
ACIDITY (%) BY HAND MACHINE + PLATHFORM BY HAND MACHINE + PLATHFORM
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C. Saglam et al. / APCBEE Procedia 8 (2014) 334 – 342
7 6 5 4 3 2 1 0
By Hand
Mach + Plat.
By Hand
De-stone Olives
Whole Olives
De-stone Olives
Whole Olives
De-stone Olives
Whole Olives
De-stone Olives
Whole Olives
ACIDITY (%) PEROKSIT VALUE (meqO2/kg)
Mach + Plat.
Fig. 5. Acidity and peroxide value of whole olives and de-stone olives were collected by hand and machine plathform in Ayvalik and Gemlik
ACIDITY (%)
PEROXIDE VALUE
GEMLIK
2,1 2,05 2 1,95 1,9 1,85 1,8 1,75 1,7
2,06
1,87
Whole olives
(meqO2/kg)
GEMLIK
2,02
1,84
6,6 6,4 6,2 6 BY HAND 5,8 MACHINE+PLATFORM 5,6 5,4 5,2
5,69
BY HAND
5,68
MACHINE+PLATFORM
Whole olives
De-stone olives
6,46
6,44
De -stone olives
Fig. 6. Acidity and peroxide value of whole olives and de-stone olives in Gemlik.
Table 2. Acidity and peroxide statistical analysis of whole olives and de-stone olives in Gemlik.
Mach. + Plat.
By Hand
Harvesting Method
N
Acidity (%)
Peroksit Value (meqO2/kg)
Whole olives
3
1,8733 ± 0,014
5,6933 ± 0,003
De-stone olives
3
1,8400 ± 0,006
5,6833 ± 0,009
Whole olives
3
2,0633 ± 0,009
6,4400 ± 0,023
De-stone olives
3
2,0200 ± 0,012
6,4600 ± 0,006
Statistical Analizes Summary (F Values)
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Whole olives De-stone olives ** P ≤ 0,01
Acidity (%)
Peroksit Value (meqO2/kg)
124,962** 194,400**
1024,000** 5428,900**
According to the Fig.6. and table.2 that the results derived from the samples of GEMLİK variety show that the difference between the harvesting methods with respect to acidity and peroxide values are considered to be important pertaining to both the whole and de-stone olives. ACIDITY (%)
PEROXIDE VALUE
AYVALIK 2,26
2,3 2,25 2,2 2,15 2,1 2,05 2 1,95 1,9
2,09
Whole olives
(meqO2/kg)
AYVALIK
2,23
2,05
6,11
7 6 5 4 BY HAND 3 MACHINE+PLATFORM 2 1 0
4,52
BY HAND MACHINE+PLATFORM
Whole olives
De-stone olives
6,07 4,46
De-stone olives
Fig. 7. Acidity and peroxide value of whole olives and de-stone olives in Ayvalik.
Table 3. Acidity and peroxide statistical analysis of whole olives and de-stone olives in Ayvalik
Mach. + Plat.
By Hand
Harvesting Method
N
Acidity (%)
Peroksit Value (meqO2/kg)
Whole olives
3
2,0900 ± 0,006
4,5200 ± 0,012
De-stone olives
3
2,0500 ± 0,006
4,4633 ± 0,009
Whole olives
3
2,2633 ± 0,009
6,1100 ± 0,006
De-stone olives
3
2,2300 ± 0,006
6,0700 ± 0,006
Statistical Analizes Summary (F Values)
Whole olives De-stone olives ** P ≤ 0,01
Acidity (%)
Peroksit Value (meqO2/kg)
270,400** 486,000**
15168,600** 23232,400**
According to the Fig.7. and table 3. that the results derived from the samples of AYVALIK variety show that the difference between the harvesting methods with respect to acidity and peroxide values are considered to be important pertaining to both the whole and de-stone olives. Peroxide value (meqO2/kg, PV) is a measure of oxidative rancidity and a guide to olive oil quality. The PV is one of the most frequently determined quality indices during olive oil production, storage and marketing [10]. Our results for the PV showed that this value in the olive oils of the manufacturing from whole olives for
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the Ayvalık variety was higher significantly (P< 0.01) than that of the manufacturing from de-stone olives. As for Gemlik variety, the olive oils of the manufacturing from whole olives were only characterized by high PV in by hand harvesting method. The results for Gemlik variety also were found to be significant (P< 0.01). As for influencing harvesting methods, there were similarly variations among their PV for Gemlik variety. Comparing the effects of the harvesting methods for the Ayvalık variety, however, the PV showed statistically significant differences. Our findings different with the finding by [6] and [8]. In contrast, several research studies showed oxidative stability increases in olive oils of the manufacturing from de-stone olives [2], [7]. Table 4. Acidity and peroxide statistical analysis of olives were collected by hand and machine plathform in Gemlik
De-stone oliv.
Wholol iv.
