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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%) and olive obtained from the ground before harvesting time, corresponding to Fallen Olive Fruit (oil yields 30%). The purpose of this research was to determine the effect of olive category on the quality of virgin olive oil (VOO). Analytical indicators, such as free acidity, peroxide value, and UV absorbance at 232–270 nm, showed higher values in Fallen Olive Fruit Oil, while pigments, total phenols, and oxidative stability exhibited lower values compered to Fresh olive oils. Similarly, Fallen Olive Fruit Oil has a lower oleic acid concentration, while the sterol content of the two samples remained nearly consistent across the two crop seasons. Furthermore, the phenolic percentage emanated from Chemlali olive oil varies according to the type of olive fruit, with Fresh olive oil having the highest concentration. [ABSTRACT FROM AUTHOR]

Several compositional parameters (fatty acids, tocopherols, polar phenols and volatiles) in virgin olive oils from varieties located at the center of Tunisia, namely Baldi, Chemchali, Neb Jmel, Tounsi and Besbessi from Gafsa and Chemchali and Sehli cultivated in Sidi Bouzid, were studied. To the best of our knowledge, this is the first study focusing on the chemical composition of virgin olive oils (VOO) from Sidi Bouzid. Significant differences were found between varieties from Sidi Bouzid and Gafsa in monounsaturated saturated fatty acid levels, some volatile compounds and γ-tocopherol amounts. Notably, Tounsi and Baldi VOOs showed the highest six carbon atoms alcohol contents, whereas Neb Jmel VOO revealed the highest aldehyde six carbon atoms content. Fatty acid composition, as well as tocopherol content, showed differences among different VOO. Principal component analysis and hierarchical component analysis on polar phenols, fatty acids, tocopherols and volatiles data evidenced a good discrimination among oils from the different investigated varieties. [ABSTRACT FROM AUTHOR]

This work is aiming to characterize the fatty minor compounds of Kabylian virgin olive oils (Kabylian-VOOs) obtained from Chemlal, Azeradj and Bouichert olive cultivars. The content of sterols, triterpenic dialcohols, diterpenic alcohols, aliphatic alcohols, triterpenic alcohols, fatty acid alkyl esters (FAAEs) and waxes were determined. The most abundant common sterols were β-sitosterol and Δ5-avenasterol that were in high level in Azeradj-VOO and Chemlal-VOO, respectively. The wax and FAAEs content were close to limits set by the last trade standard regulation for all samples. Low amounts of aliphatic alcohols were found with a predominance of hexacosanol while high concentrations of triterpenic alcohols were found, in particular in Azeradj-VOO. The most abundant detected phytosterols were cycloartenol (823.60–2158.46 mg/kg), β-sitosterol (706.78–976.66 mg/kg), butyrospermol (580.00–787.32 mg/kg) and Δ5-avenasterolv (237.30–449.33 mg/kg) for all samples. Multivariate statistical analyses showed a good discrimination according to the fatty alcohols although the composition of Chemlal-VOO was closer to that of Bouichert-VOO. The Azeradj-VOO alcoholic composition was different from others and it's the richest one in phytosterols. In summary, each Kabylian-VOO had its own alcoholic fingerprint in which cycloartenol (a 4,4′-dimethylsterol) was the main species, 2158.46 ± 32.24 mg/kg in the case of Azeradj-VOO. [ABSTRACT FROM AUTHOR]

