Quality Assessment in Gemlik PDO Olives Based on Regional Differences, Oil, and Pigment Contents Within the SDG Goals

Abstract

This study examined how some physicochemical properties of Gemlik olives (Olea europaea L. cv. Gemlik) grown in five different regions of Türkiye (Antalya, Aydın, Balıkesir, Manisa, and Hatay) differed during two harvest seasons. The study was conducted to find out how changes in climate, soil composition, and leaf nutrients in the different regions affect fruit ripening, oil accumulation, and fruit pigmentation. Water, dry matter, oil, chlorophyll, and carotenoid contents analyses were performed on Gemlik olives. Balıkesir olives yielded the most oil (64.04% and 57.10% of dry weight), but Aydın and Manisa olives yielded less oil (16-17% of dry weight). Hatay had the most pigments (40.64 mg/kg chlorophyll and 235.63 mg/kg carotenoids). Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) showed that oil and pigment changes are linked to environmental factors such as temperature, salt, and soil magnesium. This study ties in with the UN Sustainable Development Goals (SDGs 2, 12, and 13). It will also ensure quality and resilience to climate change within Protected Designation of Origin (PDO) systems.

Keywords

• Gemlik olive
• oil content
• pigments (chlorophyll and carotenoids)
• climate
• soil interact
• sustainable growth

References

1. Akçay, U. Ç., Özkan, G., Şan, B., Dolgun, O., Dağdelen, A., & Konuşkan, D. B. (2014). Genetic stability in a predominating Turkish olive cultivar, Gemlik, assessed by RAPD, microsatellite, and AFLP marker systems. Turkish Journal of Botany, 38(3), 430–438. https://doi.org/10.3906/bot-1309-23.
2. AOAC. (2016). Official methods of analysis of AOAC International (20th ed.). American Oil Chemists’ Society.
3. AOCS. (2017). Official methods and recommended practices of the AOCS (7th ed.). American Oil Chemists’ Society.
4. Aparicio-Ruiz, R., Mínguez-Mosquera, M. I., & Gandul-Rojas, B. (2010). Thermal degradation kinetics of chlorophyll pigments in virgin olive oils. 1. Compounds of series a. Journal of Agricultural and Food Chemistry, 58(10), 6200-6208. https://doi.org/10.1021/jf9043937
5. Ben Yahia, Y., Barakate, M., Bouaziz, M., & Ksouri, R. (2019). Variability of carotenoid contents in different cultivars of Olea europaea L. during fruit ripening. Scientia Horticulturae, 248, 297–303. https://doi.org/10.1016/j.scienta.2019.01.048
6. Boussadia, O., Steppe, K., Zgallai, H., El Hadj, S. B., Braham, M., Lemeur, R., & Van Labeke, M. C. (2010). Effects of nitrogen deficiency on leaf photosynthesis, carbohydrate status and biomass production in two olive cultivars ‘Meski’ and ‘Koroneiki’. Scientia Horticulturae, 123(3),336-342. https://doi.org/10.1016/j.scienta.2009.09.023
7. Broadley, M. R., White, P. J., Hammond, J. P., Zelko, I., & Lux, A. (2007). Zinc in plants. New Phytologist, 173(4), 677–702. https://doi.org/10.1111/j.1469-8137.2007.01996.x
8. Dag, A., Kerem, Z., Yogev, N., Zipori, I., Lavee, S., & Ben-David, E. (2011). Influence of time of harvest and maturity index on olive oil yield and quality. Scientia Horticulturae, 127(3), 358-366. https://doi.org/10.1016/j.scienta.2010.11.008

