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Variability of vitamin E in virgin olive oil by agronomical and genetic factors
Abstract
In this work the effect of genetic and agronomic factors on virgin olive oil tocopherol content and composition has been studied. For genetic effect, olive oil from thirty olive cultivars has been analyzed; for agronomic factor evaluation, three olive cultivars have been monitored during fruit ripening for three consecutive crop years. Total tocopherol content has ranged between 84 and 463 mg/kg, α-tocopherol represented more than 95%, β-tocopherol was found at very low concentrations whereas γ-tocopherol varied from 1 to 29 mg/kg. Tocopherols in virgin olive oil have a significant genetic component. Variability by crop year was due to the rainfall levels, and oils from the drier crop year (1998/99) showed the highest tocopherol content. However, this effect was cultivar-dependent, with ‘Hojiblanca’ cultivar the most affected. In general, tocopherols decreased during the ripening process, and although γ-tocopherol showed an increase for the last harvesting dates, this trend was related to the chlorophyll losses in the oil.
... Numerous studies have investigated the influence of climate conditions on the chemical properties of olive oils [12][13][14][15][16][17]. The composition of olive oil primarily consists of triglycerides, other glycerol esters, and some free fatty acids, accounting for approximately 99% of the oil's content. ...
... However, a significant difference related to the crop year (p-value < 0.05) was observed for β-tocopherol, which increased from 1.3 to 2.0 mg/kg; that is, 68% of the plants under study increased the content of this compound in the second year (Table S2). Although no significant differences in α-tocopherol were observed in the present study, there are several authors who report that there are certain factors that affect the amount of this vitamer, namely the maturation of the fruit influences the amount, decreasing during ripening [17], the cultivar [13], low temperatures, and precipitation also influence the amount of vitamer (less precipitation, higher content) [47]. Table 2. Tocopherols (α-, β-, and γ-) and total vitamin E mass contents (mean ± standard deviation, mg/kg of olive oil) for olive oils extracted from olives of centenarian olive trees located in the Côa Valley (Portugal), for two consecutive crop years (2020 and 2021), and respective variation with crop-year (∆, in %). ...
... The average concentration of vitamin E in the oils was 260 mg/kg, with a maximum value of 369 mg/kg ( Table 2). These findings align with the existing literature on olive oils, where vitamin E concentrations typically range from 80 to 500 mg/kg [17], and βtocopherol concentrations typically vary from 1 to 2 mg/kg, consistent with previous studies [34]. ...
In recent years, occurrences of heat waves and drought have become increasingly frequent, highlighting the undeniable impact of climate change. The rise in temperatures and decline in rainfall have had severe repercussions on olive trees’ behavior and olive oil production. This study aims to evaluate the effects of two-year climate variations on olive oils from centenarian olive trees situated in the Côa Valley region of Northern Portugal. A selection of 25 centenarian plants was made, and the climate influence on fatty acid content, tocopherols, individual phenols, oxidative stability, and antioxidant activity was assessed over two consecutive years. During the second year of the study, a significant variation (p-value < 0.05) in the proportion of palmitic acid was observed, which increased from 12.9% to 13.6%. Conversely, stearic and arachidic acids exhibited a decrease from 2.7% to 2.3% and from 0.37% to 0.35%, respectively. Analysis of the oils revealed a noteworthy difference (p-value < 0.05) in the concentration of β-tocopherol. The concentration of oils derived from hydroxytyrosol and tyrosol significantly decreases (p-value < 0.005) during the second year. Additionally, significant differences (p-value < 0.005) were observed in the total phenol content and the percentage of ABTS inhibition, both of which decreased in the second year. These findings reinforce the notion that climatic conditions play a key role in shaping the composition of olive oils.
... Another factor that affected the contents of tocopherols was geographical region. Other authors have also widely recognized it (Beltrán et al., 2010). The variation in temperature, rainfall and altitude may explain the influence of geographical regions (Beltrán et al., 2010). ...
... Other authors have also widely recognized it (Beltrán et al., 2010). The variation in temperature, rainfall and altitude may explain the influence of geographical regions (Beltrán et al., 2010). A drier climate may lead to higher content of tocopherols (Aguilera, Beltrán, Ortega, Fernández, Jiménez, & Uceda, 2005). ...
... However, the impact was cultivar-dependent. Thus, the effect extent of climate conditions on tocopherol content was controversial (Beltrán et al., 2010). According to the results reported in the literature, α-tocopherol varies by up to 300 mg/kg while β-, γ-, and δ-tocopherols vary from trace to 25 mg/kg (Ballus et al., 2014). ...
