Monocultivar Extra Virgin Olive Oil Research Articles

Is the volatile compounds profile a suitable tool for authentication of virgin olive oils (Olea europaea L.) according to cultivars? A study by using HS-SPME-GC-MS and chemometrics

Sensory characteristics of Virgin Olive Oil (VOO) strongly influence consumer preferences. These characteristics are also affected by the varietal origin of the olives used for producing the oils, and consequently a reliable approach is strongly required to authenticate the varietal origin of VOO. However, an approach is still missing to differentiate VOOs of the most worldwide spread cultivars, thus protecting consumers and producers from frauds. The aim of this research was to propose chemometric models for discriminating monocultivar virgin olive oils of nine widespread cultivars. 72 volatile compounds of 320 monocultivar samples from 4 crop seasons and several geographic areas were quantitated by a validated HS-SPME-GC-MS method. The VOCs able to discriminate among cultivars were selected through ANOVA: most of them belonged to the lipoxygenase pathway. A PLS-DA model was successfully validated, with percentages of correct classification up to 95.9% after external validation. Three clusters of cultivars were then defined using Agglomerative Hierarchical Clustering and Correlation Analysis. LDA and PLS-DA models correctly classified 94% of samples in the three clusters. The results indicated that the volatile profile of samples of diverse cultivars are not completely independent from each other, and that specific groups of cultivars showed strong similarities not given by the geographic origin. Overall, this study will contribute to protect from frauds and to valorize monocultivar extra virgin olive oils.

Microbiological and Enzymatic Activity Modulates the Bitter Taste Reduction in Decanted Coratina Olive Oil.

Coratina monocultivar extra virgin olive oil (EVOO) is known for its level of bitterness, which, if too high, can cause consumer acceptance problems. The aim of this study was to modulate the bitter taste of freshly produced olive oil through endogenous enzymatic activity and microbiota during the decantation phase. The opalescent appearance of the newly produced EVOO was substantially reduced during the first three months of decantation due to the deposition of more than 90% of suspended material, consisting of vegetation water and suspended solid particles. The high content of biophenols and the reduction in water concentration in the oil samples negatively affected the survival of yeasts, which were absent in the oil samples at the end of the third month of decantation. The oleuropeinolytic activity was very intense during the first month of decantation, whereas the reduction in the bitter taste associated with the aglycons was consistent only in the second and third months of decantation. At the end of decantation, the sensory notes of bitterness in the Coratina EVOO were reduced by 33%, lowering the position on the value scale without altering the other qualitative parameters whose values fell within the limits of the commercial EVOO class.

Effects of the Filtration on the Biotic Fraction of Extra Virgin Olive Oil.

Filtration is a widely used process in the production of extra virgin olive oil. We studied the influence of filtration performed with cotton filters and cellulose filter press on the biotic components of the oily mass containing probiotic traits in two freshly produced monocultivar extra virgin olive oils. The concentration of bacteria was reduced from 100% to 28%, while that of fungi was reduced from 100% to 44% after filtration, according to the filtration system and the initial contamination of the original monocultivar extra virgin olive oil. Compared with the control, the yeast content in the oil samples filtered with cotton filters was reduced from 37% to 11% depending on the cultivar. In the oil filtered with cellulose filter press, the yeast content reduced from 42% to 16%. The viable yeast that passed through the oily mass during the filtration process with cellulose filter press, unlike all the other samples, were unable to survive in the oil after a month of storage. The possible health benefits of compounds from both the biotic and abiotic fraction of the oil, compared to the control, were significantly low when filtered with the cellulose filter press.

Oleocanthal Quantification Using 1H NMR Spectroscopy and Polyphenols HPLC Analysis of Olive Oil from the Bianchera/Belica Cultivar.

The cultivar Bianchera is an autochthonous variety from the eastern part of northern Italy, but it is also cultivated in the Slovenian and Croatian peninsula of Istria where it is named Belica (Slovenia) and Bjelica (Croatia). The properties of oleocanthal, a natural anti-inflammatory ibuprofen-like compound found in commercial monocultivar extra virgin olive oils, were determined by means of both quantitative 1H NMR (qNMR) and HPLC analyses, where qNMR was identified as a rapid and reliable method for determining the oleocanthal content. The total phenolic content (TPC) was determined by means of the Folin–Ciocalteau method and the major phenols present in the olive oils were also quantified by means of HPLC analyses. All these analyses confirmed that the cultivar Bianchera was very rich in polyphenols and satisfied the health claim provided by the EU Commission Regulation on the polyphenols content of olive oils and their beneficial effects on human health.

