Evaluation of potential and real quality of virgin olive oil from the designation of origin “Aceite Campo de Montiel” (Ciudad Real,Spain)

The potential and real qualities of virgin olive oils from the DO “Aceite Campo de Montiel” were evaluated. The regulated physicochemical and sensory parameters, the stability parameters and the fatty acid, sterol and triterpenic dialcohol compositions were analysed. The results of the regulated parameters in the potential quality study classified all the analysed oils into the “extra virgin” category. The varieties Picual and Cornicabra showed remarkably high stability, due to their high tocopherol and total polyphenol contents. Oleic and linoleic acids were the most useful fatty acids used to discriminate the predominant varieties, Picual and Cornicabra, from the others. The variety Cornicabra stood out due to its high campesterol content, Arbequina due to its low β-sitosterol content and high 24-methylenecholesterol, Δ5-avenasterol, Δ7-stigmastenol and total sterol contents, and Picual for its high sitostanol content. All the analysed samples in the real quality study were classified in the “extra virgin” category according to the regulated physicochemical parameters, but only 69% of them qualified if the sensory parameters were also taken into account. The predominance of the varieties Picual and Cornicabra in the study area was mainly responsible for the high oil stability and reflects the fatty acid and sterol compositions of the oils from the oil mills in the potential quality study.     

Changes in the oxidative state of extra virgin olive oil used in baked Italian focaccia topped with different ingredients

Four different types of “focaccia” (Italian flat bread) prepared with the same dough and the same extra virgin olive oil but with different seasonings, were analyzed. Lipids were extracted from each sample using the Folch method. The indices commonly used to assess oil quality, the amounts of trans fatty acids and compounds of triglyceride polymerization, oxidation and hydrolysis, were determined in all the samples to better assess the degree of oxidation and hydrolysis of the oils. The findings showed that, once baked, the oil sampled from the different types of focaccias could not be included in the virgin category. The level of oxidation of the baked samples was greater than that in the uncooked oil. However the results obtained showed that the level of degradation of the extracted oils was lower than that found in edible refined oils and it seemed to be influenced by the topping used to flavour the focaccias.     

鲜榨山茶油与特级初榨橄榄油营养价值的比较

以鲜榨山茶油和特级初榨橄榄油为研究对象,对其理化指标、脂肪酸组成和营养成分进行测定并比较。结果表明:鲜榨山茶油在理化指标上与特级初榨橄榄油相当,脂肪酸组成与特级初榨橄榄油相似,但油酸含量高于特级初榨橄榄油,棕榈酸和硬脂酸含量低于特级初榨橄榄油;在维生素E、角鲨烯、植物甾醇等天然生物活性物质方面媲美特级初榨橄榄油。     

Characterization of several hazelnut (Corylus avellana L.) cultivars based in chemical, fatty acid and sterol composition

Nineteen cultivars of hazelnuts (Corylus avellana L.) collected during the 2001 crop, from Vila Real, Portugal, were analysed for chemical composition, including moisture, total oil content, crude protein, ash, carbohydrates and nutritional value. Fat was the predominant component, ranging from 59.3 to 69.0%. Total oil was extracted and analysed for fatty acid and sterol compositions and oxidative stability. Fatty acid and sterol compositions were determined by Gas–Liquid Chromatography coupled to a Flame Ionisation Detector (GLC/FID). Monounsaturated fatty acids, particularly oleic acid, were predominant (78.7–84.6%). Total phytosterol content ranged from 133.8 to 263.0 mg/100 g of oil. Among the nine sterols identified and quantified, β-sitosterol was the major one with a mean percentage of 83.6%, while Δ⁵-avenasterol and campesterol were the second and the third components of the group with mean values of 6.1 and 5.8%, respectively. Since hazelnut oil can be used in olive oil adulteration, the values obtained were compared with published mean values of olive oils from different geographical origins.     

橄榄油市场行情及其与其他植物油的脂肪酸组成和微量营养成分比较

旨在更全面、深入地了解橄榄油,对2010—2021年世界橄榄油的产量和消费量以及2015—2019年中国橄榄油的进口量进行了统计分析,测定不同品牌和不同等级市售橄榄油(特级初榨橄榄油、混合橄榄油和混合油橄榄果渣油)与9种其他植物油的脂肪酸组成和微量营养成分,并分析比较其差异。结果显示：世界橄榄油的产量和消费量常年维持在300万t左右,其中欧盟占比最大,分别为58.71%～76.68%和48.73%～62.15%;2015—2019年中国橄榄油产量仅在0.5万～0.7万t,而消费量和进口量分别达到了3.9万～5.75万t和3.86万～5.37万t;不同品牌和不同等级市售橄榄油的脂肪酸组成整体差异不大,但微量营养成分存在明显差异,其中特级初榨橄榄油的角鲨烯、多酚含量明显高于混合橄榄油和混合油橄榄果渣油,而混合油橄榄果渣油的甾醇和总生育酚含量最高;与一级菜籽油、一级玉米油、一级葵花籽油、一级大豆油和亚麻籽油等其他植物油比较,特级初榨橄榄油的油酸、角鲨烯和多酚含量最高,而甾醇和总生育酚含量偏低。     