China has become increasingly interested in producing olive oil in recent years. In this study, we determined the characteristics of virgin olive oil in five typical cultivars (cv. 'Arbequina,' 'Coratina,' 'Ezhi 8,' 'Frantoio,' and 'Koroneiki') from two of the most suitable production areas for olive cultivation in China. In addition, linear discriminant analysis (LDA) was used to differentiate oils originating from various cultivars and geographical origins. Heatmap was also constructed to describe the differences straightly. Compared to Xichang oils, Longnan oils generally contained higher levels of C18:0, lignans, total esters and total furans, and lower levels of phenolic acids and phenolic alcohols. A variety of cultivars differed in total sterols, hydroxytyrosol derivatives, and volatile compounds. Coratina oils showed excellent properties in two regions. Our findings are closely related to select the optimum olive cultivars in different regions to promote the development of Chinese olive industry scientifically.
... Monovarietal VOO may be further connected to the origin of production, thus establishing products with specificity of origin linked to their typicity of distinctive sensory, nutritional and health promoting properties. Physicochemical and sensory profiling of monovarietal VOOs from major oil cultivars have been performed both in their country of origin, such as Greece (Mousa et al., 1996), Italy (Pacetti et al., 2020), Israel (Dag et al., 2013), Lebanon (El Riachy et al., 2019), Portugal (Peres et al., 2016), Spain (Matos et al., 2007;Gómez-Rico et al., 2008) and Tunisia (Baccouri et al., 2008), as well as in countries foreign to their origin (Beltrán et al., 2010;Dabbou et al., 2010;Dag et al., 2013;El Riachy et al., 2019;Wang et al., 2021). Minor, autochthonous olive cultivars lately attract mounting interest due to their excellent adaptation to traditional olive cultivation regions and their role in mitigating genetic erosion (Jiménez et al., 2013;Rotondi et al., 2017;Trentacoste et al., 2020). ...
... Total tocopherol (TTC) content and α-tocopherol content of monovarietal Cypriot VOOs was moderate to high compared to reported values for Italian (Pacetti et al., 2020) and Turkish (Özcan et al., 2019) monovarietal as well as multi-varietal VOOs (Beltrán et al., 2010). Significant differences were registered however between Cypriot VOOs with TTC being notably higher in 'Korakou' and 'Kato Drys' than 'Ladoelia'. ...
... Significant differences were registered however between Cypriot VOOs with TTC being notably higher in 'Korakou' and 'Kato Drys' than 'Ladoelia'. Moreover, although the TTC, α-, β-and γ-tocopherol concentrations declined in all VOOs with maturity, the rates of decline differed among cultivars, corroborating previous researchers (Beltrán et al., 2010). The outstanding TTC of 'Korakou' in early maturity (385 mg kg − 1 ) is remarkable but so is its sharp decrease (45 %) by late maturity. ...
Agricultural water demand in the Mediterranean region is expected to increase due to climate change. The application of deficit irrigation practices may improve the efficiency of water use in orchards, by accounting for changes in environmental conditions and in the tree growth. The main goal of this study was to improve our understanding on the effect of deficit irrigation on physiology, morphology, yield, and oil quality of ‘Koroneiki’ olive trees. The effect of two deficit irrigation treatments and three harvest dates on olive yield and oil quality were investigated in a 17-year old, low-density ‘Koroneiki’ orchard in Cyprus, during a high crop load year. For the sustained deficit irrigation (SDI) treatment 70% ETc was applied over the irrigated period, while the regulated deficit irrigation (RDI) consisted of 70% ETc during water-stress sensitive growth stages (shoot growth, flowering, bud initiation) and 35% ETc during water-stress tolerant growth stages (pit hardening, oil accumulation). Environmental conditions and volumetric soil water content of the 70-cm rootzone were monitored. A Kc of 0.37 was derived for the irrigated period from daily water balance computations, excluding rain days. No significant effects of the two irrigation treatments were found on morphology, physiology, fruit yield and oil quality. Midday stem water potential reached − 4 MPa in September as a result of increasing fruit load. Leaf conductance ranged between 65 and 228 mmol m⁻²s⁻¹, with highest values obtained under high soil water conditions and a vapour pressure deficit of 3.6 kPa. Yields were approximately 9 tons ha⁻¹ in both irrigation treatments while water productivity was 1.4 and 1.0 kg oil m⁻³ irrigation water in SDI and RDI, respectively. Maximum phenolic content was found in early December, reaching on average 202 mg kg⁻¹ oil in both irrigation treatments. Overall, irrigation water use in RDI was 32% less than in SDI, whereas oil quality was only affected by the harvest date.
