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Contribution to the establishment of a protected designation of origin for Meknès virgin olive oil: A 4-years study of its typicality
Abstract
Protected designations of origin (PDO) constitute, nowadays, one of the most important differentiation strategies used for the promotion and commercialization of virgin olive oil (VOO). Obtaining these distinctive labels entails a deep,study of the inherent features and characteristics of a VOO linked to a given geographical production area. The aim of this study was to perform the physicochemical and sensorial quality characterization of Meknes VOO, as well as the determination of its compositional profile. Thus, a total of 298 olive oil samples from Picholine marocaine cultivar, obtained from 12 industrial olive oil mills, located in three sub-areas of Meknes region, were analyzed over four consecutive seasons, paying particular attention to the determination of physicochemical quality indices, sensorial evaluation, total phenol content, pigment content, tocopherol and fatty acid composition. Results show that, besides an interannual variation, VOOs from Meknes region are characterized by high physicochemical and sensory quality, as well as a homogeneous composition regardless of the production sub-area.
... Plusieurs processus de transformations chimiques et de synthèse de substances organiques mineures ont eu lieu au cours de la maturité des olives provoquant des modifications de la qualité de l'huile. En effet, des études réalisées sur l'huile d'olive ont montré que la teneur totale en composés phénoliques et en chlorophylles (Schéma 1) diminuait lorsque le fruit atteignait son stade de maturité optimal variant, pour le cas de la Picholine marocaine entre 2,8 et 3,5 (Ajana et al., 1999;Bajoub et al., 2014). ...
... Au cours de l'entreposage de l'huile d'olive, divers composés chimiques disparaissent et d'autres apparaissent suite, entre autres, aux réactions de lipolyse et d'oxydation. Bajoub et al., (2014) ont utilisé la chromatographie en phase liquide couplée à la spectroscopie de masse (CPL-SM) pour caractériser et quantifier des composés phénoliques de 261 HOV originaires de sept régions du nord du Maroc. L'application de l'ACP sur les cinq groupes phénoliques (sécoiridoïdes, alcools phénoliques, lignanes, flavonoïdes et acides phénoliques) a permis de discriminer clairement les échantillons selon leurs origines géographiques. ...
... C'est dans ce cadre, que plusieurs méthodes d'authentification de l'huile d'olive ont été développées ; parmi lesquelles, on peut citer les méthodes chimiques, sensorielles et chromatographiques. En effet, en se basant sur la composition en antioxydants (polyphénols et tocophérols), les méthodes chromatographiques ont permis d'authentifier les huiles d'olive en fonction de leurs origines géographique et botanique (Bajoub et al., 2014). Cependant, la plupart de ces méthodes sont destructives, coûteuses et longues à mettre en oeuvre, et permettent d'évaluer l'état de qualité de l'huile d'olive plus que son origine. ...
In the field of olive oil, quality and authenticity are among the criteria of consumer purchase. Indeed, consumers are increasingly looking for food products of good and healthy quality where origin must be certified. In this context, the purpose of the present thesis project was to develop new analytical and methodological approaches to determine the quality and authenticity of virgin olive oils (VOO). To better understand the concept of quality, theoretical work on the olive oil sector, the olive oil extraction process, biochemical and chemical reactions taking place during the olive oil extraction, storage, as well as the methods of analysis applied to determine the quality and authenticity of olive oil were performed.
The 1st part of this thesis was devoted to study the potentiality of classical and spectral methods to authenticate 41 VOO samples collected during two crop seasons (2015/2016 and 2016/2017) according to their geographic origin (Beni-Mellal/Khenifra, Fès/Meknès, Marrakech/Safi, Northern and Eastern regions) and variety (Arbéquine, Arbozana, Moroccan Picholine, and Languedoc Picholine). The chemical analyses (free acidity, peroxide value, k232, k270, and the chlorophyll level) did not allow the authentication of VOO samples according to their geographic origins and varieties. The fluorescence and mid infrared (MIR) spectra acquired on the VOO samples allowed to discriminate VOO samples according to their geographic origins (96.72 and 91.87%, respectively) and varieties (95.12 and 91.87%, respectively). This trend was confirmed following the application of partial least square regression (PLSR) to the fluorescence spectra since an excellent prediction of free acidity (R2 = 0.98), and peroxide value (R2 = 0.96), and good prediction of k232 (R2 = 0.88), k270 (R2 = 0.88), and chlorophyll level (R2 = 0.89) were observed, suggesting that fluorescence and MIR spectra could be considered as a fingerprint of olive oil to evaluate their quality and authenticity. The 2nd part of the thesis aimed to determine the potentiality of front-face fluorescence (FFFS) and MIR spectroscopies to monitor the aging and to predict the chemical parameters of 14 VOO samples collected during 2015/2016 crop season. The results showed clear discrimination of VOO samples according to their storage time since 96.67% of correct classification was obtained for the 5 groups aged 7 days, and 3, 6, 12, and 18 months, respectively from the fluorescence and infrared spectra. These results were confirmed by the excellent prediction of the storage time following the application of the PLSR, support vector machine regression (SVMR), principal components regression (PCR) and multiple linear regression (MLR), to the emission spectra acquired after excitation set at 430, 290 and 270 nm since R2 = 0.98, ratio of prediction deviation (RPD) = 7.9, and root mean square error of prediction (RMSEP) = 24 days was noted. Similar results were obtained concerning the prediction of chemical properties of VOO since the validation models allowed to obtain R² ranging between 0.98 and 0.99 for free acidity, peroxide value, k232, k270, and the chlorophyll level. Finally, in the 3rd part of this work, spectral methods demonstrated their ability to detect the adulteration of Moroccan extra VOO with other types of olive oils of low quality (VOO, ordinary VOO, lampante VOO, pomace, and refined olive oils) at different levels varying between 5 and 50%. Indeed, an excellent prediction of the adulteration level was obtained since R2 = 0.99 and RMSEP = 1.28% were obtained by applying PLSR and PCR on the fluorescence spectra. Similar results were obtained by using MIR spectroscopy. The results obtained from this thesis demonstrated the potential of spectral methods combined with chemometric tools to determine the quality and authenticity of VOO, which can build a solid basis for the development of rapid and effective methods.
... Indeed, polyphenol compounds are well known as natural antioxidants inhibiting the oxidation of olive fruit and oil basing on the mechanism of scavenging hydroxyl and lipid radicals by trapping intermediate peroxyl radical (Mart ın-Pel aez et al. 2013). In this context, tocopherol and polyphenol compounds were used to predict the quality of OO knowing that qualitative and quantitative composition of these minor compounds depends on several factors such as the geographical origin, the cultivars, the attack of insects, the mode of irrigation of trees, the maturity index, the storage conditions of fruits and oil, the harvesting methods, and the extraction modes (Mraicha et al. 2010, Bajoub et al. 2014. ...
... The OO labeled as protected designation of origin (PDO), protected geographical indication (PGI) or registered designation of origin (RDO) are typified by some specific characteristics related to variety, geographical origin, agronomic conditions, fruit ripeness milling/extraction process, and so on (Bajoub et al. 2014). Taking into consideration that foods presenting high-value are the most vulnerable products for falsification (Kamal and Karoui 2015), the OO labeled as PDO, PGI and RDO are subjected to different types of frauds. ...
... The authors explained this trend by the fact that the high levels of antioxidant (Polyphenol and vitamin E) in VOO in lower orchards limit their oxidation. By using chemical analyses, Bajoub et al. (2014) failed to differentiate between EVOO according to their geographical and botanical origins. Indeed, the authors depicted that the state of fruit before harvesting, as well as the agronomic and industrial parameters from harvesting to conditioning, are among the main factors that affect significantly (P < 0.05) the chemical properties. ...
The determination of the quality and authenticity of olive oil becomes more and more required by producers, consumers, and authorities to thwarter falsification. Several analytical techniques including chemical, sensory, chromatography, and so on, are used for the determination of the quality and authenticity of olive oil. Although these methods are considered as the reference ones, they are cumbersome, time-consuming and destructive. Therefore, rapid analytical techniques such as fluorescence, ultraviolet-visible, near infrared, and mid infrared spectroscopies, electronic sensing, among others, are more and more used for the determination of the quality and authenticity of olive oils. This review will identify current gaps related to different analytical techniques in olive oil authentication and discuss the drawbacks of existing analytical methods concerning olive oil authenticity from 2010 up to now.
... While several studies showed a decrease in PV during ripening due to a decrease in lipoxygenase enzyme (Bajoub et al., 2014;Köseo glu et al., 2016;Nsir et al., 2017), others showed an increase due to olive oil's lower content of antioxidant compounds or to higher content of PUFA (Gambacorta et al., 2010;Jolayemi et al., 2016). The traditional processing techniques (press system) were found to yield olive oil with higher FA due to the increase in lipolytic enzyme that would favor triglyceride hydrolysis (Ammar et al., 2014;Khdair et al., 2015), and higher PV due to the contact of samples with metal surface of traditional equipment (Vekiari et al., 2007), or with light and air while grinding using a millstone (Serhan et al., 2016). ...