Evaluation and Origin Discrimination of Two Monocultivar Extra Virgin Olive Oils, Cultivated in the Coastline Part of North-Western Greece

Extra virgin olive oil (EVOO) quality and authenticity are important and challenging factors nowadays for the assurance of consumers’ protection, prevention of unfair competition, and disruption of the national economy by a false declaration of origin. Hence, the recognition of EVOO authenticity is of great interest in terms of commercial and quality aspects. The objective of this study was to evaluate and discriminate monovarietal extra virgin olive oils of the two dominant olive cultivars, Lianolia Kerkyras and Koroneiki, produced in the coastline part of Western Greece, based on their chemical characteristics, followed by statistical and chemometric analysis in order to profile for the first time the typical characteristics of Lianolia Kerkyras as well as to identify possible markers for authenticity purpose. A total of 104 olive oil samples were collected. Both cultivars had an overall high quality profile as far as their basic qualitative parameters (free fatty acid, peroxide value, and UV spectrometric indices) are concerned. A higher concentration in the mono-unsaturated oleic acid characterize olive oils of cv. Koroneiki compared to cv. Lianolia Kerkyras, while a clearly higher concentration in the poly-unsaturated linoleic acid was observed in olive oils of cv. Lianolia Kerkyras. In addition, olive oil samples of cv. Koroneiki showed a clear lower total sterols concentration with a percentage of 40.9% not surpassing the required EU Regulatory limit of 1000 mg/kg, an observation which strengthens previous published results of our research group and depicts an overall “intrinsic characteristic” of cv. Koroneiki. As far as the profile of the individual sterols is concerned, Lianolia Kerkyras samples exhibited higher mean value for the total sterol content as well as for β-sitosterol, the major phytosterol in olive oils, compared to the relative values of Koroneiki. Significant differences in the sterolic and fatty acid composition of the examined olive oil samples were shown by means of statistical analysis demonstrating a strong botanical effect and depicting that those compositional markers can be suggested as possible authenticity tools.

Comparison and Discrimination of Two Major Monocultivar Extra Virgin Olive Oils in the Southern Region of Peloponnese, According to Specific Compositional/Traceability Markers.

The qualitative characteristics and chemical parameters were determined for 112 virgin olive oil samples of the two dominant olive cultivars in the southern region of Peloponnese, cv. Koroneiki and cv. Mastoides. As no relevant data exist for this geographical area, yet one of the most important olive-growing regions in Greece, this study aimed to evaluate and evidence the differences on specific chemical characteristics of the oils because of their botanical origin. Olive oils of Koroneiki variety were characterized by a three-fold lower concentration in heptadecanoic and heptadecenoic acid compared to oils of cv. Mastoides. In addition, Mastoides oils exhibited higher β-sitosterol and total sterols concentration and lower Δ-5-avenasterol and total erythodiol content compared to Koroneiki olive oils Analysis of variance and principal component analysis of the GC-analyzed olive oil samples showed substantial compositional differences in the fatty acid and sterolic profile between Koroneiki and Mastoides cultivars. Hence, results demonstrate that the fatty acid and sterolic profile can be used as exceptional compositional marker for olive oil authenticity.

EFFECTS OF FİLTRATİON PROCESS AND STORAGE TİME ON THE CHEMİCAL CHANGES AND SENSORY PROPERTİES OF OLİVE OİL EXTRACTED FROM TURKİSH USLU CULTİVAR