... Monovarietal VOO may be further connected to the origin of production, thus establishing products with specificity of origin linked to their typicity of distinctive sensory, nutritional and health promoting properties. Physicochemical and sensory profiling of monovarietal VOOs from major oil cultivars have been performed both in their country of origin, such as Greece (Mousa et al., 1996), Italy (Pacetti et al., 2020), Israel (Dag et al., 2013), Lebanon (El Riachy et al., 2019), Portugal (Peres et al., 2016), Spain (Matos et al., 2007;Gómez-Rico et al., 2008) and Tunisia (Baccouri et al., 2008), as well as in countries foreign to their origin (Beltrán et al., 2010;Dabbou et al., 2010;Dag et al., 2013;El Riachy et al., 2019;Wang et al., 2021). Minor, autochthonous olive cultivars lately attract mounting interest due to their excellent adaptation to traditional olive cultivation regions and their role in mitigating genetic erosion (Jiménez et al., 2013;Rotondi et al., 2017;Trentacoste et al., 2020). ...
... Total tocopherol (TTC) content and α-tocopherol content of monovarietal Cypriot VOOs was moderate to high compared to reported values for Italian (Pacetti et al., 2020) and Turkish (Özcan et al., 2019) monovarietal as well as multi-varietal VOOs (Beltrán et al., 2010). Significant differences were registered however between Cypriot VOOs with TTC being notably higher in 'Korakou' and 'Kato Drys' than 'Ladoelia'. ...
... Significant differences were registered however between Cypriot VOOs with TTC being notably higher in 'Korakou' and 'Kato Drys' than 'Ladoelia'. Moreover, although the TTC, α-, β-and γ-tocopherol concentrations declined in all VOOs with maturity, the rates of decline differed among cultivars, corroborating previous researchers (Beltrán et al., 2010). The outstanding TTC of 'Korakou' in early maturity (385 mg kg − 1 ) is remarkable but so is its sharp decrease (45 %) by late maturity. ...
Oil content, extractability, chemical composition and oxidative stability of three monovarietal (‘Ladoelia’, ‘Kato
Drys’ and ‘Korakou’) virgin olive oils (VOOs) were examined at progressive stages of fruit maturity. Oxidative
stability was assessed on a Rancimat System, phenols and tocopherols by HPLC-DAD and fatty acid (FA) profiles
by GC-FID. Oil extractability was highly cultivar-specific and unaffected by maturity stage. ‘Ladoelia’ exhibited
excellent extractability and satisfactory VOO composition and oxidative stability, with moderate phenolic and
diverse tocopherol content. ‘Kato Drys’ was rich in monounsaturated FA that imparted superior oxidative stability
and poor in polyunsaturated and saturated FA. Monovarietal VOOs exhibited higher correlation of
oxidative stability with the C18:1/C18:2 ratio (r = 0.80, p < 0.0001) than with the total phenolic content (TPC; r
= 0.436, p < 0.05), suggesting that phenolic association with oxidative stability might be specific to individual
phenolic compounds than to TPC. Late harvest of ‘Ladoelia’ and ‘Kato Drys’ was liable to drastic rise in free
acidity. Poor extractability, low oil and oleic acid contents undermined the suitability of ‘Korakou’ for VOO
production. The current findings contribute towards the establishment of typicity for monovarietal VOOs.
... Moncorvo and Vila Nova de Foz Côa). The tocopherol profile was similarly to that of olive oil, with α-tocopherol representing more than 90% of the total tocopherol content [33]. The amounts quantified in the present work were much higher than those observed for oleaster oil from Algeria, which varied from 87 to 182 mg/kg of oil [7] and Turkey, with values lower than 40 mg/kg of oil [34] but were of the same order of magnitude of those reported by Baccouri [27], for seven populations from Tunisia (309.5-781.8 ...
... When comparing the results obtained in Table 3, for oleaster oils, with similar studies with olive oils obtained from cultivated varieties, it can be concluded that the oils from the studied oleaster samples presented, in general, higher values of α-, βand γ-tocopherol contents, than the traditional ones (12.2-630 mg/k of olive oil) [33,35]. Additionally, the amounts of γ-tocopherol observed in the present work were much higher, in some cases of five orders of magnitude, compared to those reported for varietal olive oils and also for oleaster oils from other regions. ...
