Comparison of the chemical composition and the organoleptic profile of virgin olive oil from two wild and two cultivated Tunisian Olea europaea

Preliminary Evaluation of the Effect of Domestication on the Marketable and Nutritional Quality of B. aegyptiaca (L.) Delile Oil from Algeria

Balanites aegyptiaca is a multipurpose fruit tree that grows wild in many arid and semi-arid African areas; however, recent domestication efforts have been undertaken to protect the species from the threat of urbanization and climate change. Within this context, the impact of the domestication of Algerian B. aegyptiaca was evaluated on its seed oil, which is already valued as food. Hence, oils from wild and domesticated trees were comparatively investigated for their physicochemical and compositional quality. Both oil types had a good oxidative stability and met the requirements for human consumption in terms of the saponification index, the free acidity, and the peroxide value. Moreover, they showed a comparable FA composition, with high levels of oleic and linoleic acids, which are beneficial for the consumer's health. Domestication led to a statistically significant decrease in the tocopherols and polyphenols in the oil. The phytosterols and squalene were slightly lower in the domesticated oil than in the wild relative, although no statistically significant differences were observed. A comparable mineral profile was revealed and the minimal variations in the trace elements between the oils could be related to the natural variability in the seeds. Hopefully, this study will encourage the domestication of B. aegyptiaca as a sustainable strategy for enhancing its socioeconomic value in Algerian rural areas.

Wild and cultivated olive trees: Nutraceutical insights of extra virgin olive oils in cardiovascular and ocular diseases

Extra virgin olive oil (EVOO) from Olea europaea (cultivated olive tree) and the oil obtained from the wild olive variety or acebuche (ACE oil from Olea oleaster) contain an extraordinary number of bioactive molecules. These include oleic acid, sterols, tocopherols, triterpene compounds, and polyphenols. Both oils are known for their healthy properties and are considered to be a nutraceutical tool against cardiovascular diseases, including arterial hypertension, preeclampsia, and ocular diseases such as glaucoma or diabetic retinopathy. The benefits of EVOO and ACE oil stem from their anti-inflammatory, antioxidant, and anti-cancer properties. They also have potential as prebiotic compounds. In this update, we synthesise and illustrate the various characteristics and beneficial effects of olive oils from different varieties of olive trees, with special emphasis on Olea oleaster, also known as Olea europaea, L. var. sylvestris.

Oleaster oil (Olea europaea sylvestris) effects on the efficiency of the reproductive system of diet-induced obese male Wistar rats

OBJECTIVES

Obesity is the result of oxidative stress (OS), which appears to be linked to male infertility. Oleaster oil has multiple therapeutic virtues due to its richness in natural bioactive compounds. This study aimed to evaluate the effect of Algerian oleaster oil on the reproductive system effectiveness of diet-induced obese male Wistar rats.

METHODS

The oil was extracted with an oleodoseur from the oleaster fruits. Rats were fed for 28 weeks two diets: a normal diet (NC group, n=8) and a high-fat, high-sucrose diet (HFHS group, n=32). The obese rats in the HFHS group were then split into three groups at random: the HFHS group, which continued to receive the HFHS diet; the HFHS L-OO group; and the HFHS H-OO group, which received for 6 weeks, respectively, in combination with the HFHS diet, oleaster oil at 1.5 and 3 mL/100 g body weight (BW). Then, the animals were sacrificed. Semen and testes were removed for semen analysis, OS, and histopathological evaluation.

RESULTS

The oleaster oil diet induces an improvement in sperm count and viability and a decrease in the percentage of fragmented sperm DNA compared to the group fed the HFHS diet, preserving the testes against OS with a highly significant decrease in testicular MDA. This beneficial effect of oleaster oil on the reproductive efficiency of rats fed the HFHS diet was dose-dependent.

CONCLUSIONS

The results showed that the oil decreased body weight, prevented OS and improved male reproductive indicators in HFHS-fed animals. The potential positive effects of oleaster oil on fertility biomarkers may be attributed to its ability to mitigate OS.