Evaluation of oxidative stability of sweet and bitter almond oils under accelerated storage conditions

This study aimed to investigate the oxidative stability of cold-pressed bitter and sweet almond oil under accelerated aging conditions. The oxidative stability of both oils was analyzed using as physicochemical metrics: fatty acid (FA) composition, sterol content, chlorophyll and carotenoid level, tocopherol level, iodine index, free fatty acid, Peroxide value and specific extinction coefficients K232–K270. The variations of these parameters were evaluated over four weeks at 60 °C. The results showed that carotenoid, total sterol, and tocopherol levels were decreased, the free fatty acid, Peroxide value, K232 and K270 parameters increased slightly for both oils, while, FA profiles and Iodine value did not significantly vary over four weeks. After four weeks, sweet almond cold-pressed oil still presents an excellent physicochemical profile. Bitter almond oil presents after the same delay much less satisfactory properties.     

Effect of storage on refined and husk olive oils composition: Stabilization by addition of natural antioxidants from Chemlali olive leaves

Two samples of refined olive and husk oils have been analysed in order to evaluate the influence of storage time on their quality. The following parameters were determined: peroxide values, absorption coefficients K270 and K232, Rancimat induction time, sterols and fatty acid contents. Six months storage at 50 °C in the dark revealed a loss in oil stability. This finding was reflected by the greater increase in peroxide value and a decrease of Rancimat induction time and sterol content. The enrichment of refined olive and husk oils with olive leaves and its hydrolysate extract resulted in an appreciable resistance to oxidative deterioration due to its phenolic antioxidants content. Oleuropein and hydroxytyrosol were the major compounds in Chemlali olive leaves extract and hydrolysate solution, respectively. The antiradical activity of leaves extract as well as its hydrolysate solution was evaluated and compared to that of the BHT. The antioxidant activity of the enriched refined olive and husk oils with leaves and hydrolysate extracts at 400 ppm showed that the latter had the highest protective effect against oil oxidation. Oils with added hydrolysate extract had the lower peroxide value and the higher stability measured with a Rancimat method. After six months of storage the induction time increased from 23.3 to 83.5 h for refined olive oil and from 16.6 to 49 h for husk oil. Furthermore, during oil storage, there was no significant variation in fatty acid composition. However, the total sterol concentration of the oils treated with hydrolysate extract increased. The results suggested that hydrolysate and leaves extracts are excellent antioxidants and can serve as substitutes for synthetic antioxidants.     

Lipid oxidation-related characteristics of gim bugak (Korean fried cuisine with <Emphasis Type="Italic">Porphyra</Emphasis>) affected by frying oil

The effect of frying oil on the lipid oxidation, antioxidants, and in vitro antioxidant activity of gim bugak was studied. Bugak was prepared by pan-frying at 180 °C in unroasted sesame, soybean, extra virgin olive, or palm oil. The degree of lipid oxidation based on conjugated dienoic acid and p-anisidine values was higher in the bugak fried in soybean or sesame oil with high contents of polyunsaturated fatty acids and tocopherols. However, the oil oxidation was lower in olive and palm oils, which showed higher degradation of tocopherols and polyphenols than in sesame or soybean oil during frying. Although the bugak fried in palm oil contained less antioxidants than that fried in soybean or sesame oil, the in vitro antioxidant activity was not different (p > 0.05). Results suggest that palm oil can replace unroasted sesame oil for the preparation of gim bugak with improved lipid oxidative stability and health functionality.     