... These differences could be attributed to genetic factors. In fact, Beltrán [33] and Baccouri [28] concluded that tocopherols are genetically regulated and are highly cultivar-dependent. Tocopherols play important roles, acting as antioxidants, and therefore protecting lipids in human body and stored oils from oxidation and, in this sense, oleaster oils could be foreseen as important sources of these bioactive compounds, with high oxidative stability. ...
Oleaster (Olea europaea var. sylvestris), or the wild olive tree, has great interest as a source of genetic material for olive breeding programs. Nevertheless, information about its oil composition is scarce. In the present work, the characterization of oleaster fruit morphology and oil chemical composition from three different tree populations in Northeastern Portugal (Moncorvo, Alijó and Vila Nova de Foz Côa) was performed. The three studied populations presented some morphological differences in the fruits, but similar oil chemical composition. Oleic acid (68.9–70.6%) was the most abundant fatty acid. High variability was observed in total tocopherol content, ranging between 263 and 503 mg/kg. Additionally, high amounts of total sterols were found, from 1742 to 2198 mg/kg of oil. A rich composition in phenols was found with 14 phenolic compounds identified. The evaluated parameters for oleander oils allowed discriminating the oils according to the geographical origin and were consistent with those commonly found in olive oil, showing that they are particularly rich in antioxidants and can be exploited in breeding programs to increase the amounts of bioactive compounds in cultivated oils.
... Natural olive oil is regarded as among the healthiest foods owing to its unsaturated fatty acids, phenolic compounds, phytosterols, and carotenoids (Beltrán et al., 2010;Uylaşer & Yildiz, 2014;Mailer & Gafner, 2020). Olive oil phenolics are composed of phenolic compounds with secoiridoid structures and tocopherols (Pérez et al., 2019). ...
... Particularly α-tocopherol is the most prevalent form of Vitamin E found in human blood and tissues more than 95% of the total tocopherol content. Natural olive oils contain tocopherols in a wide range of 50-1410 mg/kg which is higher than other vegetable oils (Boskou, 2009;Beltrán et al., 2010;Pérez et al., 2019). Vitamin E compounds are well-known for their potential to limit lipid peroxidation in cell membranes and scavenge reactive oxygen species, thus to protect tissues from subsequent oxidative damage (Schneider, 2005;Mocchegiani et al., 2014). ...
A quick, simple, environmentally friendly and cost‐effective screening approach for identifying parameters of adulteration in cold‐pressed olive oil (CPOO) was developed. The technique focused on the electrochemical examination of the peak of alpha‐tocopherol oxidation on pencil graphite electrode (PGE). Rapeseed oil (RO), sunflower oil (SO), and corn oil (CO) were added to local CPOO in varying amounts, and the mixtures were then tested by differential pulse voltammetry (DPV) on PGE. Voltammetric analysis of CPOO and its artificially created mixtures with other commercial oils have demonstrated statistically significant discrimination with an ability to detect adulteration under the level of 10% on weight basis. The method's relative standard deviation (RSD) was 20%, and the α‐tocopherol in CPOO cut‐off value was 30.98 ± 12.57 nA. As far as our knowledge, no data on utilisation of voltammetric techniques for the detection of olive oil adulteration are available to date by using PGE. The results showed that the developed method is capable of detection of adulteration in natural olive oils without any pretreatment.
... Vitamin E is a fat-soluble antioxidant that protects cells from oxidative damage and other diseases [44][45][46][47]. Natural (plant) sources of vitamin E provide alpha, beta, gamma, and delta tocopherol and tocotrienol from homogentisic acid [48]. Olive oil (especially extra virgin olive oil) is an example of a source of vitamin E [48]. ...
... Natural (plant) sources of vitamin E provide alpha, beta, gamma, and delta tocopherol and tocotrienol from homogentisic acid [48]. Olive oil (especially extra virgin olive oil) is an example of a source of vitamin E [48]. In this study, given the high content of bioactives (polyphenols and antioxidants in general), we mainly analyzed olive flours, pastas, and digestive products for the content of vitamin E by HPLC analysis. ...