Application of oleaster leaves (Elaeagnus angustifolia L.) essential oil and natural nanoparticle preservatives in frankfurter-type sausages: An assessment of quality attributes and stability during refrigerated storage

The effects of oleaster leave essential oil (OLEOs: 1000 and 2000 ppm) in combination with nisin nanoparticles (200 ppm) and ε-polylysine nanoparticles (2000 ppm) on the physicochemical, microbiological and sensory properties of the emulsion-type sausages without added chemical nitrite/nitrate salts were evaluated during 45 days of storage. Nanoparticle attributes were assessed, including encapsulation efficiency (EE%), zeta potential, nanoparticles size, FTIR analysis, and thermal stability (DSC). Overall, ε-PL nanoparticles (ε-PL-NPs) were thermally more stable and showed higher EE% (91.52%) and zeta potential (37.80%) as compared to nisin nanoparticles (82.85%) and (33.60%), respectively. The use of combined ε-PL-NPs (2000 ppm) + Ni-NPs (200 ppm) with oleaster leaves essential oil (2000 ppm) resulted in a higher pH value (5.88), total phenolic content (10.45 mg/100 g) and lower TBARS (2.11 mg/kg), and also decreased total viable bacteria (1.28 Log CFU/g), Clostridium perfringens (1.43 Log CFU/g), E. coli (0.24 Log CFU/g), Staphylococcus aureus (0.63 Log CFU/g), and molds and yeasts (0.86 Log CFU/g) count in samples at day 45 in comparison to the control (120 ppm nitrite). The consumers approved sensory traits in nitrite-free formulated sausages containing ε-PL-NPs and Ni-NPs combined with OLEOs.

Sensitive Detection of Hydroxytyrosol in Extra Virgin Olive Oils with a Novel Biosensor Based on Single-Walled Carbon Nanotubes and Tyrosinase

Hydroxytyrosol (HT) is an important marker for the authenticity and quality assessment of extra virgin olive oils (EVOO). The aim of the study was the qualitative and quantitative determination of hydroxytyrosol in commercial extra virgin olive oils of different origins and varieties using a newly developed biosensor based on a screen-printed electrode modified with single-layer carbon nanotubes and tyrosinase (SPE-SWCNT-Ty). The enzyme was immobilized on a carbon-based screen-printed electrode previously modified with single-layer carbon nanotubes (SPE-SWCNT-Ty) by the drop-and-dry method, followed by cross-linking with glutaraldehyde. The modified electrode surface was characterized by different methods, including electrochemical (cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS)) and spectrometric (Fourier transform infrared (FTIR) spectroscopy) methods. Cyclic voltammetry was used for the quantitative determination of HT, obtaining a detection limit of 3.49 × 10⁻⁸ M and a quantification limit of 1.0 × 10⁻⁷ M, with a wide linearity range (0.49–15.602 µM). The electrochemical performance of the SPE-SWCNT-Ty biosensor was compared with that of the modified SPE-SWCNT sensor, and the results showed increased selectivity and sensitivity of the biosensor due to the electrocatalytic activity of tyrosinase. The results obtained from the quantitative determination of HT showed that commercial EVOOs contain significant amounts of HT, proving the high quality of the finished products. The determination of the antiradical activity of HT was carried out spectrophotometrically using the free reagent galvinoxyl. The results showed that there is a very good correlation between the antiradical capacity of EVOOs, the voltammetric response and implicitly the increased concentration of HT. SPE-SWCNT-Ty has multiple advantages such as sensitivity, selectivity, feasibility and low cost and could be used in routine analysis for quality control of food products such as vegetable oils.

Morphological and Eco-Geographic Variation in Algerian Wild Olives

Algerian wild olives can represent an important resource for cultivated olive breeding, since they are characterized by great morphological variability. Moreover, they grow in different bioclimatic environments, including dry and hot climates, making the collections of wild olives a good source of abiotic stress resistance traits. Our study aimed to investigate the morphological diversity of 175 wild olive trees collected in North Algeria along with a wide range of different bioclimatic habitats for studying traits of olive accessions in relation to their different ecogeographical parameters. Wild olive trees were found in five different bioclimates areas spanning from humid to Saharan areas. They showed high variation in all traits, in particular fruit and stone weight, which expressed the highest coefficient of variation, and a high positive correlation between fruit weight/width. Cluster analysis separated the samples into two groups mostly based on fruit and stone size, while no relationship was observed with the area of sampling. Only the Saharan samples showed significantly different foliar and fruit characteristics compared to samples from other bioclimatic areas.