... with TPC ranging between 75.4 and 358 mg GAE/kg. Internationally, significantly lower TPC ranges were obtained in studies conducted in Spain (42.1-124 mg GAE/kg)(Gimeno et al., 2002) and Algeria (85-126 mg GAE/kg)(Bengana et al., 2013), whereas higher ranges were found in ones conducted in Chile (209-493 mg GAE/kg)(Romero et al., 2016), Tunisia (212-1167 mg GAE/kg)(Mansour et al., 2015), Italy (308-469 mg GAE/kg)(Ragusa et al., 2017) and Morocco (217-669 mg GAE/kg)(Bajoub et al., 2014); similar ranges (52-259 ppm) were obtained in Jordan byKhdair et al. (2015) and in Italy (139-279 mg GAE/kg) byNegro et al. (2019). The TPC variation was attributed to several factors, including:water availability(Anastasopoulos et al., 2011); maturity level(Borges et al., 2017); irrigation regime; crushing machine and its velocity(Serhan et al., 2016); malaxation time and temperature(Serhan et al., 2016); ...
Purpose
This study aims to identify the effect of selected agro-industrial factors associated with the olive oil phenolic composition, total phenolic content (TPC), antioxidant capacity and oxidative stability index (OSI). The study also aims to assess the relationship between the quality indices and each of the individual phenol, TPC, antioxidant capacity and OSI.
Design/methodology/approach
Olive oil samples (n=108) were collected from Lebanese northern (Akkar and Zgharta-Koura) and southern (Hasbaya and Jezzine) regions, at three harvesting times (early, intermediate, late) and using different types of mills (traditional, sinolea, two- and three-phase decanters). The samples were analyzed using official standard methods.
Findings
The highest TPC, antioxidant capacity and OSI were obtained in early harvested olive oil, using two-phase decanters for TPC and three-phase decanters for antioxidant capacity and OSI. A prediction model, including the free acidity, K232, TPC, C18:2, C18:0, tyrosol and apigenin, was obtained; it allowed to predict very highly significantly the OSI ( p < 0.001). Apigenin, tyrosol and C18:2 recorded the highest standardized coefficients ( ß ^+= 0.35) and thus had the highest influence on OSI. As per antioxidant capacity of olive oil, another very highly statistically significant prediction model was constructed ( p < 0.001). It included only two predictors, oleacein and TPC, with the latter having the most influence ( ß ^+= 0.37).
Originality/value
The overall results highlighted the detrimental effects of agro-industrial factors on olive oil chemical composition, and this contributes significantly to improve olive oil’s quality and characteristics, which are important for the product economical and nutritional values.
... Figure 4 depicts the standard/average sensory profile of the studied samples, having two categories: intense fruitiness and medium fruitiness. More details can be found in [33]. In the second study [34], particular attention was paid to the characterization of phenolic compounds from oils produced in Meknès region. ...
... Sensory averaged profiles of Meknès monovarietal olive oils: (a) intense fruitiness profile; (b) medium fruitiness profile (reproduced with permission from[33]). ...
Geographical indications (GIs) implementation is, nowadays, one of the most prominent differentiation strategies used in olive oil market. The proliferation of these labels, however, causes debate and controversy, in particular regarding their usefulness, effectiveness, and suitability of some protected areas to acquire them. This chapter discusses the use of GI labels in olive oil market, and proposes a four-stage methodological approach to examine the potential of Meknès region—a Moroccan olive growing area—to acquire a GI label. Based on this approach, Meknès region territorial dimensions were defined, the typicality of its olive oil was characterized, a general scheme for the GI recognition was proposed, and the adopted strategy to enhance the meaning of this label on domestic, national, and international markets was highlighted. The main findings of this study justify the suitability of Meknès region to protect its olive oil with a GI label.
-The different categories included the sum of the individual amount of the following compounds: simple phenols (hydroxytyrosol, tyrosol, and oxidized hydroxytyrosol), lignans (pinoresinol, acetoxypinoresinol, and syringaresinol), flavonoids (luteolin and apigenin), phenolic acids (p-coumaric acid), secoiridoids (decarboxymethylated form of elenolic acid, desoxy elenolic acid, elenolic acid, decarboxymethyl oleuropein aglycone, methyl decarboxymethyl oleuropein aglycone, decarboxymethyl ligstroside aglycone, dehydro oleuropein aglycone, oleuropein aglycone (and its isomers), methyl oleuropein aglycone, and ligstroside aglycone (and its isomers)), and other compounds (quinic acid).
... First, the variety, the maturity degree of olive fruit, the harvesting conditions, and/or the extraction system could be the origin of the differences observed in the initial chemical parameters [29]. ...
This study examines the feasibility of using mid infrared (MIR) spectroscopy for monitoring the quality of 14 Moroccan virgin olive oil samples belonging to three (3) varieties, originated from three (3) geographical origins, extracted with different systems, irrigated and fertilised with different modes.
The application of principal component analysis (PCA) and factorial discriminant analysis (FDA) on MIR spectra data allowed to discriminate perfectly the samples according to their storage time with 96.87% of correct classification.
The obtained results were confirmed following the application of three different multivariate regression tools namely partial least squares regression (PLSR), principal component regression (PCR) and support vector machine regression (SVMR) applied on MIR spectra data, since excellent prediction of R² = 0.99 and RMSEP = 17.05 days was observed. In addition, the evaluation of the effectiveness of MIR spectroscopy to predict the chemical parameters allowed to obtain excellent validation models with R² ranging between 0.98 and 0.99 for free acidity, peroxide value, chlorophyll level, k232 and k270.
... On the one hand, the ratio of MUFA to PUFA is a potential indicator to evaluate the stability of olive oil. In this study, the MUFA and PUFA ratios of oil from some varieties, including Samples 12 (Cornicabra), 31 (Lechín), 11 (Leccino) etc. were above 20, suggesting that they might have better oxidation stability than oils from other varieties [29]. This may be more conducive to the preservation of olive oil, prolonging its shelf life. ...
The main objective of this study was to evaluate the quality and select the best varieties from 85 olive varieties in the Liangshan region, China, from the perspective of oil content, fatty acid, and triacylglycerol compositions. Although 85 varieties of olive oil showed no difference in the type of fatty acid composition and the distribution of triglycerides, they varied greatly in the oil content, the relative proportion of fatty acids, and triglycerides. Principal component analysis (PCA) and cluster and heatmap analysis clearly divided the 85 samples into three groups. Group A included 36 varieties and was characterized by high oleic acid, mono-unsaturated fatty acids (MUFA), eicosenoic acid, OOO (glyceryl trioleate), and OOL (1-oleic acid-2-oleic acid-3-linoleic acid glycerides) contents, but rare palmitoleic acid, SFA (saturated fatty acid), and POP (1-palmitic acid-2-oleic acid-3-palmitic acid glycerides) levels. Group B contained 9 varieties of olive, with the main characteristics of high oleic acid, linolenic acid, MUFA, MUFA/PUFA, SFA, and OLnO (1-oleic acid-2-linolenic acid-3-oleic acid glycerides) content, but low in linoleic acid, PUFA (polyunsaturated fatty acid), PLL levels and ratio of omega-6 to omega-3 polyunsaturated fatty acids. Group C comprised 40 varieties, identified by high linoleic acid and PUFA levels but low ratios of oleic acid, MUFA, OOO, MUFA/PUFA, and the ratio of omega-6 to omega-3 polyunsaturated fatty acids. Combined with the oil content (FW) (%) of 85 varieties, we suggested four distinguished varieties in Group A, namely Lechín, Coratina, Koroneiki, and Arbosana; three distinguished varieties in Group B, namely Picual, Ezhi, Cornicabra; two distinguished varieties in Group C namely Frantoio and Arbequina as the objects of large-scale cultivation by Chinese cultivators. More importantly, the obtained data also demonstrated that some locally bred specific varieties, such as Zhongze-3 and Yuntai, had interesting unsaturated fatty acids and had cultivation and popularization value in China.
... The ratios of MUFA to polyunsaturated fatty acids (PUFA) and C18:1 to C18:2 are potential indicators for evaluating VOO characteristics (Bajoub et al., 2014). From the third to the last harvest, MUFA/PUFA and C18:1/C18:2 had a similar decreasing evolution trend among all the analyzed VOO samples. ...