Upper Mesopotamia is a part of Turkish territory is the homeland of the olive tree with a wide range genetic resource. This is the first report on chemical composition and oxidative stability of olive oil extracted from Uslu cultivar grown locally in a small amount. In this research, a Turkish olive cultivar named as “Uslu” locally grown in Akhisar was used for production of monocultivar extra virgin olive oil by using Mobile Olive Oil Processing Unit”. Olive oil samples were bottled before and after filtration and stored up to 24 months. Some chemical properties such as free fatty acid content, peroxide value, moisture content, UV absorbance value, minor and major components (fatty acid composition, tocopherols, total phenol compounds and phenolic composition), were determined during storage for 24 months. Chemical parameters such as free fatty acid, peroxide value except UV absorption values of both filtered and unfiltered “Uslu” olive oil samples were in agreement with the trade standards of International Olive Council (IOC). Color values of EVOO changed from green to yellow while UV absorbance values altered during storage. Very low free fatty acidy (0.2%) values which are unusual for commercial olive oils in Turkey were obtained for filtered and unfiltered samples. A slight increase was seen for unfiltered sample at the end of storage. Filtration had no detectable effect on fatty acid profile. Filtered sample had higher total phenols (407.64±4.051 ppm) and α-tocopherol (237 and 123.31 ppm) contents than unfiltered ones and their contents decreased approximately 50% at the end of storage. Luteolin was the most abundant phenolic compound and its concentration decreased from 268.65±5.428 to 93.57±0.541ppm during storage. It seemed effect of filtration was more obvious on total phenolic contents. This study was good practice for producing premium extra virgin olive oil by using Mobile Olive Oil Processing Unit. The results obtained in this study showed that Uslu olive oils has a unique chemical composition and a good oxidative stability with high tocopherols and phenolics contents that are uncommon in most of the commercial olive oils.

A preliminary study on the potential of front face fluorescence spectroscopy for Italian mono-cultivar extra virgin olive oil discrimination

Front-face fluorescence method has been used to obtain fluorescence excitation emission matrix (EEM) characteristic of various Italian monocultivar extra virgin olive oil (EVOO), Mixed EVOO, and lower grade virgin olive oil. Specific region of EEM has been explored using principle component analysis. It was found that EEM region of excitation 250-400 and emission 280-620 nm could be used to discriminate each sample type of different cultivar, mixed sample, and virgin olive oil sample. The important fluorescence peaks for the discrimination belong to unique combination of tocopherols, tocotrienols, phenolic compounds, oxidation products, and vitamin E. These results show that frontface fluorescence EEM spectroscopy has a potential to be used for monocultivar EVOO discrimination.

A preliminary study on the potential of front face fluorescence spectroscopy for Italian mono-cultivar extra virgin olive oil discrimination

Front-face fluorescence method has been used to obtain Fluorescence Excitation Emission Matrix (EEM) characteristic of various Italian monocultivar Extra Virgin Olive Oil (EVOO), Mixed EVOO, and lower grade Virgin Olive Oil (VOO). Specific region of EEM has been explored using Principle Component Analysis (PCA). It was found that EEM region of excitation 250-400 and emission 280-620 nm could be used to discriminate each sample type of different cultivar, mixed sample, and virgin olive oil sample. The important fluorescence peaks for the discrimination belong to unique combination of Tocopherols, Tocotrienols, Phenolic compounds, Oxidation products, and Vitamin E. These results show that front-face Fluorescence EEM spectroscopy has a potential to be used for monocultivar EVOO discrimination.

Changes occurring in chemical composition and oxidative stability of virgin olive oil during storage

In present study, “Saurani” Turkish olive monocultivar extra virgin olive oil (EVOO) was extracted by using Mobile Olive Oil Processing Unit (MOOPU)” (TEM Oliomio 500-2GV, Italy). Free fatty acid content, peroxide value, moisture content and UV absorbance value, minor and major components and quality characteristics changes were surveyed during a year storage. “Saurani” olive oil samples weren’t categorized as EVOO according to the trade standards of International Olive Council (IOC) based on peroxide value, UV absorbance values after five and two months of storing, respectively. Free fatty acid content of VOO samples increased during 12 months’ storage, but it was under the IOC limitation for extra virgin olive oil (< 0.8%). According to the results, color values of VOO changed from green to yellow while UV absorbance values altered during storage. Total phenol content decreased from 342.95 to 252.42 ppm in EVOO samples during a year storage time. Luteolin was the most abundant phenolic compound and its decrement was 10%. Tyrosol content of VOO samples increased from 2.80 to 8.81 ppm. Except tyrosol, other phenolic compounds’ concentration decreased after a year storage time. α-tocopherol contents of VOO sample were 324.60 ppm. After 12 months of storage, about 20.48% of α-tocopherol content was destroyed. Amounts of phenolic and tocopherol isomers decreased during storage as expected. Results of this study showed that chemical composition and oxidative stability of VOO samples changed significantly.

