Chemical Composition Of Olive Oil Research Articles

Chemical composition of olive oil – an essential component of the Mediterranean diet and its impact on human health

The Mediterranean diet is known for its many health benefits, including the low prevalence of cardiovascular disease, atherosclerosis, diabetes, obesity, and cancer. Olive oil is considered an essential component of the Mediterranean diet. The consumption of olive oil is associated with many beneficial effects on the human body, most of which are attributed to its phenol content, which varies between cultivars due to different processing and extraction procedures, with only 0.3-1.5% of phenols being transferred to the oil from the olive fruit. Many studies suggest that olive oil phenolic compounds have a protective role in preventing cardiovascular diseases, cancer, diabetes mellitus type 2, metabolic syndrome, obesity, inflammation, and neurodegenerative diseases. Additionally, recent epidemiological research has shown that regular olive oil consumption is associated with increased longevity. Keywords: olive oil, phenols, health benefits

Chemical Composition and In vitro Antidiabetic Effects of Olea europaea Linn. (Olive)

Background: Olive oil and fruits are essential components of Mediterranean diets. The olive tree is a prevalent plant species and one of the important cultivated crops of the Mediterranean region. The present study aimed to evaluate the effectiveness of olive in achieving glucose homeostasis through the inhibition of carbohydrate metabolizing enzymes using in vitro models and also determine the chemical composition of olive oil by GC/MS. Methods: The chemical composition of olive oil was determined by GC/MS and its antidiabetic activity was assessed through inhibition α-amylase and α-glucosidase enzymes in in vitro models. Results: The olive oil analysis by GC/MS yielded 41 constituents amounting to 98.21% of total oil composition. Oleic acid, 3-(octadecyloxy) propyl ester (19.34%), arachidonic acid (11.25%), oleic acid (6.07%), Docosahexaenoic Acid (DHA) (9.50%), pentadecanoic acid (5.53%), palmitic acid (3.86%), and linoleic acid (3.13%) were the major components of olive oil. Olive oil and extract produce dosedependent inhibition of α-amylase and α-glucosidase enzymes. The IC50 values for olive oil, olive extract, and acarbose were found as 210.50±4.76, 121.8±3.18, and 91.04±2.16 μg/mL, respectively, against the α-amylase enzyme. The IC50 values for olive oil, extract, and acarbose were found as 204.3±3.41, 165.04±5.27 and 116.5±2.17 μg/mL, respectively, against the α-glucosidase enzyme. Conclusion: The result of this study concluded that olive oil has oleic acid and its ester derivatives as major constituents. The study findings also confirm the traditional claim of olive use in the treatment of diabetes mellitus.

Quality characteristics and chemical evaluation of Chemlali olive oil produced under dairy wastewater irrigation

The present work aimed to study the effect of using Treated Wastewater (TWW) to irrigate Chemlali olive trees on the quality characteristics and chemical composition of olive oils. This research was conducted in orchards cultivated in the center of Tunisia where olive trees were subjected to different irrigation treatments during two consecutive years; (CT) 0 % ETc, (T1) 20 % ETc and (T2) 40 % ETc. Results showed that irrigation with TWW whatever the level didn’t significantly affect oil standard quality indices (free acidity, K232, K270 and peroxide value) and pigment contents. Furthermore, α-tocopherol amount was maintained stable which may explain the preservation of fatty acids against oxidation after TWW irrigation. Moreover, this last did not induce phenolic compounds contents variation. A decrease of some volatile compounds giving oil undesirable attributes (octanal and acetic acid) and a maintain of those offering good characteristics like the fruity odor were observed.