The aim of this research was to evaluate the levels of antioxidants and polyphenols in pasta enriched with either carrot or olive leaf flours after simulating gastrointestinal digestion. Pasta samples were prepared with fixed amounts of carrot and olive leaf flours (15% and 6% of the total mixture, respectively). We measured the antioxidant capacity and polyphenol content at different stages of the pasta production process, starting from the initial flour to the cooked pasta, and tested samples of the liquid component and solid waste resulting from the digestion process. The antioxidant activity was measured by the FRAP method, while the polyphenol content was measured by the Folin–Ciocalteu method. Vitamin E contents were measured by HPLC. The pasta enriched with carrot (1.26 ± 0.05 mmol/100 g) and olive leaf (2.9 ± 0.07 mmol/100 g) exhibited higher antioxidant power compared to the unenriched pasta (0.8 ± 0.1 mmol/100 g). The polyphenol content followed a similar trend, with values of 131.23 ± 3.08 for olive flour-enriched pasta, 79.15 ± 1.11 for carrot flour-enriched pasta, and 67.5 ± 1.39 for the wheat-only pasta. The pasta samples maintained their antioxidant and polyphenol levels even after undergoing the simulated digestion process. Significantly, the liquid component of the pasta with olive leaf flours had the highest levels of antioxidants and polyphenols during all stages of the digestion process. According to the results of this study, pasta enriched with carrot and olive leaf flours shows promising potential for improving nutritional and functional properties by increasing antioxidant and polyphenol content. The samples were also evaluated by a sensory panel, which showed that fortification modified the perception of some organoleptic attributes without affecting the overall taste of the pasta.
... Tocopherols (vitamin E compounds) are found in seed oils in four different forms: α-, β-, γ-, and δ-tocopherols (Ergönül & Köseoğlu, 2014) but in EVOO, δ-tocopherol has not been detected, only α-, β-, and γ-tocopherols have been described, with α-tocopherol representing more than 95% of the total tocopherol content (Beltrán et al., 2010). Tocopherol content and composition depend on several agronomic factors, including the cultivar, fruit ripeness, and agroclimatic conditions (Beltrán et al., 2010). ...
... Tocopherols (vitamin E compounds) are found in seed oils in four different forms: α-, β-, γ-, and δ-tocopherols (Ergönül & Köseoğlu, 2014) but in EVOO, δ-tocopherol has not been detected, only α-, β-, and γ-tocopherols have been described, with α-tocopherol representing more than 95% of the total tocopherol content (Beltrán et al., 2010). Tocopherol content and composition depend on several agronomic factors, including the cultivar, fruit ripeness, and agroclimatic conditions (Beltrán et al., 2010). Some of the efforts developed to combat EVOO fraud have focused on the tocopherol profile as a potential marker able to detect adulteration with high selectivity, sensitivity, and accuracy. ...
The growing demand for extra virgin olive oil (EVOO), appreciated for its unique organoleptic properties and health benefits, has led to various fraudulent practices to maximize profits, including dilution with lower value edible oils. The adulterated oils would be of poor nutritional quality, more readily oxidized, and may contain unhealthy substances formed during processing. Nevertheless, the range of available techniques to detect fraud in EVOO production has been growing. Reliable markers of EVOO adulteration include fatty acids and minor components such as sterols, tocopherols, triterpene alcohols, phenolic compounds, phospholipids, volatile compounds, and pigments. Additionally, increasing consumer interest in high‐quality EVOO has led to the development of robust scientific methods for its traceability.
This review focuses on (i) the usefulness of certain compounds as markers of EVOO adulteration; (ii) the potential health risks of consuming adulterated EVOO; and (iii) reliable methods for the geographical traceability of olive oil. In conclusion, fraudulent production practices need to be detected to preserve the beneficial health effects of EVOO and to avoid the potential risks associated with ingesting substandard oil. In this work, as EVOO certification and regulatory framework limitations have already been extensively reviewed, we focus our attention on biomarkers that guarantee both the authenticity and traceability of oil, and consequently its health properties. When it is unavailable to obtain a high‐resolution mass spectrometry full fingerprint, stigmastadienes and the sterolic profile are proposed as reliable markers.
... Tocopherols are present in variable quantities within the fraction of EVOO minor constituents. For example, Beltrán et al. (2010) in [39] reported a total tocopherol content between 84 and 463 ppm by studying thirty cultivars of EVOO, monitored during fruit ripening for three consecutive growing seasons. The TO values recorded in test T0 of the two varieties under study were not high, 150 ppm in Nocellara del Belice and 128 ppm in Cerasuola cv. ...
... Tocopherols are present in variable quantities within the fraction of EVOO minor constituents. For example, Beltrán et al. (2010) in [39] reported a total tocopherol content between 84 and 463 ppm by studying thirty cultivars of EVOO, monitored during fruit ripening for three consecutive growing seasons. The TO values recorded in test T0 of the two varieties under study were not high, 150 ppm in Nocellara del Belice and 128 ppm in Cerasuola cv. ...
