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Summary: A quick, simple, environmentally friendly and cost‐effective screening approach for identifying parameters of adulteration in cold‐pressed olive oil (CPOO) was developed. The technique focused on the electrochemical examination of the peak of alpha‐tocopherol oxidation on pencil graphite electrode (PGE). Rapeseed oil (RO), sunflower oil (SO), and corn oil (CO) were added to local CPOO in varying amounts, and the mixtures were then tested by differential pulse voltammetry (DPV) on PGE. Voltammetric analysis of CPOO and its artificially created mixtures with other commercial oils have demonstrated statistically significant discrimination with an ability to detect adulteration under the level of 10% on weight basis. The method's relative standard deviation (RSD) was 20%, and the α‐tocopherol in CPOO cut‐off value was 30.98 ± 12.57 nA. As far as our knowledge, no data on utilisation of voltammetric techniques for the detection of olive oil adulteration are available to date by using PGE. The results showed that the developed method is capable of detection of adulteration in natural olive oils without any pretreatment. [ABSTRACT FROM AUTHOR]

SUMMARY: Advances in olive oil research have blossomed in recent years, and articles on olive oil have been widely recorded. However, a comprehensive and systematic bibliometric analysis of olive oil research has not been completed. Through a systematic literature search, we consolidated 7003 papers from the Web of Science Core Collection database. This bibliometric analysis was carried out to examine the article growth, geographical distribution, and analysis of journals/research areas/authors/keywords. The results revealed the following: (1) Exponential growth was shown in the annual number of publications (R2 = 0.9791). The geographical distribution is biased to a few countries, especially Spain, Italy, and Greece in the Mediterranean region, placing a larger focus on olive oil research. (2) Quality analysis‐related research acted as a link between keyword groups, the disease prevention and treatment‐related research of olive oil received decreasing interest, while authentication and quality analysis‐related research of olive oil showed the opposite trend, by‐products‐related research of olive oil got waving interests over the whole period. (3) Improvement is needed in the degree of olive oil with international collaboration. This is the first time that hotspots and trends in olive oil research have been shown. [ABSTRACT FROM AUTHOR]

Objective: Chronic stress‐induced oxidative damage and protease synthesis cause a loss of extracellular matrix components promoting human skin ageing. The administration of antioxidant compounds, such as those observed in olive oil, may attenuate stress‐induced ageing signs in human skin. Thus, the aim of this study was to investigate the effect of olive oil administration in ex vivo stressed human skin. Methods: Explants of human skin were treated with high levels of epinephrine (as observed in stressed patients) and olive oil in medium for 13 days. Cultures treated with medium alone were used as controls. Results: Olive oil reversed the high epinephrine level‐induced reduction in epidermis and dermis thickness and collagen fibre content in ex vivo human skin. The increase in the production of reactive oxygen species (ROS) and malondialdehyde levels (an index of lipid peroxidation) promoted by high levels of epinephrine were also attenuated by olive oil in ex vivo human skin. Moreover, olive oil was able to reverse the high epinephrine level‐induced increase in extracellular signal‐related kinase 1/2 (ERK 1/2) and c‐JUN (a major component of transcription factor AP‐1) phosphorylation and protein matrix metalloproteinase‐2 (MMP‐2) expression in ex vivo human skin. Conclusion: Olive oil attenuates stress‐induced ageing signs (thinner dermis and collagen fibre loss) in ex vivo human skin by reducing MMP‐2 expression, ROS production, and ERK 1/2 and c‐JUN phosphorylation. [ABSTRACT FROM AUTHOR]

Summary: Triacylglycerols (TAGs) compositions of ten commercial olive oil samples were analysed using an ultra‐performance convergence chromatography (UPC2) combined with a quadrupole time‐of‐flight mass spectrometry (Q‐TOF MS). A total of twenty‐three TAGs were characterised based on their Q‐TOF MS accurate molecular weight and MS2 fragment ion profiles, and seventeen of those were reported in olive oils for the first time. O‐O‐O was the most abundant TAG in all tested olive oil samples, followed by P‐O‐O, O‐O‐S and O‐O‐L. G‐G‐B had the lowest relative concentration in all the TAGs, ranging 0.02–0.08% of the total sample weight. The results from this study are important for further understanding the nutritional value and stability of olive or other edible oils. The chemical compositions of triacylglycerols in ten commercial olive oil samples were analysed using UPC2 combined with Q‐TOF MS. A total of 23 triacylglycerols were identified based on their accurate molecular weight and MS2 fragment ion profiles. 17 TAG compounds were reported in olive oils for the first time. O‐O‐O is the most abundant TAG in all tested olive oil samples; G‐G‐B had the lowest relative concentration in all the TAGs. The combination of UPC2 and Q‐TOF MS could be utilized to accurately determine triacylglycerol composition and sn‐positions of the fatty acids of edible oils. [ABSTRACT FROM AUTHOR]