Effect of Maturity and Environmental Conditions on Chemical Composition of Olive Oils of Introduced Cultivars in Morocco

This work aims at evidencing the quality and chemical composition of extra virgin olive oils according to stages of maturity and in relation to the geographical location of olives. Three different olive cultivars (Moroccan Picholine, Languedoc Picholine, and Frantoio), grown in two different locations in Morocco (Errachidia and Marrakech), were studied during the two crop years (2016 and 2017) at three stages of maturity (green, purple, and black). This work has been carried out by analyzing several parameters, such as the quality characteristics (acidity and peroxide value), the chemical composition (total phenol content and fatty acid composition) of the oils, and also the fruit characteristics of the olives (maturity index, fruit water content, and oil content). The results obtained in this study indicate that as maturity advanced, there was a slight rise in oil content and acidity, while there was a decrease in fruit water content and peroxide value in both locations during the two crop years. The fatty acid composition of extra virgin olive oil showed a significant increase of linoleic acid and polyunsaturated fatty acids (PUFAs) and a decrease of oleic acid, palmitic acid, monounsaturated fatty acids (MUFAs), and MUFA/PUFA ratio as the maturation process progressed. A significant gradual decrease was noted in total phenol content and bitterness intensity from the green stage to the black. Moreover, olive oil composition differed clearly between the two sites. Therefore, the olive cultivar, harvesting date, and geographic location influence the olive oil characteristics.

Characterisation of Monovarietal Olive Oils Obtained from Croatian cvs. Drobnica and Buza during the Ripening Period.

The aim of this study was the monitoring of the chemical composition of olive oil at different ripening stages to determine the appropriate harvesting time during any given crop season in the northern Adriatic region. For this purpose, from September to November, two Croatian olive cultivars (Drobnica and Buza) were taken from two different olive orchards and for the respective olive oils, prepared on a laboratory scale, the major saponifiable, unsaponifiable and phenolic compounds were determined. Based on the chemical analyses performed, the optimal harvesting time has been set in October for both cultivars. Buza had a higher oleic acid, but lower total sterols, squalene and total alkanols. Compared to the local cultivars, the studied cultivars had a high total phenolic content and antioxidant activity. The antioxidant activity and concentrations of total phenols correlated with α-tocopherol in oil samples taken during the ripening progress. Finally, trace minerals detected in Buza and Drobnica oil differed, which can be an indicator of oxidative stability and authenticity of oils.

Effects of Geographical Location on Chemical Properties of Zarazi Virgin Olive Oil Produced in the South of Tunisia

The effects of geographical location on the chemical composition of olive oil of Zarazi cultivar growing in four different regions in the south of Tunisia (Sfax, Tataouin, Matmata and Medenin) were evaluated. Quality indices, oxidative stability, tocopherol content, fatty acid, sterol and phenolic compositions, were analyzed for each oil sample. Significant differences were detected depending on the growing area (p< 0.05). In general, the main secoridoids, were present in higher levels in the oil obtained from olives of Sfax region. Statistical analyses showed that acidic and sterolic compositions of olive oil were significantly modified according to the growing regions. The Principal Component Analysis of the different analyzed compounds indicated that the factor “geographical location” significantly affected olive oil quality, and highlighted the high quality of oil samples of Sfax, in terms of their high oxidative stability and their richness in bioactive compounds.

Effect of Edaphoclimatic Region and Fruit Ripening Stage on Fatty Acid Profile of Tree Olive Oil Cultivars

Background: The chemical composition of olive oil will change regarding to cultivar, ripening stage and edaphoclimatic regions. The effect of two edaphoclimatic regions (Fasa and Tarom), two fruit ripening stages (purple and black) and three olive cultivars (Arbequina, Koroneiki, and Roghani) were studied. Methods: Some functional physicochemical properties (fruit weight, ratio of flesh/stone weight, fruit size, oil content, fatty acid composition, and nutritional indexes) for three olive cultivars were tested. Results: The statistical results indicated that the average weight of fruit in Tarom is higher than that in Fasa. Oil content reduced during maturity period in both regions in Koroneiki (43.20 to 33.75% in Fasa and 36.91 to 34.16% in Tarom) and in Roghani of Tarom (48.97 to 42.97%), while the value increased in Roghani of Fasa (22.19 to 30.57%) and remained unchanged in other samples. The oleic acid is higher than other fatty acids in all cultivars and regions, while increased in Koroneiki of Fasa and decreased in Arbequina and Roghani of Fasa and Tarom and Koroneiki of Tarom during maturity period. The ratio of 3/6 during maturity period decreased in all samples except in the oil from Koroneiki of Fasa and Roghani of Tarom. The PUFA/SFA increased in the oil from Arbequina of Fasa (0.80 to 0.86) and Koroneiki (0.53 to 0.63 and 0.42 to 0.49) and Roghani (0.66 to 0.94 and 0.78 to 0.90) of Fasa and Tarom, respectively, while decreased in Arbequina of Tarom (0.71 to 0.69). Conclusion: In most samples, fruits in last ripening stage have lower content of oil, moisture, F/S ratio and oxidative stability. So, in order to produce high yield and quality olive oil, recommended that, olive fruit harvesting was done before the end of complete maturity progress, in purple stage.