Fatty Acids,Sterols, Polyphenols,and Chlorophylls of Olive Oils Obtained from Tunisian Wild Olive Trees (Olea europaea L. Var. Sylvestris)

Olive (Olea europaea L.) includes cultivated olive trees (var. europaea) and wild olive trees or oleaster (var. sylvestris) as two botanical varieties. These olive varieties were widely spread in the Mediterranean Region. The aim of this study was to determine fatty acid compositions, sterols, polyphenols, and chlorophylls of oils obtained from 12 wild olive trees from Northern Tunisia. Two dominated oil cultivars in Tunisia (Chétoui and Chemlali) were also used to compare results. The fatty acid methyl ester and the sterol compositions were analyzed using gas-liquid chromatography and thin layer chromatography methods, respectively. The polyphenols and chlorophylls were determined using the calorimetrical method. Results indicated that oils extracted from wild olives displayed good balanced fatty acid compositions, sterols, polyphenols, and chlorophylls. Qualitatively, for wild and cultivated olive oils, the oil has an identical composition, whereas the quantitative variation showed that some wild trees seem to be interesting oil sources as two Tunisian dominated cultivars. The highest oleic acid and polyphenol contents were 71.55% and 537.6 mg/kg of oil found in wild olives (OIch2, OIch1). The β-sitosterol was the major sterolic fraction and ranged from 84.72 to 75.70% according to the wild olives. Consequently, wild olives would be a new future edible olive oil source, as well as commonly cultivated ones.     

Characteristics of olive fruits and extra‐virgin olive oils obtained from olive trees growing in Appellation of Controlled Origin ‘Sierra Mágina’

Olives and olive oils from Appellation of Controlled Origin (ACO) ‘Sierra Mágina’ have been analysed during the 1997/98 harvest. The territory of this ACO has been subdivided into four zones of different characteristics. The olives were harvested on two occasions (November 1997 and January 1998). Various parameters were analysed, such as the ripening index, the average volume, the average weight of 100 olives and 100 stones, the pulp/stone ratio, the industrial yield, etc. From these olives, olive oils were extracted using an Abencor system, and the free acidity, the peroxide index, the coefficients K₂₇₀ and K₂₃₂ and the fatty acid composition were determined. The analysis of the results obtained, as well as principal component analysis, demonstrates a marked variability in the fruits, but the corresponding olive oils show fairly homogeneous compositions that are difficult to distinguish by sensory analysis. The olive oils from this ACO are extra‐virgin olive oils characterised by low acidity, a high content of oleic acid and a high ratio of unsaturated to saturated fatty acids. The most important sensory attributes are fruity, woody‐fig, green, bitter and pungent. Copyright © 2003 Society of Chemical Industry     

Quality assessment of edible vegetable oils used as liquid medium in canned tuna

An experimental investigation was conducted to assess the quality of vegetable oils used as liquid medium in preserved fish. Sixteen tuna preserves were tested, including two in extra virgin olive oil, nine in olive oil (refined olive oil plus virgin olive oil) and five in refined seed oil. Next to the traditional routine analyses prescribed by the EEC Regulation N° 2568/91 (useful for a preliminary characterisation of oils used as liquid medium), the content of trans isomers of unsaturated fatty acids was determined and the analysis of polar compounds was performed by HPSEC (high performance size-exclusion chromatography). The acid composition showed the presence of highly unsaturated fatty acids, typical of fish lipids. Trans isomers were always absent in extra virgin olive oils, whereas they were always present in olive oils and in refined seed oils. Triglyceride oligopolymers, oxidised triglycerides and diglycerides, measured by means of the HPSEC analysis of polar compounds, ranged within 0.13-1.07%, 0.51-2.36% and 0.96-4.02%, respectively. The HPSEC analysis of polar compounds and the determination of trans isomers enabled better assessment of the quality of different types of oils used as liquid medium for canned tuna.     

Analytical evaluation of two monovarietal virgin olive oils cultivated in the south of Tunisia: Jemri‐Bouchouka and Chemlali‐Tataouin cultivars

BACKGROUND: The characterisation of virgin olive oils from two Tunisian cultivars, growing in the Tataouin zone, namely Jemri‐Bouchouka, a rare olive cultivar, and Chemlali‐Tataouin, was carried out. Several analytical parameters were evaluated; these include quality index, fatty acids, phenolic, chlorophyll, carotenoid, squalene, α‐tocopherol compositions and oxidative stability. RESULTS: Jemri‐Bouchouka olive oil had the highest value of oleic acid (74.50%) while Chemlali‐Tataouin was characterised by a high percentage of palmitic acid (14.75%), which makes this oil freeze at a low temperature. On the other hand, Jemri‐Bouchouka oil was characterised by a low phenolic and α‐tocopherol content (267.72 mg GAE kg^?1 and 278.34 mg kg^?1, respectively). Ten phenolic compounds were identified. The main phenols found in the two olive oils were oleuropein aglycon and pinoresinol. All phenolic compounds showed significant correlations with oxidative stability. CONCLUSION: The analytical parameters of virgin olive oil that were determined in this study were greatly influenced by cultivar. © 2012 Society of Chemical Industry     