BACKGROUND: The present study aimed to investigate how olive maturity indices (MI) (2.5, 3.5 and 4.5 MI) affect the aroma, aroma‐active compounds, fatty acid profiles and color properties of cv. Nizip Yaglik olive oils. Various techniques for extracting volatiles from oil materials are available in the literature. Aroma compounds were extracted by the solvent‐assisted flavor evaporation extraction method for the first time in olive oil. RESULTS: The type and number of aroma‐active compounds varied according to maturity periods of olives. A total of 22, 21 and 20 different key odorants were found in aromatic extracts of samples with 2.5, 3.5 and 4.5 MI, respectively. The most potent aroma‐active compounds based on flavor dilution (FD) factor values were hexanal (green) for 2.5 MI (FD: 1024) and 3.5 MI (FD: 512), as well as 1‐penten‐3‐ol (green‐leafy) for 4.5 MI (FD: 512). CONCLUSION: Overall, olive oils obtained from unripe and medium‐ripe olives had stronger green and fruity odours compared to ripe olives. Principal component analysis demonstrated that oils were clearly discriminated according to their general physicochemical analysis, fatty acids, aroma profiles and key odorants. The results of the present study show that the olive maturity period has a significant influence on the quality parameters of olive oil. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Several studies demonstrate a strong interest in learning more about phenolic transfer during oil extraction, with the main goal of increasing the phenolic concentration in olive oils. We aimed to propose and apply a new methodological approach for evaluating phenolic transfer from olives into oil during milling, based on the quantification of phenolic content in whole lyophilized fruits and the corresponding oils and considering the oil extraction yields. RESULTS: We investigated the phenols transferred into the oil during olive milling in continuous extraction systems in Tuscany. In 2012, oils were extracted from cultivar Frantoio by a two‐phase extraction system; in 2016, oils were extracted from cultivars Leccio del Corno and Arbequina by a three‐phase extraction system. Results highlighted very low percentages of extracted phenols: up to 0.40% by the two‐phase system and up to 0.19% by the three‐phase system (0.08% for cultivar Arbequina and 0.19% for cultivar Leccio del Corno). CONCLUSION: The usefulness of a simple and effective methodological approach for evaluating the extracted phenols was highlighted. Values of extracted phenols were up to 25 times lower than previous literature data. The proposed approach is applicable in all types of milling processes. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The effect of the experimental conditions on assessing the global volatile profile of extra virgin olive oils (EVOO) by headspace solid‐phase microextraction/gas chromatography‐mass spectrometry (HS‐SPME/GC–MS) is studied to obtain maximization of the total peak areas of the compounds. Response Surface Methodology (RSM) is applied to Arbequina EVOO, and the influence of oil quantity, extraction time, and extraction temperature on the total area and extraction of the major desirable compounds is analyzed. The experimental data are adequately fitted into second‐order polynomial models with non‐significant lack of fit (p > 0.05) and coefficients of determination (R2 and R2‐adjusted) higher than 0.88 and 0.78, respectively. A strong similarity is found between the predicted and experimental values. Furthermore, the surface plots show that the extraction of the volatile compounds is favored with increasing extraction temperature, time, and oil quantity. The extraction conditions to obtain the maximum response of “green” volatile compounds from Arbequina olive oil by HS‐SPME placed in 50 mL vials are 4.6 g of oil, 43 min, and 59 °C. Practical Applications: The findings of the present work show that specific conditions of HS‐SPME/GC–MS affect the extraction of volatile compounds from cv. Arbequina olive oil and establish the optimum extraction parameters to more efficiently determine the global profile of this fraction, taking into account the organoleptic characteristics of the cultivar. The results also contribute to the knowledge of the volatile profile of the monovarietal olive oil cv. Arbequina, which is one of most cultivated and consumed types of olive oil worldwide. The effects of oil quantity, extraction time, and temperature on the extraction of volatile compounds from the olive oil of the widespread Arbequina variety are investigated. The main volatiles found are C6 compounds, including aldehydes, alcohols, and the corresponding esters. The volatile profile is more affected by temperature and time than the oil quantity. The application of long times and high temperatures increases the total area and the extraction of Z‐3‐hexen‐1‐ol acetate and E‐2‐hexenal to which are associated sensory traits of cut‐green, tomato, and medium bitter taste. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Natural compounds are more frequently used against Anisakis, responsible for the important fish‐borne disease anisakidosis. The aim of the study was to evaluate the effectiveness of enriched Tunisian olive oil with different spices (cumin, turmeric, clove, thyme, and lemon) against Anisakis larvae type 1. RESULTS: In vitro experiment: larvae were submerged separately in the aforementioned oils and then examined to check viability. For each oil, LT50 and LT100 were calculated. Turmeric and cumin oils are the most effective against the parasites; followed by lemon, thyme and clove oils. For the in vivo experiment, turmeric and cumin oils were tested in anchovy fillets previously artificially parasitized with L3 larvae. Cumin was the most effective against parasites (dead after 5 days) compared with turmeric (8 days). For the two oils, the resulting odor was pleasant, as was the taste, while changes in color were much more evident in turmeric fillets. CONCLUSION: All the flavored oils demonstrated a good nematodical action against Anisakis. Cumin oil was the most effective against encysted larvae. Turmeric oil showed the best activity in the in vitro experiment. The use of flavored oils in the marinating process could represent an efficient strategy to devitalize Anisakis. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: Eight artificial neural networks were developed as predictive models for regulated and nutritional parameters of oils obtained from vertical centrifugation. The networks were designed considering the NIR spectra of oily must at its exit from the horizontal decanter centrifuge, and the flows and temperatures of the oil and of the addition water. The results obtained in all the networks designed indicated the good creative capacity of the neural models through their quality indicators (RER and RPD). The correlations between the real data and those predicted by the networks were within the range of 0.76–0.99, the UV absorption networks (K232 and K270) being those which gave lower correlations. For polyphenols, tocopherols and carotene and chlorophyll pigments, the te‐Student external validation test makes a reliable prediction of these parameters. With predictive models, the vertical centrifuge can be modeled and regulated as well as monitored on‐line to control and optimize the clarification phase within the extraction process of extra virgin olive oil (EVOO). Practical applications: The predictive ANN can use to regulate and model the vertical centrifuge to obtain an EVOO of a maximum regulated and nutritional quality possible, reducing water and energy consumption. Besides, with on‐line prediction of oil characterization, it will be possible to perform a correct classification prior to its storage in the cellar. [ABSTRACT FROM AUTHOR]

Two samples of triacylglycerols i.e., olive oil and triolein, and one sample of diacylglycerol were investigated. In the course of compression, the density of the samples was determined by measurements of the change of piston position in a pressure chamber and volume correction due to chamber expansion under pressure. The speed of sound was evaluated from the time of flight of an ultrasonic impulse between emitting and receiving transducers placed in the high pressure chamber. The adiabatic compressibility, the intermolecular free length, the molar volume, the van der Waals' constant b and the surface tension were evaluated from the density, the speed of sound and the average molecular mass. All tested liquids undergo a high-pressure phase transition. Discontinuities in the measured isotherms of the physicochemical parameters of the investigated oils indicate the presence of high-pressure phase transitions. Moreover the time dependent change of pressure at constant volume during the phase transition was measured. The fundamental difference in the molecular structure of these acylglycerols influences their behavior significantly under high pressure. [ABSTRACT FROM AUTHOR]

Mature 'Chondrolia Chalkidikis' olives were processed in an industrial olive oil mill equipped with a three-phase decanter. Water was added to the decanter at a 1:2 water-to-paste ratio. Olive mill waste water (ΟΜWW) was used to replace the added water at a rate of 50 or 100%. Following the final separation, the obtained oil was used for chemical analysis and sensory evaluation. All oils had similar acidity, peroxide and Κ values. OMWW-treated olive oils presented higher total phenolic content and higher antioxidant activity based on DPPH and oven tests, but lower chlorophyll and carotenoids content. However, there was no significant difference between the 50 and 100% replacement. The phenolic profile of the treated olive oils analyzed by quantitative Η NMR revealed more than twofold oleocanthal and oleacein as well as oleuropein and ligstroside aglycone contents than in the control. Sensory evaluation of treated oils also showed an enhancement of fruity, bitter and pungent attributes compared to the control. [ABSTRACT FROM AUTHOR]

Microwave-assisted extraction is compared with a more classical technique, Soxhlet extraction, to determine the content of triterpene acids in olive skins. The samples used in their original unmilled state and milled were extracted with ethyl acetate or methanol as solvents. The optimized operating conditions (e.g., amount and type of solvent, and time and temperature of extractions) to attain the better extraction yields have been established. For the identification and quantitation of the target compounds, an ultra high performance liquid chromatography with tandem mass spectrometry method was employed. The best results were achieved using the microwave-assisted extraction technique, which was much faster than the Soxhlet extraction method, and showed higher efficiency in the extraction of the triterpenic acids (oleanolic and maslinic). [ABSTRACT FROM AUTHOR]

Traceability and authenticity of olive oils in Croatia were probed by a versatile analytical approach using spiral MALDI-TOF MS system for the triacylglycerol (TAG) analysis. Molecular ion patterns were shown to represent specific data for statistical analysis, in which differences of cultivar regions of Croatian coast were recognized. This pilot project allows indications to be followed in high throughput procedures with high number of samples to get statistically relevant data for discrimination of olive oils from different geographic sites. Additionally, the fragmentation in the TOF/TOF MS provided distinct highly valuable data for assignment of acyl residues. In this way molecular species with different fatty acid substituents can be clearly assigned and possible isomeric mixtures identified. Practical applications: Olive oil TAG analysis is important to determine authenticity of olive oil and detect adulteration. This work shows that spiral MALDI-TOF MS analysis of TAG composition is a promising method for tracing geographical differences in olive oils. Triacylglycerol composition of Croatian extra virgin olive oils was determined by spiral MALDI-TOF MS technology. Obtained data were analyzed by Principal Components Analysis to establish relations between TAG composition and geographical origin and proved useful for assessment of Croatian olive oil origin. [ABSTRACT FROM AUTHOR]