Olive oils produced in different years from different varieties were studied with UV–Vis spectroscopy for classification and prediction. Multivariate models were created with second derivative spectral data, and tested with external validation sets. For varietal classification, orthogonal partial least square discriminant analysis resolved oil samples into various classes with correct classification rate more than 89% for validation set (n = 20). A sample of fresh and stored oils were also classified with a correct classification rate more than 90% for validation set (n = 20). In the predictions of chemical parameters (70 for calibration, 30 for validation), the combination of UV–Vis spectroscopy with orthogonal partial least square regression models showed potential for simultaneous quantification of chlorophylls (0.6–5.6 mg/kg; R val 2 , 0.79; RPD, 1.97); carotenoids (0.6–3.3 mg/kg; R val 2 , 0.80; RPD, 2.38); ratio of mono to polyunsaturated fatty acids (3.6–8.8; R val 2 , 0.77; RPD, 1.90), oleuropein derivatives (1.2–62.3 mg/kg; R val 2 , 0.66; RPD, 1.77), and total phenol content (62.2–505 mg/kg; R val 2 , 0.67; RPD, 1.74), although showed poor to moderate results for the quantification of free fatty acid (0.3–5.4%; R val 2 , 0.67; RPD, 1.64); monounsaturated fatty acids (66-76.5%; R val 2 , 0.71; RPD, 1.67); polyunsaturated fatty acids (8.6–18.2%; R val 2 , 0.73; RPD, 1.65). The models were unable to estimate oxidative stability, saturated fatty acids, and individual phenolics such as hydroxytyrosol, pinoresinol, luteolin, total phenolic acids ( R val 2 , 0.26–0.64; RPD, 0.60–1.52). Results showed the capacities of UV–Vis spectroscopy for classification of olive oils, and prediction of total pigments and phenol content and ratio of mono to polyunsaturated fatty acids. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance (NMR) spectroscopy has been extensively used to date for the analysis of olive oil samples and constitutes a valuable tool particularly for the study of the triacylglycerol fraction, which is the major fraction of olive oils. In this report, we demonstrate the usefulness of one-dimensional NMR spectroscopy (1H and 13C NMR) for the non-destructive analysis of the triacylglycerol fraction of olive oils. To achieve this goal, 13C spectral editing technique known as distortionless enhancement by polarization transfer (DEPT), namely 13C NMR DEPT 45, 13C NMR DEPT 90, 13C NMR DEPT 135 was used for the analysis of the triacylglycerol fraction of the olive oil sample owing to the simplification on peak assignments of 13C spectra. The suitability and usefulness of those DEPT experiments using different angle values in only one pulse sequence will be explored on the interpretation of 13C NMR spectra. In overall, DEPT tool improves the sensitivity of the analysis due to the enhancement in the signal-to-noise ratio, which is important for this type of analysis contributing to the characterization of olive oils. [ABSTRACT FROM AUTHOR]

Six refined olive oil samples were characterized to have wide ranges of compositional indicators (the ratio between monounsaturated and polyunsaturated fatty acids = 3.9–9.6; peroxide value = 1.3–7.0 meq/kg; acid value = 0.4–0.6 mg/g; total tocopherols = 150–459 mg/kg; total phenolics = 11–39 mg/kg). Oxidative stability index (OSI) and frying stability time (the time required to reach a total polar compounds, TPC, of 25%, a conjugated diene value, CDV, of 25 mmol/l, and a carbonyl value, CV, of 47 µmol/g) of the olive oils were monitored under two thermal (Rancimat at 110–140 °C) and frying (at 180 °C) processes, respectively. The values of OSI ranged from 7.1 to 16.9 h at 110 °C, which significantly decreased to 0.9–1.9 h at 140 °C. Frying stability times were calculated to be 38.3–56.6 h, 25.6–64.1 h, and 32.4–55.3 h in terms of TPC, CDV, and CV, respectively. The greatest correlations (R2 ≥ 0.97) were obtained between the OSI at 110 °C and the frying stability times. The CV-based frying stability times provided the highest correlations at all temperatures used in the thermal process. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study is to evaluate the formation of the increase of Δ-7-stigmastenol during the chemical refining of pomace olive oil (POO) and the optimal neutralization by NaOH concentration of 20 °Be at a temperature of 70 °C. A comparison has been made between virgin olive oil (VOO) and consecutive steps of refining process in the amounts of Δ-7-stigmastenol of the POO oil samples. Among the oils, refined olive oil particularly the neutralized olive oil (NOO) by soda (NaOH) contained a high-level of Δ-7-stigmastenol. A mean result found in NOO by different concentration of NaOH from 15 to 25 °Be showed increased values significantly (p < 0.05) from 0.70 ± 0.01% to 0.78 ± 0.01% of Δ-7-stigmastenol and increased significantly (p < 0.05) the levels of erythrodiol and uvaol from 26.34 ± 0.39% to 28.11 ± 0.42%. Then, the concentration of the ∆-7-stigmastenol was evaluated using a GC-MS instrument. Besides, further analyses were performed to ensure the uniqueness of the peak of Δ-7-stigmastenol and absence of any overlap. In all cases, the level of Δ-7-stigmastenol was higher than the limit set by the International Olive Council.Graphical abstract: [ABSTRACT FROM AUTHOR]