Determination of some chemical and quality parameters of changes in turkish Sari Ulak monocultivar extra virgin olive oil during 12 months of storage

In this study Turkish monocultivar extra virgin olive oil (EVOO) “Sarı Ulak” was extracted by using the Mobile Olive Oil Processing Unit (TEM Oliomio 500-2GV, Italy). Changes in minor and major components and quality characteristics, free fatty acid content, peroxide value and UV absorbance value, were surveyed during a year’s storage period. “Sarı Ulak” olive oil samples were classified as EVOO according to the trade standards of the International Olive Council (IOC) based on free fatty acid, peroxide value, K232 and ΔK values up to the eighth month of the storage period. The results have shown that color values of EVOO changed from green to yellow slowly while UV absorbance values changed during storing. Total polyphenol content of extra virgin olive oil decreased from 205.17 ppm to 144.29 ppm during a year’s storage. Luteolin was the most abundant phenolic compound, and its concentration changed from 184.33 ppm to 115.06 ppm. Apigenin concentration was differed from 2.67 to 1.06 ppm during storing. The initial level of α-tocopherol contents was 184.51 ppm, it decreased to 147 ppm at the end of storage time. After 12 months of storing, about 20 % of α-tocopherol content was destroyed. The amounts of phenolic and tocopherol isomers decreased during storage as expected.

Discrimination of flavoured olive oil based on hyperspectral imaging.

The aim of the work was to use the hyperspectral imaging as an analytical tool for the classification of flavoured olive oils, according to composition of the starting blends, crop season, flavouring methods, and flavouring agent. For this reason, in the crop season 2013-2014, three mono-cultivar extra virgin olive oils (Coratina, Peranzana, Ogliarola) were used in different proportions to produce three blends, which were successively flavoured by infusion. From each blend, 3 types of flavoured olive oils were produced: basil, chilli pepper, and garlic + chilli pepper. In the crop season 2014-2015, the study was limited to one of the blends used in the previous season and the basil, chilli pepper, and garlic + chilli pepper flavoured olive oils were produced by infusion or by malaxation. Blends and flavoured oils were submitted to hyperspecral imaging in the 400-1000nm region. To discriminate the oil samples, ANOVA analysis was performed at each wavelength. Wavelengths in the range 400-570nm and around 695nm allowed the discrimination of samples.

LC-DAD/ESI-MS/MS characterization of phenolic constituents in Tunisian extra-virgin olive oils: Effect of olive leaves addition on chemical composition

The aim of the present research is to evaluate the chemical characterization of main compounds from Tunisian monocultivar extra virgin olive oil (EVOO) (‘Chemlali’, ‘Chétoui’, ‘Zalmati’ and ‘crossbreeding Chemlali by Zalmati’) extracted after the addition of different amounts (0% and 3%) of olive leaves. As expected for extra virgin olive oil, the main sterols found in all analyzed samples were β-sitosterol, ∆-5-avenasterol, campesterol and clerosterol. Stigmasterol, 24-methylene-cholesterol, cholesterol, campestanol, sitostanol, ∆-7-stigmastenol, ∆-5,24-stigmastadienol, and ∆-7-avenasterol were also found in all samples, but in lower amounts. Most of these compounds were significantly affected by the cultivars but not to be affected by added leaves at 3% to olives prior to the extraction process. The obtained results revealed that 14 phenolic compounds belonging to different phenolic types were characterized and quantified by an effective HPLC-DAD-ESI-MS/MS method. In all the studied olive oil samples, dialdehydic form of elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA), oleuropein aglycon (3,4-DHPEA-EA), and ligstroside aglycon (p-HPEA-EA) were the most abundant compounds. In addition, EVOO from ‘Chétoui’ cultivar extracted with 3% of olive leaves presented the highest amount of individual phenolic compounds.

As oil blending affects physical, chemical, and sensory characteristics of flavoured olive oils

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, K232, 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.

