Doç. Dr. Dilşat BOZDOĞAN KONUŞKAN ve Arkadaşları

J Am Oil Chem Soc (2016) 93:1499–1508
DOI 10.1007/s11746-016-2904-8
ORIGINAL PAPER

Effects of Variety, Maturation and Growing Region on Chemical Properties, Fatty Acid and Sterol Compositions of Virgin Olive Oils
Dilsat Bozdogan Konuskan¹ · Burcu Mungan^1
1Food Engineering Department, Faculty of Agriculture, Mustafa Kemal University, Hatay, Antakya, Turkey

Received: 11 July 2016 / Revised: 21 July 2016 / Accepted: 15 September 2016 / Published online: 26 September 2016 © AOCS 2016

Abstract 
Chemical properties, fatty acid and sterol com-positions of olive oils extracted from Gemlik and Halhalı varieties grown in Hatay and Mardin provinces in Turkey were investigated during four maturation stages. The olive oil samples were analyzed for their chemical properties such as free acidity, peroxide value, total carotenoid, total chlorophyll, total phenolic contents, antioxidant activity, fatty acid and sterol compositions. Chemical properties, fatty acids and sterol profiles of olive oil samples gener-ally showed statistically significant differences depending on the varieties, maturation and growing areas (p < 0.05). As free fatty acid contents and total phenolic contents increased, total carotenoid and chlorophyll contents decreased throughout the maturity stages. Total carote-noid and chlorophyll contents of oil samples from Mardin were higher than those of Hatay. The total phenolic com-pounds of olive oil samples ranged from 20.62 in Gemlik to 525.22 mg GAE/kg oil in Halhalı from Hatay. In general, the phenolic contents and antioxidant activities of olive oil samples were positively associated. Oleic acid content was the highest 71.53 % in H1 samples in Hatay. Total sterol contents were 1194.33 mg/kg in Halhalı and 2008.66 mg/ kg in Gemlik from Hatay. Stigmasterol contents of oils obtained from Hatay were lower than those of Mardin. Oleic acid, palmitic acid, β-sitosterol, ∆-5-avenasterol and campesterol contents fluctuated with maturation for each of variety from both growing regions. These results showed that the variety, growing area and maturation influence the chemical properties, fatty acid and sterol compositions.
Keywords  Olive cultivar · Maturity · Growing region · Fatty acid · Sterol

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Sterol Compositions of  Virgin Olive Oils

Copyright ©2021 by Japan Oil Chemists’ Society
doi : 10.5650/jos.ess20179
Oleo Sci. 70, (1) 51-58 (2021)

Quality Properties, Fatty Acid and Sterol Compositions of East Mediterranean Region Olive Oils
Okan Demirag¹ and Dilsat Bozdogan Konuskan^2＊
Food Control Laboratory Directorate, Çanakkale, TURKEY
Faculty of Agriculture, Department of Food Engineering, Hatay Mustafa Kemal University, Hatay, TURKEY
Abstract
In this study, important physicochemical properties, fatty acid and sterol compositions of olive oils from the olives which harvested from Mersin (Buyuk Topak Ulak, Gemlik, Sari Ulak), Adana (Gemlik), Osmaniye (Gemlik) and Hatay (Gemlik, Kargaburun, Hasebi, Halhali) in the Eastern Mediterranean region of Turkey have been investigated. Ripening index and oil yield analysis of the olives and free fatty acids, peroxide value, UV absorbance (K₂₃₂, K₂₇₀), fatty acid composition, sterol composition, erythrodiol+uvaol content, and total sterol analysis of the olive oil samples were carried out. The levels of free acidity in the olive oil samples ranged from 0.39% (Hatay Gemlik: HG3) to 2.23% (Mersin Gemlik: MG). Peroxide value ranged from 8.87 to 18.87 meq O₂/kg. As K₂₃₂ values in the oils fluctuated between 1.4370 and 2.3970, K₂₇₀ values varied between 0.1270 and 0.1990. The results showed that all ΔK values were lower than the maximum legal limit of 0.01. The main fatty acid in all oil samples was oleic acid, ranging from 58.72% (Hatay Hasebi: HHs) to 74.54% (Hatay Gemlik: HG2). Palmitic acid values were within the percentage of 12.83% (Hatay Kargaburun: HK) to 18.50% (HHs). Total sterol content varied from 720.41 mg/kg (Hatay Kargaburun: HK) to 4519.17 mg/kg (Buyuk Topak Ulak: BTU). The β-sitosterol percentage of olive oils ranged from 76.12% (Adana Gemlik: AG) to 94.23% (Buyuk Topak Ulak: BTU). The results of this study indicated that variety significantly affect the quality indices, fatty acid and sterol compositions of olive oils significantly varied among varieties.
Key words: olive oil, quality indices, fatty acids, sterols

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Quality Properties

J Food Sci Technol (November 2017) 54(12):4067–4077 DOI 10.1007/s13197-017-2879-y
ORIGINAL ARTICLE

Antioxidant activity, sterol and fatty acid compositions of Turkish olive oils as an indicator of variety and ripening degree

Hasan Ozkan Yorulmaz¹  Dilsat Bozdogan Konuskan^1
1Faculty of Agriculture Food Engineering Department, Mustafa Kemal University, Hatay, Turkey
Revised: 6 September 2017 / Accepted: 19 September 2017 / Published online: 4 October 2017
Association of Food Scientists & Technologists (India) 2017

Abstract
This study was carried out to determine the effect of three ripening stages (green, spotted and ripe) on fatty acid, sterol composition and antioxidant activity of olive oils from three olive varieties (Sarı Hasebi, Gemlik and Halhalı) widely grown in the eastern Mediterranean region of Turkey. The variety had a significant effect on the fatty acids, sterols and total phenolic content. Halhalı oil had the lowest oleic acid content (67.28%), while Sarı Hasebi oil had the highest (75.61%). Total phenolic content varied between 163.02 mg GAE/kg oil and 749.28 mg GAE/kg oil. Halhalı oil showed the highest antioxidant activity (IC₅₀ = 66 lg/ml) whereas Sarı Hasebi oil showed the lowest one (IC₅₀ = 2617 lg/ml). The total content of sterols in olive oils ranged from 358 mg/kg in Sarı Hasebi to 1092.33 mg/kg in Halhalı. The b-sitosterol content of olive oils varied between 80.72 (Sarı Hasebi) and 87.81% (Halhalı). D-5-avenasterol content ranged between 3.34 (Halhalı) and 7.30% (Gemlik). Variety and ripening degree significantly affected the b-sitosterol, D-5-avenasterol and erythrodiol ? uvaol contents of oils. Finally, these results showed that sterol and fatty acid compositions can be used as indicators of variety and ripening degree among virgin olive oils.
Keywords: Olive oil Fatty acids Antioxidant activity Sterols Ripening Variety

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Antioxidant Activity