Characteristics of Some Wild Olive Phenotypes (Oleaster) Selected from the Western Mountains of Syria

This study presents the evaluation of some technological and production specifications of 20 selected wild olive (oleaster) phenotypes from Hama Province, western–central Syria. The analyses of oil quantity showed that the olive oil (OO) extracted ranged from 10.43 to 29.3%. The fatty acid composition determined by gas chromatography (m/m%, methyl esters), conforming to commercial standards, showed the percentages of palmitic (ranged 13.2–15.06%), stearic (2.27–4.2%), arachidic (0.42–0.7%), palmitoleic (0.73–1.25%), oleic (64.29–73.17%), linoleic (8.96–16.45%), and linolenic (0.23–1.6%). Our results suggest that, despite being in a harsh environment and lacking agricultural service, two wild olive phenotypes (WA4, WA6) are interesting since their fruits showed high-quality properties (fruit weight 2.16, 3.24 g; flesh 75.83, 86.2, respectively), high content of OO% (29.27, 29.01, respectively), and better fatty acid composition (oleic % 68.45, 66.74, respectively). This enables them to be a very promising introductory feature in olive genetic improvement processes. Thus, both phenotypes were adopted tentatively as inputs, the first for oil purposes and the second for dual purposes (oil and table olives). It will be important to further evaluate these promising phenotypes in terms of their OO minor compounds, as well as their ability to resist biotic and abiotic stresses.

Evaluation of Olive Oil Quality with Electrochemical Sensors and Biosensors: A Review

Electrochemical sensors, sensor arrays and biosensors, alongside chemometric instruments, have progressed remarkably of late, being used on a wide scale in the qualitative and quantitative evaluation of olive oil. Olive oil is a natural product of significant importance, since it is a rich source of bioactive compounds with nutritional and therapeutic properties, and its quality is important both for consumers and for distributors. This review aims at analysing the progress reported in the literature regarding the use of devices based on electrochemical (bio)sensors to evaluate the bioactive compounds in olive oil. The main advantages and limitations of these approaches on construction technique, analysed compounds, calculus models, as well as results obtained, are discussed in view of estimation of future progress related to achieving a portable, practical and rapid miniature device for analysing the quality of virgin olive oil (VOO) at different stages in the manufacturing process.

Genome Wide MeDIP-Seq Profiling of Wild and Cultivated Olives Trees Suggests DNA Methylation Fingerprint on the Sensory Quality of Olive Oil

Secondary metabolites are particularly important to humans due to their pharmaceutical properties. Moreover, secondary metabolites are key compounds in climate change adaptation in long-living trees. Recently, it has been described that the domestication of Olea subspecies had no major selection signature on coding variants and was mainly related to changes in gene expression. In addition, the phenotypic plasticity in Olea subspecies was linked to the activation of transposable elements in the genes neighboring. Here, we investigated the imprint of DNA methylation in the unassigned fraction of the phenotypic plasticity of the Olea subspecies, using methylated DNA immuno-precipitation sequencing (MeDIP-seq) for a high-resolution genome-wide DNA methylation profiling of leaves and fruits during fruit development in wild and cultivated olives from Turkey. Notably, the methylation profiling showed a differential DNA methylation in secondary metabolism responsible for the sensory quality of olive oil. Here, we highlight for the first time the imprint of DNA methylation in modulating the activity of the Linoleate 9S lipoxygenase in the biosynthesis of volatile aromatic compounds. Unprecedently, the current study reveals the methylation status of the olive genome during fruit ripening.

Comparative Oil Composition Study of the Endemic Moroccan Olive (Olea europaea subsp. maroccana) and Wild Olive (var. Sylvestris) in Central West Morocco