The olive management in China is rarely reported. This study evaluates the influence of drupes ripening on virgin olive oil (VOO) quality of four main varieties (Olea europaea L., cultivars Ezhi‐8, Koroneiki, Leccion, and Frontoio) cultivated in Northwest China. Quality indices, fatty acid profiles, polyphenols, terpenic acids, tocopherols, and squalene contents are tested at four ripening stages from September to November. The contents of linolenic acid, saturated fatty acids, triterpenic acids, and squalene in all VOO samples decreased during ripening; in contrast, the oleic acid, linoleic acid, nervonic acid (first reported in VOOs), cinnamic acid, p‐coumaric acid, apigenin, and naringenin (contents) increased. The dynamics of the major phenolic compounds, such as hydroxytyrosol, tyrosol, and secoiridoids, were cultivar‐dependent. The two‐way ANOVA and Fisher's LSD test showed that oil compositions varied depending on the ripeness stage and cultivar. Moreover, this latter had more influence than harvest dates on the VOO features. Besides, by applying the orthogonal partial least squares discriminant analysis, several key metabolites (C18:1, oleanolic acid, maslinic acid, oleacein, oleocanthal, and α‐tocopherol) differentiate the four cultivars. In contrast, squalene, oleanolic acid, maslinic acid, oleocanthal, luteolin, and α‐tocopherol could effectively differentiate the four harvesting dates.
... Important variations were found among extraction systems as well as traditionally extracted oil (AO). Values of quality indices including moisture, acid value, peroxide value, and both UV extinction coefficients were in line with the published literature for 'Moroccan Picholine' and other Mediterranean cultivars grown in various environments [9,15,[29][30][31][32]. Such differences could be ascribed to a set of factors such as genotypic, pedoclimatic conditions, ripening degree, extraction technology and conditions, etc. ...
Olive oil is an important component of Mediterranean diet widely, consumed thanks to its numerous health-healing properties. Its quality is dependent upon a set of factors (genotypic, environmental, agronomic practices, ripening, etc). These are well documented, but little is known about the impact of extraction technology on ‘Moroccan Picholine’ olive oil quality. In this paper, physicochemical traits of olive oil (cv ‘Moroccan Picholine’) were investigated according to extraction technology namely super pressure (SP), 2-phase (2P), and 3-phase (3P) systems as well as traditionally extracted oil (Alwana Oil, AO). The obtained results revealed significant differences (p < 0.05) in terms of the studied physicochemical traits. The investigated oil samples were classified as extra-virgin olive oil. Oil samples from super pressure and AO marked by high records of peroxide value, acidity, K270, fatty acids and trans fatty acids likely due to partial oxidation during extraction. AO was marked by high MUFA, stigmasterol, brassicosterol, 2P displayed high SFA and β-sitosterol, and 3P had high PUFA, SFA, ∆7-avenasterol, and ∆7-stigmasterol. These results were confirmed by principal component analysis, cluster analysis and artificial neural networks. In conclusion, continuous systems (2- and 3-phase) produced olive oil of better quality as compared to super-pressure and traditionally extracted oil.
... Indeed, out of 14 samples, 9 samples are classified as EVOO, 4 as VOO, and 1 sample as lampante VOO. This could be due to the difference in the maturity degree of olive fruit, the harvesting conditions, and/or the extraction system (Bajoub et al., 2014). ...
This study examines the ability of fluorescence spectroscopy for monitoring the quality of 70 Moroccan virgin olive oils belonging to three varieties and originating from three regions of Morocco. By applying principal component analysis and factorial discriminant analysis to the emission spectra acquired after excitation wavelengths set at 270, 290, and 430 nm, a clear differentiation between samples according to their storage time was observed. The obtained results were confirmed following the application of four multivariate classification methods: partial least squares regression, principal component regression, support vector machine, and multiple linear regression on the emission spectra. The best prediction model of storage time was obtained by applying partial least squares regression since a coefficient of determination (R²) and a root mean square error of prediction (RMSEP) of 0.98 and 24.85 days were observed, respectively. The prediction of the chemical parameters allowed to obtain excellent validation models with R² ranging between 0.98 and 0.99 for free acidity, peroxide value, chlorophyll level, k232, and k270.
... Important variations were found among extraction systems as well as traditionally extracted oil (AO). Values of quality indices including moisture, acid value, peroxide value, and both UV extinction coefficients were in line with the published literature for 'Moroccan Picholine' and other Mediterranean cultivars grown in various environments [9,15,[29][30][31][32]. Such differences could be ascribed to a set of factors such as genotypic, pedoclimatic conditions, ripening degree, extraction technology and conditions, etc. ...
Xanthomonas arboricola pv. juglandis generates severe damage to different walnut cultivars. The bacterium is carried through water and can enter plants through natural plant openings. The objective of this work was to analyze the anatomical characteristics of leaves and fruits of two walnut cultivars, Chandler and Franquette, and relate these traits to disease severity. Leaf disease severity (SevH) was determined using the modified Spielman's damage scale. Stomatal density (DE), length and width of stomata were measured using a microscope, and the size and density of lenticels (DL) in the fruits were measured using a stereoscopic microscope, with an ocular micrometer. Fruit disease severity (SevF) was evaluated using a scale that included 4 levels of severity. The results showed significant differences in SevH and DE between cultivars. Stomatal size presented statistical differences only in length, being greater in Chandler. A strong correlation (r = 0.98) was found between SevH and DE. In addition, significant differences were observed between Chandler and Franquette in terms of SevF and DL. However, no differences were observed in lenticel size. The results obtained allow inferring that DE and DL should be taken into account when analyzing the susceptibility or tolerance of cultivars against walnut blight.
... Chlorophyll and carotenoid concentrations were determined according to the method described by Minguez-Mosquera et al. [29] and Bajoub et al. [52] with a few modifications starting with 0,25 g of homogenized oil dissolved in 25 ml of cyclohexane and subsequently mixed. The optical density was then recorded for carotenoid and chlorophyll measurements at a wavelength of 470 nm and 670 nm respectively, using a PG INSTRUMENTS T60 UV-Spectrophotometer and Quartz cuvettes. ...
Color and pigment analyses are not required by the majority of olive oil marketing standards. However, it is a basic attribute that is highly associated, by most consumers, with the idea of quality. In this study, we aim at providing a fast non-invasive method for routine analysis that can be used on a large scale in the laboratories of olive oil analysis starting from pigment quantification and color range measurements. A selection of 172 virgin olive oil samples obtained in Tunisia between 2018 and 2019 were used for this purpose. Chlorophyll and carotenoid contents were analyzed using a UV spectrophotometer standard method while color range was measured using digital images taken under controlled conditions. All samples showed high significant differences in chlorophyll and carotenoid contents (p <0,01) confirming that the visual selection of the set of samples was satisfactory for this study. Chlorophyll content varied from 3,0 to 28,3 ppm for samples SM137 and SM96 respectively, while carotenoids oscillated between 0,7 and 6,2 ppm for SM138 and SM100 respectively. Principal component analysis using chlorophyll and carotenoids contents along with RGB-CYMY color measurements showed a higher significant correlation P<0,05 between pigment contents and Red, Green, Blue and Yellow colors. Bivariate tests suggest that although color and pigments are correlated, color range assessment using digital imaging may represent a more sensitive method to discriminate olive oil according to cultivar, geographical origin, maturation index and year of harvest.
... The sample ascribed to lampante VOO belongs to Moroccan Picholine, extracted by three phase systems, and originated from a cold weather region (Fez/ Meknes). The classication of the 41 samples into three classes could be ascribed to the differences in the harvesting conditions, and/or the extraction system, as noted by Bajoub et al. 26 Chlorophyll compounds are pigments responsible for the green/yellow to gold colour of olive oil, and they are inuenced by several agricultural factors including irrigation, fertilisation, harvesting period, and particularly, extraction system. 27 It is well-known that little pro-oxidative action will occur if there is a low content of chlorophyll pigments in olive oil, thus ensuring good storage of olive oil. ...
This study examines the feasibility of using front face fluorescence spectroscopy (FFFS) to authenticate 41 virgin olive oil (VOO) collected from 5 regions in Morocco (Fez/Meknes, Eastern, Northern, Beni-Mellal/Khenifra and Marrakech/Safi) during 2 consecutive crop seasons (2015-2016 and 2016-2017). By applying factorial discriminant analysis (FDA) jointly to the emission spectra acquired after excitation wavelength set at 270, 290, and 430 nm, a clear discrimination between VOO according to their geographic origin (96.72% of correct classification) and variety (95.12% of correct classification) was observed. This trend was confirmed following the application of partial least square regression (PLSR) to the fluorescence spectra where excellent prediction of free acidity (R2= 0.98) and peroxide value (R2= 0.96), and good prediction of k232 (R2= 0.88), k270 (R2= 0.88) and chlorophyll content (R2= 0.89) was observed.
... The samples ascribed to LVOO belong to Moroccan Picholine, extracted by three-phase system and originating from a coldweather region (Fez/Meknes). This classification could be due to the difference in the harvesting conditions, and/or the extraction system, as pointed out by Bajoub et al. 22 Chlorophyll compounds are pigments responsible for the green/yellow to gold colour of olive oil, which are influenced by several agricultural factors, including irrigation, fertilization, harvesting period, and particularly the extraction system. 23 It is well known that low levels of chlorophyll pigments in olive oil avoid the pro-oxidative action of these pigments and thus ensure good preservation of olive oil. ...