The suitability of sterol profiles established by HPLC-MS as a tool to discriminate between seven cultivars of Tunisian virgin olive oils (VOOs) was evaluated in this study. Moreover, some cultivars (Chemchali, Fouji and Zarrazi) have been also classified according to their maturity index. A total of nine sterol peaks, which appeared in all samples, were used to develop linear discriminant analysis (LDA) models able to distinguish Tunisian VOOs according to their cultivar or maturity index. An excellent predictive classification was obtained since all samples were correctly classified. Therefore, it has been demonstrated that sterol profiles are a powerful tool to discriminate VOOs coming from different cultivars and maturity indexes. [ABSTRACT FROM AUTHOR]

In this study, trace element contents and stable carbon isotope ratios of olive oils were determined to evaluate their potential as authentication parameters. Forty-nine virgin olive oil samples (VOOs) from six different locations of the western part of Turkey (İzmir, Manisa, Aydın, Muğla, Bursa and Edremit Bay) were analysed with ICP-MS and EA-IRMS. V, Mn, Ni, Cu, Ba, Na, K, Ca, Fe, Mg, Pb, As, Co, Cr and Zn were found in the olive oil samples and determined δC stable istope ratios. Data from the olive oil samples were compiled and classified with chemometric approach. The results showed that there is significant potential to successfully authenticate olive oils according to Fe and Zn on the Manisa and δC have dominant effect on the location of Edremit Bay. As a result, the outcome of this study could be used to identify the geographical origin of olive oils especially for the Manisa and Edremit Bay locations. [ABSTRACT FROM AUTHOR]

The discrimination of organic and conventional production has been a critical topic of public discussion and constitutes a scientific issue. It remains a challenge to establish a correlation between the agronomical practices and their effects on the composition of olive oils, especially the phenolic composition, since it defines their organoleptic and nutritional value. Thus, a liquid chromatography-electrospray ionization-quadrupole time of flight tandem mass spectrometric method was developed, using target and suspect screening workflows, coupled with advanced chemometrics for the identification of phenolic compounds and the discrimination between organic and conventional extra virgin olive oils. The method was optimized by one-factor design and response surface methodology to derive the optimal conditions of extraction (methanol/water (80:20, v/ v), pure methanol, or acetonitrile) and to select the most appropriate internal standard (caffeic acid or syringaldehyde). The results revealed that extraction with methanol/water (80:20, v/ v) was the optimum solvent system and syringaldehyde 1.30 mg L was the appropriate internal standard. The proposed method demonstrated low limits of detection in the range of 0.002 (luteolin) to 0.028 (tyrosol) mg kg. Then, it was successfully applied in 52 olive oils of Kolovi variety. In total, 13 target and 24 suspect phenolic compounds were identified. Target compounds were quantified with commercially available standards. A novel semi-quantitation strategy, based on chemical similarity, was introduced for the semi-quantification of the identified suspects. Finally, ant colony optimization-random forest model selected luteolin as the only marker responsible for the discrimination, during a 2-year study. [ABSTRACT FROM AUTHOR]

Olive oil commercialization has a great impact on the economy of several countries, namely Tunisia, being prone to frauds. Therefore, it is important to establish analytical techniques to ensure labeling correctness concerning olive oil quality and olive cultivar. Traditional analytical techniques are quite expensive, time consuming and hardly applied in situ, considering the harsh environments of the olive industry. In this work, the feasibility of applying a potentiometric electronic tongue with cross-sensitivity lipid membranes to discriminate Tunisian olive oils according to their quality level (i.e., extra virgin, virgin or lampante olive oils) or autochthonous olive cultivar (i.e., cv Chétoui and cv Shali) was evaluated for the first time. Linear discrimination analysis coupled with the simulated annealing variable selection algorithm showed that the signal profiles of olive oils' hydroethanolic extracts allowed olive oils discrimination according to physicochemical quality level (classification model based on 25 signals enabling 84 ± 9% correct classifications for repeated K-fold cross-validation), and olive cultivar (classification model based on 20 signals with an average sensitivity of 94 ± 6% for repeated K-fold cross-validation), regardless of the geographical origin and olive variety or the olive quality, respectively. The results confirmed, for the first time, the potential discrimination of the electronic tongue, attributed to the observed quantitative response (sensitivities ranging from −66.6 to +57.7 mV/decade) of the E-tongue multi-sensors towards standard solutions of polar compounds (aldehydes, esters and alcohols) usually found in olive oils and that are related to their sensory positive attributes like green and fruity. [ABSTRACT FROM AUTHOR]