Six wild olive subspecies (Olea europaea L.) are currently recognised globally, with two taxa cooccurring in the argan tree area in Central West Morocco: the widespread Mediterranean subspecies europaea var. Sylvestris (the so-called oleaster) and the microendemic subspecies maroccana. Despite its taxonomic and ecological importance, the chemical composition of subsp. maroccana oil remains poorly known. Therefore, the aim of this study is to investigate the oil content and the chemical composition of subsp. maroccana and var. Sylvestris as well as comparing their proprieties during two consecutive years (2017 and 2018) from the same geographical area. The fatty acid and the sterol compositions were analysed using gas chromatography. Additionally, the tocopherol content was determined using high-performance liquid chromatography. The total amount of unsaturated fatty acids was higher in maroccana (85.24%) than that in oleasters (79.05%). Additionally, the tocopherol and phytosterol content of the maroccana oil (1232.35 mg/kg and 312.75 mg/100 g, resp.) was approximately twofold higher than in oleasters (661.35 mg/kg and 210.06 mg/100 g, resp.). Analysis of variance and principal component analysis (PCA) of the chemical composition highlighted a significant difference between the quantitative and qualitative properties of their oil. Finally, these findings suggest that maroccana oil could be considered as a potential source of vitamin E, essential fatty acids, and sterols and can provide a nutraceutical oil for the local population. While this work contributes to the study of olive tree biodiversity, further investigations are still necessary to guide the putative nutraceutical use of subspecies maroccana.

Extra Virgin Olive Oil: Lesson from Nutrigenomics

Extra virgin olive oil (EVOO) consumption has a beneficial effect on human health, especially for prevention of cardiovascular disease and metabolic disorders. Here we underscore the peculiar importance of specific cultivars used for EVOO production since biodiversity among cultivars in terms of fatty acids and polyphenols content could differently impact on the metabolic homeostasis. In this respect, the nutrigenomic approach could be very useful to fully dissect the pathways modulated by different EVOO cultivars in terms of mRNA and microRNA transcriptome. The identification of genes and miRNAs modulated by specific EVOO cultivars could also help to discover novel nutritional biomarkers for prevention and/or prognosis of human disease. Thus, the nutrigenomic approach depicts a novel scenario to investigate if a specific EVOO cultivar could have a positive effect on human health by preventing the onset of cardiovascular disease and/or chronic inflammatory disorders also leading to cancer.

The activity of commercial antimicrobials, and essential oils and ethanolic extracts of Olea europaea on Streptococcus agalactiae isolated from pregnant women

BACKGROUND

Streptococcus agalactiae also known as Group B Streptococcus (GBS) is a major cause of disease in pregnant women and new born babies where it causes early and late onset disease characterised by sepsis, pneumonia and meningitis. Ten to 37 % of pregnant women in the world are colonised with GBS while intrapartum antibiotic prophylaxis has led to significant reduction in early onset disease. The increase in drug resistant microorganisms has become a major threat. Development of vaccines is still in progress so there is need for new and safer alternatives to treatment.

METHODS

Benzyl penicillin, Ampicillin, Cefotaxime, Ceftriaxone, Levofloxacin, Erythromycin, Clindamycin, Linezolid, Vancomycin, Tetracycline and Cotrimoxazole, Olea europaea leaf extracts and essential oil were tested against GBS isolates from South Africa and Namibia.

RESULTS

The isolates showed 100% sensitivity to benzyl penicillin, ampicillin, ceftriaxone, levofloxacin, linezolid, vancomycin, O. europaea leaf extracts and essential oils. Only one isolate (0.6%) was resistant to cefotaxime and 23.4 and 10.4% were resistant to clindamycin and erythromycin respectively.

CONCLUSION

GBS isolates showed sensitivity to O. europaea extracts at low minimum inhibitory concentrations. Β lactams are still the drugs of choice for treatment of GBS disease but O. europaea extracts potent as an alternative source of antimicrobials.

Profile of Fatty Acids, Tocopherols, Phytosterols and Polyphenols in Mediterranean Oils (Argan Oils, Olive Oils, Milk Thistle Seed Oils and Nigella Seed Oil) and Evaluation of their Antioxidant and Cytoprotective Activities

BACKGROUND

The effects of vegetable oils on human health depend on their components. Therefore, their profiles of lipid nutrients and polyphenols were determined.

OBJECTIVE

To establish and compare the fatty acid, tocopherol, phytosterol and polyphenol profiles of Mediterranean oils: cosmetic and dietary argan oils (AO; Morocco: Agadir, Berkane); olive oils (OO; Morocco, Spain, Tunisia); milk thistle seed oils (MTSO; Tunisia: Bizerte, Sousse, Zaghouane); nigella seed oil (NSO).

