This study comprehensively evaluated the fruit and oil characteristics of 26 olive genotypes from 2016/17-2019/20. The research focused on physicochemical quality parameters and purity criteria to classify the oils as extra virgin olive oil (EVOO) and explore their genetic and biochemical diversity. All analyzed oils met EVOO standards for free acidity (<= 0.8% oleic acid), peroxide value, and UV absorbance (K232, K270), except one sample (Ters Yaprak). Phenolic content ranged widely (160.40-738.94 mg CAE/kg oil), correlating with oxidative stability (6.00-20.80 h). Oleic acid (65.29%-76.88%) and linoleic acid (5.63%-15.10%) were the dominant fatty acids, with variations linked to cultivar and climate. Total beta-sitosterol (93.59%-96.55%) and Delta 7-stigmastenol (0.18%-0.72%) were key markers for authenticity, though two samples exceeded Delta 7-stigmastenol limits. alpha-Tocopherol (159.91-423.48 mg/kg) was the primary antioxidant, with Memecik, Ayval & imath;k cultivars showing high levels. Phenolic content strongly influenced these attributes. Principal Component Analysis (PCA) revealed that phenolic content, oxidative stability, and fatty acid composition were the primary discriminators among cultivars. PCA results showed that variation in fatty acid, TAG, sterol compositions across 26 olive genotypes from 2016/17-2019/20 was primarily driven by genotype and harvest year, with no strong geographical clustering but distinct profiles for certain varieties such as Domat, Uslu, and E & scedil;ek Zeytini. Olive Varieties of the Aegean Region demonstrated exceptional quality, meeting EVOO standards with high phenolic and tocopherol content. Notable varieties such as Memecik, Ayval & imath;k exhibited superior oxidative stability underscoring their commercial and nutritional value. This study provides critical data for conserving genetic resources and promoting regional olive oils in competitive markets.
Extra virgin olive oils obtained from the Ayvalık, Memecik, Gemlik, Çekişte, and Sarı Ulak Turkish cultivars were evaluated to determine their chemical composition, quality classification, authenticity indicators, and sensory characteristics. Standard quality parameters, including free fatty acidity, peroxide value, and ultraviolet absorbance (K232, K270), were analyzed in accordance with International Olive Council (IOC) regulations. The majority of the samples met the criteria for extra virgin olive oil. The oleic acid content varied by variety and region, with Ayvalık and Memecik showing notably high levels. Sterol profile analyses revealed distinctive chemical markers that indicate authenticity and quality. Sensory analysis results showed that regional differences had a significant impact on aroma, taste, and overall acceptability. Oils from Ayvalık and Memecik received high scores for positive sensory attributes such as fruitiness, bitterness, and pungency. The results show that the chemical and sensory qualities of olive oil are directly influenced by both genetic diversity and growing conditions, which underscores the importance of conserving local varieties and promoting regional production methods.
Extra virgin olive oil (EVOO) is highly valued for its rich composition of bioactive compounds and high oleic acid content, which contribute to its nutritional quality and oxidative stability; however, its high market value has led to increasing adulteration with cheaper vegetable oils, raising concerns for consumer safety and product authenticity. To address this issue, international organizations such as the International Olive Council (IOC), FAO, and OLAF have established standards to ensure quality and traceability, although natural variations in fatty acid composition (typically 55–85% oleic acid) due to cultivar, origin, and processing conditions complicate authentication. In this context, Raman spectroscopy has emerged as a rapid, non-destructive, and reliable analytical technique capable of providing detailed molecular information without extensive sample preparation (Ryoo et al., 2017; Li et al., 2018).When combined with chemometric methods such as PLS, PLS-DA, andDD-SIMCA, Raman spectroscopy can detect adulteration at low levels, often below 5%, while advanced approaches including surface-enhanced Raman spectroscopy (SERS), temperature-modulated analysis, and interval-based methods (iPLS and siPLS) further improve sensitivity and accuracy, achieving detection limits as low as 0.5% (Farley et al., 2016; Hashem et al., 2020). The use of optimized preprocessing techniques such as standard normal variate (SNV), along with careful selection of instrumental parameters, enhances model performance, and the integration of machine learning algorithms enables classification accuracies exceeding 90%. Portable Raman systems allow for real-time, in situ analysis, making this technique highly suitable for routine quality control and authentication in the olive oil industry.