BACKGROUND
Olive oil provides a wide range of health‐promoting compounds. The quality of olive oil is an even more complex concept as it is affected by several factors, such as variety, season, stage of maturation, extraction processing, and so on. The main objective of this study was to determine the potential of chemical and mid‐infrared spectroscopy techniques to determine the quality and authenticity of virgin olive oil (VOO). For this, we studied 41 VOOs originating from five regions of Morocco (Fez/Meknes, Eastern, Northern, Beni‐Mellal/Khenifra, and Marrakech/Safi) and produced using different agricultural and technological conditions during two successive crop seasons (2015–2016 and 2016–2017).
RESULTS
By applying principal component analysis and factorial discriminant analysis with leave‐one‐out validation to the mid‐infrared spectroscopy, clear discrimination between VOO samples according to their geographic origin and variety was observed, with correct classification rates of 91.87% and 91.87% being observed respectively. The application of partial least‐squares regression to mid‐infrared and chemical data sets allowed excellent prediction of free acidity, peroxide value, k270, and chlorophyll level with R² of 0.99, 0.97, 0.98, and 0.93 respectively, and good prediction of k232 (R² = 0.84).
CONCLUSION
The results demonstrate that mid‐infrared spectroscopy coupled with chemometric tools could be used as a rapid screening tool for evaluating the overall quality and authenticity of VOO. © 2020 Society of Chemical Industry
... It is known that the quality of extra virgin olive oil depends on many factors, including cultivation and harvesting conditions, storage and processing steps. Another important factor is an olive cultivar (variety) and climate conditions 9 . The most important fatty acid is oleic acid, which is a monounsaturated fatty acid that controls cholesterol levels and has an important role in oil stability. ...
Abstract: The aim of this study is to characterize the extra virgin olive oil obtained from the
most abundant olive cultivar grown in Aljouf area of the northern part of Saudi Arabia which
is Sorani. Twenty samples were collected from each orchards in Sakaka, Dumat Aljendal, and
Qurryat during two seasons (2015 and 2016) and were examined for the main International
Olive Council chemical quality parameters (acidity, peroxide value, and UV absorption (K232
and K270). In addition, the fatty acid profile of olive oil samples was also analyzed, including
the more commonly present fatty acids (oleic, palmitic, linoleic, stearic, linolenic and
palmitoleic acids) together with the total polyphenolic content (from 157 to 287 mg /kg), the
iodine value and the refractive index. The acidity of the samples analyzed were (0.64-0.88),
peroxide value were (5.5-10.1) and iodine value were (76.8-91.7). The variation of the
obtained results may be attributed to the different geographical and climatic reasons as well as
other conditions such as the production process, harvesting, storage and extraction method.
Key words : Olive oil, physical and chemical properties, Aljouf, Saudi Arabia.
... Studies about phenolic compounds present in VOO have been performed pursuing diverse objectives, such as for instance, to observe their link with agronomical factors and technological conditions of production, 12−15 assessing the influence of climate and soil, olive cultivar, extraction system, processing conditions, etc. 6,16−20 The samples selected in most of this kind of investigations are olive oils coming from the main producing areas of the world (Spain, Italy, Greece, Morocco, among others); 13,17,21,22 however, oils originating from other production regions, such as Argentina, lack this valuable information. ...
The aim of this work was to achieve a preliminary characterization of the profile of the phenolic fraction of virgin olive oils (VOOs) from Maipú (Mendoza, Argentina). Thus, 25 commercial VOO samples from Arauco, Arbequina, Picual, Frantoio, Changlot, Empeltre, Nevadillo, Manzanilla and Coratina (both monovarietals and blends) were analyzed using LC-ESI-QTOF MS and LC-ESI-IT MS for identification and quantification purposes, respectively. A rapid LC method (15 min) accomplished quantitative information about a total of 40 phenolic compounds, including secoiridoid derivatives, which have not been evaluated before in samples coming from the sub-region so-called Maipú (Mendoza province, Argentina). The results make evident that olive oils coming from Mendoza can be considered as important sources of phenolic bioactive compounds, exhibiting similar phenolic compounds levels to those shown by oils from other typical world production regions. Moreover, some distinctive features of Arauco variety (Argentinean autochthonous variety) were pointed out; indeed, a correlation between flavonoids content and botanical variety was established herewith.
... Thus, to avoid possible influence of the fruits maturity stage on the phenolic profiles of the studied oils, in this study, only samples picked at a ripening index within the range 3.0-3.5 were considered. This range is commonly advised for the production of high quality olive oils in Meknès region [42]. A total of 203 samples were considered, the remaining were kept for other experiments. ...
Olive oil phenolic fraction considerably contributes to the sensory quality and nutritional value of this foodstuff. Herein, the phenolic fraction of 203 olive oil samples extracted from fruits of four autochthonous Moroccan cultivars (“Picholine Marocaine”, “Dahbia”, “Haouzia” and “Menara”), and nine Mediterranean varieties recently introduced in Morocco (“Arbequina”, “Arbosana”, “Cornicabra”, “Frantoio”, “Hojiblanca”, “Koroneiki”, “Manzanilla”, “Picholine de Languedoc” and “Picual”), were explored over two consecutive crop seasons (2012/2013 and 2013/2014) by using liquid chromatography-mass spectrometry. A total of 32 phenolic compounds (and quinic acid), belonging to five chemical classes (secoiridoids, simple phenols, flavonoids, lignans and phenolic acids) were identified and quantified. Phenolic profiling revealed that the determined phenolic compounds showed variety-dependent levels, being, at the same time, significantly affected by the crop season. Moreover, based on the obtained phenolic composition and chemometric linear discriminant analysis, statistical models were obtained allowing a very satisfactory classification and prediction of the varietal origin of the studied oils.
... As far as this point is concerned, there has been a remarkable proliferation of research works focused on the development of suitable methods chromatographic, spectroscopic/ spectrometric and DNAbased techniques to classify and discriminate among olive oils from different geographical origins 8 10 . Others have conducted studies in order to establish geographical origin of the selected olive oils Picholine marocaine by the assessment of different chemical components as geographical markers in combination with chemometric tools 11 . ...
The quality of olive oil is defined as a combination of characteristics that significantly determine its acceptance by consumers. This study was carried out to compare sensorial and chemical characteristics of sixty ‘Chétoui’ extra virgin olive oils (EVOOc) samples from six northern areas in Tunisia (Tebourba (EVOOT); Other regions (EVOON): Mornag, Sidi Amor, El Kef, Béjà and Jendouba). Trained panel taste detected ten sensory attributes. EVOOT and EVOON were defined by ‘tomato’ and ‘grass/ leave notes, respectively. Twenty one volatile compounds from EVOOc were extracted and identified by Headspace Solid-Phase Microextraction followed by Gas Chromatography- Flame Ionization Detector. Principal component and cluster analysis of all studied parameters showed that EVOOT differed from EVOON. Sensory and volatile profiles of EVOOc revealed that the perception of different aromas, in monovarietal olive oil, was the result of synergic effect of oils’ various components, whose composition was influenced by the geographical growing area.
... Indeed, till October 2013, there was only one recognized PDO for the extra VOO (Tyout-Chiadma, located in the South of Morocco) and one official PGI (Ouazzane, located in the North of this country). Another PDO for the extra VOO produced in Meknès territory is in the process of characterization of its typicality and it is expected that will enlarge the list in the near future (Bajoub et al., 2014). ...
... In these areas, the olive oil sector plays a dynamic socio-economic development role due to the loyalty of the local farmers to olive trees cultivation and the presence of important olive oil processing companies; as a matter of fact the olive oil sector is the engine of job growth in the economy of these regions. Moreover, some of these areas are highly esteemed for their ancestral olive oil production history and the excellent quality of their olive oils [3]. ...
The triacylglycerols composition of monovarietal Picholine Marocaine olive oils, produced in seven of the most productive areas in northern Morocco, has been established for the first time, starting a register of typicality and geographical identity of Moroccan olive oils. Two hundred seventy‐nine olive samples were collected over two consecutive crop seasons (2011/2012 ( n = 140) and 2012/2013 ( n = 139)), the analysis of the triacylglycerol profiles of the obtained oils was performed using high performance liquid chromatography, the influence of the region of provenance was investigated, and chemometric data analysis (including principal components analysis, linear discriminant analysis, partial least squares–discriminant analysis, and soft independent modeling of class analogies) was used to differentiate the studied samples according to their geographical origin. Twenty‐one triacylglycerols were characterized and the variability observed among the studied samples could be related to the production area. The combination of triacylglycerols composition with chemometrics provided a powerful tool to verify the geographical origin of north Moroccan olive oils.