METHODS

The biochemical profiles were determined by gas chromatography-flame ionization, high performance liquid chromatography and gas chromatography, coupled with mass spectrometry as required. The antioxidant and cytoprotective activities were evaluated with the KRL (Kit Radicaux Libres) and the fluorescein diacetate tests on nerve cells treated with 7-ketocholesterol (7KC).

RESULTS

The fatty acid profile revealed high linoleic acid (C18:2 n-6) content in AO, OO, MTSO and NSO. The highest levels of oleic acid (C18:1 n-9) were found in AO and OO. The tocopherol profile showed that Agadir AO contained the highest amount of α-tocopherol, also present at high level in MTSO and Tunisian OO; Berkane AO was rich in γ-tocopherol. The phytosterol profile indicated that β-sitosterol was predominant in the oils, except AO; spinasterol was only present in AO. Polyphenol profiles underlined that OO was the richest in polyphenols; hydroxytyrosol was only found in OO; few polyphenols were detected in AO. The oils studied have antioxidant activities, and all of them, except NSO, prevented 7KC-induced cell death. The antioxidant characteristics of AO were positively correlated with procatechic acid and compestanol levels.

CONCLUSION

Based on their biochemical profiles, antioxidant and cytoprotective characteristics, AO, OO, and MTSO are potentially beneficial to human health.

Electrochemical Sensor-Based Devices for Assessing Bioactive Compounds in Olive Oils: A Brief Review

Electrochemical bioinspired sensor devices combined with chemometric tools have experienced great advances in the last years, being extensively used for food qualitative and quantitative evaluation, namely for olive oil analysis. Olive oil plays a key role in the Mediterranean diet, possessing unique and recognized nutritional and health properties as well as highly appreciated organoleptic characteristics. These positive attributes are mainly due to olive oil richness in bioactive compounds such as phenolic compounds. In addition, these compounds enhance their overall sensory quality, being mainly responsible for the usual olive oil pungency and bitterness. This review aims to compile and discuss the main research advances reported in the literature regarding the use of electrochemical sensor based-devices for assessing bioactive compounds in olive oil. The main advantages and limitations of these fast, accurate, bioinspired voltammetric, potentiometric and/or amperometric sensor green-approaches will be addressed, aiming to establish the future challenges for becoming a practical quality analytical tool for industrial and commercial applications.

Using Wild Olives in Breeding Programs: Implications on Oil Quality Composition

A wide genetic diversity has been reported for wild olives, which could be particularly interesting for the introgression of some agronomic traits and resistance to biotic and abiotic stresses in breeding programs. However, the introgression of some beneficial wild traits may be paralleled by negative effects on some other important agronomic and quality traits. From the quality point of view, virgin olive oil (VOO) from olive cultivars is highly appreciated for its fatty acid composition (high monounsaturated oleic acid content) and the presence of several minor components. However, the composition of VOO from wild origin and its comparison with VOO from olive cultivars has been scarcely studied. In this work, the variability for fruit characters (fruit weight and oil content, OC), fatty acid composition, and minor quality components (squalene, sterols and tocopherols content and composition) was studied in a set of plant materials involving three different origins: wild genotypes (n = 32), cultivars (n = 62) and genotypes belonging to cultivar × wild progenies (n = 62). As expected, values for fruit size and OC in wild olives were lower than those obtained in cultivated materials, with intermediate values for cultivar × wild progenies. Wild olives showed a remarkably higher C16:0 percentage and tocopherol content in comparison to the cultivars. Contrarily, lower C18:1 percentage, squalene and sterol content were found in the wild genotypes, while no clear differences were found among the different plant materials regarding composition of the tocopherol and phytosterol fractions. Some common highly significant correlations among components of the same chemical family were found in all groups of plant materials. However, some other correlations were specific for one of the groups. The results of the study suggested that the use of wild germplasm in olive breeding programs will not have a negative impact on fatty acid composition, tocopherol content, and tocopherol and phytosterol profiles provided that selection for these compounds is conducted from early generations. Important traits such as tocopherol content could be even improved by using wild parents.