Agriculture 4.0 is gaining more attention, and all companies are thinking about innovating machines to increase income and improve the quality of the final products. In the agro-food sector, there is space for innovation, as it is far behind the industrial sector. This paper reports an industrial-scale study on the application of an innovative system for the extraction of Sicilian EVOO (extra virgin olive oil) to improve both process management and the quality of the product. Based on previous studies, the authors suggested an innovative machine equipped with a SCADA (supervisory control and data acquisition system) for oxygen and process duration monitoring and control. The objective of the research was thus to discuss the development of a SCADA platform applied to the malaxer and the establishment of an optimized approach to control the main process parameters for obtaining high-quality EVOO. The SCADA system application in the EVOO extraction process allowed a qualitative improvement of the Sicilian EVOO of Nocellara del Belice and Cerasuola cultivars. The use of the innovative system made it possible to increase the values of tocopherols (by about 25%) in Cerasuola cultivar and total phenol content (by about 30%) in Nocellara del Belice cultivar EVOOs.
... 6,7 Tocopherols are a minor olive oil component that form part of the group of compounds that comprise vitamin E, and they have an important role as natural antioxidants in oil stability and shelf life. 8 ⊍-Tocopherol is the main tocopherol homolog (90%) in virgin olive oils, along with lesser amounts of γ-tocopherol and sometimes ⊎-tocopherol. Their exact concentrations differ between cultivars and change during fruit ripening. ...
... The highest tocopherol concentrations in olive oil were reported in low-rainfall years in Spain or when a deficit irrigation was applied. 8,16 Less is known about growth temperature effects, although it has been found that a lower altitude location with presumably higher temperatures had higher tocopherol concentrations than at a higher altitude. 17 In annual crops, responses of tocopherols to temperature have been mainly studied for soybean seeds, with elevated temperatures either increasing or decreasing individual or total tocopherol compounds depending on the timing, severity, and duration of the elevated temperatures. ...
BACKGROUND
Tocopherols and sterols are minor components of virgin olive oils that contribute to oil quality. Based on observations at different geographical locations, it has been suggested that environmental temperature during fruit growth affects tocopherol and sterol oil concentrations in olive fruit. However, controlled experiments have not been conducted to directly assess their responses to temperature. In this study, a manipulative experiment using open‐top chambers (OTCs) was performed in the field to evaluate the responses of these oil components to a moderate air temperature increase during oil accumulation in young trees of two olive cultivars (Arbequina, Coratina). The two temperature levels in the OTCs were a control about 1 °C above ambient temperature (T0) and a heated treatment (T+) with a target temperature of 4 °C above T0.
RESULTS
Total tocopherol and sterol oil concentrations in olive fruit were generally higher in the T+ temperature treatment than in the control at the end of the oil accumulation period. The increase in total tocopherols in T+ appeared to be related to a decrease in fruit oil concentration with heating. Individual sterols showed both significant increases and decreases due to T+, and some differences in response occurred between the two cultivars.
CONCLUSION
These findings provide evidence that growth temperature affects tocopherol and sterol oil concentrations in olive fruit at the end of the oil accumulation period. Cultivars should be carefully chosen for new olive‐growing regions, and the results could be relevant for global warming scenarios in existing growing regions. © 2021 Society of Chemical Industry.
... The obtained values of the α-tocopherols are consistent with those published by [35]. The presence and the evolution of the α-tocopherols were genetically related while significant differences were observable between the two studied years. ...
... The presence and the evolution of the α-tocopherols were genetically related while significant differences were observable between the two studied years. Annual biochemical changes and differences in annual rainfall and temperature are known to be responsible for the different conditions of each year that accelerate or delay ripening by increasing or decreasing the content of vitamins such as tocopherols [35,36]. [26] documented that their level is influenced by the harvest method and the storage temperature and time. ...
The production of ‘Premium’ olive oil depends in large part on the quality of the fruit. Small producers see themselves confronted with vast investments and logistic snags when they intend to optimize the harvesting. Today, manual harvesting devices promise less damaged fruit when compared to the traditional methods with nets while the use of a cooling room on the farm is suggested as a solution when the harvesting needs to be stretched out over several days. The use of a manual inverted umbrella during the harvest, together with a storage of up to 14 days at 5 °C, was studied for three cultivars (‘Arbequina’, ‘Picual’, and ‘Verdial’). Ten parameters of the produced oil were examined in two consecutive years together with an extended sensory analysis in the first year. The results underline the importance of the used harvesting and conservation method on the quality of the extracted oil, although the effect size of each factor varied in time and according to the cultivar. The results indicate that small producers with financial and logistic restrictions can obtain a high-quality product following the actions shown in this work, being able to compete in terms of quality in the market, either by combining both methods or by choosing the one that guarantees the best results given the cultivar and the specific storage time they need to consider.