Practical applications: Moroccan legislations established Geographic Indication labels for adding value to typical products. However, the general procedure to control the geographical authenticity of these protected products remains based on the traceability of their production and there is a lack of appropriate and reliable tools for their geographical unambiguous authentication and control. In this work, geographical authentication models for classifying olive oil samples (based on triacylglycerols composition) have been developed and evaluated, achieving adequate classification and prediction rates for oils coming from the main north Moroccan olive growing areas. The results obtained herein, could represent a significant contribution to the control of the geographical authenticity of Moroccan olive oils.
The triacylglycerols composition of monovarietal Picholine Marocaine olive oils, from seven of the most productive areas in northern Morocco, is established in this study, analyzing 279 olive samples (over two consecutive crop seasons) by high performance liquid chromatography and Chemometrics.
Virgin olive oil is a highly appreciated edible oil, considered as a relevant component of the Mediterranean diet. The spread of this foodstuff all over the world is making, to a certain extent, that new markets and consumers are getting used to this "Mediterranean's golden treasure". Currently, there is great momentum in research relating virgin olive oil intake to healthiness, which has been mainly associated with its phenolics content. Phenolics are considered health-promoting compounds due to their multifaceted biochemical actions that can potentially reduce the risk of various health problems. Yet, since the health-promoting effects of various phenolic compounds have been widely attributed to their metabolic products rather than the naturally occurring forms, the assessment of virgin olive oil phenolics bioavailability is still gaining immense attention and considered a great hot topic among researchers. In the first section of this contribution, the main groups of phenolic compounds identified in virgin olive oil are described, their qualitative and quantitative variability is discussed while analytical approaches applied for their determination are highlighted. The second section reports the beneficial health properties of virgin olive oil consumption related to its phenolics content paying special attention to their bioavailability.
A utilização do fruto advindo da Oliveira é um dos principais ingredientes para preparação de alimentos. O fruto conhecido como azeitona, tem um alto teor de óleo e a partir dele é obtido o precioso azeite de oliva. Essa árvore pertence à família das oleáceas, e é sabido que existem mais de 30 espécies diferentes cultivadas de Olea europaea L. Esta fruta além de apresentar características que sejam destinadas a culinária contém propriedades funcionais que são desenvolvidas pelos compostos encontrados em sua constituição. O presente estudo se deteve a apresentar e descrever as propriedades funcionais existentes nesse azeite e a importância da utilização desse óleo mono-insaturado na manutenção da saúde. Trata-se de uma revisão bibliográfica de caráter qualitativo e descritivo. Como critério de inclusão na integra foram lidos trabalho que envolveu as características do azeite e sua influência positiva em uma boa alimentação, como também seus benefícios para a saúde destacando as propriedades. Estes compostos são evidenciados nas literaturas sobre suas propriedades benéficas à saúde, e que são incluídos a vitamina E, pigmentos, fitoesteróis e compostos fenólicos. Os benefícios descritos apresentam uniformidade entre si, evidenciando o a atuação antioxidante, anti-inflamatória, quimiopreventiva e principalmente na redução da lipoproteína de baixa densidade. Portanto, investigação científica possibilitou a obtenção de resultados e informações que demonstraram as propriedades funcionais do azeite de oliva. Faz-se importante dizer que mesmo apresentando tais atividades o uso moderado desse alimento é imprescindível para que ao invés de auxiliar no processo de saúde ele venha a atuar como desregulador metabólico.
The sensory quality of olive oils is influenced by the diversity and concentration of volatile and non-volatile compounds that vary according to cultivar, and edaphic, climatic, and cultivation conditions, which allows for establishing the origin of the product. In addition, since this crop has been recently introduced in Brazil, little is known about the performance of cultivars in this region, where investments in this activity have been made. Thus, relevant aspects about the chemical and sensory quality of olive oils are presented and discussed, as well as how these aspects influence the identity of the product.
Wine encapsulates the expression of multiple inputs – from the vineyard location and environment to viticultural and winemaking practices – collectively known as terroir. Each of these inputs influence a wine's chemical composition and sensory traits, which vary depending on cultivar as well as provenance. These aspects underpin the overall concept of wine typicity, an important notion that enables wine from a delimited geographical area to be differentiated and recognisable in national and international wine markets. Indeed, consumers are increasingly more aware of the significance of regionality and may use this to influence their purchasing decisions. Understanding which sensory attributes represent regional typicity and how these are best conveyed to consumers is therefore important for the prosperity and reputation of producers. As reviewed herein, the sensory typicity of wine can be identified using different types of testing methods, with the most effective being a combination of approaches, such as sorting task in combination with descriptive sensory analysis. Consumer perceptions of regionality and wine typicity are then examined to provide insight into their behaviours. This includes consideration of the importance of origin to perceptions of quality and typicity, in terms of meeting expectations and engaging consumers. Based on the literature reviewed, it is proposed that wine typicity can be defined as a juxtaposition of unique traits that define a class of wines having common aspects of terroir involving biophysical and human dimensions that make the wines recognisable, and in theory, unable to be replicated in another territory.
Six olive oils extracted from the cultivars Arbequina, Arbosana, Coratina, Frantoio, Koroneiki, and Picual from 2017 and 2018 harvests, cultivated in Pinheiro Machado, Rio Grande do Sul, Brazil, were evaluated for standard oil composition parameters and bioactive constituents (pigments, tocopherols, and phenolic compounds). Multivariate principal component analysis (PCA) and univariate ANOVA and Fisher's LSD test were used to verify the effect of cultivar and harvest year on oil composition. Olive oil composition met extra virgin olive oil (EVOO) standard parameters and was influenced by both cultivar and harvest year. EVOO produced in 2018 had greater chlorophyll, caffeic acid, ligstroside aglycone, hydroxyoleuropein aglycone, syringic acid, and hydroxytyrosol acetate contents than the EVOOs from 2017. Linoleic acid, ferulic acid, ligstroside aglycone, and hydroxytyrosol acetate were the variables whose contents most contributed to differentiation of oils by cultivar in both harvest years. Chemical characterization analyses allowed for the differentiation of oil composition based on harvest year and cultivar. Metabolic quality data obtained here support the establishment of a local EVOO profile and the compounds that most contributed to treatment differentiation may serve as markers that can be utilized in determining origin, cultivar, and harvest year. Practical applications: Olive production in Brazil is recent and is based on European cultivars which have not been bred for the local environmental conditions. Therefore, the measurement of olive oil metabolic quality will determine cultivar adaptability to local edaphoclimatic conditions as well as assist in the establishment of a standard of identity for the product and promote the development of its market. Olive oil produced in Southern Brazil showed high quality, and was especially rich in phenolic compounds. Although harvest year influenced oil composition, oil from both harvests met EVOO standards and cultivar specific metabolic markers were observed. This study provides the foundation for olive producers in Southern Brazil to seek authentication of the geographical origin of olive oil. This article is protected by copyright. All rights reserved
The characteristics of eight varieties of virgin olive oil (Arbosana, Arbequina, Coratina, Cornicabra, Frantoio, Koroneiki, Picual, and Ezhi 8) obtained in two successive crops in the southwest of China (Xichang, Sichuan Province) were investigated. Significant differences (P < 0.05) were observed in physicochemical properties, fatty acid profile, minor component contents, and oxidative stability between different varieties of olive oils. The physicochemical properties of all samples met IOC standards for extra virgin olive oil, while in Koroneiki, olive oils were present the optimum oxidation stability among studied varieties. The results of hierarchical cluster analysis and principal component analysis (PCA) showed a good classification between varieties based on their qualitative characteristics. Koroneiki and Ezhi 8 olive oils were significantly different from other varieties mainly due to color, fatty acid profile, and minor components. PCA result also showed that harvest crop influences the characteristics of samples mainly due to the variance of temperature and rainfall.
Some functional micronutrients used in authentication of extra virgin olive oils (EVOOs) are sterols, phenols, volatiles, tocopherols, and carotenoids, with remarkable results. This chapter describes the latest trends on the use of minor components composition of EVOOs for their authentication. Several studies have demonstrated the ability of sterol content and profile to discriminate EVOOs from edible vegetable oils (EOs) or lower quality olive oils, such as lampante olive oils (LOOs) or refined olive oils (ROOs), and for adulteration tracing. The sterol content variation among different cultivars can be useful in order to authenticate olive oils according to their cultivar. The total quantity and quality of polyphenols in EVOOs are very sensitive to variations in olive fruit cultivar, fruit maturity stage during harvesting time, environmental conditions, agricultural practices, and origin area, and therefore can be used for authentication of olive oils.