This study aims to characterize the composition of the volatile compounds in Turkish extra virgin olive oils (EVOOs) produced from three cultivars-Ayvalik, Gemlik, and Memecik-harvested in the South Marmara, South Aegean, and North Aegean regions during the 2014/15 and 2015/16 crop seasons. A total of 135 EVOO samples were obtained using industrial-scale 2-phase and 3-phase extraction systems. These samples were then analyzed using solid-phase microextraction (SPME) coupled with gas chromatography (GC). Among the twelve volatiles identified, trans-2-hexen-1-ol and cis-2-penten-1-ol exhibited the highest levels of abundance across all samples and seasons. Subsequently, 1-penten-3-one, hexanal, and cis-3-hexenyl acetate were identified, and it was determined that these contribute to the green and fruity sensory profile of high-quality olive oil. Two- and three-factor analyses of variance (ANOVA) revealed that volatile concentrations were significantly influenced by variety, harvest season, and extraction system. It is significant that 1-penten-3-one was found to be significantly influenced by both season and variety (p < 0.05), while 1-penten-3-ol exhibited a multifactorial dependency, with significant two-way interactions (season x variety, season x system, variety x system). Furthermore, PLS-DA-based classification successfully distinguished samples according to olive variety, indicating that volatile profiles could serve as reliable markers for authenticity and geographic origin. These findings underscore the potential of using volatile compounds as quality indicators and for geographic labelling in the olive oil industry.
The valorization of agro-industrial by-products represents a key strategy for promoting a sustainable food industry. This study explores the potential of ultrasound-assisted enrichment to improve both the nutritional profile and the oxidative stability of extra virgin olive oil (EVOO) through the incorporation of Phoenix dactylifera L. seeds, a resource that remains largely underutilized. The impact of seed addition was evaluated in four monovarietal EVOOs (Chemlal, Tefehi, Aghenfes, and Aguenaou). The effects on fatty acid composition, carotenoids, chlorophylls, tocopherols, total phenolic compounds (TPC), antioxidant activity, and oxidative stability were examined. Under optimal conditions (10 min, 50
The chemical and sensory characteristics of virgin olive oil (VOO) and extra virgin olive oil (EVOO) are assessed in this study, with an emphasis on the relationships between chemical profiles and sensory attributes such as fruitiness, bitterness, pungency, and defect presence. To evaluate their composition and sensory qualities, 18 samples of each type of oil, primarily Chemlali cultivars from various Tunisian regions, were examined. According to chemical analysis, VOO had a richer pigment profile than EVOO because it had a far higher chlorophyll and carotenoid. As for the fatty acid analysis, VOO had a larger percentage of the oleic acid concentration, while EVOO had more palmitic acid. This difference is probably what affects the oils' oxidative stability and sensory qualities. On the other hand, EVOO samples displayed higher concentrations of volatile and phenolic chemicals, which may improve their antioxidant capacity and sensory qualities. While VOO had discernible defects, sensory examination showed that EVOO had a more pronounced fruity profile and was consistently free of sensory defects. While pungency and bitterness were similar for both oil types, EVOO's lack of flaws complies with consumer preferences and premium olive oil quality requirements. EVOO's distinct nutritional profile, characterized by higher oleuropein and TPC levels (p < 0.05), increased Δ-7-stigmastenol (p < 0.001), and exclusive campestanol, enhances its antioxidant potential and cholesterol-regulating properties. These findings underline the influence of chemical composition on sensory perception in olive oils and highlight cultivar and regional differences. Both oils provide antioxidant and cholesterol-regulating benefits, but their unique chemical and sensory properties determine their suitability for different culinary and medical uses. The correlation between sensory attributes and chemical markers offers information on how to maximize quality of olive oil for desired flavor profiles and nutritional benefits.