... The α-tocopherol content of the examined EVOOs (73 to 202 mg/kg) is within the range reported for Greek EVOOs. Psomiadou et al. [37] stated that Greek olive oils have α-tocopherol levels that are among the highest found, ranging from 98 to 370 mg/kg, although even higher levels have been reported for olive oils from Tunisia (478 mg/kg) [34] and Spain (502 mg/kg) [23]. Relatively high concentrations have also been found for the Koroneiki cultivar from different regions [38,39] ranging from 324 to 350 mg/kg. ...
... According to the literature [13], the content of γ-tocopherol ranges between 8.9 and 13.4 mg/kg; these values that are in good agreement with the results of the present study (2 to 20 mg/kg). Béltran et al. [23], studying different cultivars from Spain, concluded that the cultivar was the most important variation factor for γ-tocopherol. This is in agreement with our results. ...
Extra virgin olive oil (EVOO) is an important component of the Mediterranean diet and a highly priced product. Despite the strict legislation to protect it from fraudulent practices, there is an increasing demand to characterize EVOOs and evaluate their authenticity. For this purpose, 68 monovarietal EVOOs, originating from three regions of Greece (Peloponnese, Crete, and Lesvos) and two local cultivars (Koroneiki and Kolovi), were obtained during the harvesting period of 2018–2019. Fatty acids, squalene, and tocopherols were determined chromatographically according to official methods in order to study the effect of cultivar and geographical origin. Squalene and γ-tocopherol differed significantly amongst the cultivars tested. Koroneiki samples exhibited higher squalene content than Kolovi samples, whereas the opposite was observed for γ-tocopherol. The tocopherol level was highly geographical dependent, with EVOOs from Peloponnese displaying the highest concentration of α-tocopherol, whereas the content of γ-tocopherol was significantly higher in samples from Lesvos. Unsupervised and supervised multivariate analysis resulted in a satisfactory grouping of EVOOs according to cultivar. γ-Tocopherol, squalene, and the majority of fatty acids were the most discriminant variables, with γ-tocopherol, linoleic, linolenic, and gadoleic acid being present at higher levels in samples from the Kolovi cultivar. Koroneiki samples were characterized with higher levels of squalene, palmitic, palmitoleic, and arachidic acid.
... As antioxidant compounds, the secoiridoids also have an inhibiting effect on lipid oxidation. Tocopherols were included because their level of occurrence in EVOO allows the use of the claim "rich in vitamin E", according to EU regulations [13,14,29]. Since tocopherols are also present in many other kinds of edible oils [4], and their amount is sometimes higher than that in EVOO (e.g., sunflower oil, albeit refined, can contain a concentration of tocopherols 2.5-3.5 greater), the significance of the fatty acid composition and the secoiridoid phenolic compounds on the NVS was chosen to be higher than that of tocopherols. ...
Extra virgin olive oil (EVOO) is a valuable product and is highly appreciated by consumers for its great nutritional value. However, to date, there has been a lack of uniform systems capable of ranking the nutritional value of EVOO based on its chemical composition in terms of macro- and micronutrients (including phenolic compounds and tocopherols). The aim of this study was to propose a scoring algorithm to rank the nutritional value of EVOO samples, considering their chemical composition in macro- and micronutrients and their sensitivity to oxidation phenomena. Data from more than 1000 EVOO samples were used to assess the variability of the data, considering the selected negative parameters (free acidity, peroxide value, spectrophotometric indices) and positive components (composition in tocopherols via HPLC-DAD, phenolic compounds via HPLC-DAD, and fatty acids via GC-MS) so as to ensure the universal validity of the scoring algorithm. The dataset included samples from the main producing countries worldwide, in addition to Australia, across several production years; data were selected to represent different production realities. A mathematical model was set up for each chemical component, resulting in six variable values. By combining these values with a dimensionless constant value, the algorithm for computing the nutritional value score (NVS) was defined. It allows the nutritional value of an oil to be ranked on a scale of 0 to 100 based on its chemical composition. The algorithm was then successfully tested using chemical data from about 300 EVOO samples obtained from laboratories from different Italian regions. The proposed NVS is a simple and objective tool for scoring the nutritional value of an EVOO, easy to understand for both producers and consumers.