In Morocco there is a need, in terms of chemical characterization, concerning the classification of the Moroccan Picholine virgin olive oil according to different geographical areas. In addition to the chemical analysis of bases (acidity and peroxide) we are interested in the fatty acid composition and application of chemometrics coupled with infrared spectroscopy in order to discriminate between virgin olive oils in the Tadla Azilal region. A series of 142 samples of Moroccan Picholine olive cultivars were crushed in mills in the region of Tadla Azilal during two crop years; 2009/2010 and 2010/2011. The average acidity of olive oil coming from the plain is 2.0 in terms of oleic acid percentage. This acidity is 2.7 for the foothills case and close to the mountain oils value (2.6). The average index of peroxide is 13.5, 6.6 and 8.6 for respectively oils from the plain, the foothills and mountains. The chemical composition of fatty acids was determined using the gas chromatograph after bypass esters methyl. The oils of the mountain would be slightly richer in oleic acid (71.8%) compared to those of the plain (70.4%) and foothills (68.5%). The values of the average unsaturation index are strongly correlated with oleic acid levels. The principal component analysis (PCA) of olive oils shows that there is discrimination between the oils coming from the three geographical zones in the Tadla Azilal area.
Au Maroc, Il y a un besoin en termes de caractérisation chimique pour une classification de l’huile d’olive vierge de la Picholine marocaine selon différents zones géographiques. En plus des analyses chimiques de bases (acidité et indice de peroxyde) nous nous sommes intéressés à la composition en acides gras et l’application de la chimiométrie couplée à la spectroscopie infrarouge pour pouvoir discriminer entre les huiles d’olives vierges de la région Tadla Azilal. Une série de 142 échantillons d'olives de la variété “Picholine marocaine” ont été triturés au sein des moulins de la région de Tadla Azilal durant les deux campagnes oléicoles 2009/2010 et 2010/2011. La moyenne de l’acidité des huiles d’olive de la plaine en pourcentage massique d’acide oléique est de 2,0 ; celle des huiles du piedmont est de 2,7, valeur proche de celle des huiles de la montagne (2,6). L’indice de peroxyde moyen est de 13,5 ; 6,6 et 8,6 respectivement les huiles provenant de la plaine, le piedmont et la montagne. La composition chimique en acides gras a été déterminée à l’aide de la chromatographie en phase gazeuse après dérivation en esters méthyliques. Les huiles de la montagne seraient légèrement plus riches en acide oléique (71,8%) par rapport à celles de la plaine (70,4%) et du piedmont (68,5%). L’analyse en composantes principales (ACP) des spectres en moyen Infrarouge des huiles d’olives montre qu’il y a certaines discriminations entre les huiles provenant des trois zones géographiques de la région de Tadla Azilal.
Harvesting plays a major role in the virgin olive oil production line, being the most expensive single component, but also due to its significant effect on the whole year's produce. Previous studies have focused on the effects of harvest timing on either oil yield or quality. Here we determined the separate and combined effects of harvesting date, fruit maturation, cultivar and fruit load on olive oil quality and quantity. Cultivars typical to the Middle East region were selected: the traditional cv. Souri and the newer cv. Barnea, grown under intensive conditions. The results demonstrate fundamental differences between the two cultivars with respect to harvest strategy. In high-yielding ‘Barnea’, oil accumulation continued throughout the ripening season resulting in increasing yield of oil with time while maintaining high quality. Hence, exploiting the production potential in ‘Barnea’ requires late harvest and advanced fruit maturity. However, in heavily loaded ‘Souri’, oil accumulation was accompanied by early massive shedding of fruits. Furthermore, late harvest and advanced maturation in ‘Souri’ were associated with a sharp increase in free fatty acids combined with a rapid decline in polyphenol content, and in MUFA to PUFA and saturated to unsaturated fatty acid ratios, all resulting in loss of oil quality. Rapid decline in oil yield coupled with deterioration of oil quality call for early harvesting at low maturity index in ‘Souri’. In medium-yielding trees of both cultivars, maturation progressed more rapidly, resulting in earlier harvest to utilize optimal oil potential.
The chlorophylls are responsible for the characteristic green color of the olive fruits and their products. Virgin olive oil (VOO) is obtained from processing olives only by mechanical and physical means under conditions ensuring that the natural characteristics of the fruit composition are maintained as far as possible. In terms of the total chlorophyll content of oil, the extraction process entails a loss of chlorophyll of up to 80%. Many factors, both agronomical and technological, can affect the presence of green pigments in VOO. The analysis of green pigments in olives and/or oil requires an initial phase of extraction of these compounds from the solid and fluid matrix, followed by the selective separation and subsequent identification of the different components of the chlorophyll fraction. The aim of this review article is to summarize and critically analyze the available information about chlorophylls in VOO.
Olive oil was always appreciated for its quality and since the seventies some designations of origin for olive oil were recognized in Spain. Under the European regulation R 2081/1992 for protected designations of origin (PDO), these designations increased for olive oil activity. The studies of the regulations for the PDO show some different policies according to the European countries: some regulations, as in France or Italy, privilege the olive tree culture and some, as in Spain, Portugal or Italy focus on olive oil characterization.
Among vegetable oils, virgin olive oil (VOO) has nutritional and sensory characteristics that to make it unique and a basic component of the Mediterranean diet. The importance of VOO is mainly attributed both to its high content of oleic acid a balanced contribution quantity of polyunsaturated fatty acids and its richness in phenolic compounds, which act as natural antioxidants and may contribute to the prevention of several human diseases. The polar phenolic compounds of VOO belong to different classes: phenolic acids, phenyl ethyl alcohols, hydroxy-isochromans, flavonoids, lignans and secoiridoids. This latter family of compounds is characteristic of Oleaceae plants and secoiridoids are the main compounds of the phenolic fraction. Many agronomical and technological factors can affect the presence of phenols in VOO. Its shelf life is higher than other vegetable oils, mainly due to the presence of phenolic molecules having a catechol group, such as hydroxytyrosol and its secoiridoid derivatives. Several assays have been used to establish the antioxidant activity of these isolated phenolic compounds. Typical sensory gustative properties of VOO, such as bitterness and pungency, have been attributed to secoiridoid molecules. Considering the importance of the phenolic fraction of VOO, high performance analytical methods have been developed to characterize its complex phenolic pattern. The aim of this review is to realize a survey on phenolic compounds of virgin olive oils bearing in mind their chemical-analytical, healthy and sensory aspects. In particular, starting from the basic studies, the results of researches developed in the last ten years will be focused.
This chapter focuses on the results obtained using 13C NMR spectroscopy. It describes in detail all information obtainable from the 13C NMR spectrum and reports two important studies: the first one on the relationship between the olive oil fatty acid composition and olive oil cultivar, and the second one on an agronomic problem regarding the choice of the cultivar to be grown in a non-Mediterranean area. In order to study the effect of the cultivar on the olive oil composition, olive oils coming from monovarietal cultivars were chosen with the precise restriction to be all grown in the same area with a very homogeneous microclimatic condition; in this way, the pedoclimatic influence on olive oil composition can be negligible. Therefore, 60 extra virgin olive oils from the same Italian region (South-Western Sicily) obtained from four monovarietal cultivars (Biancolilla, Tonda Iblea, Cerasuola, Nocellara del Belice) were analyzed by 13C NMR technique.
The geographical traceability of virgin olive oil can be controlled by chemical species that are linked to the production area. Trace elements are among these species. The hypothesis is that the transfer of elements from the soil to the oil is subjected to minor variations and therefore this chemical information can be used for geographical traceability. In order to confirm this hypothesis, the trace elements of virgin olive oils from south-western Spain were analysed, and the same elements were determined in the corresponding olive-pomaces and soils. The differences in the concentration were studied according to cultivars and locations. Results show some coincidences in the selection of elements in soils (W, Fe, Na), olive-pomace (W, Fe, Na, Mg, Mn, Ca, Ba, Li) and olive oils (W, Fe, Mg, Mn, Ca, Ba, Li, Bi), which supports their utility in traceability. In the case of olive oils, 93% of the samples were correctly classified in their geographical origins (96% for Beas, 77% for Gibraleón, 91% for Niebla, and 100% for Sanlúcar de Guadiana).
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.
Among vegetable oils, extra virgin olive oil (EVOO) has nutritional and sensory characteristics that make it unique and a basic component of the Mediterranean diet. EVOO has always been used over the centuries for its preventive and therapeutic properties, as well as precious and valuable dietary lipidic condiment. Benefic effects of a diet rich in EVOO on the human health, especially in prevention and/or reduction of hypercholesterolaemia, serum lipoprotein levels and atherosclerosis, hypertension, cardiovascular diseases and thrombotic risk, oxidation and oxidative stress, obesity and type 2 diabetes, inflammatory processes and cancer are discussed in these review. Recent studies suggest also its role in regulating the sense of satiety. The chemical compounds of EVOO that may contribute to its overall therapeutic characteristics, the epigenetic and physiological mechanisms involved are focused, taking into account the most important studies in the literature of the last years.