NMR and statistical study of olive oils from Lazio: A geographical,ecological and agronomic characterization

NMR and statistical procedures were used to analyse olive oils obtained from trees grown in different areas of Lazio, an Italian region, under different irrigation conditions. In order to obtain information on “real” commercial olive oils and to study the effects of some agronomical and ecological factors on the olive oil composition, we studied commercial multi-varietal olive oils, all produced in well-characterized areas of Lazio. ¹H and ¹³C NMR techniques, coupled to a suitable multivariate statistical procedure, were used to analyse 72 multi-varietal extra virgin and PDO (Protected Denomination of Origin) olive oils harvested in 2003, from the northern area, the centre and the southern area of Lazio. The intensity of selected ¹H and ¹³C NMR variables were submitted to three different statistical methods, namely, analysis of variance (ANOVA), principal component analysis (PCA) and linear discriminant analysis (LDA). ¹H and ¹³C NMR spectroscopy allowed us to obtain a good chemical characterization of the samples, giving information on major and minor compounds with an experimental error exactly the same and always extremely low for all the analyzed components. As a result of the statistical analysis, olive oils from the same geographical areas were well grouped. Since the amounts of some minor volatile components, such as aldehydes, terpenes and squalene, as well as, the content of β-sitosterol, the most important sterol present in olive oils, are sensitive to the pedoclimatic conditions, the intensity of the corresponding NMR signals turned out to be the most discriminating factors in the geographic classification. Moreover, the NMR and statistical protocol allowed us to investigate the roles of irrigation and altitude on the olive oil composition: the contents of oleic and saturated fatty acids turned out to be strongly influenced by the irrigation practice, whereas the content of volatile compounds was sensitive to the altitude of the olive trees. As a result of our study, olive oils were well grouped according to the irrigation practice as well as to the altitude at which olive trees were grown.     

CHEMICAL AND PHYSICOCHEMICAL CHARACTERISTICS OF PECAN (CARYA ILLINOENSIS) OIL NATIVE OF THE CENTRAL REGION OF MEXICO

The pecan ( Carya illinoensis ) kernels and oils from twenty-two different native trees of the central region of Mexico were evaluated through chemical and physicochemical parameters. The main constituent of the kernels was a high lipid content (70–79% wt/wt d. b.) with a large proportion of oleic acid (55–75% wt/wt). The concentration of α-, γ-, and δ-tocopherols in the oils extracted from Mexican native pecans, was substantially higher than those in the varieties commonly reported in the literature (i.e., Stuart, Desirable and Schley). However, the fatty acid and tocopherol composition of the pecan oil did not fully explain the high oxidative stability (OSI values from 8.5 to 10.8 h at 110C) observed in some oils, which might indicate the presence of some other natural antioxidants with activity at 110C. In general, the oxidative stability, the melting and crystallization properties, and the viscosity of pecan oils were similar or superior to those of extra-virgin olive oil and unrefined sesame oil. The results obtained indicated how oleic, linoleic, and linolenic acids are biosynthetically interrelated in vegetable tissues. The relationships among the concentrations of these fatty acids determined     

Olive oil traceability by means of chemical and sensory analyses: A comparison with SSR biomolecular profiles

The relationship between genetic diversity and phenotype in olive, instrumental to improve the efficacy of olive clonal selection, is still far from being fully understood. This work reports on a comparison made between plant SSR genetic data and quality of monovarietal olive oils. Nine monovarietal oils produced by selected genotypes were characterised under chemical and sensory profiles. Fatty acid compositions were determined to evaluate quantitative differences among oils; some fatty acids are actually highly correlated with the genetic matrix, and PCA of fatty acids composition explains 85.53% variability. Moreover some oils characterised by high levels of oleic acid appeared interesting from a nutritional standpoint. Organoleptic profiles evidenced differences especially for the attributes defined as “pleasant flavours”; oils obtained by different genetic matrices were characterised by different flavour intensities of tomato or artichoke, almond or aromatic herbs, correspondence analysis among sensory pleasant attributes and olive oil samples explaining 91.68% variability.     