Phenolic compounds in mono-cultivar extra virgin olive oils from Algeria

The high oxidative stability of virgin olive oil is related to its high monounsaturated/polyunsaturated ratio and to the presence of antioxidant compounds, such as tocopherols and phenols. In this paper, the isolation of phenolic compounds from virgin olive oil from several Algerian varieties was tested and discussed in order to know its potential uses and benefits. Quantification of phenolic and o-diphenolic substances was performed using the traditional Folin-Ciocalteau method and the sodium molybdate reaction, respectively. The qualitative and quantitative characterizations of phenolic compounds were carried out by HPLC. The experimental results show that tyrosol, hydroxytyrosol and 4-HBA (4-hydroxybenzoic acid) are the main individual phenolic compounds identified in the varieties studied. The varieties with large fruits ( Grosse du Hamma, Aghenfas, Azeradj, Aguenaou, Aberkane, Bouchouk de Guergour, X-Aghenfas, Rougette de Guelma, Sigoise ) are clearly distinguished from the varieties with medium-sized and small fruits by having the highest levels of individual phenolic compounds. Moreover, varieties with small fruits ( Hamra, Chemlal, Boughenfas, Limli, Aimel and Mekki ) presented the highest levels of oleuropein.

Influence of harvest year and cultivar on wax composition of olive oils

AbstractOlive oils extracted from Italian cultivars grown in the Region of Calabria, Southern Italy were analyzed for their wax ester composition, for three successive harvest years. Three autochthonous cultivars from Calabria: Cassanese, Ottobratica, and Sinopolese and seven allochtonous cultivars: Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino, and Picholine were considered. This work demonstrates the presence of significant differences (ANOVA) for the different wax ester compounds present in these olive oils, taking into consideration the cultivar and the harvest year. The studied olive oils present a good wax ester composition according to both EU and IOC regulations. The cultivar Ottobratica showed the highest wax ester content, whereas Itrana presented the lowest content.Practical applications: Wax esters are naturally present on the drupe cuticle and are transferred into olive oil by means of mechanical extraction and especially by solvent extraction on an industrial scale. They are a legal parameter contained in the European Union regulation and in the International Olive Oil Council regulation. Wax esters are a quality indicator for olive oil evaluation, especially to detect a fraudulent admixture of pomace olive oil in labeled extra virgin olive oil or in labeled monocultivar extra virgin olive oil. The adaptability of allochthonous cultivars in a different geographical area is also demonstrated.

Optimization of the Measurement of Italian Monocultivar Extra Virgin Olive Oil Antioxidant Power Via the Briggs–Rauscher Reaction

In this paper, the overall antioxidant power of monocultivar extra virgin olive oil (EVOO) from Marche Region (Italy) was determined modifying, for the first time, the Briggs–Rauscher (BR) method to account for the water insolubility of the samples. The modification can pave the way to extend the BR antioxidant capacity assay to other real food systems that are usually heterogeneous mixtures and to easily take into account synergistic effects of antioxidants and food matrix that are essential to determine the antioxidant capacity; the pH of the method is the pH of gastric fluids, and this is noteworthy if we take into account that lipid peroxidation is amplified at this pH. The method is simple, rapid, and inexpensive. The interplay among antioxidant activity and total phenol content is rewarding and witness the feasibility of the method for the fast screening of antioxidant activity of EVOO samples.

Study of the phenolic composition of spanish and italian monocultivar extra virgin olive oils: Distribution of lignans, secoiridoidic, simple phenols and flavonoids

The aim of the present study was to compare the phenolic content in selected monocultivar extra virgin olive oils. Analyses were carried out by HPLC/DAD/MS on Picual, Picuda, Arbequina and Hojiblanca oils from Spain and Seggianese and Taggiasca oils from Italy. Oils from cultivar Picual showed similar characteristics to those of Seggianese oils, with total amounts of secoiridoids of 498.7 and 619.2 mg/L, respectively. The phenolic composition of Arbequina oils is close to that of the Taggiasca variety with lignans among the main compounds. The determination of free and linked OH–Tyr, by way of an acid hydrolysis, represents a rapid and suitable method, especially when standards are not available, to determine antioxidant potentialities in terms of MPC, particularly for fresh extra virgin olive oils rich in secoiridoidic derivatives.