The effect of different irrigation treatments on the quality and antioxidant compounds of the virgin olive oil obtained from Memecik variety was determined in this study, which was carried out in three consecutive years. For this purpose, six different irrigation treatments (25%, 50%, 75%, 100% and 125%) were applied to an olive orchard using the drip method. According to quality criteria, free acidity and peroxide value were not influenced by the amount of irrigation. Differences in fatty acids among oil samples were found statistically significant. Among the hydroxytyrosol, gallic acid, oleuropein, chlorogenic acid, caffeic acid, vanillic acid, p-coumaric acid, ferulic acid, luteolin and apigenin, hydroxytyrosol and vanillic acid were influenced by the amount of irrigation water applied to olive trees, and there was a significant relationship among the irrigation treatments. Generally, an increase in the amount of irrigation water given was accompanied by a reduction in bitterness indices and total chlorophyll contents. In terms of oil yield and chemical quality, 25% irrigation treatment could be recommended under experimental conditions.
Gemlik is a cultivar that grows in a distinct region of Turkiye and is ideal for brine fermentation olives have high levels of oleic acid (74%), total phenol (190 mg/kg), and dry matter (57%), while being low in linoleic acid (8%). The pH values and salt contents were observed to be in the range of 4.1 to 4.3 and 3.9% to 4.8%, respectively. During the fermentation of Gemlik table olives, a mass transfer occurred, resulting in a reduction in reducing sugar and total sugar contents as well as an increase in the salt content of the olives. Despite the reduction of phenolic content in both Gemlik PDO and non-PDO table olives, their antioxidant capacity remains high after fermentation. The oil content, antioxidant activity, phenolic contents, palmitic, palmitoleic, oleic, and linoleic acids were all found to be significant variables in distinguishing between Gemlik PDO and non-PDO table olives using PLS-DA analysis. There is a statistically significant correlation between the phenolic content and oleic (0.588) and linoleic (-0.659) acids (p < 0.05). Bursa PDO and Izmir non-PDO exhibit enhanced nutritional quality and antioxidant activity, unequivocally differentiating them from Hatay and Mersin non-PDO Gemlik table olives with 98% accuracy through discriminant analysis (p < 0.05). PLS-DA and DA can effectively identify variations in the quality of Turkish-style black table olives preserved in brine, originating from PDO and non-PDO growing areas.
In this study, It was aimed to determine the effects of different production and preservation methods on the shelf life and quality of the Gemlik variety natural black table olives produced with low salt (2%). For this purpose the olives processed with traditional Turkis turning black olive using starter culture The MAP (Modified athmosphere packaging), vacuum and gamma irradiation method (1, 3 and 5 kGy) was applied for the first time in the preservation of table olives. The reducing effect of 5 kGy dose on total phenolic substance and DPPH antioxidant activity was found to be higher than other doses. During storage, pH (4.30-4.83) and titratable acidity (0.68-1.02%) values of black table olives changed in normal course. At the and of the fermentation and storage, total phenolic substance and DPPH antioxidant activity decreased and were found statistically significant (p<0.01). During the storage period, the total amount of phenolic matter in olives in normal production (without starter culture) decreased from 232 to 144 mgCAE/100g and in starter culture added table olives from 200 to 138 mgCAE/100g. As a result of the study, it was ensured that table black olives produced with less salt (2%) could be stored on the shelves for at least 6 months without using any preservatives. In addition, radiation effect on quality was relatively similar to other applications.
Isotope ratio mass spectroscopy (IRMS) and nuclear magnetic resonance (NMR) spectroscopy techniques are two of the analytical methods that are used to characterize food products. The aim of this study is to classify extra virgin olive oil (EVOO) samples collected from different regions of Turkey based on H-1 and C-13 NMR spectra along with IRMS d(13)C carbon isotope ratio data by using chemometrics multivariate data analysis methods. A total of 175 EVOO samples were analyzed in 2014/15 and 2015/16 harvest seasons. Multivariate classification and clustering models were used to identify geographical and botanical origins of the EVOOs. IRMS results showed that there was no significant difference in terms of d(13)C values between the years in terms of harvest year (p > 0.05), only extraction phase and variety were statistically significant factors (p < 0.05). The interactions of the factors showed that the harvest year x variety interaction is important. The outcomes of this research clearly indicated that considering the partial least squares discriminant analysis result with NMR spectra, the percent success of the model in the South Marmara, North Aegean, and South Aegean region samples were 95%, 95.7%, and 96.4% in the model set, respectively. The results showed that by using classification and clustering models, geographic marking and labeling of these oils can be carried out regardless of differences in year and production systems (2 and 3 phase extraction system) according the NMR analysis.