Healthy virgin olive oil: a matter of bitterness

Virgin olive oil (VOO) is the pillar fat of Mediterranean diet. It is made from olive fruits and obtained by squeezing olives without any solvent extraction. Respect to the seed oils, an unique polar polyphenol-rich fraction gives VOO a bitter and pungent taste. The recent substantiation by European Food Safety Authority (EFSA) of a health claim for VOO polyphenols may represent an efficient stimulus to get the maximum health benefit from one of the most valuable traditional product of Mediterranean countries educating consumers to the relationship between the VOO bitterness and its health effect. Agronomical practices and new processing technology to avoid phenolic oxidation and hydrolysis and to enhance the aromatic components of the VOO have been developed and they can be used to modulate taste and flavor to diversify the products on the market. VOOs having high concentration of phenol compounds are bitter and pungent therefore many people do not consume them, thus loosing the health benefits related to their intake. In this paper, the chemist's and nutritionist's point of view has been considered to address possible strategies to overcome the existing gap between the quality perceived by consumer and that established by expert tasters. Educational campaigns emphasizing the bitter-health link for olive oils should be developed.

Evolution of fatty alcohols in olive oils produced in Calabria (Southern Italy) during fruit ripening

A study was conducted on olive oils extracted from olives collected in South West Calabria (Southern Italy) over three harvest years 2010-2011-2012. Three autochthonous cultivars were considered: Cassanese, Ottobratica and Sinopolese and seven allochtonous cultivars: Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino and Picholine. Thin Layer Chromatography - Gas Chromatograph (TLC-GC) technique permitted the separation and analysis of the fatty alcohol compounds. A general decline in fatty alcohol content was found during the three months of sampling, most evident in hexacosanol. Pendolino showed the greatest decline. A less evident decrease was measured in the odd chained fatty alcohols, mainly in heptacosanol. Both harvest date and cultivar significantly influenced the fatty alcohol content. This is the first report about the fatty alcohol variation during ripening in olive oil produced in South West Calabria (Southern Italy).

Volatile profile, phytochemicals and antioxidant activity of virgin olive oils from Croatian autochthonous varieties Mašnjača and Krvavica in comparison with Italian variety Leccino

Virgin olive oils (VOOs) obtained from the fruits of Croatian autochthonous varieties Mašnjača and Krvavica were extensively characterized for the first time. Investigated oils were compared with the oil obtained from Italian variety Leccino, grown and processed under the same conditions. Headspace volatile profile, tocopherols, chlorophylls, carotenoids and total phenolic content, peroxide value, % acidity, K₂₃₂, K₂₇₀ as well as antioxidant activity (DPPH) of the oils’ hydrophilic fractions (HFs) including their phenolic composition were assessed by means of HS-SPME/GC-MS, HPLC-FL, HPLC-DAD and spectrophotometric methods, respectively. Most of the studied quality parameters varied between the cultivars. The main volatile compounds detected in all tested olive oils were the C6 compounds derived from polyunsaturated fatty acids through the lipoxygenase pathway. Krvavica oil was characterized by hexanal (8.8%–9.4%). Leccino oil contained the highest percentage of (E)-hex-2-enal (73.4%–74.0%), whereas (Z)-hex-3-enal (21.9%–25.0%) and (E)-hex-2-enal (27.6%–28.9%) dominated in Mašnjača oil. Leccino oil contained the highest amount of tocopherols (312.4 mg/kg), chlorophylls (7.3 mg/kg), carotenoids (4.2 mg/kg) and total phenols (246.6 mg/kg). The HF of Leccino oil showed the highest antioxidant capacity (1.3 mmol TEAC/kg), while the HFs of Mašnjača and Krvavica oils exhibited the activity of 0.5 mmol TEAC/kg.

Effect of addition of olive leaves before fruits extraction process to some monovarietal Tunisian extra-virgin olive oils using chemometric analysis

The analysis of the effect of cultivar and olive leaves addition before the extraction on the different analytical values revealed significant differences (p < 0.05) in some parameters, mainly in peroxide value, phenols and tocopherol contents, and oxidative stability. Aroma profiles were also influenced by the different varieties and the addition of different amounts (0% and 3%) of olive leaves. Twenty-three compounds were characterized, representing 86.1-99.2% of the total volatiles. Chétoui cultivar has the highest amount of (E)-2-hexenal, followed by Chemlali cultivar, whereas (E)-2-hexen-1-ol was the major constituent of Zalmati and crossbreeding Chemlali by Zalmati cultivars. Sensory analysis showed that Chemlali and Chétoui Zarzis possessed a high fruity, bitter, and pungent taste, whereas the Zalmati and crossbreeding Chemlali by Zalmati had a 'green' taste among its attributes. Indeed, the taste panel found an improvement of the oil quality when an amount of olive leaves (3%) added to the olives fruits.