Harvesting Method
N
Acidity (%)
Peroksit Value (meqO2/kg)
By Hand
3
1,8733 ± 0,014
5,6933 ± 0,003
Machine + Platform
3
2,0633 ± 0,009
6,4400 ± 0,023
By Hand
3
1,8400 ± 0,006
5,6833 ± 0,009
Machine + Platform
3
2,0200 ± 0,012
6,4600 ± 0,006
Statistical Analizes Summary (F Values) Acidity (%) 4,545 8,895*
By Hand Machine + Platform *P ≤ 0,05
Peroksit Value (meqO2/kg) 1,125 0,706
ACIDITY (%) PEROXIDE VALUE (meqO2/kg)
GEMLIK 2,06
2,1
2,02
2 1,9
1,87
1,84
1,8 1,7 BY HAND
MACHINE+PLATFORM
GEMLIK
6,6 6,4 6,2 Whole Olives 6 De-stone Olives 5,8 5,6 5,4 5,2
6,44 6,46
Whole Olives
5,69 5,68
De-stone Olives
BY HAND
MACHINE+PLATFORM
Fig. 8. Acidity and peroxide value of olives were collected by hand and machine plathform in Gemli
Data presented in the above Fig. 8. and table 4. show that while acidity was significantly affected has the method of harvest only in machine + platform harvestinng, whereas both acidity and peroxide values were not affected significantly by hand harvesting which depended on the olives being de-stone or whole in the GEMLIK variety. With regards to the AYVALIK variety, while acidity was significantly affedted by hand harvest only, the peroxide value was signifikantlyaffedted in both hand harvest and machine + platform harvest (Fig. 9 and table 5). The results appearing different than those found in the GEMLIK variety. As results, for the manufacturing from de-stone olives, positive variations in the factors (concentration and activity of lipolytic enzymes etc.) which influencing hydrolytic deterioration reactions can decrease the FFA (%) content. According to numerous research studies, an increase in the enzymes activity (lipoxygenese,
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peroxidase etc.), a decrease in the total antioxidant capacity (tocopherol, phenols contents etc.) can influence on the PV in the manufacturing from whole olives. However, effects of olive variety on the PV are also important. Table 5. Acidity and peroxide statistical analysis of olives were collected by hand and machine plathform in Ayvalik
De-stone oliv.
Whololiv .
Harvesting Method
N
Acidity (%)
Peroksit Value (meqO2/kg)
By Hand
3
2,0900 ± 0,006
4,5200 ± 0,012
Machine + Platform
3
2,2633 ± 0,009
6,1100 ± 0,006
By Hand
3
2,0500 ± 0,006
4,4633 ± 0,009
Machine + Platform
3
2,2300 ± 0,006
6,0700 ± 0,006
By Hand Machine + Platform ** P ≤ 0,01 * P ≤ 0,05
Statistical Analizes Summary (F Values) Acidity (%) Peroksit Value (meqO2/kg) 24,000** 15,211* 10,000 24,000**
ACIDITY (%)
PEROXIDE VALUE
AYVALIK
2,3 2,25 2,2 2,15 2,1 2,05 2 1,95 1,9
2,26
2,09
2,23
2,05
BY HAND
MACHINE+PLATFORM
(meqO2/kg)
AYVALIK
7 6 5 Whole Olives 4 De-stone Olives 3 2 1 0
6,11 4,52
6,07
4,46 Whole Olives De-stone Olives
BY HAND
MACHINE+PLATFORM
Fig. 9. Acidity and peroxide value of olives were collected by hand and machine plathform in Ayvalik
4. Conclusions In conclusion, the values derived from the implementation of the platform we have developed shows that there are not big differences from the average values, despite the minor differences from picking with hand. Hence, it can be recommended that this platform can help to avoid olive harm which leads to decrease in the quality of the olive oil and it can provide labor and time saving so that this platform can be used especially in small businesses as an alternative harvesting method. References [1] Dag, A.; Ben-Gal, a.; Yermiyahu,u.; Basheer, l.; Nir, Y. and Kerem, Z., 2008. The effect of irrigation level and harvest mechanization on virgin olive oil quality in a traditional rain-fed ‘Souri’ olive orchard converted to irrigation. J Sci Food Agric 88:1524– 1528.
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[2] Mulinacci, N., Giaccherini, C., Innocenti, M., Romani, A., Vincieri, F.F., Marotta, F., Mattei, A., 2005. Analysis of extra virgin olive oils from stoned olives. J. Sci. Of Food and Agric., 85, 662-670. [3] Sievers, G.P., Hynninen, H., 1977. J. Chromatogr. 134, 359-366. [4] Yulan, R., Bingren, X., Xiaohua, Z., Zhimei, W., Shaofei, X., and Jianping, X., 2009. Quantitative and qualitative determination of acidvalue of peanut oil using near-infrared spectrometry. Journal of Food Engineering Volume: 93 Issue: 2 P: 249-252 JUL 2009. [5] IUPAC. Standard Methods for the Analysis of Oils, Fats and Derivatives. International Union Pure and Applied Chemistry Division Commission on Oils, Fats and Derivatives, 7th ed., Blackwell Jevent Publishers, 1987, Oxford. [6] A. Del Caro, V. Vacca, M. Poiana, P. Fenu, A. Piga. 2006. Influence of technology, storage and exposure on components of extra virgin olive oil (Bosana cv) from whole and de-stoned fruits, Food Chemistry, 98 (2) 311–316. [7] Tekin, A., Yorulmaz, A. veTuran, S. (2008). Çekirdeksizüretiminveazotaltındamalaksiyonunzeytinyağınınoksidatifstabilitesi, yağasidive sterol kompozisyonunaetkisi, I.National Olive Congres, 17-18 May 2008, Edremit, Balıkesir. [8] Amirante P., Clodoveo ML., Dugo G., Leone A., Tamborrino A. 2006. Advance technology in virgin olive oil production from traditional and de-stoned pastes: Influence of the introduction of a heat exchanger on oil quality. Food Chemistry 98 (4) 797-805 [9] Ranalli, A., Benzi, M. Gomes, T., Delcuratolo, D., Marchegiani, D., Lucera, L. 2007. Concentration of natural pigments and other bioactive components in pulp oils from de-stoned olives. Innovative Food Science and Emerging Technologies, 8 (3) 437-442. [10] Nouros G.P., Constantinos A.G., Moschos G.P. (1999). Direct paralel flow injection multichannel spectrophotometric determination of olive oil peroxide value. AnalyticaChimicaActa 389,239-245