Effects of malaxation temperature and harvest time on the chemical characteristics of olive oils

The aim of the study was to determine the effects of harvest time and malaxation temperature on chemical composition of olive oils produced from economically important olive varieties with a full factorial experimental design. The oils of Ayvalik and Memecik olives were extracted in an industrial two-phase continuous system. The quality parameters, phenolic and fatty acid profiles were determined. Harvest time, olive variety and their interaction were the most significant factors. Malaxation temperature was significant for hydroxytyrosol, tyrosol, p-coumaric acid, pinoresinol and peroxide value. Early and mid-harvest oils had high hydroxytyrosol and tyrosol (maximum 20.7mg/kg) and pigment concentrations (maximum chlorophyll and carotenoids as 4.6mg/kg and 2.86mg/kg, respectively). Late harvest oils were characterized with high peroxide values (9.2–25meqO2/kg), stearic (2.4–3.1%) and linoleic acids (9.3–10.4%). Multivariate regression analysis showed that oxidative stability was affected positively by hydroxytyrosol, tyrosol and oleic acid and negatively by polyunsaturated fatty acids.

Changes in the Physicochemical and Nutritional Parameters of Picual and Arbequina Olive Oils during Frying

Deep fat frying is an important cooking process in Mediterranean countries. Olive oil is a very convenient fat to use for this culinary purpose. The chemical composition of olive oils differs from edible oils in terms of fatty acid and antioxidant compounds that gives olive oil its greater stability. The aim of this work was to describe the stability of Picual and Arbequina olive oil during deep frying of frozen potatoes in comparison with high oleic sunflower oil. Changes in different physicochemical and nutritional parameters were studied during frying. Picual olive oil had a higher stability in comparison with high oleic sunflower oil and Arbequina olive oil. Picual olive oil is very suitable for frying because it is able to undergo the greatest number of frying cycles without exceeding the limits allowed by regulations. This behavior is due to its phenolic content, the lower loss in tocopherol and better stability. Practical Applications The information gained from this research could be very appropriate for consumers and for the industry to know which variety of olive oil is more suitable for frying longer frying cycles without exceeding the limits allowed by regulation and remain in good quality.

Biochemical Characterization of Turkish Extra Virgin Olive Oils from Six Different Olive Varieties of Identical Growing Conditions

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

An Overview of the Authentication of Olive Tree and Oil

Abstract 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.

Determination of apolar and minor polar compounds and other chemical parameters for the discrimination of six different varieties of Tunisian extra-virgin olive oil cultivated in their traditional growing area

A study on the characterization of Tunisian extra-virgin olive oil varieties produced in their place of origin has been carried out. Due to the influence of the genotype and environmental, agronomic and technological factors on the chemical composition of olive oil and its quality, all the olives studied were collected on the same season, and the oil was obtained under the same processing technique. Several analyses were performed to characterize the different olive oils: free acidity, peroxide value, fatty acid composition, radical scavenging activity, Rancimat assay, pigments content and phenolic compounds by HPLC–MS. In order to evaluate all the results obtained (36 parameters for each variety), different statistical analyses were used to discriminate the extra-virgin olive oil varieties: one-way analysis of variance was performed to check significant differences among cultivars (p ≤ 0.05); PCA was applied to the data showing that variables such as oleic, linoleic, quinic and vanillic acids, apigenin, luteolin, taxifolin, oleuropein aglycon, pinoresinol acetate, elenolic acid and oxidative stability allowed discriminating among the different varieties of extra-virgin olive oil studied. Besides, LDA model was able to classify the samples depending on their geographical origin in Tunisia (North, Centre and South).