This paper primarily extends research on applying and comparing high-speed countercurrent chromatography (HSCCC) and high-performance liquid chromatography (HPLC) in semi-preparative isolation of decarboxymethyl oleuropein aglycone (3,4-DHPEA-EDA), a bioactive secoiridoid, from extra-virgin olive oil (EVOO). An EVOO phenolic extract (EVOO-PE) was obtained by solid-phase extraction (SPE), and this extract was subjected to one run using the maximum loading capacity of each methodology without loss of resolution. For this sample set, the HSCCC method proved to be a more efficient approach regarding loading capacity, solvent consumption, and throughput compared with the HPLC method. However, the purity of the target from HPLC was superior to that of HSCCC, as the number of theoretical plates could not match that of HPLC. Therefore, we propose that HPLC should be used when higher purities are required, despite higher costs. In addition, HPLC is orthogonal and complementary to HSCCC, and can often provide straightforward resolution of otherwise difficult separations by HSCCC. Practical applications: Our results indicate that the optimized HSCCC is an economic process, and hence, a good candidate for further scaling-up to preparative and industrial scales, as long as the chromatographic profile of the sample itself is simple enough to achieve good resolution, or a very high purity of the compound of interest is not required. For those cases, HPLC would provide superior target purity but would result in higher costs. This paper compares high-speed countercurrent chromatography (HSCCC) and high-performance liquid chromatography (HPLC) in semi-preparative isolation of decarboxymethyl oleuropein aglycone (3,4-DHPEA-EDA), a bioactive secoiridoid, from extra-virgin olive oil (EVOO). An EVOO phenolic extract (EVOO-PE) was obtained by solid-phase extraction (SPE), and this extract was subjected to one run using the maximum loading capacity of each methodology without loss of resolution. For this sample set, the HSCCC method proved to be a more efficient approach regarding loading capacity, solvent consumption, and throughput compared with the HPLC method. However, the purity of the target from HPLC was superior to that of HSCCC, as the number of theoretical plates could not match that of HPLC. [ABSTRACT FROM AUTHOR]

BACKGROUND: Olive oil contains compounds with interesting biological activities which are influenced by the cultivar, the geographic origin and other factors. The aims of this work were to (1) investigate these factors in Neb Jmel olive oil from various Tunisian origins; (2) determine the influence of geographic conditions on phenolic composition of Neb Jmel olive oil and consequently on the antioxidant compounds; and (3) verify whether oils could be discriminated based on geographical origin. RESULTS: The characterisation of extra-virgin Neb Jmel olive oil produced in its original location has been conducted. Owing to the effect of the genotype and environmental, agronomic and technological factors on the chemical composition of olive oil and its quality, all studied olives were collected at the same season, and their oil obtained under the same processing technique. Many analyses were carried out to characterise the different olive oils: free acidity, peroxide value, fatty acid composition, Rancimat assay, pigments content and phenolic compounds by 1H NMR. A recently developed method for the direct measurement of the oleocanthal and oleacein levels in olive oil by quantitative 1H NMR was applied. The method was applied to the study of four Neb Jmel olive oils samples, and a broad variation of concentrations of all four secoiridoids was recorded. The concentration of each ranged from 55 to 529mgkg-1 and the sum of the four major secoiridoids (known as D3) ranged from436 to 1063mgkg-1. CONCLUSION: The quantification of major phenolic compounds of olive oil by NMR indicated that environmental conditions influence the production of qualitative phenolic fractions. All these compounds can be used as base 'markers' to characterise and differentiate these olive oil on geographic origin. [ABSTRACT FROM AUTHOR]

A flow injection system with amperometric detection at potentials poised at +0.4 and +0.9 V was used to evaluate intensity of the bitter taste in monovarietal Extra Virgin Olive Oils (EVOO). Results from the proposed method were based on the extraction of the bitter constituents of the virgin olive oil samples in methanol-water, followed by the direct amperometric measurement. These potentials were selected according to the hydrodynamic voltammogram of oleuropein, one of the most prominent and bitter phenolic compound found in EVOO. The amperometric detection was applied on 32 monovariatal EVOO samples. Results were correlated with the phenolic profile measured by high performance liquid chromatography (HPLC). The amperometric signal at +0.9 V mainly correlated with the total phenols of the samples (R2=0.81), whereas the signal at +0.4 V mainly correlated with oleuropein aglycone (3,4 DHPEA-EDA, R2=0.79). Bitterness intensity of the samples was evaluated by a trained sensory panel of experts and the results compared to those obtained by the amperometric flow system. The best correlation with the bitter taste was achieved by the sensor at +0.4 V (R2=0.72). A calibration model based on partial least squares was built with three variables, namely the sensors set at +0.4 and +0.9 V and the total phenol content of the EVOO extracts. The model showed a moderate capacity to predict the bitterness of the EVOO samples using leave one out method, (R2=0.75) and in prediction of a test set of samples (R2=0.7). Such approach is very promising for future studies. [ABSTRACT FROM AUTHOR]

Background Olives dropped on the ground naturally sometimes are not separated from those fresh and healthy collected from the tree for harvest and processing. In this work we compared the quality, ethanol content and bioactive components of virgin olive oils from ground-picked olives, tree-picked fruits and their mixture. Results Ground-picked olives produced 'Lampante' virgin olive oils; these are of a lower quality category, because of important alterations in chemical and sensory characteristics. Ethyl esters showed the highest values, although under the regulated limit. The mixture of ground and tree-picked olives gave oils classified as 'virgin' because of sensory defects, although the quality parameters did not exceed the limits for the 'extra' category. Ethanol content showed a significant increase in the oils from ground- picked olives and their mixture with respect to those from tree-picked fruits. Furthermore, bioactive compounds showed a significant decrease as fruit quality was poorer. Conclusion Ground-picked olives must be harvested and processed separately since they produce low-quality virgin olive oils with sensory defects and lower concentrations of bioactive compounds. The higher acidity and ethanol concentration observed in oils from ground-picked fruits or their mixture may help ethyl ester synthesis during storage. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Bitter taste is a positive sensory attribute in olive oil. However, if the bitter taste is too strong, it may be perceived as a negative attribute for the consumers. The aim of this work was to design a liquid-liquid extraction using water as a solvent to decrease the total phenol content of Arbequina olive oil and as consequence its bitter taste. Different olive oil-to-water ratios were assayed and mixing was conducted by flowing nitrogen to avoid oxidation. After 15 min, a constant total phenols concentration was reached in the olive oil independently of the olive oil-to-water ratios assayed. Lower percentage of olive oil in the mix was more efficient for phenol extraction. A mathematical equation was proposed to calculate the Arbequina olive oil-to-water ratio in the mix to remove a desired phenol percentage. After removing phenols, the obtained olive oil had a similar physico-chemical quality as untreated olive oil with a similar content of phenols. Practical applications: By using obtained mathematical equations the phenolic content in Arbequina olive oil can be modulated by liquid-liquid extraction. It is a fast and easy method to achieve the desired bitterness in olive oil. When in a mill oils with high intensity of bitterness are obtained, this method could be a solution to open new markets by offering more equilibrated products for consumers not used to olive oil. Liquid-liquid extraction using water as a solvent is useful to partial removal of the total phenol content and bitterness index in Arbequina olive oil. [ABSTRACT FROM AUTHOR]

In this study in order to introduce a new vegetable oil, oxidative stability and chemical characteristics of Pistacia khinjuk kernel oil (PKKO) as compared with P. atlantica kernel oil (PAKO) and extra virgin olive oil (EVOO) were investigated. Oxidative stability of studied oils was considered based on the conjugated diene value (CDV), carbonyl value (CV) and oil/oxidative stability index (OSI) through an 8-h thermal process at 170 °C. Also, chemical characteristics [fatty acid composition, unsaponifiable matter (USM), total tocopherols (TT), total phenolics (TP) and total sterols (TS), iodine value, saponification number and waxes] of these oils were analyzed. The ratio of polyunsaturated fatty acids to saturated fatty acids and the oxidizability (Cox) value of PKKO (1.14 and 2.78; respectively) were between those of PAKO (2.37 and 4.23; respectively) and EVOO (1.14 and 2.78; respectively). USM content of the three studied oils was between 1.1 and 1.51 %. TT and TP contents of PKKO (619.4 and 26.6 ppm) were lower than those of PAKO (845.33 and 75.22 ppm) and higher than those of EVOO (365.23 and 19.78 ppm). TS contents of PKKO, PAKO and EVOO were 2,500, 2,150 and 3,800 ppm, respectively. Oxidative stability data indicated that PKKO is the most resilient oil against lipid oxidation, followed by PAKO and EVOO. CDV significantly increased by the lowest speed for PKKO, followed by PAKO and EVOO. Increase of CV and reduction of OSI for PKKO, PAKO and EVOO were 29.2, 128 and 338.7 and 32.8, 67.9 and 79.3 %; respectively. [ABSTRACT FROM AUTHOR]