Physicochemical properties and oxidative stabilities of mealworm (<Emphasis Type="Italic">Tenebrio molitor</Emphasis>) oils under different roasting conditions

Physicochemical properties and oxidative stabilities of mealworm (Tenebrio molitor) oils under different roasting conditions were investigated. Oils were extracted using n-hexane from mealworms roasted at 200°C for 0, 5, 10, and 15 min and physicochemical properties and oxidative stabilities of oils were analyzed. Roasting increased the color intensity and the oleic acid and δ-tocopherol contents, but decreased linoleic acid, and α- and γ-tocopherol contents. An improvement in oxidative stability was observed in roasted mealworm oils, demonstrated by induction time and peroxide values. Mealworm oil contained abundant essential fatty acids and exhibited a superior oxidative stability.     

Healthier oils stabilized in konjac matrix as fat replacers in n − 3 PUFA enriched frankfurters

Nutritional, sensory and technological properties of frankfurters as affected by reformulation processes designed to reduce fat content and improve fatty acid profile were investigated. Healthier oils stabilized in oil in water emulsion or in konjac matrix gel were used as fat replacers. Results showed that improved fat content by the replacement of pork backfat with konjac gel and by the addition of healthier oils stabilized by various different systems, both resulted in products with very similar characteristics. From a nutritional standpoint, reformulated frankfurters with konjac gel and/or added a healthier oil combination may claim “reduced fat content” and/or “high omega 3 fatty acid content” according to European Regulation, since they could contain less than 30% of the fat in the reference product and more than 0.6 g of ALA/100 g and more than 80 mg of the sum of EPA plus DHA per 100 g, respectively. Chill storage over 40 days generally had little effect on the technological characteristics of frankfurters.     

The effects of genotype and extraction methods on chemical composition of virgin olive oils from Traslasierra Valley (Córdoba,Argentina)

This work was carried out to assess the influence of two extration methods (two-phase centrifugation and pressure) on oil quality from four olive varieties cultivated at Traslasierra Valley, Córdoba, Argentina. Analysis of the effect of the extraction system, on the values of analytical determinations, revealed statistically significant differences in some parameters, mainly in free fatty acid and phenol contents, and K₂₇₀ values. Oxidative stability showed a significant positive correlation with phenol content. Most of the quality indices and fatty acid compositions showed significant variations among olive varieties. Nevadillo variety had the highest values of oleic acid, whereas Manzanilla was noteworthy for its higher content of phenolic compounds. Accordingly, pressure-extracted oil from the Manzanilla variety presented better oxidative stability.     

Distribution of simple phenols,phenolic acids and flavonoids in Turkish monovarietal extra virgin olive oils for two harvest years

Monovarietal extra virgin olive oils extracted from six dominant and economically important Turkish olive cultivars (memecik, erkence, domat, nizip-yaglik, gemlik, ayvalik) were examined for their simple phenolics, phenolic acids and flavonoid compounds over 2005 and 2006 harvest years. Total phenol contents, oxidative stabilities and chromatic ordinates as colour parameters were also measured. The most typical phenolic compounds that were identified in both years are hydroxytyrosol, tyrosol, vanillic acid, p-coumaric acid, cinnamic acid, luteolin, and apigenin. Multivariate data were analysed by principal component and partial least square-discriminant analyses. It was observed that phenolic profiles of olive oils depended highly on harvest season. In addition, oils of different olive cultivars have different distribution of phenols. No significant correlation was observed between oxidative stability and phenolic compounds. Increase in peroxide value over an accelerated oxidation period of 11 days showed weak correlations with total phenol content, vanillin, syringic acid and colour parameter a^∗, as 0.56, 0.55, −0.42, and 0.51, respectively, in terms of correlation coefficient r.     

Influence of the different oils used in dough formulation on the lipid fraction of taralli

Abstract: An experimental investigation was carried out to evaluate the quality of taralli as a function of the type of oil used in their dough formulation. To this end, 4 types of oil (extra virgin olive oil, olive oil, olive‐pomace oil, and refined palm oil) were utilized to prepare taralli to investigate on the lipid fraction degradation and evaluate the taralli acceptability by consumers. The data obtained pointed out that taralli manufactured with extra virgin olive oil were significantly more appreciated than those made with refined oils due to their visual appearance and odor. Moreover, with respect to the other kinds of oil, the use of extra virgin olive oil led to significantly lower values (P < 0.05) of specific absorption at 232 and 270 nm (K₂₃₂ and K₂₇₀, respectively) and of triacylglycerol oligopolymers. It also proved to present a much lower content in oxidized triacylglycerols and diacylglycerols than olive‐pomace oil and refined palm oil, respectively. Furthermore, trans fatty acid isomers were absent in taralli made with extra virgin olive oil but were constantly present in those produced with refined oils.