Aroma is an important quality criterion for extra virgin olive oil. The goal of this study was to determine C and C volatile compounds in different Turkish olive oils. Two factors namely (1) olive cultivar including Ayvalik, Memecik, and Topakasi, and (2) harvest time (ripening degree) were studied. Both factors significantly affected the volatile profiles of the studied oils. Headspace solid phase micro-extraction with GC/MS was used to detect volatiles in different olive oils. The detected volatile compounds included up to 11 compounds (4 from C, and 7 from C). Hexanal and ( E)-2-hexanal were predominated as the major volatiles in Ayvalik, and Memecik oils, while pentanal, and hexanal were predominated in Topakasi oil. Topakasi oil was also characterized by its low content of ( E)-2-hexenal. The only clear trend observed during ripening of olives was the increase in the total content of esters. Therefore, the information obtained in this study is useful in selecting the proper harvest time for each cultivar according to the desired volatile compounds found in the oil. [ABSTRACT FROM AUTHOR]

Changes occurring in refined olive pomace oil (ROPO) blended with refined palm oil (RPO) during repeated frying cycles were monitored. Four ratios of ROPO/RPO blends were prepared: (100:0), (75:25), (50:50) and (25:75). The effect of deep-frying was studied by assessing the changes in iodine value, acid value, color value and fatty acids composition. The results show that the mixture ROPO/RPO (25:75) is the most stable compared with other blends. The fate of 3-MCPD and glycidyl esters during deep-frying was investigated showing no endogenous formation of the esters during 16 h of deep-frying. [ABSTRACT FROM AUTHOR]

Tocopherols are natural fluorophores of great importance for the characterization and authentication of virgin olive oil. Herein, a single automatic multicommuted flow method has been developed for the determination of total tocopherol content as well as the semi-quantitative estimation of α-tocopherol in extra virgin olive oil (EVOO) samples. Only appropriate dilution of samples with 2-propanol was necessary for their direct analysis by a multicommuted flow injection (MCFIA) manifold based on three solenoid valves with fluorescence detection. The peak height at λ = 330 nm (emission) with λ at 296 nm was used as analytical signal. Linear response was observed within the range from 50 to 350 mg of tocopherols (expressed as α-tocopherol kg olive oil), suitable to cover the usual range for tocopherols in (extra) virgin olive oil ((E)VOO)). The results were consistent with those obtained by reversed-phase HPLC reference method, whereas the analysis time was significantly reduced. The sample frequency of the proposed automatic method was close to 40 samples h, in contrast to typically 15-30 min required by HPLC. The method is fast, straightforward, cost-effective, and easy to implement in routine laboratories for screening purposes. [ABSTRACT FROM AUTHOR]

A prototype gas chromatography-ion mobility spectrometry (GC-IMS) system, hyphenating temperature-ramped headspace GC to a modified drift time IMS cell, was evaluated and compared to a conventional, isothermal capillary column (CC)-IMS system on the example of the geographical differentiation of extra virgin olive oils (EVOO) from Spain and Italy. It allows orthogonal, 2D separation of complex samples and individual detection of compounds in robust and compact benchtop systems. The information from the high-resolution 3D fingerprints of volatile organic compound (VOC) fractions of EVOO samples were extracted by specifically developed chemometric MATLAB® routines to differentiate between the different olive oil provenances. A combination of unsupervised principal component analysis (PCA) with two supervised procedures, linear discriminant analysis (LDA) and k-nearest neighbors (kNN), was applied to the experimental data. The results showed very good discrimination between oils of different geographical origins, featuring 98 and 92% overall correct classification rate for PCA-LDA and kNN classifier, respectively. Furthermore, the results showed that the higher resolved 3D fingerprints obtained from the GC-IMS system provide superior resolving power for non-targeted profiling of VOC fractions from highly complex samples such as olive oil. [ABSTRACT FROM AUTHOR]