Varieties of the olive cultivar Arbequina have recently been cultivated in Turkey. The objective of the study is to characterize and evaluate extra-virgin olive oils (EVOO) produced from Arbequina grown in the Aegean and Mediterranean regions of Turkey. Major and minor components such as carotenoids, squalene, phenolics and tocopherols were studied to assess their effects on product quality and health benefits. The samples, identified as ArbqI and ArbqA, were from the Izmir and Adana provinces, respectively. Samples were analyzed by GC-FID to determine fatty acid composition, sterol composition, TAG profile and squalene content. Individual phenolic fractions were analyzed by LC-MS/MS and tocopherol isomers were determined by HPLC. According to the results obtained from this study; Total phenolic content (TPC) of the samples were 454.68 and 50.86 mg Gallic acid/kg oil for ArbqI and ArbqA, respectively. Hydroxytyrosol and tyrosol were determined to be the main phenols. The major tocopherol isomer found in ArbqI and ArbqA was α-tocopherol with levels of 179.55 and 202.5 mg/kg oil, respectively. β-Carotene levels in both samples were similar at 0.2 mg/kg. Findings of this study were compared with the literature on Arbequina olive oil produced in different countries. It was determined that Arbequina olive oil of high quality can be produced in Turkey, especially in the Aegean region. [ABSTRACT FROM AUTHOR]

Continuous application of high power ultrasound (HPU) on olive paste previous to malaxation at laboratory scale for virgin olive oil (VOO) extraction and its effect on process yield and the VOO quality have been studied. For the VOO samples, we determined the quality indices (free acidity value, peroxide value, K232, K270), bitterness, volatile composition, phenolic content (total and biophenols), tocopherol content, and pigments. The application of ultrasound induced a quick heating of the paste from 20 to 28°C. The sonication treatment improved the industrial oil yield by 1% and the oil extractability by 5.74%. Moreover the HPU treatment did not cause changes in the quality indices, fatty acid composition and volatile aromatic compounds of the VOO. Furthermore the fat autoxidation process was not accelerated by this treatment. Meanwhile oil obtained from olive pastes treated with HPU showed higher content of tocopherol, chlorophylls and carotenoids whereas a reduction in phenolic content and bitterness index was observed. Practical applications: The high power ultrasound (HPU) treatment of olive paste, before malaxation during the virgin olive oil (VOO) elaboration process, can improve the oil extraction yield without alteration of its quality parameters. The olive paste instantaneous heating observed with the HPU can allow the reduction of the malaxation step duration. The results obtained nowadays at laboratory scale are promising for the possibility of the continuous HPU treatment introduction in the olive oil elaboration process as aid or alternative to the malaxation. For this purpose further experiment at pilot and industrial scale are needed. Continuous application of high power ultrasound before malaxation and its effect on the oil extractability and virgin olive oil characteristics. [ABSTRACT FROM AUTHOR]

The new health claim on 'olive oil polyphenols' recently approved by the European Commission has produced a dramatic increase in the interest in these antioxidant compounds. Although this interest has been focused mostly on extra virgin olive oils (EVOOs), virgin olive oils (VOOs) qualified as having non-oxidative sensory defects, mostly caused by fermentation and the action of fungi on olives, may still have a considerable amount of phenols, even though their sensory quality is not flawless. This study is focused on the phenol composition of all the VOO categories: EVOOs with their ample variability in phenolic composition, VOOs with slight defects, lampante virgin olive oils (LVOO), and reference materials of defective VOOs. The average content of phenols in the analyzed EVOOs (410 ± 16 mg/kg) is higher than the recommended consumption by the health claim (250 mg/kg). VOOs qualified with non-oxidative defects contain high concentrations of phenols (234 ± 27 mg/kg), but only samples characterized by the wet-wood sensory defect show concentrations of phenols close to 250 mg/kg. Practical application: This study has demonstrated that VOOs with slight sensory defects still have a high concentration of phenols, providing antioxidant properties regarding health benefits and stability. The health claim should be not only applied to the extra virgin olive oil category, but also to some virgin olive oils with sensory defects. Profiles of phenols according to their main sensory defect. Picual (A), Hojiblanca (B), rancid (C), winey-vinegary (D), fusty (E), and musty (F). [ABSTRACT FROM AUTHOR]

In this research, the evaluation of the pre-heating effect on olive paste before malaxation was performed. The olive paste was treated by means of a tubular heat exchanger. The heat exchanger performances on yield and olive oil quality were evaluated considering two different types of olive paste obtained, respectively, by means of a disc crusher and a de-pitter machine. The experimental tests were conducted on an industrial olive oil extraction plant. The results of the experimental test showed that it is possible to reduce the malaxation time by about 10 min, maintaining constant the extraction yield, when a disc crusher was used. On the other hand, using the heat exchanger to condition the de-stoned paste, a reduction of the malaxation time compared to the control test was observed, but with significant loss in extraction yield. Concerning the olive oil quality, the flash thermal treatment of the olive paste after the crushing operation improves the phenolic and volatile compound content significantly with respect to the traditional process, in which the malaxation time has a duration of at least 30 min. By employing a tubular heat exchanger we observed some advantages, like the reduction of malaxation time and the improving of phenolic and volatile compounds. Practical applications: The practical application of this research concerns the possibility of evaluating the effects inherent in the insertion of a tubular heat exchanger before the malaxer, in an industrial olive oil extraction plant. The effects were evaluated on an industrial scale olive oil extraction plant considering these quantitative parameters: extraction efficiency of the decanter and the amount of oil lost in the husk. The olive oil quality was also evaluated. The research provides useful information to the operators of the olive oil sector and to researchers in understanding the changes manifested in the extraction plant in traditional configuration and innovative configuration with the tubular heat exchanger. A tubular heat exchanger to pre-heat the olive paste in an industrial olive oil extraction plant. [ABSTRACT FROM AUTHOR]

The possibility of improvement of olive paste extractability by addition of talc or NaCl (1, 2, and 3% mass ratio in olive paste), or their combinations ('talc 1.5% + NaCl 1.5%'; 'talc 1% + NaCl 2%'; 'talc 2% + NaCl 1%'), was investigated on a laboratory scale. Volatiles in oil samples were determined by headspace solid-phase micro-extraction with GC-MS, while ortho-diphenols were assessed by solid phase extraction and UV-VIS spectrophotometer. Significantly higher extractability of oil (from 25 to 29% compared to control, p < 0.05) was obtained by 3% of talc or NaCl and their combinations in mass ratio 1:2 or 2:1. At 3% addition level, no significant decrease of C6 aldehydes was observed, while significant increase of C6 alcohols (talc or salt) as well as of C5 compounds and terpenes (salt) occurred. Mass ratio of ortho-diphenols in oil was not influenced by talc, while NaCl led to significantly higher values compared to control (by 10-15%, p < 0.05). Practical applications: The influence of processing aids on characteristics of virgin olive oil has mainly been evaluated through the standard chemical quality parameters, while limited information about desirable volatile compounds of thus obtained extra virgin olive oils has been published so far. The results of this research show that NaCl can be used not only as a tool for enhancing the extractability, but also as a means for improving the nutritional value of virgin olive oils from cultivars which generally show low levels of hydrophilic phenols. The efficiency of talc and NaCl (processing aids acting on the basis of physical principles) in improvement of so-called difficult olive paste extractability is similar, but the advantages of NaCl are less pronounced changes of compounds responsible for fruity aroma, as well as increase of ortho-diphenols, compounds known for their antioxidant activity and health-promoting properties. [ABSTRACT FROM AUTHOR]