Oil composition and genetic biodiversity of ancient and new olive (Olea europea L.) varieties and accessions of southern Italy

The present study is focused on determining the olive oil fatty acid composition of ancient and recent varieties of the Campania region (Italy), but also on molecularly characterizing the most common cultivated varieties in the same region, together with olive trees of the garden of the University Campus of Salerno and of three olive groves of south Italy. Fatty acid methyl esters in the extra virgin oil derived olive fruits were determined, during three consecutive harvests, by gas chromatography. The statistical analysis on fatty acid composition was performed with the ffmanova package. The genetic biodiversity of the olive collection was estimated by using eight highly polymorphic microsatellite loci and calculating the most commonly used indexes. "Dice index" was employed to estimate the similarity level of the analysed olive samples, while the Structure software to infer their genetic structure. The fatty acid content of extra virgin olive oils, produced from the two olive groves in Campania, suggests that the composition is mainly determined by genotype and not by cultural practices or climatic conditions. Furthermore, the analysis conducted on the molecular data revealed the presence of 100 distinct genotypes and seven homonymies out of the 136 analysed trees.

1H nuclear magnetic resonance study of olive oils commercially available as Italian products in the United States of America

Multivariate analysis of ¹H NMR data has been used for the characterization of 12 blended olive oils commercially available in the U.S. as Italian products. Chemometric methods such as unsupervised Principal Component Analysis (PCA) allowed good discrimination and gave some affinity indications for the U.S. market olive oils compared to other single cultivars of extra virgin olive oil such as Coratina and Ogliarola from Apulia, one of Italy’s leading olive oil producers, Picual (Spain), Kalamata (Greece) and Sfax (Tunisia). The olive oils commercially available as Italian products in the U.S. market clustered into 3 groups. Among them only the first (7 samples) and the second group (2 samples) showed PCA ranges similar to European references. Two oils of the third group (3 samples) were more similar to Tunisian references. In conclusion, our study revealed that most EVOO (extra virgin olive oils) tested were closer to Greek (in particular) and Spanish olive oils than Apulia EVOO. The PCA loadings disclose the components responsible for the discrimination as unsaturated (oleic, linoleic, linolenic) and saturated fatty acids. All are of great importance because of their nutritional value and differential effects on the oxidative stability of oils. It is evident that this approach has the potential to reveal the origin of EVOO, although the results support the need for a larger database, including EVOO from other Italian regions.

Oleaster oil positively modulates plasma lipids in humans

The olive tree had been domesticated during the early Neolithic in the Near East, and more than 1000 different cultivars have been identified to date. However, examples of wild olive trees (Olea europaea oleaster) can still be found in the Mediterranean basin. Evidence of oleaster use for oil production can be found in historical and sacred texts, such as the Odyssey, the Holey Koran, and the Holey Bible. While the nutritional and healthful properties of olive oil are actively being explored, there are no data on the human actions of oleaster oil. Therefore, we investigated the effect of prolonged, i.e., 1 month, consumption of oleaster oil on the lipid profile of a 40 healthy Algerian subjects (aged 27.9 ± 3.85 years), as compared to nonconsumers from the same area. Plasma urea, creatinine, and uric acid concentrations and glycemia did not significantly differ, at the end of the study, between controls and oleaster-oil-supplemented subjects. Conversely, we recorded significant decreases of plasma triglyceride concentration (-24.8%; p < 0.05), total cholesterol (-12.13%; p < 0.05), and low-density lipoprotein-cholesterol (LDL-C) (-24.39%; p < 0.05) in oleaster-oil-treated subjects. Concomitantly, high-density lipoprotein-cholesterol (HDL-C) concentrations were significantly increased (17.94%; p < 0.05) by oleaster oil administration. In conclusion, we show that oil obtained from feral olive trees, i.e., oleasters, improves the plasma lipid profile of healthy volunteers.