Detailed regions of excitation and emission wavelengths for extra virgin olive oil samples have been extracted from three dimensional front-face fluorescence spectra. Information was applied to establish a right-angle fluorescence procedure. A right-angle device was assembled and tested with simultaneous excitation from 200 to 400 nm and registration of the fluorescence signal emitted from 400 to 850 nm. A principal component analysis was performed on the signal ranging from 400 to 550 nm from spectra of olive oils officially categorized as extra virgin in order to model the expected variability of compounds related to oxidative processes. Such model was useful to monitor the spectral evolution of extra virgin olive oil samples acquired at retail markets, which were exposed to indirect light during 2 months, through the analysis of the effect on their scores. Three relevant peaks characterized such evolution, with local maxima at around 434 to 437, 464 to 469 and 510 to 518 nm. Polynomial relationship was found between the evolution of those peaks and that of the chlorophyll, at around 670 to 673 nm, with R values of 0.98 and 0.99. [ABSTRACT FROM AUTHOR]

Extra-virgin olive oils used in the production of flavoured oils can derive from a single cultivar or can be a blend of two or more mono-varietal oils. In order to investigate the effects of the characteristics of the oil blends on the quality of the deriving flavoured oils, three mono-cultivar extra-virgin olive oils (Coratina, Peranzana, Ogliarola) were used to produce three blends, which were successively flavoured by infusion. From each blend, three types of flavoured olive oils were produced: basil, chilli pepper, and garlic + chilli pepper. Mono-varietal extra-virgin olive oils, blends, and flavoured oils were submitted for routine analyses and for determination of polar compounds, phenolic profile, antioxidant activity, and volatile profiles. The panel and consumer tests were also carried out on the flavoured oils. Along with the undoubted influence of the flavouring agents, the quality parameters of each blend changed and their changes greatly depend on the starting blend. The parameters mostly affected by oil blend were: acidity, K, peroxide values, diacylglycerols, polar compounds, total phenolics, antioxidant activity, and phenolics such as p-coumaric acid, tyrosol acetate, vanillic acid, tyrosol, hydroxytyrosol, hydroxytyrosol acetate, dialdehydic form of elenolic acid linked to tyrosol, and ligstroside aglycone, oleuropein aglycone. The effects of oil blending were rather limited on volatile profiles and sensory characteristics. [ABSTRACT FROM AUTHOR]

The malaxation conditions were studied in order to evaluate the composition of secoiridoid derivatives of Picual virgin olive oil using response surface methodology. Secoiridoid derivatives are the most abundant phenolic compounds in virgin olive oil: 3,4-DHPEA-EDA; 3,4-DHPEA-EA; p-HPEA-EDA; p-HPEA-EA. The temperature range studied was 20-60 °C, time 20-60 min, and the talc dosage 0.5-2.5 %. Also, fruit ripening and irrigation management were studied during one season in an orchard of Andalusia (Spain). The content of secoiridoid derivatives increases with increasing malaxation temperature of the olive paste. However, the content of secoiridoid derivatives from oleuropein (3,4-DHPEA-EDA and 3,4-DHPEA-EA) decreases with mixing time, while the content of secoiridoid derivatives from ligstroside ( p-HPEA-EDA and p-HPEA-EA) increases. On the other hand, the secoiridoid derivatives from oleuropein increase with increasing maturity index while secoiridoid derivatives from ligstroside decrease in the range studied. Finally, the olive oils from olives cultivated without irrigation have more secoiridoid derivatives than olive oils from olives cultivated with irrigation. [ABSTRACT FROM AUTHOR]