The aim of this study was to provide an additional element of knowledge and evaluation on extra virgin olive oil from the Italian region Calabria, belonging to the Grossa di Gerace cv. Then, the following chemical, physical-chemical, and sensory analyses have been performed: free acidity, peroxide value, UV spectrophotometric indices, ethyl esters, waxes, tocopherols, fatty acids, triglycerides, sterols, alcohols, phenolic substances, dynamic headspace volatile compounds, and sensory profile. The analytical investigation allowed us to highlight the great potential of this cultivar: a 'quality' product that will satisfy consumer expectations for a particular food, and especially a 'typicality' because of its unique attributes in the zone of production. According to the results provided by the analysis carried out on the extra virgin olive oil samples from 'Grossa di Gerace' and its mixtures with another important cultivar of Calabria, 'Carolea,' and thanks to statistical tools, 17 variables have been identified that could be considered markers of single cultivar olive oils of 'Grossa di Gerace': phytol, palmitic acid, 1-hexanol, trans-2-hexen-1-ol, α-amyrin, 3,4-DHPEA-EA-H, palmitoleic acid, apigenin, methyl-luteolin, geranylgeraniol, 3,4-DHPEA-EA, OOL + LnPP, PoOO, PoOP + SPoL + SOLn + SPoPo, citrostadienol, luteolin, and trans-2-hexenal. The Principal Components Analysis (PCA) applied to the 17 variables has permitted us to distinguish blends with more than 10% of 'Carolea.' Practical applications: The study carried out on single cultivar extra virgin olive oil of Grossa di Gerace has been executed for several practical applications: (i) the knowledge of the chemical profile of the oil is useful to define the sensory, nutritional, and conservative quality of this product; (ii) the identification of analytical parameters is useful for a Protected Denomination of Origin (PDO) characterization; (iii) to protect the single cultivar extra virgin olive oil, inserted into the ATP, from mixtures with other oils, by the identified analytical markers. According to the results provided by the analysis carried out on the extra virgin olive oil samples from 'Grossa di Gerace' and its mixtures with another important cultivar of Calabria, 'Carolea,' and thanks to statistical tools, 17 variables have been identified that could be considered markers of single cultivar olive oils of 'Grossa di Gerace.' The Principal Components Analysis applied to the 17 variables has permitted us to distinguish blends with more than 10% of 'Carolea.' [ABSTRACT FROM AUTHOR]

BACKGROUND: The volatile fraction of virgin olive oil is characterised by low molecular weight compounds that vaporise at room temperature. In order to obtain an aroma profile similar to natural olfactory perception, the composition of the volatile compounds was determined by applying dynamic headspace gas chromatography, performed at room temperature, with a cryogenic trap directly connected to a gas chromatograph--mass spectrometer system. Samples were also evaluated according to European Union and International Olive Council official methods for sensory evaluation. In this paper, the composition of the volatile fraction of 25 extra virgin olive oils from different regions of Italy was analysed and some preliminary considerations on relationships between chemical composition of volatile fraction and sensory characteristics are reported. RESULTS: Forty-two compounds were identified by means of the particular analytical technique used. All the analysed samples, classified as extra virgin by the panel test, never present peaks whose magnitude is important enough in defected oils. The study was focused on the evaluation of volatile compounds responsible for the positive impact on olive odour properties ('green--fruity' and 'sweet') and olfactory perception. CONCLUSION: Chemometric evaluation of data, obtained through headspace analysis and the panel test evaluation, showed a correlation between chemical compounds and sensory properties. On the basis of the results, the positive attributes of virgin olive oil are divided into two separated groups: sweet types or green types. Sixteen volatile compounds with known positive impact on odour properties were extracted and identified. In particular, eight compounds seem correlated with sweet properties whereas the green sensation appears to be correlated with eight other different substances. The content of the compounds at six carbon atoms proves to be very important in defining positive attributes of extra virgin olive oils and sensory evaluation. [ABSTRACT FROM AUTHOR]

The influence of agronomical factors (two growing areas and four harvest periods) and storage conditions of virgin olive oils (room temperature, +4 and −20 °C) on tocopherols was investigated on two cultivars having significantly different tocopherol content (Oblica 269-443 mg/kg, Leccino 403-784 mg/kg). α-Tocopherol accounted for 97 % of total tocopherols and its content decreased during ripening of both cultivars. In a warmer growing area both cultivars gained a higher γ-tocopherol content while only Leccino showed a higher content of α-tocopherol. After 12 months of storage α-tocopherol content decreased by up to 27 %. Lower storage temperatures did not always contribute to the higher stability of α-tocopherol compared to room temperature. [ABSTRACT FROM AUTHOR]

Extra virgin olive oils were extracted from six different major olive cultivars (Gemlik, Ayvalik, Domat, Akhisar, Memecik, Arbequina) cultivated in the Aegean region of Turkey. Fatty acid, sterol and tocopherol compositions were analyzed and the results were compared by multivariate statistical analysis. Olive samples were collected from the same orchard in order to limit the contribution of parameters such as climate, soil quality and agricultural practices to the total variance of chemical composition of olive oils. Principal component analysis (PCA) showed that cultivars can be clearly distinguished on the basis of fatty acid and sterol composition. It is of interest to note that palmitoleic acid content of Arbequina, a Spanish cultivar, is significantly ( p < 0.05) higher than the local Turkish cultivars in question and it is the only olive sample whose palmitoleic acid concentration is higher than that of the stearic acid concentration, exhibiting a divergent composition from the local Turkish cultivars. β-Sitosterol and Δ5-avenasterol contents of the oils are significantly correlated ( r = −0.989, p < 0.05) and this results in a discriminative axis on the PCA loading plot. Tocopherol composition was relatively insufficient in discriminating the olive varieties. Regarding tocopherol compositions Gemlik cultivar is distinguished from other cultivars with its γ-tocopherol content, which is in average two times higher than that of other cultivars. The result of the present compositional study provides important data which can be used for olive oil authenticity studies in Turkey. [ABSTRACT FROM AUTHOR]

The aim of this study was to classify Turkish commercial extra virgin olive oil (EVOO) samples according to geographical origins by using surface acoustic wave sensing electronic nose (zNose™) and machine vision system (MVS) analyses in combination with chemometric approaches. EVOO samples obtained from north and south Aegean region were used in the study. The data analyses were performed with principal component analysis class models, partial least squares-discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA). Based on the zNose™ analysis, it was found that EVOO aroma profiles could be discriminated successfully according to geographical origin of the samples with the aid of the PLS-DA method. Color analysis was conducted as an additional sensory quality parameter that is preferred by the consumers. The results of HCA and PLS-DA methods demonstrated that color measurement alone was not an effective discriminative factor for classification of EVOO. However, PLS-DA and HCA methods provided clear differentiation among the EVOO samples in terms of electronic nose and color measurements. This study is significant from the point of evaluating the potential of zNose™ in combination with MVS as a rapid method for the classification of geographically different EVOO produced in industry. [ABSTRACT FROM AUTHOR]

A simple, precise, accurate and selective method was developed and validated for determination of malondialdehyde (MDA) in olive oil. Separation was achieved on a reversed-phase C column using a mobile phase consisting of methanol/0.8 % phosphoric acid (10:90, v/v), at a flow rate of 1.0 ml/min and UV detection at 220 nm. This method was validated according to the requirements for new methods, which include accuracy, precision, selectivity, robustness, a limit of detection, limit of quantitation (LOQ), linearity and range. The current method demonstrated good linearity over the range of 0.5-1000 ppm of MDA with r greater than 0.999. The recovery of MDA in olive oil ranged from 97.1 to 99.1 %. The method was selective where MDA was distinctly separated from other compounds of the oil with good resolution. The method was also precise where the RSD of the peak areas of replicate injections of MDA standard solution were less than 1 %. The degree of reproducibility of the results obtained as a result of small deliberate variations in the method parameters and by changing the analytical operators proved that the method is robust and rugged. The low LOQ of MDA (0.5 ppm) using this method enables quantitation of MDA at low concentration. [ABSTRACT FROM AUTHOR]