Olive oil stability under deep-frying conditions

The suitability of different commercial olive oil categories for domestic frying was investigated. Oil samples were taken every 3h of frying and evaluated for free acidity, peroxide and p-anisidine values, specific extinction coefficients, oxidative stability, fatty acids, vitamin E, β-carotene and total phenols, until the total polar compounds achieved the maximum legal value (25%). All olive oils were fried during more time than the commercial vegetable oil blend taken for comparison (from 24 to 27h, against 15h). The extra-virgin Protected Designation of Origin (PDO) olive oil was characterized by reduced levels of oxidation and hydrolysis, and superior amounts of minor antioxidant compounds. The “olive oil” commercial category behaves similarly, but “Cobrançosa” olive oils performance was slightly worse, and clearly different between years, highlighting the importance of blending different cultivars. The vegetable oil, despite containing significantly higher amounts of vitamin E, was highly susceptible to oxidation under frying conditions when compared to all olive oils.The results also show that the chemical composition of olive oils, particularly the amount of natural antioxidants, are important parameters in their predictive behavior along the frying process, but mostly that olive oil is clearly resistant to frying conditions, independently to the commercial category chosen.

Influence of chemical composition of olive oil on the development of volatile compounds during frying

In this study, 15 virgin olive oils from an industrial oil plant in the Abruzzo region were analyzed in terms of the volatile compounds responsible for the characteristic odor and olfactory perception of virgin olive oils and its modification upon frying (up to 60 min of heat treatment). Dynamic headspace–gas chromatography–mass spectrometry analysis was used to evaluate the volatile profile before and after each frying step and examine correlations with qualitative characteristic of oil (fatty acid composition, total phenolic compound content, tocopherols and pigments). The chemometric approach (genetic algorithms–partial least squares/multiple linear regression) developed for this study is a novel model for data treatment to select important variables in olive oil composition and understand their influence on spoilage during frying. An inverse correlation between oleic acid content and formation of toxic volatiles such as acrolein and crotonal during frying was demonstrated. Moreover, it was also observed that pigments such as chlorophylls, pheophytins, and carotenoids may prevent the formation of some aldehydes during frying.

Chemical composition of olive oils of the cultivar Colombaia

The chemical composition of monovarietal olive oils from the cultivar Colombaia was studied. Free acidity, peroxide value and UV absorbance attested to the good quality of the analyzed oils. Their fatty acid composition appeared to be quite different from the typical fatty acid profile of olive oils from Liguria but met the limits reported in the EC Regulations for olive oils. On the contrary, the amounts of Δ 7 -stigmastenol were often higher than the 0.5 % limit set by EC Regulations and total s-sitosterol was below the minimum 93 % limit. The composition of polar compounds and of the volatile fraction was representative of the peculiar organoleptic character of these oils. Thus, the anomalous sterol composition of the monovarietal oils from the cultivar Colombaia calls for blending with other oils. Moreover, the use of these oils for the production of PDO oils “Riviera Ligure” must also be carefully controlled because it changes their nutritional and sensorial features

Influence of extraction system, production year and area on Cornicabra virgin olive oil: a study of five crop seasons

This paper describes a study of the influence of the extraction system, crop season and production area on the chemical composition and quality of Cornicabra virgin olive oils ( n=152) from five successive crop seasons (from 1994/1995 to 1998/1999). Analysis of the effect of the extraction system (dual-phase, triple-phase decanters and pressure) on the values of analytical determinations, revealed statistically significant differences ( P⩽0.05) in a few parameters only, mainly in antioxidant content (total phenols and α-tocopherol) and oxidative stability. All quality indices and major fatty acid and sterol compositions presented significant statistical differences ( P⩽0.001) with respect to the year of production, with the exception of total phenols. The crop season is therefore a critical variable, since the chemical composition of the olive oil may vary considerably from one year to the next. Many of the analytical parameters varied among the five production areas considered, in the provinces of Toledo and Ciudad Real. The results appear to confirm the general consensus on the quality of Cornicabra virgin olive oils from Castilla-La Mancha, namely that oils from mills located in the south and southeast of the province of Toledo are generally of higher quality.