Practical applications: Many studies on various aspects of nutrition indicated that many human diseases are influenced by lifestyle, in which the diet has an important aspect. The use of extra virgin olive oil is especially important from early childhood and throughout adult life to contribute to hinder the aging process. The importance of preventive and sometimes curative action, carried out by its various components in several pathological conditions has emerged from clinical, experimental, and epidemiological studies which, in many cases, are accompanied by indisputable scientific evidences. Taking into account the most important studies in the literature of the last years, the chemical compounds of extra virgin olive oil and the physiological mechanisms involved in their curative/health effects are the focus of this article.
Phenolic compounds have a high importance in olive oil because of their effect on shelf life and sensory properties. This study reports on the HPLC profiles of the phenolic compounds of virgin olive oils obtained from Arbequina olives from the harvesting in a super‐intensive orchard under a linear irrigation system. In addition, phenolic content, carotenoid and chlorophyllic pigments, and oxidative stability were analyzed. Total phenol content and 3,4‐DHPEA‐EDA increased up to a maximum throughout the ripening process. The simple phenols tyrosol and hydroxytyrosol acetate increased throughout the ripening process, however, there was not found a clear trend in hydroxytyrosol content. Minor constituents such as vanillic acid and p ‐coumaric acid increased up to a maximum and then decreased, since vanillin decreased progressively throughout the time of harvest. 3,4‐DHPEA‐EDA and lignans were present in considerable amounts in the studied samples, while oleuropein aglycone was present in a low amount. Total phenol content and oil stability followed the same trend throughout the study, so a very good correlation was established between them. Total secoiridoids and, specifically, 3,4‐DHPEA‐EDA seemed to be responsible for oil stability. The pigment content decreased during ripening, and not a positive correlation was found between pigments and oil stability.
Practical applications : The results can be used to determine the best time for harvesting in order to obtain olive oils with different phenols and pigment contents. This is important for sensory characteristics of the olive oils and also for olive oil stability.
Long used in sacred ceremonies and associated with good health, the nutritional and health promoting benefits of olives and olive oils have been proven by an ever-increasing body of science. From cardiovascular benefits to anti-microbial, anti-cancer, antioxidant activity and effects on macrophages and aptoptosis to cellular and pathophysiollogical process, olives and olive oils are proving important in many healthful ways. For example, reactive components in olive oils or olive oil by-products have now been isolated and identified. These include tyrosol, hydroxytyrosol, 3,4-dihydroxyphenyl acetic acid elenolic acid and oleuropein. Oleic acid is the main monosaturated fatty acid of olive oil. These have putative protective effects and modulate the biochemistry of a variety of cell types including those of the vascular system. Some but not all components have been characterised by their putative pharmacological properties. It is possible that usage of these aforementioned products may have beneficial application in other disease. However, in order for this cross-fertilization to take place, a comprehensive understanding of olives and olive oils is required. Finding this knowledge in a single volume provides a key resource for scientists in a variety of food an nutritional roles. Every chapter is well referenced and have a very useful summary points section. This comprehensive work provides research information into the pharmacological and nutritional benefits of the olive components, and addresses not only the wide range of potential health benefits of these products, but the factors that may impact their efficacy, including compositional effects based on the country of origin or processing technique.
Authentic extra-virgin olive oils from 7 different regions (Italy – 3 regions, Greece – 4 regions) have been investigated by 1H Nuclear Magnetic Resonance (NMR) fingerprinting in combination with multivariate statistical analysis. In order to cover the dominating lipid signals as well as signals from compounds of low abundance in the oil, both a simple one pulse experiment and an experiment with multiple saturation of the lipid signals was applied to each sample. Thus, the dynamic range of concentrations covered by the two experiments was of the order of 100,000 allowing for a more comprehensive NMR assessment of the samples. Monte-Carlo embedded cross-validation was used to demonstrate that a combination of principal component analysis, canonical analysis, and classification via nearest class mean can be used to predict the origin of olive oil samples from 1H NMR data. Given the rather limited number of samples tested, correct prediction probabilities of 78% were achieved with region specific correct predictions between 53% and 100%.
The chemical composition of virgin olive oil is determined by numerous factors. The aim of this study was to evaluate the influence of the olive ripening stage, and crop year on the quality indices of Koroneiki cv. virgin olive oil of organic vs non-organic cultivation. Drupes of organic and of non-organic cultivation were sampled at four successive ripening periods in crop years 2000 and 2004. Quality indices, total and simple polyphenols, terpenic acids, squalene, fatty acid profile, and sterols were measured. Statistical analysis demonstrated that peroxide value differed according to cultivation method and according to crop year. Organic Koroneiki cv. olive oils exhibited higher total phenols content. Total phenols differed mainly according to crop year and maturation phase, but also according to cultivation method. Total unsaturated and saturated fatty acids differed according to cultivation method, crop year and maturation. Oleic and palmitoleic acids varied according to cultivation method and according to maturation process. Cholesterol, campesterol and stigmasterol differed according to maturity, while β-sitosterol differed according to crop year. Overall, olive oil from organic cultivation was of superior quality compared to non-organic, while composition of olive oils was greatly variable during maturation, whereas it was also affected by the crop year.
The color of olive oils, and of foods in general, can influence consumer choices to a large extent and can be related to the processing treatments they have undergone. Olive oil color is due to 2 types of pigments, chlorophylls and carotenoids, which are attracting the attention of the scientific community due to the probable health benefits they can provide. Appropriate methodologies for the meaningful definition of the color of olive oil are therefore necessary for various reasons. In this review, we discuss the importance of olive oil color and the applicable legislation and regulation, including sections devoted to the pigments accounting for the growing importance as likely health-promoting substances. Furthermore, we review in depth the different approaches (visual and instrumental methods) used for color measurements in the last 50 y. Instrumental methods have been shown to be highly appropriate for objective assessments and also for the rapid determination of the pigments.
The chemical composition of virgin olive oil may be influenced by genotype and different agronomic (i.e. fruit ripeness degree, water supply) and technological factors. This article reports the evaluation of the influence of the olive ripening stage on the quality indices, the major and the minor components and the oxidative stability of the two main monovarietal Tunisian cultivars (cvv. Chétoui and Chemlali) virgin olive oils. Moreover, the olives cv. Chétoui were tested in a rain-fed control and an irrigation regime. The oils sampled at five different ripeness stages were submitted to liquid chromatographic determination (HPLC-DAD/MSD) of their quali-quantitative phenolic and tocopherolic profiles. Moreover, the triacylglycerol and fatty acid compositions, and minor components such as squalene, pigments and their relation with the oil oxidative stability were evaluated. The tested oils showed very good correlation between the oxidative stability and the concentrations of total phenols, practically secoiridoids and α-tocopherol.
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During the olive drupes (Olea europaea L.) development we have observed significant correlations (r = 0.82, r = 0.82 and r = 0.64 for Arbequina, Farga and Morrut varieties) between l-phenylalanine ammonia-lyase enzymatic activity (PAL, EC 4.3.1.5) and the olive drupe phenolic content. l-Phenylalanine ammonia-lyase activity and the total phenol content in olive drupes suffered a decrease when the maturation processes began. Total phenol content decrease could be used as a differential since it decreased regularly in the Arbequina cv. during maturation, while their content in the Farga and Morrut cv. underwent an important decrease due probably to high variability on ripening index of Arbequina variety. Oleuropein could be used as maturation parameter at harvesting period since in Morrut and Farga cv. showed ten and six times more oleuropein than Arbequina cv. It also could be used as a maturation parameter luteolin and luteolin-7-glucoside, which had higher values in Arbequina cv. (653–62 mg kg−1, respectively) than in Farga (222–25 mg kg−1) and Morrut cv. (201–not detected mg kg−1) at harvesting period. The data obtained during the fruit development indicate than phenol content and composition, in particular oleuropein, luteolin and luteolin-7-glucoside will be useful for biochemical characterisation of olive drupes of different O. europaea L. varieties.