The objectives of this work were to study the impact of aromatization by sweet lemon and sweet orange peels on olive oil quality, chemical composition and heat stability. Flavored olive oils were prepared by maceration of sweet lime and sweet orange zests at 1, 3 and 5 %. The oil samples were kept at 60 °C for 40 days. Physicochemical tests (FFA, PV, oxidative stability, polyphenols and pigments contents) were carried out. The antioxidant activity (β-carotene-linoleate bleaching assay, DPPH radical scavenging and reducing power) was also tested. Results indicated that the addition of citrus zests contributed to the increase in polyphenols and carotenoids contents. Moreover, it led to an increase in the DPPH-radical scavenging activity (99.50 % for flavored olive oil with sweet orange zests at 5 %). Flavored olive oils with sweet orange zests were more stable to heat treatment than those flavored with sweet lemon zests. The degradation rate of bioactive compounds was lower for virgin olive oil comparing to flavored oils. [ABSTRACT FROM AUTHOR]

Virgin olive oil and beeswax were used to prepare four oleogel emulsions (EM1-EM4) through simultaneous oleogelation emulsification, and these oleogels were compared with breakfast margarine (BM). The melting temperatures of the oleogel emulsions ranged from 52.29 to 57.52 °C, while it was 40.36 °C for the BM sample. Similarly, the solid fat content (SFC) of the oleogel emulsions was between 3.57 and 3.68 % at 20 °C, and that of BM was 7.70 %. Except the EM3 sample, all oleogel emulsions exhibited mechanical stability. The firmness and stickiness values of the oleogel emulsion samples were lower than those of the BM sample, but they remained almost constant through 90 days of storage. Furthermore, the fine water droplets and needle-like beeswax crystals within the continuous oil phase were stable during the storage. The X-ray diffraction patterns of the samples revealed that the oleogel emulsions contain crystals similar to β′ polymorphs, characterized by a homogenous, smooth and fine texture. The presence of inter and intramolecular hydrogen bonds was proved by Fourier Transform Infrared (FT-IR) measurements. The developed oleogel emulsions were found to be stable in terms of texture, color and oxidation during 90 days of storage. In conclusion, these oleogel emulsion products can be used as margarine/spread stocks. [ABSTRACT FROM AUTHOR]

We aimed at investigating oxidative stability and changes in fatty acid and tocopherol composition of extra virgin olive oil (EVOO) in comparison with refined seed oils during short-term deep-frying of French fries, and changes in the composition of the French fries deep-fried in EVOO. EVOO samples from Spain, Brazil, and Portugal, and refined seed oils of soybean and sunflower were studied. Oil samples were used for deep-frying of French fries at 180 °C, for up to 75 min of successive frying. Tocopherol and fatty acid composition were determined in fresh and spent vegetable oils. Tocopherol, fatty acid, and volatile composition (by SPME-GC-MS) were also determined in French fries deep-fried in EVOO. Oil oxidation was monitored by peroxide, acid, and p-anisidine values, and by Rancimat after deep-frying. Differential scanning calorimetry (DSC) analysis was used as a proxy of the quality of the spent oils. EVOOs presented the lowest degree of oleic and linoleic acids losses, low formation of free fatty acids and carbonyl compounds, and were highly stable after deep-frying. In addition, oleic acid, tocopherols, and flavor compounds were transferred from EVOO into the French fries. In conclusion, EVOOs were more stable than refined seed oils during short-term deep-frying of French fries and also contributed to enhance the nutritional value, and possibly improve the flavor, of the fries prepared in EVOO. [ABSTRACT FROM AUTHOR]

The organic matter content in original and chemically treated olive oil mill wastewater obtained from a three phase extraction plant was profiled by a resin fractionation procedure to evaluate changes in its characteristics after acid cracking as well as chemical treatment by FeCl3 coagulation, electrocoagulation with stainless steel electrodes, and an advanced oxidation processes (Fenton's reagent). For this purpose, untreated, acid-cracked, and chemically treated wastewater samples were fractionated into hydrophobic and hydrophilic (acid-base-neutral) structures using XAD-8, XAD-4, AG-MP-50, and Duolite A-7 resins. Structural distribution analysis of the untreated samples indicated that hydrophobic structures were the major (75-95%) components of the wastewater's organic matter content. For the total phenols parameter, a significant fraction (56%) appeared to be hydrophobic neutral coinciding with the acute toxicity of the olive oil mill wastewater. A significant amount of oil and grease as well as particulate organic matter could be removed by subjecting the original wastewater sample to acid cracking. FeCl3 coagulation appeared to be effective in the removal of hydrophobic fractions whereas electrocoagulation and the Fenton's reagent were also effective in the removal of hydrophilic organic matter. After chemical treatment of the olive oil mill wastewater, a significant shift in its structural distribution pattern was observed from mainly hydrophobic to more hydrophilic fractions. [ABSTRACT FROM AUTHOR]

BACKGROUND Sensory analysis is a crucial tool for evaluating the quality of extra virgin olive oils. One aim of such an investigation is to verify if the sensory attributes themselves - which are strictly related to volatile and phenolic compounds - may permit the discrimination of high-quality products obtained by olives of different cultivars and/or grown in various regions. Moreover, a crucial topic is to investigate the interdependency between relevant parameters determining consumer acceptance and objective sensory characteristics evaluated by the panel test. RESULTS By statistically analysing the sensory results, a grouping - but not discriminatory - effect was shown for some cultivars and some producing areas. The preference map shows that the most appreciated samples by consumers were situated in the direction of the 'ripe fruity' and 'sweet' axis and opposite to the 'bitter' and 'other attributes' (pungent, green fruity, freshly cut grass, green tomato, harmony, persistency) axis. CONCLUSION Extra virgin olive oils produced from olives of the same cultivars and grown in the same areas shared similar sensorial attributes. Some differences in terms of expectation and interpretation of sensory characteristics of extra virgin olive oils might be present for consumers and panellists: most of the consumers appear unfamiliar with positive sensorial attributes, such as bitterness and pungency. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Olive oil phenolic compounds have been correlated to several health benefits. Nevertheless, the use of such information for commercial purposes was forbidden until 2006, when a European Regulation on health claims in food products was enacted (Reg. 1924/2006). In the case of olive oil, Regulation 432/2012 states that the health effect can be claimed only if the oil contains more than 5mg of hydroxytyrosol and its derivatives (e.g., oleuropein complex and tyrosol) in 20 g of oil. The present work deals with the optimization of a method for performing hydrolysis after the extraction of polyphenols from olive oil was optimized, followed by derivatization and gas chromatographic analysis. The derivatization step was carefully optimized comparing different reagents and testing their efficiency, both on a standard solution and in a real sample conveniently spiked. Some commercial samples were analyzed and the results compared with the total amount of polyphenols calculated according the recommended method reported by the InternationalOlive Council.Agood correlation was obtained between the twomethods (higher than 0.900). Practical applications: The proposed method is useful to determine if a marketed oil can claim health benefit according to the European Regulation n. 432/2012. The possibility to use such a claim is very important from a marketing point of view for the olive oil company; however, at present there is not any official method to assess the requirements. This method is rapid and gives efficient and reliable results using a common GC-FID for the final determination. [ABSTRACT FROM AUTHOR]