During the extraction, a portion of oil remains trapped inside the cells and its release requires the degradation of the walls and cell membranes, especially when the fruits have not reached a maximum maturity which is likely to cause an optimal embrittlement of the parietal structures and cell membrane. This can be done by specific enzymes necessary for the degradation of various cellular barriers. Three different enzyme treatments proteolytic, pectolytic or both are applied on the Moroccan Picholine olives from veraison to maturity of the fruit. The effect of these treatments is evaluated by olive oil diffusion, its phenolic content (PC) and cellular embrittlement determination of olives during ripening. The pectolytic activities lead to a significant increase in both the oil extractability (76 % at veraison and 14 % at maturity) and the PC (up to 50 % of gain compared to the control at veraison and 27 % at maturity). The proteolytic activities applied alone have no significant effect on the extractability and the polyphenols levels of oils. Furthermore, when these proteolytic activities are added in combination with the pectolytic activities, the oil extractability is doubled at veraison and its flowing up to 99 % at maturity that barely 84 % in the control in addition to a richness of polyphenols which can reach 84 % more compared to the control. This increase in polyphenols wealth is probably due to the degradation of cell walls, cellular and vacuolar membranes by enzyme activities releasing PCs that were previously associated with these structures in the drupe. [ABSTRACT FROM AUTHOR]

Purpose: The contribution of extra virgin olive oil (EVOO) macro- and micro-constituents in heart oxidative and inflammatory status in a hypercholesterolemic rat model was evaluated. Fatty acid profile as well as α-tocopherol, sterol, and squalene content was identified directly in rat hearts to distinguish the effect of individual components or to enlighten the potential synergisms. Methods: Oils and oil-products with discernible lipid and polar phenolic content were used. Wistar rats were fed a high-cholesterol diet solely, or supplemented with one of the following oils, i.e., EVOO, sunflower oil (SO), and high-oleic sunflower oil (HOSO) or oil-products, i.e., phenolics-deprived EVOO [EVOO(−)], SO enriched with the EVOO phenolics [SO(+)], and HOSO enriched with the EVOO phenolics [HOSO(+)]. Dietary treatment lasted 9 weeks; at the end of the intervention blood and heart samples were collected. Results: High-cholesterol-diet-induced dyslipidemia was shown by increase in serum total cholesterol, low-density lipoprotein cholesterol, and triacylglycerols. Dyslipidemia resulted in increased malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α) levels, while glutathione and interleukin 6 levels remained unaffected in all intervention groups. Augmentation observed in MDA and TNF-α was attenuated in EVOO, SO(+), and HOSO(+) groups. Heart squalene and cholesterol content remained unaffected among all groups studied. Heart α-tocopherol was determined by oil α-tocopherol content. Variations were observed for heart β-sitosterol, while heterogeneity was reported with respect to heart fatty acid profile in all intervention groups. Conclusions: Overall, we suggest that the EVOO-polar phenolic compounds decreased MDA and TNF-α in hearts of cholesterol-fed rats. [ABSTRACT FROM AUTHOR]

Three different flavoring methods of olive oil were tested employing two different herbs, thyme and oregano. The traditional method consist in the infusion of herbs into the oil. A second scarcely diffused method is based on the addition of herbs to the crushed olives before the malaxation step during the extraction process. The third innovative method is the implementation of the ultrasound before the olive paste malaxation. The objective of the study is to verify the effect of the treatments on the quality of the product, assessed by means of the chemical characteristics, the phenol composition and the radical scavenging activity of the resulting oils. The less favorable method was the addition of herbs directly to the oil. A positive effect was achieved by the addition of herbs to the olive paste and other advantages were attained by the employment of ultrasound. These last two methods allow to produce oils "ready to sell", instead the infused oils need to be filtered. Moreover, the flavoring methods applied during the extraction process determine a significant increment of phenolic content and radical scavenging activity of olive oils. The increments were higher when oregano is used instead of thyme. Ultrasound inhibited the olive polyphenoloxidase, the endogenous enzyme responsible for olive oil phenol oxidation. This treatment of olive paste mixed with herbs before malaxation was revealed as the most favorable method due to the best efficiency, reduced time consumption and minor labor, enhancing the product quality of flavored olive oil. [ABSTRACT FROM AUTHOR]

The recent description of the presence of exogenous plant microRNAs from rice in human plasma had profound implications for the interpretation of microRNAs function in human health. If validated, these results suggest that food should not be considered only as a macronutrient and micronutrient supplier but it could also be a way of genomic interchange between kingdoms. Subsequently, several studies have tried to replicate these results in rice and other plant foods and most of them have failed to find plant microRNAs in human plasma. In this scenario, we aimed to detect plant microRNAs in beer and extra virgin olive oil (EVOO)--two plant-derived liquid products frequently consumed in Spain--as well as in human plasma after an acute ingestion of EVOO. Our hypothesis was that microRNAs present in beer and EVOO raw material could survive manufacturing processes, be part of these liquid products, be absorbed by human gut and circulate in human plasma. To test this hypothesis, we first optimized the microRNA extraction protocol to extract microRNAs from beer and EVOO, and then tried to detect microRNAs in those samples and in plasma samples of healthy volunteers after an acute ingestion of EVOO. [ABSTRACT FROM AUTHOR]