Virgin olive oils (VOO) obtained from olives grown in different regions of our country, under changing climatic conditions, show different sensory and chemical properties. Due to the fact that primary production is affected by climatic and agricultural conditions and VOOs are supplied to the market by only physical processing. In order to determine whether these deviations are due to climatic conditions, VOOs were obtained from the olive samples collected from 39 orchards in four Region where VOO production is intense in Turkey. Analyzes were carried out regarding the quality and purity criteria of the VOOs. Samples were collected in 2017/18-2020/21 harvest years (-2 on-2 off). The maturity index (MI) values of olives and free fatty acidity (FFA), fatty acid ethyl esters (FAEE), delta-7-stigmastenol values of olive oils ranged between 0.94-4.15 and 0.07-1.27 (in oleic acid %), 1.56-27.32 mg/kg, 0.16-1.14%, respectively. Delta-7-stigmastenol values in 21 samples were outside the limit specified in the legislation (0.50-1.14%). The Fatty acid methyl esters (FAME) and FAEE of all olive oil samples were within the specified limits. In the study, multiple regression analysis was performed to investigate whether there is a relationship between climate data and delta-7-stigmastenol values by years. According to this result, it has been determined that the delta-7-stigmastenol value is high when the annual average relative humidity is low and the annual average temperature is high. There is an urgent need to make forward-looking plans due to climate change.
The current study was conducted on olive fruit from the Chemlali cultivar gathered during two successive crop seasons and divided into two groups: olive plucked off the tree (Fresh olive) (oil yields 23
In this study, quality parameters and oxidative stability of olive oils added with olive leaf (OL), an agricultural by-product extracted by the supercritical carbon dioxide (SCD) method, were evaluated. The SCD OL extraction method was applied at 100 degrees C, 100 bar and 80 minutes. Extracts containing phenolic substances obtained from olive leaves were added to refined olive oil (ROO) (E) at concentrations of 350 (A), 200 (B), 150 (C) and 60 mg CAE/kg oil (D). Olive oil samples were stored in clear glass bottles for 12 months under light (L) and dark (D) conditions. Samples were analysed at 0, 3, 6, 9 and 12 months of storage period. The results of the analyses revealed that the amount of free fatty acid values (FFAV), peroxide value (POV), total phenolic content (TPC), chlorophyll (TChl) and carotenoid (TCar) content and oxidative stability index (OSI) increased as the olive leaf extract (OLE) addition ratio increased. When the effect of OLE concentration on the amount of a- tocopherol was examined, it was determined that the amount of a- tocopherol was higher in ROO (E) and this amount decreased with the addition of OLE. In the samples which OLE was added, odours like alcohol, henna and dried herbs were detected as a result of sensory analysis. Principal component analyses (PCA) indicated that olive oils were discriminated clearly based on the concentrations of OLEs. As a result, it was determined that the TPC, TChl and TCar content and OSI values were the highest in the A sample, which was stored in the dark and had the highest OLE content. Sample A, which is rich in antioxidant components, can be said to be the best example enriched with OLE, apart from sensory properties. In terms of the content of AT, which is equivalent to vitamin E, we can say that the E sample stored in the dark has the best properties except for the sensory properties.
Turkey is considered the homeland of olives and is one of the important olive oil producers of the world. With the increasing number of trees, the necessity to complete olive harvest in a short time, like 3-4 months, makes mechanization necessary. The use of mechanical devices during olive harvest causes an increase in the number of leaves, shoots, and branches in the harvested product. Leaf separation systems used in cleaning non-olive materials in olives are generally inadequate in cleaning olives containing dense leaves obtained due to the use of new generation harvesting machines. For this reason, to develop an innovative sorting/cleaning prototype to provide more efficient cleaning, it is necessary to determine the machine efficiency, oil efficiency, olive oil quality and composition of machines. Total phenolics, chlorophyll and carotenoid contents, induction period and DPPH antioxidant activity values of olive oil obtained after traditional suction fan system (TSFS) application were higher than olive oils obtained after new generation blown and drum sieve system (NGBDSS) application. However, the α-tocopherol content of olives was low in the samples obtained by TSFS. The fatty acid composition of olive oils obtained from both applications was similar. Our study determined that there were 13 volatile compounds in the olive oil obtained after applying the TSFS, and there were 6 volatile compounds in the olive oil obtained with the application of NGBDSS. When the sensory properties of olive oils were analyzed, it was found that olive oils obtained from both applications were similar to the fruitiness, bitterness, and pungency of olive oils obtained after applying NGBDSS.