Olive oil composition has been investigated using chemical approaches, since the composition has a direct impact on its quality and safety and it may be used for certification purposes. In this paper, eleven monovarietal and twelve commercial Portuguese olive oils were analyzed to determine spectrophotometrically their total polyphenol content, ortho-diphenols and antioxidant activity. The phenolic profiles of these olive oils were also studied by high performance liquid chromatography. The lowest phenolic content and antioxidant activity were observed for monovarietal olive oils, however, among these group, 'Cobrançosa' and 'Redondil' cultivars showed the highest values of these two chemical parameters. In commercial olive oils, the concentration of polyphenols, determined according to the Folin-Ciocalteu method, and the antioxidant activity (ABTS method) ranged from 97.37 ± 1.10 to 219.7 ± 1.50 mg GAE/kg of oil and from 387.2 ± 20.00 to 997.5 ± 30.90 µmol Trolox/kg, respectively. The study of the phenolic profile demonstrated that the highest concentrations of the most abundant compounds in olive oil (tyrosol, hydroxytyrosol and oleuropein) are present in commercial olive oils. The correlation coefficient between total phenolics and antioxidant activity was statistically significant ( r = 0.95, p < 0.0001). The same was observed for ortho-diphenol content and antioxidant capacity ( r = 0.94, p < 0.0001). [ABSTRACT FROM AUTHOR]

Seventy olive oil samples with protected geographical indication ( PGI) or designation of origin ( PDO) were analysed for fifty-one target pesticides by means of gas chromatography coupled to mass spectrometry. The highest detection rates were observed for penconazole ( n = 20), α-endosulfan ( n = 18), β-endosulfan ( n = 16) and flufenoxuron ( n = 12). Four of the seventy investigated samples contained pesticide residues in levels exceeding MRLs. However, the investigated samples showed decreased occurrence and levels of pesticides residues in comparison with previous studies concerning samples from Greek conventional and organic cultivations. According to Spearman matrix, powerful correlations were obtained between α-endosulfan and β-endosulfan, detected as pair in thirteen samples and between flufenoxuron and penconazole detected as pair in eleven samples. Among Greek olive oil samples, the Cretan ones showed the lower detection rates and the lowest average number of detected pesticides per sample (1.75) in the case of pesticides positive samples. [ABSTRACT FROM AUTHOR]

A mild sample handling method able to minimize polyphenol degradation due to endogenous enzymes during the sample preparation permitted the assessment of polyphenol decay in the oily fraction of the olives during their storage before processing. During 7 days of storage at 15°C, the concentration of polyphenols in the olives was stable in vegetation water, whereas in the oily fraction of the fruits it remained almost constant in the first 3 days and then decreased rapidly. The polyphenol decay of the oily fraction of the stored olives can be attributed to the oxidoreductase enzymes of the fruit as well as those produced by the microbiota grown in the carposphere during storage. The activity of phenoloxidase in the olive pulp decreased drastically in the first 2 days of storage, and then decreased gradually, whereas peroxidase activity showed a gradual reduction throughout the entire storage period. The microbiological analysis showed a rapid increase of bacteria and yeast number during the first 4 days, then the values leveled out during the storage period. Phenoloxidase activity of microbic origin was low during the first 3 days then increased rapidly, whereas peroxidase activity increased during the first 3 days then leveled out to the same values for the duration of the storage time. Practical applications: The mild sample handling method of extraction studied was able to minimize olive oil polyphenol degradation during the sample preparation due to the endogenous enzymes of the olive fruits. The use of this method allows for the improvement of virgin olive oil quality, through the assessment of polyphenol concentration decay during all the stages of olive oil production, including that of fruit storage before processing. [ABSTRACT FROM AUTHOR]

Global climate change leads to the exposure of olive orchards to higher temperatures than in the past. We followed yield and quality parameters of olive oils from Barnea, Coratina, and Picual, under hot climatic conditions through different levels of ripeness. Oil yield per tree increased throughout the monitoring period due to continuous oil accumulation. Toward the last harvest date, significant fruit drop occurred, which resulted in substantial loss in oil yield. Maximal oil yield was obtained in Barnea at a maturity index of 2.1-2.5, in Coratina at 2.3 and in Picual at 3.2. A reduction in quality parameters was found with delay of harvest date: free fatty acid content increased and the ratio of monounsaturated to polyunsaturated fatty acid declined, but only in one season. Nevertheless, all parameters remained within the trade standard for extra virgin olive oil (EVOO). In contrast to most previous studies, no consistent reduction was observed in total polar phenol content in the oils. Hence, maximizing oil yield should be the main criterion for the determination of harvest date under these conditions. It is therefore suggested that olives exposed to hot climate be harvested earlier than those in typical Mediterranean climate areas. Practical applications: Harvest timing has a strong effect on both oil yield and quality. However, in most of the studies published on the topic until now only a sample of fruit was taken to determine oil accumulation and quality, but little or no information is available on oil yield at tree level, which is an important parameter from the grower's perspective. Moreover, this study describes changes in oil yield and quality along the ripening period, under hot climatic conditions prevailing in Jordan Valley. The Mediterranean basin region, where more than 90% of the world's olive oil is produced is expected to be exposed to higher temperatures in the future due to global climate changes. The current work provides information on the effect of those unfavorable growing conditions on oil production and quality. One of the major findings is the necessity to harvest early (in a relatively low ripening index) under those conditions. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate chemical and physical stability and consumers' acceptance of olive oil flavoured with oregano essential oils ( EOs; Compacto, Cordobes, Criollo and Mendocino). Samples of olive oil were added with 0.05% EO and stored in dark ( D) and light ( L) conditions for 126 days. Samples with oregano EO had lower lipid oxidation indicator values [ K232, K269, peroxide value ( PV) and anisidine value], especially in darkness. Olive oil with Cordobes EO in D had the lowest PV (18.71 meq O2 kg−1). Using prediction equations, 20 meq O2 kg−1 PV in olive oil should be reached in 34 days in L control sample and in 126 days in the Cordobes EO sample in darkness. Samples with Cordobes and Criollo EOs in darkness had the highest chlorophyll content after 126 days (2.91 and 2.88 mg kg−1, respectively). Sensory analysis showed that oregano EO addition in olive oil was detected by panellists in discriminative test and affected consumer acceptance. [ABSTRACT FROM AUTHOR]

Characterization of 15 polycyclic aromatic hydrocarbons (PAHs) in extra virgin, virgin, second centrifugation, lampante, refined, crude olive pomace, and refined olive pomace oils was carried out in 24 different types of olive oils and seven different types of pomace oils produced in Turkey and Spain. The extraction method was followed by liquid-liquid extraction, a solid phase clean up using C18 and Florisil cartridges, and evaporation. Then the evaporated residue dissolved in tetrahydrofuran/methanol 50:50 v/v, was analyzed by reversed phase high-performance liquid chromatography with fluorescence detector using two excitations (280, 256 nm) and emission (410, 446 nm) wavelenghts channels. PAHs content of crude and refined olive pomace oils were found higher than in the other oils. In the samples analyzed, the highest concentrations of PAHs corresponded to benzo[ ghi]perylene, naphthalene, pyrene, acenaphthene, benzo[ k]fluoranthene, and phenanthrene. [ABSTRACT FROM AUTHOR]