A new sensing system for the detection of thermal deterioration of extra virgin olive oil based on long period fibre grating is reported. It is demonstrated the feasibility of long period fibre grating sensor for the analysis of high refractive index edible oils. The detection principle is the wavelength dependence of the attenuation bands of a TiO-coated long period fibre grating on the changes in the refractive index of the medium surrounding the cladding surface of the optical fibre. The quality of the sensor was tested by measuring the wavelength shift of the attenuation bands in response to thermal deterioration of an edible oil (extra virgin olive oil) with refractive index higher than the fibre cladding. Absorption spectroscopy has allowed the effects of thermal deterioration to be detected, for example, in the decreasing of the absorption band at 677 nm, attributed to chlorophyll A. A detection limit of about 5 min at 180 °C and of about 2 min at 225 °C was observed for the sensing system. The proposed sensing system could lead to the realisation of a biochemical sensor for the food industry. The change in refractive index of extra virgin olive oil as a function of heating time and temperature was systematically measured for the first time. [ABSTRACT FROM AUTHOR]

Background/objectives:Effects of high-protein diets that are rich in saturated fats on cell adhesion molecules, thrombogenicity and other nonlipid markers of atherosclerosis in humans have not been firmly established. We aim to investigate the effects of high-protein Malaysian diets prepared separately with virgin olive oil (OO), palm olein (PO) and coconut oil (CO) on cell adhesion molecules, lipid inflammatory mediators and thromobogenicity indices in healthy adults.Methods:A randomized cross-over intervention with three dietary sequences, using virgin OO, PO and CO as test fats, was carried out for 5 weeks on each group consisting of 45 men and women. These test fats were incorporated separately at two-thirds of 30% fat calories into high-protein Malaysian diets.Results:For fasting and nonfasting blood samples, no significant differences were observed on the effects of the three test-fat diets on thrombaxane B2 (TXB2), TXB2/PGF1α ratios and soluble intracellular and vascular cell adhesion molecules. The OO diet induced significantly lower (P<0.05) plasma leukotriene B4 (LTB4) compared with the other two test diets, whereas PGF1α concentrations were significantly higher (P<0.05) at the end of the PO diet compared with the OO diet.Conclusion:Diets rich in saturated fatty acids from either PO or CO and high in monounsaturated oleic acid from virgin OO do not alter the thrombogenicity indices-cellular adhesion molecules, thromboxane B2 (TXB2) and TXB2/prostacyclin (PGF1α) ratios. However, the OO diet lowered plasma proinflammatory LTB4, whereas the PO diet raised the antiaggregatory plasma PGF1α in healthy Malaysian adults. This trial was registered at clinicaltrials.gov as NCT 00941837. [ABSTRACT FROM AUTHOR]