What makes the structure and dynamics of coupled natural and human systems difficult to interpret in the Mediterranean is the extreme diversity in space and time of both environments and human societies. The succession of civilizations that waxed and waned in the Mediterranean Basin over several millennia has had great impacts on biota and ecosystems everywhere in the basin. A complex ‘coevolution’ has been claimed to shape the interactions between ecosystem components and human societies. Two opposing schools of thought traditionally have considered the consequences of human pressures on Mediterranean ecosystems. The ‘Ruined Landscape’ or ‘Lost Eden theory’ argues that human action resulted in a cumulative degradation and desertification of Mediterranean landscapes. The second school argues that humans actually contributed to keeping Mediterranean landscapes diverse since the last glacial episode. With this debate in mind, I show the following: (1) One cannot understand the components and dynamics of current biodiversity in the Mediterranean without taking into account the history of human-induced changes; (2) The various systems of land use and resource management that provided a framework for the blossoming of Mediterranean civilizations also had profound consequences on the distribution and dynamics of species, communities, and landscapes; (3) The processes of domestication of plant and animal species, which first occurred in the eastern Mediterranean area some 10,000years ago, contributed to the increase of certain components of biodiversity at several spatial scales. Positive and negative feedback cycles between cultural practices and natural systems at the local and regional levels have kept ecosystems robust and resilient; (4) Assuming that human action can, to a certain extent, be considered a large-scale surrogate for natural sources of ecosystem disturbance, such patterns give support to the diversity-disturbance hypothesis—specifically, intermediate levels of disturbance have promoted biological diversity; (5) Intraspecific adaptive variation increased as a result of human-induced habitat changes over millennia, resulting in bursts of differentiation during the later Holocene of local ecotypes and gene pools of domesticated and wild plant and animal species, with region-specific characters fitting them to local climate and environmental conditions. High intraspecific adaptive variation also arose from earlier natural processes of the Pleistocene, mainly from a combination of periodic refugia formation and climate dynamics. During the Holocene, the main sources of disturbance came increasingly from humans, specifically from the coupled cultural and natural modifications of community and landscape structure. It is concluded that a high degree of resilience of Mediterranean ecosystems resulted in a dynamic coexistence of human and natural living systems, which in some cases provided stability, while fostering diversity and productivity (Blondel and Aronson, 1999). The word “design” used in the title and elsewhere in this paper metaphorically indicates that the long-lasting influence of human impacts resulted in an unintentional shaping of individual components of landscapes.
The chlorophyll and carotenoid content of virgin olive oils from five varieties harvested at varying degrees of ripeness were
determined. Colors were evaluated from the chromatic ordinates L*, a*, b* of the absorption spectrum. Oil color changes for
different varieties or stages of ripeness are directly related to pigment content and a* and b* values. The statistical study
made on both series of parameters proves that there is a good correlation between them. The carotenoid content and b* have
one of the best correlation coefficients (r) and is easily measured. This methodology evaluates chlorophyll and carotenoid
content, an additional attribute for evaluation of virgin olive oil quality.
A simple and reliable method for the evaluation of the phenolic fraction of extra virgin olive oils (EVOO) by capillary electrochromatography (CEC) with UV–Vis detection, using lauryl acrylate (LA) ester-based monolithic columns, has been developed. The percentages of the porogenic solvents in the polymerization mixture, and the mobile phase composition, were optimized. The optimum monolith was obtained with a monomers/porogens ratio of 40:60% (wt/wt) using a LA/1,3-butanediol diacrylate ratio of 70:30% (wt/wt) and a 1,4-butanediol/1-propanol ratio of 25:75% (wt/wt). A satisfactory resolution between the phenolic compounds was achieved in less than 25 min with a 15:85 (v/v) ACN–water buffer containing 5 mM formic acid at pH 3.0. The method was applied to the analysis of the phenolic fraction of EVOO samples. Using linear discriminant analysis of the CEC phenolic profiles, the EVOO samples belonging to three different geographical origins (Croatia, Italy and Spain) were correctly classified with an excellent resolution among all the categories.
A sensory analysis of 112 virgin olive oils was performed by a fully trained taste panel. The samples were divided in “defective” and “not defective” on the basis of their olfactory attributes. Then, the “not defective” samples were classified into “low”, “medium” and “high” according to the fruity aroma intensity perceived by assessors. All samples were also analysed by FT-NIR and FT-IR spectroscopy and processed by classification methods (LDA and SIMCA). The results showed that NIR and MIR spectroscopy coupled with statistical methods are an interesting technique compared with traditional sensory assessment in classifying olive oil samples on the basis of the fruity attribute. The prediction rate varied between 71.6% and 100%, as average value. The spectroscopic methods, combined with chemometric strategies, could represent a reliable, cheap and fast classification tool, able to draw a complete fingerprint of a food product, describing its intrinsic quality attributes, that include its sensory attributes.
The aim of this work was to study the influence of the stage of fruit ripening on analytical parameters which determine oil quality during four successive crop seasons, in an attempt to establish an optimum harvesting time for ‘Cornicabra’ olives. The majority of the analytical parameters, i.e. peroxide value, UV absorption at 270 nm, pigments, sensory scores, oleic acid and total sterols, diminished during ripening, whereas free acidity, linoleic acid and Δ-5-avenasterol increased. Oil extraction yield, oxidative stability, natural antioxidants and campesterol showed more complex behaviour. On the basis of the evolution of the analytical parameters studied the best stage of maturity of ‘Cornicabra’ olive fruits for processing seems to be a ripeness index higher than 3.0 and lower than 4.0–4.5. Results indicated that probably less than 25% of commercial ‘Cornicabra’ virgin olive oils were extracted from olives harvested at an optimum ripeness index. It is therefore of crucial recommendation to the industry to bring forward harvesting to further improve the quality of the virgin olive oil produced.
Chromatographic profiles obtained by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography (GC) were processed as continuous and non-specific signals through multivariate analysis techniques in order to select and identify the most discriminate volatile marker compounds related to the geographical origin of extra virgin olive oils. The blind analysis of the chromatographic profiles was carried out on several steps including preliminary mathematical treatments, explorative analysis, feature selection and classification. The results obtained through the application of stepwise linear discriminant analysis (SLDA) method revealed a perfect discrimination between the different Spanish geographical regions considered (La Rioja, Andalusia and Catalonia). The assignment success rate was 100% in both classification and prediction by using cross validation procedure. In addition, it must be noted that the proposed strategy was able to verify the geographical origin of the samples involving only a reduced number of discriminate retention times selected by the stepwise procedure. This fact emphasizes the quality of the accurate results obtained and encourages the feasibility of similar procedures in olive oil quality and traceability studies. Finally, volatile compounds corresponding to the predictors retained were identified by gas chromatography-mass spectrometry (GC-MS) for a chemical interpretation of their importance in quality virgin olive oils.
The initial stability of virgin olive oil depends on various factors, among which are the variety and the degree of fruit ripeness. The former, which genetically determines the composition of the olive and its oil, also marks, to some extent, its stability. However, oil stability changes as the olive ripens, so it is obvious that the degree of ripeness is an important factor. The oils were obtained by the Abencor system. Acidity, peroxide index, UV absorption at 232 and 270 nm, sensory analysis, fatty acid composition, tocopherols, phenolic compounds, orthodiphenolic compounds, sterols, pigments, and oxidative stability were determined, and the results were analyzed statistically. During ripening there was a decrease in all of the parameters studied except linoleic acid, Delta-5-avenasterol, and oil content, which increased. Virgin oils showed very good correlation between stability and the concentrations of total phenols, o-diphenols, tocopherols, chlorophyll pigments and carotenoids, linoleic and linolenic acids, total sterols, beta-sitosterol, and Delta-5-avenasterol.
The evaluation of the influence of olive ripening degree on the stability of extra virgin olive oils by the determination of the oxidative stability index, the DPPH(*) radical test, and the quali-quantitative analysis of phenolic compounds, as well as the study of the variation of their sensory profiles, plays a key role in the assessment of the overall olive oil quality. Olives of the cv. Nostrana di Brisighella grown in the north-central Italian region of Emilia-Romagna were picked at four different stages of ripeness and immediately processed in an experimental mill. The polar extracts of oil samples were submitted to spectrophotometric analysis of total phenols and o-diphenols and to liquid chromatographic determination of their quali-quantitative profile (HPLC-DAD/MSD). To attain a complete description of oil samples, fatty acid composition, ultraviolet indices (K(232), K(270), and deltaK), free acidity degree, and peroxide value were also determined according to the European Union methods stated in Regulation 2568/91 (1, Off. J. Eur. Communities 1991, L248, 1-82). Sensory quantitative descriptive analysis (QDA) and triangular tests were performed to establish the influence of olive ripening degree on the resulting oil's organoleptic properties. The evolution of the analytical parameters studied shows that the ripeness stage of Nostrana di Brisighella olives that yields the best oil corresponds to a Jaén index value between 2.5 and 3.5. Oils produced from olives harvested within this time frame present a superior sensory profile accompanied by the highest possible chemical and nutritional properties.
Since ancient times the olive tree (Olea europaea), an evergreen drought- and moderately salt-tolerant species, has been cultivated for its oil and fruit in the Mediterranean basin. Olive is unique among the commercial important oil crops for many reasons. Today, it ranks sixth in the world's production of vegetable oils. Due to its nutritional quality, olive oil has a high commercial value compared with most other plant oils. Olive oil has a well-balanced composition of fatty acids, with small amounts of palmitate, and it is highly enriched in the moneonic acid oleate. This makes it both fairly stable against auto-oxidation and suitable for human health. Nevertheless, it is the presence of minor components, in particular phenolics, contributing for oil's high oxidative stability, color and flavor, that makes olive oil unique among other oils.
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