In this research, 14 hybrid table olive genotypes were used as material which were harvested from Olive Breeding Parcels in Atatürk Central Horticultural Research Institute (Yalova/TURKEY) and their maturation index, oil content, fatty acid composition and omega-6:omega-3 fatty acid ratio were evaluated. These genotypes were generated by crossing Gemlik, Manzanilla, Ascolana, Edinciksu, Uslu, and Tavşan yüreği olive cultivars during cross breeding studies of a national project. Oil was obtained from fruit of olive genotypes by cold pressing. Maturation index and oil content of genotypes were determined between 2.6-6.4 and 22.43-28.12 (%). Linolenic acid distributions in fatty acid composition of genotype's oil were detected between 0.5-1.33 (% in fatty acids). Some olive genotypes' oils had high linolenic characteristics that they have potential for supporting the necessary intake of omega-3. Also, some of them have had the desired omega-6/omega-3 fatty acid ratio which were between 3.74 and 4.00. Practical applications: Olive oil is a traditional product of Mediterranean basin and commonly consumed all over the world. But there is a need to improve yield, quality and nutritional value of olive oil. For this reason, there breeding studies were conducted. One of them was carried out in Ataturk Central Horticultural Research Institute. Here domestic and foreign olive cultivars were crossed to generate new olive genotypes since 1990. This research aimed to determine the olive oil of these obtained olive genotypes which had higher oil and omega-3 content and lower omega-6:omega-3 fatty acid ratio. Generating the high omega-3 content olive oil by cross breeding is one of the cheapest, simplest and most natural ways of obtaining omega-3 and delivering it to the consumer. [ABSTRACT FROM AUTHOR]

A global approach has been developed to study the influence of ripening of olive fruits on the phenolic fraction present in virgin olive oil from different genotypes of olives. For this purpose, a non-targeted method based on the analysis of phenolic extracts by MS in high resolution mode was applied. The phenolic profiles obtained by liquid chromatography - quadrupole-quadrupole-time-of-flight (LC-QqTOF) were compared by statistical multivariate analysis tools such as principal component analysis and heat correlation maps. In overall terms, discrimination was only observed for specific crop dates and ripening index values, which should be ascribed to a strong influence of the genotype. The ripening process of each genotype was also studied to demonstrate the variation of phenolic profile in relation to the ripening index. This study was also extended to a panel of representative phenols appreciated by their health and nutritional properties. The application of omics technologies to plant breeding programs could be considered as one of the main pillars on which improvement of products quality can be supported. Practical applications: Olive oil phenols are of a great interest since they contribute to autoxidation stability, health properties, and organoleptic characteristics of virgin olive oil. These phenols are considered a key to assess virgin olive oil quality. This study is focused on the effect of the ripening process on the phenolic fraction from a metabolomics point of view. This advanced omics technology (foodomics) applied to plant breeding programs can be one of the pillars to improve products quality. [ABSTRACT FROM AUTHOR]

In this work, a first level investigation was carried out to study the extra virgin olive oils (EVOOs) obtained from secular olive trees of Apulia region. Microextracted olive oil samples from selected and genetically characterized olive trees were studied by 1H NMR-based metabolomic approach and multivariate analysis, according to cultivar and geographic origin, within the Apulia region. The 1H NMR spectra of oils were analyzed by several pattern recognition methods, using both unsupervised (principal component analysis) and supervised (partial least squares discriminant analysis, orthogonal partial least squares discriminant analysis (OPLS-DA)) statistical techniques. EVOOs obtained from secular olive trees could be easily differentiated by OPLS-DA not only depending on the used cultivars but also according to their geographical origin within the different districts of the Apulia region, such to justify a larger biodiversity maintenance of Apulia secular germplasm. Therefore, differences in chemical composition and NMR profiles of EVOOs may be explained either by cultivars or geographic areas. Practical applications: About 10% of the genetic olive tree patrimony within the Apulia region consists of the secular olive trees. A recently introduced regional law (No 14 of June 4th, 2007) allows to exploit oil produced from secular olive trees by labeling it with the special mention: 'extra virgin oil from the Apulia secular olive trees'. Characterization of extra virgin olive oils obtained from secular trees may be an optimal solution to increase the value for this product and make it available on the market. On the other hand this economic issue is very important to preserve the unique landscape offered by the ancient olive groves of the Apulia region in south east Italy. [ABSTRACT FROM AUTHOR]

Olive oils extracted from Italian cultivars in South West Calabria, Southern Italy were analyzed for their triglyceride composition, for three successive harvest years 2005-2006-2007. Three autochthonous cultivars from Calabria (Cassanese, Ottobratica and Sinopolese) and seven allochtonous cultivars (Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino and Picholine) were considered. All cultivars showed a trilinolein content ≤ 0.10% of the total triglycerides, the equivalent carbon number42 (ECN42) content was always less than 0.75% of the total triglycerides. Triolein ranged from a minimum of 28.60% ± 2.12 in Nocellara Messinese to a maximum of 48.25% ± 2.67 found in Coratina. This work demonstrates the presence of significant differences (ANOVA) for the different triglyceride compounds present in these olive oils, taking into consideration the cultivar and the harvest year. Practical applications: Practical applications for the study entitled 'Influence of cultivar and harvest year on triglyceride composition of olive oils produced in Calabria (Southern Italy)' regard the possibility of knowing the triglyceridic composition of olive oil produced in South West Calabria (Southern Italy) from ten cultivars, three autochtonous from Calabria: Cassanese, Ottobratica and Sinopolese and seven allochtonous cultivars: Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino and Picholine. It is very important to understand if and how cultivar and harvest year influence the triglyceridic composition. In addition, the adaptability of the allochthonous cultivars in a different geographical context can be also evaluated by comparing olive oil triglyceride data between autochthonous and allochthonous cultivars. [ABSTRACT FROM AUTHOR]

Narrow hedgerows system (NHS) is a new concept of olive orchards characterized by minimum labor requirements, continuous mechanical harvesting, early bearing, high yield, and olive oil quality. In this work, the variability of phenolic composition of virgin olive oils (VOOs) was studied in three cultivars (Arbequina, Arbosana, and Sikitita), two planting systems (NHS: 1975 trees/ha and intensive system (IS): 333 trees/ha) and different harvesting dates (1 October and 26 November for the three cultivars; and three additional dates for the new olive Sikitita: 16 and 29 October; and 12 November). Phenolic compounds were extracted from the obtained VOOs by liquid-liquid extraction with 60:40 v/v methanol/water. The resulting hydroalcoholic extract was analyzed by liquid chromatography - diode-array detector - fluorescence detection (LC-DAD-FD) for individual phenols separation-quantification. Significant differences among genotypes were found for some individual phenols at the first harvesting date. At the second harvesting date, significant differences were found between genotypes and between planting systems ( p<0.05). According to the obtained results, the new Sikitita should be harvested at the beginning of the ripening period for obtaining VOO with high phenolic content. Finally, a global agronomic and oil compositional evaluation in NHS of the new cultivars bred specifically is needed for this new olive growing system. Practical applications: Narrow hedgerow is a new very high density (>1500 trees/ha) olive planting system associated to overhead vineyard harvesters that is increasingly used as it reduces drastically both labor and time needed to harvest the crop. This study focuses on the comparison of the content of phenolic compounds in olive oils originated from narrow hedgerow system and intensive system. The results can be used to determine the best time for harvesting the new olive Sikitita, recently selected for narrow hedgerow system, in order to obtain an olive oil with high phenolic content. [ABSTRACT FROM AUTHOR]

Adulteration of virgin olive oil with less expensive oils is a serious problem for the public and quality control evaluators of olive oil. That is why olive oil authenticity has become a major issue for producers, consumers, and policy makers. In order to avoid fraud to consumers, it is crucial to study the traceability of olive oil. This review covers 2 important techniques, analytical, and molecular methods, used to characterize olive oil and detect possible adulteration. Several analytical techniques are discussed for the detection of olive oil adulteration by analyzing minor and major compounds of olive oil. However, the chemical composition of olive oil can dramatically change due to the environmental and processing conditions. For this reason, the DNA-based technologies are gaining greater attention now because they are not influenced by environmental conditions and provide an opportunity for direct comparison of different genetic materials. In this review, we emphasize the great potential of different authenticity methods and discuss their practical implementation in olive oil traceability. [ABSTRACT FROM AUTHOR]