The potentiality of a multidimensional comprehensive gas chromatographic (GC × GC) method, employing a simultaneous dual detection (FID and mass spectrometer), to generate peculiar two-dimensional chromatograms to be used as a chemical fingerprint, was investigated to characterize minor compounds in edible oil, particularly olive oil. The best column combination for this application was investigated comparing two column sets (orthogonal or reverse-type), equivalent in terms of theoretical plate number, but differing in stationary phase combination. The apolar × mid-polar set gave a superior separation power, thus was used for further characterization. Different levels of information were extrapolated from the two-dimensional chromatogram. Using the FID, reliable quantification of the alkyl esters fatty acids and waxes was obtained, comparable to the results obtained using the official method, as required by the European legislation. However, thanks to a slight modification of the sample preparation method, the increased separation power obtained using the GC × GC method, and the support of the mass spectrometer detector, further diagnostic information was extrapolated considering the free sterol and tocopherol fractions. In particular, the profiles of extra virgin olive oil samples were compared with a hazelnut oil sample, highlighting that the latter was characterized by a larger number of compounds, completely absent in the extra virgin olive oil samples, which can be used to detect illegal admixtures. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Purpose: Olive oil contains several phenolic compounds possessing antioxidant activity. The aim of this study was to investigate the protective effects of olive oil phenolic extract (OOPE) and one of its constituents, gallic acid (GA) against HO-induced oxidative stress and apoptotic cell death in HeLa cells, a model for human epithelial cells. Methods: The cells were pretreated with nontoxic doses of OOPE or GA for 4, 24 and 48 h, and the intracellular reactive oxygen species (ROS) level was determined, before and after oxidative stress induction with HO. As an indicator of apoptosis, caspase 9 activity was measured. Results: All pretreatments reduced ROS generation. Four hour incubation with OOPE or GA completely inhibited ROS generation. Increases in caspase 9 activity by OOPE and GA pretreatment under harsh stress conditions were inhibited 92 and 67.8%, respectively. Conclusions: These results suggest that OOPE and GA act as powerful antioxidants against oxidative stress and exert anti-apoptotic effects. [ABSTRACT FROM AUTHOR]

The study for the elaboration and certification of four olive oil reference materials covering all the physical–chemical characteristics, defined in Commission Regulation (EC) 1989/2003, is reported herein. The different steps of the process, preparation of reference materials, homogeneity and stability studies, and characterization study have been carried out for 14 laboratories from five European countries. The certificate of analysis for these certified reference materials (CRMs) provide assigned values for concentrations of more than 50 parameters or characteristics of olive oils in compliance with the European legislation about the labeling of food products. The certified values and its corresponding uncertainties were obtained applying robust statistics to the raw data provided by the laboratories taking part in the interlaboratory study. The certificate is valid for a maximum period of 18 months from the elaboration date. These four CRMs are intended for use as a primary material for quality control and for validation of analytical methods for measurements in authentication and adulteration problems of olive oils. [ABSTRACT FROM AUTHOR]

In recent years, a large number of biological properties and an important role in the organoleptic characteristics of olive oil have been attributed to phenolic secoiridoids, such as oleacein, oleocanthal, oleuropein aglycone and ligstroside aglycone. Consequently, quantifying them is of great interest for the olive oil sector. Currently, there is no consensus in which analytical method must be use to accurately determine these compounds in olive oil, mainly owing to the lack of reference standards for calibration. In this work, analytical standards of phenolic secoiridoids have been used to develop a quantitative and rapid analytical method by UHPLC-MS/MS, in which sample extraction is not carried out. Simple dilutions of the sample with dry tetrahydrofuran and dry acetonitrile were performed before analysing them. It is worth noting that under these conditions the generation of artefacts such as acetals and hemiacetals of the aldehydic forms is highly reduced. The detection and quantification was performed with a Xevo TQS tandem quadrupole mass spectrometer. The method was validated at four concentration levels and finally applied to six samples of extra virgin olive oil. [ABSTRACT FROM AUTHOR]

Total oil content (OC) is one of the main parameters used to characterize the whole of olives entering a commercial mill, quantified by the total fresh weight of the lot and the oil concentration (%) assessed in a representative sample on olive paste, by means of chemical extraction. Nuclear magnetic resonance (NMR) and NIR spectroscopy are alternative methods even at individual olives. This work evaluates several strategies to calibrate precise NIR models for the estimation of the total OC. To this end, 278 olives were analysed covering whole season variability in terms of olive fresh-weight and the corresponding OC by chemical extraction in 31 batches. The average spectra from hyperspectral NIR images (1003–2208 nm) were computed for each fruit and the actual OC (g) of those olives determined by NMR (0.09 to 1.29 g with a precision of 0.017 g). According to the results, current batch based assessment of the OC (Soxhlet, %) in mills only reproduces 44% of the underlying heterogeneity, despite being the factory standard. The incorporation of individual NIR spectra (278) to the 31 Soxhlet values of the batches allows a 67% explanation of the OC (%) of olives. When estimating OC (g) gathering individual fresh weight and the estimation of oil concentration in olives, a standard error of prediction of 0.061 g is reached (r2 = 0.93), a precision value that approaches the potential limit according to the NMR reference (0.017 g). [ABSTRACT FROM AUTHOR]