Günümüzde yaşadığımız ve gelecekte yaşayacağımız iklim değişiklikleri ile (yağışların azalması, sıcaklık ve kuraklığın artması) tarımsal potansiyeller ve yetiştirilen türlerdeki değişimlerin yaşanması kaçınılmaz olacaktır. İklimdeki bu değişimler tarım sektörü ve özellikle zeytin sektörü için büyük önem taşımaktadır. Gelecekteki iklim koşullarındaki tahminler, zeytin ağaçları gibi çok yıllık ürünlerde, özellikle suyun, fizyolojik süreçlerin, fenolojik zamanlamaların, nihai verim ve kalite özellikleri üzerinde ciddi olumsuz etkilere neden olabileceğini ortaya koymaktadır. Sıcaklıklarda beklenen bu artışların, zeytinde büyüme mevsiminin uzunluğunu arttırabileceği, özellikle çiçeklenmede fenolojik zamanlamalarda değişikliklere yol açabileceği, daha yüksek sıcaklıklar ve artan buharlaşmanın meyve olgunlaşmasını hızlandırarak daha düşük olgunluk seviyelerinde olsa da erken hasat ihtiyacını ortaya çıkaracağı rapor edilmektedir. Bunlara bağlı olarak da meyve veriminde, sofralık zeytin ve zeytinyağı kalitesinde olumsuz etkilere neden olabileceği belirtilmektedir. İklim değişikliğine bağlı olarak ileriye dönük planlamaların yapılmasına acil ihtiyaç duyulmaktadır. İklim değişikliği ile ilgili olarak zeytin çeşitlerinin bu koşullara bağlı olarak davranışlarının nasıl olacağına odaklanılmalı ve projeler yapılmalıdır. Yeni zeytin çeşitlerinin seçiminde; hastalık ve zararlılara karşı dirençli, yüksek sıcaklıklara ve kuraklığa karşı dayanıklı, sofralık ve yağlık zeytin kalite ve antioksidan özellikleri gibi kriterler dikkate alınmalıdır.
Turkey is considered the homeland of olives and is one of the important olive oil producers of the world. With the increasing number of trees, the necessity to complete olive harvest in a short time, like 3-4 months, makes mechanization necessary. The use of mechanical devices during olive harvest causes an increase in the number of leaves, shoots, and branches in the harvested product. Leaf separation systems used in cleaning non-olive materials in olives are generally inadequate in cleaning olives containing dense leaves obtained due to the use of new generation harvesting machines. For this reason, to develop an innovative sorting/cleaning prototype to provide more efficient cleaning, it is necessary to determine the machine efficiency, oil efficiency, olive oil quality and composition of machines. Total phenolics, chlorophyll and carotenoid contents, induction period and DPPH antioxidant activity values of olive oil obtained after traditional suction fan system (TSFS) application were higher than olive oils obtained after new generation blown and drum sieve system (NGBDSS) application. However, the α-tocopherol content of olives was low in the samples obtained by TSFS. The fatty acid composition of olive oils obtained from both applications was similar. Our study determined that there were 13 volatile compounds in the olive oil obtained after applying the TSFS, and there were 6 volatile compounds in the olive oil obtained with the application of NGBDSS. When the sensory properties of olive oils were analyzed, it was found that olive oils obtained from both applications were similar to the fruitiness, bitterness, and pungency of olive oils obtained after applying NGBDSS.
This work aimed to investigate the combined effect of harvest time and crop altitude on the fruit and oil quality of two autochthonous Algerian olive cultivars, Chemlal and Azeradj. Fruit morphological characteristics, oil quality parameters, fatty acids and triacylglycerols composition, pigments, tocopherols and oxidative stability were determined. Olives were harvested at four different ripening stages in orchards located at 110, 320 and 490 m altitude, in the olive-growing region of Kabylia, northern Algeria. Results showed a good discrimination between varieties, which were characterized by specific triacylglycerols and fatty acids profile. Different chemometric analyses carried out on the oil data highlighted the strong influence of variety in relation to the factors studied. Moreover, Principal Component Analysis performed on both fatty acids and triacylglycerols profile allowed correlating the distinct composition with the different varietal sensitivities to changes in crop attitude and ripening stage. Tocopherols showed a remarkable decrease with the ripening progress. Oxidative stability was positively correlated with variations in tocopherols and monounsaturated fatty acids during maturation and altitude changes.