9. Esri. (2025). Olive cultivation climate suitability maps of the Mediterranean basin. Esri Climate Lab.
10. FAO. (2024). FAOSTAT: Crops – Olives. Food and Agriculture Organization of the United Nations.
11. Field, A. (2000). Discovering statistics using SPSS for Windows. Sage.
12. Flamminii, F., Marone, E., Neri, L., Pollastri, L., Cichelli, A., & Di Mattia, C. D. (2021). The effect of harvesting time on olive fruits and oils quality parameters of Tortiglione and Dritta olive cultivars. European Journal of Lipid Science and Technology, 123(11), 2000382. https://doi.org/10.1002/ejlt.202000382
13. Gamlı, Ö. F., & Eker, T. (2017). Determination of harvest time of Gemlik olive cultivars by using physical and chemical properties. Journal of Food Measurement and Characterization, 11(4),2022–2030. https://doi.org/10.1007/s11694-017-9585-3
14. Sedjati, S., Santosa, G. W., Yudiati, E., Supriyantini, E., Ridlo, A., & Kimberly, F. D. (2019, March). Chlorophyll and carotenoid content of dunaliella salina at various salinity stress and harvesting time. In IOP Conference Series: Earth and Environmental Science (Vol. 246, No. 1, p. 012025). IOP Publishing. doi:10.1088/1755-1315/246/1/012025
15. Gómez-del-Campo, M., León, L., & de la Rosa, R. (2008). Variability of fruit characters in olive (Olea europaea L.) progenies. Spanish Journal of Agricultural Research, 6(3), 408–417. https://doi.org/10.5424/sjar/2008063-340
16. International Olive Council. (2022). World olive oil and table olive figures – 2021/22 season.
17. Irmak, Ş., Sefer, F., Güngör, F. Ö., Susamcı, E., Güloğlu, U., Yıldırım, A., & Tusu, G. (2022). Determination of table olive characteristics of new olive varieties obtained by crossbreeding of Gemlik and Memecik variety. Journal of Agriculture Faculty of Ege University, 59(2), 195-208. https://doi.org/10.20289/zfdergi.890479
18. Kaçar, B. (1995). Bitki ve toprağın kimyasal analizleri. Ankara Üniversitesi Ziraat Fakültesi Eğitim, Araştırma ve Geliştirme Vakfı.Ozturk, H. İ.
19. Keceli, T. M., Kamiloglu, S., & Capanoglu, E. (2017). Phenolic compounds of olives and olive oil and their bioavailability. In A. Kharrazi, M., Nasrollahzadeh, S., & Karimi, R. (2022). The role of nitrogen in chlorophyll synthesis in olives. Plant Nutrition and Soil Science, 185(2), 315–322.
20. Keceli, T. M., & Celik, F. H. (2024). Discrimination of Turkish Gemlik virgin olive oils by growing regions and environmental conditions. Journal of the American Oil Chemists' Society, 101(5), 45. https://doi.org/10.1002/aocs.12791
21. Kiritsakis & F. Shahidi (Eds.), Olives and Olive Oil as Functional Foods (pp. 457–470). John Wiley & Sons. DOI:10.1002/9781119135340
22. Lazzez, A., Vichi, S., & Kammoun, M. (2008). Environmental effects on phenolic and pigment contents of olives. Food Chemistry, 111(3), 683–689.Mastralexi, A. (2019). Evolution of safety and other quality parameters of table olives. European Journal of Lipid Science and Technology, 121(1), e1800171. https://doi.org/10.1002/ejlt.201800171.
23. Lichtenthaler, H. K. (1987). Chlorophylls and carotenoids: Pigments of photosynthetic biomembranes. Methods in Enzymology, 148, 350–382. https://doi.org/10.1016/0076-6879(87)48036-1.
24. Marcelo, M. E., Jordão, P. V., Matias, H., & Rogado, B. (2010). Influence of nitrogen and magnesium fertilization of olive tree Picual on yield and olive oil quality. Acta Hortic, 868, 445-450. DOI:10.17660/ActaHortic.2010.868.62
25. Marschner, H. (2012). Marschner’s mineral nutrition of higher plants (3rd ed.). Academic Press.
26. McCune, B., & Mefford, M. J. (1999). PC-ORD: Multivariate analysis of ecological data, version 4. Gleneden Beach, Oregon: MjM Software Design.
27. Rey‐Giménez, R., & Sánchez‐Gimeno, A. C. (2024). Effect of cultivar and environment on chemical composition and geographical traceability of Spanish olive oils. Journal of the American Oil Chemists' Society, 101(4), 371-382. https://doi.org/10.1002/aocs.12774
28. Rial, R., & Falque, E. (2003). Influence of the geographical area and cultivar on the composition of olives used for oil production in Galicia (Northwest Spain). Grasas y Aceites, 54(2), 115–123. https://doi.org/10.3989/gya.2003.v54.i2.231 grasasyaceites.revistas.csic.es.
29. Roca, M., & Mínguez-Mosquera, M. I. (2001). Changes in chloroplast pigments of olive varieties during fruit ripening. Journal of Agricultural and Food Chemistry, 49(2), 832–839. https://doi.org/10.1021/jf001000l
30. Saddoud Debbabi, O., Rahmani Mnasri, S., Ben Amar, F., Ben Naceur, M. B., Montemurro, C., & Miazzi, M. M. (2021). Applications of microsatellite markers for the characterization of olive genetic resources of Tunisia. Genes, 12(2),286. https://doi.org/10.3390/genes12020286
31. Sanz-Cortés, F., Badenes, M. L., & Martínez-Calvo, J. (2001). Genetic relationships of Spanish olive cultivars using RAPD markers. HortScience, 36(2), 303–307.
32. Thompson, M., & Nicholas, D. J. D. (1989). Inductively coupled plasma atomic emission spectrometry for the determination of trace elements in biological samples. Journal of Analytical Atomic Spectrometry, 4(5), 393-397. https://doi.org/10.1039/JA9890400393
33. Tunç, Y., Yaman, M., & Yılmaz, K. U. (2024). Determination of phenotypic diversity and effective temperature sum times in some olive (Olea europaea L.) varieties by using phenological stages with multivariate analysis. Applied Fruit Science, 66, 1151–1161. https://doi.org/10.1007/s10341-024-01091-y
34. Uceda, M. ve Frias, L. (1975) Harvest dates, Evolution of the fruit oil content, oil composition and oil quality. (s. 125-130). Cordoba: Proc Segundo Seminario Oleicola Internacional.
35. Wellburn, A. R. (1994). The spectral determination of chlorophylls a and b, as well as total carotenoids, using various solvents with spectrophotometers of different resolution. Journal of Plant Physiology, 144(3), 307–313. https://doi.org/10.1016/S0176-1617(11)81192-2
36. Yılmaz-Düzyaman, H., Medina-Alonso, M. G., Sanz, C., Pérez, A. G., de la Rosa, R., & León, L. (2023). Influence of genotype and environment on fruit phenolic composition of Olive. Horticulturae, 9(10),1087. https://doi.org/10.3390/horticulturae9101087
37. Yorulmaz, H.O., & Konuskan, D.B. (2017). Antioxidant activity, sterol and fatty acid compositions of Turkish olive oils as an indicator of variety and ripening degree. J Food Sci Technol 54, 4067–4077. https://doi.org/10.1007/s13197-017-2879-y
38. Yousfi, K., Cert, R. M., & García, J. M. (2006). Changes in quality and phenolic compounds of virgin olive oils during objectively described fruit maturation. European Food Research and Technology, 223(1),117-124. https://doi.org/10.1002/jsfa.3784
39. Yruela, I. (2005). Copper in plants. Brazilian Journal of Plant Physiology, 17(1), 145-156. https://doi.org/10.1590/S1677-04202005000100012