In this study, the effects of filtration on quality parameters, chemical characteristics, antioxidant activity, and oxidative stability (OS) of Turkish olive oils during the storage period of 12 months were investigated. The olive oil free acidity (% oleic acid per 100 g of olive oil) (free fatty acidity, FFA), peroxide values (PV) (meq O-2 kg(-1) oil), and UV spectrophotometric indices (K-232 and K-270 measurements) were used for evaluating the quality parameters of olive oils. alpha-tocopherol analysis, total phenolic content (TPC), total chlorophyll and carotenoid analyses, and 2,2-diphenyl-1-picrylhydrazyl (DPPH center dot) radical-scavenging activity (RSA) assays were carried out. Chromatographic methods were applied to determine the fatty-acid and triacylglycerol (TAG) composition, the content of methyl and ethyl esters (FAEE and FAME), and the content of fatty acids of olive oils. Univariate and multivariate statistical methods were performed to evaluate results. Univariate data analysis results showed that filtration of Ayvalik, Memecik, and Domat olive oils had no considerable influence on quality parameters, antioxidant compounds, FAEE and FAME, antioxidant activity, and OS, except TPC (P < 0.05). A significant difference between the samples was determined regarding storage times of the olive oils. Principal component analysis (PCA) analysis revealed that olive oils were grouped according to storage periods of the olive oils regarding fatty-acid and triacylglycerol (TAG) composition while there was no clear separation among the samples according to the filtration process. However, qualitative and quantitative changes took place on minor and major components of olive oils during the storage period.
In this work the effect of different growing areas on olive (Ayvalık, Memecik, Gemlik, Beylik, Edincik Su, Girit, Kilis Yağlık, Sarı Ulak, Tavşan Yüreği, Topak Aşı) oil bitterness index (K225) were studied at the South Marmara, South and North Aegean, West and East Mediterranean Regions at two, two and a half (2.5), and three phase extraction system, during 2014/2015 crop season. A total of 41 virgin olive oils samples were collected from these Regions. Total phenol content and bitternes index (K225) were analyzed in the research. A Solid-Phase Extraction procedure were carried out for extraction of the bitter compounds. The results of total phenol content and K225 values showed that the Beylik olive oil was determined with the highest total phenol conent and bitterness index (K225) with 330.26 mg CAE kg-1 oil and 1.21 at 2.5 phase extraction system from Manavgat at the West Mediterranean Region, respectively. After the Beylik variety, the highest total phenol content was determined Ayvalık and Edincik Su olive oil with 291.03 and 270.62 mg CAE kg-1 oil, respectively. The Memecik and Ayvalık olive oil bitterness index (K225) was determined 0.86 and 0.85 at two phase extraction system from Muğla and Burhaniye at the South and North Aegean, respectively.
The aim of present investigation is to discriminate two important Turkish olive cultivars (Ayvalik and Memecik) by studying their triacylglycerol (TAG) compositions during storage (15 months) taken from different orchard in Ayvalik and Aydin region which have a significant potential for olive oil production in Turkey, during 2009 and 2010 harvest years. Olives were harvested by hand at 2 different maturation indices and processed by an Abencor system. The olive oil samples were stored at room temperature and they were divided into two groups including exposed to diffused daylight and dark for a period of 15 months. Multivariate classification and clustering were done by the application of unsupervised chemometrics methods such as principal component analysis (PCA) and hierarchical cluster analysis (HCA) based on the TAG profiles of the olive oil samples. PCA and HCA analysis of olive oils showed significant differences according to harvest years and cultivars. PCA scores plot showed that the samples were classified into two main groups with respect to harvest years based on the first principal component (PC1). In terms of storage effect, there was no significant change in TAG compositions among the samples from beginning of storage to 15 months of storage regardless of storage conditions (either in dark or in daylight). In addition, PCA scores plot indicated that the samples were also successfully clustered into two sub-groups according to cultivars in both years based on the second principal component (PC2).