... In general terms, a decrease is observed in most cultivars, except for cultivar 'Piñonera' that displays a characteristic increase. This general tendency towards a decrease in the oil tocopherol content during fruit ripening was already observed for most of the olive cultivars [10,36,37]. ...
The health-promoting antioxidant properties of virgin olive oil (VOO) are today considered priority targets in the new olive breeding programs. Given that these properties depend mainly on its phenolic fraction, whose origin lies in the phenolic compounds present in olive fruit, the objective of this study was to provide further insight into the accumulation dynamics of the main antioxidant compounds, including both polar phenolics and lipophilic tocopherols, during the ontogeny of the olive fruit. Data obtained show that, albeit with significant differences, all the studied genotypes share just after fruit set an intense increase in the synthesis of tyrosol and hydroxytyrosol derivatives, by far the main phenolic compounds of the olive fruit, and a subsequent steady decrease along fruit development and ripening. The accumulation dynamics of flavonoids and tocopherols were different from those of tyrosol and hydroxytyrosol derivatives, presenting a peak of synthesis just before the onset of fruit ripening, and then in general, their content decreases throughout the ripening phase. In the case of flavonoids, all genotypes also share a strong increase in the accumulation of anthocyanins in the final stages of fruit ripening, coinciding with the change in fruit color. Furthermore, the results during the fruit ripening process evidenced that the content of tyrosol and hydroxytyrosol derivatives and tocopherols in the fruit largely determines the content of these groups of compounds in the oil. The information acquired could be useful for the selection of the most suitable moment in the ontogeny of the olive fruit for the search for key genes in the biosynthesis of phenolic compounds.
... mg/kg r Tocopherol composition Tocopherol is an important factor in determining the quality of olive oil. Tocopherols are a family of vitamin E compounds that are found in many vegetable oils, including olive oil [Beltrán et al., 2010]. They play an important role in olive oil quality because they serve as natural antioxidants, which help to prevent oxidation and preserve the freshness of the oil. ...
Comprehending the variability in the chemical composition of olive oil from the same olive variety, based on its geographical origin, is essential. This study investigated the chemical composition of Chétoui olive oils from thirteen mills located in Northern Tunisia's Béja region. The chemical composition of olive oil exhibits substantial regional variability. Free acidity ranged from 0.57% to 0.73%, and peroxide values varied between 7.33 and 14.00 meq O2/kg. Total phenolic content varied as well, with values ranging from 906.53 to 1,298.60 caffeic acid eq/kg (oils from Amdoun and Testour II, respectively). Chlorophyll contents ranged from 2.03 to 7.85 mg/kg, and carotenoids from 1.28 to 3.92 mg/kg. Olive oils from Amdoun and Dogga II were the richest in these compounds. In terms of tocopherols, the range extended from 282.88 mg/kg (oil from Tibar) to 416.79 mg/kg (oil from Testour II). DPPH radical scavenging activity of the polar fraction of all olive oils was higher than that of the non-polar fraction. Fatty acid profiles were mostly similar with exception of the oil from Tibar with lower saturated fatty acid content and higher monounsaturated fatty acid content. Substantial differences in polyunsaturated fatty acid content were found. Triacylglycerol compositions differed as well, with the lowest triolein percentage around 13.66% and the highest at approximately 34.98%. In summary, this study reveals significant regional variations in the chemical composition of Chétoui monovarietal olive oil, highlighting the collection region impact on oil quality and nutritional properties.
... europaea var. europaea), used for the eating the fruit and extracting oil, displays significant phenotypic variation in fruit quality and yield traits [1][2][3][4][5][6][7][8][9][10][11][12][13]. Despite the importance of understanding their control of olive fruit size and ripening, the hormonal regulatory mechanisms underlying olive fruit growth and ripening, as well as the relative roles of the plant hormones on different olive fruit traits, remain poorly understood. ...
The cultivated olive (Olea europaea L. subsp. europaea var. europaea) is one of the most valuable fruit trees worldwide. However, the hormonal mechanisms underlying the fruit growth and ripening in olives remain largely uncharacterized. In this study, we investigated the physiological and hormonal changes, by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS), as well as the expression patterns of hormone-related genes, using quantitative real-time PCR (qRT-PCR) analysis, during fruit growth and ripening in two olive cultivars, ‘Arbequina’ and ‘Picual’, with contrasting fruit size and shape as well as fruit ripening duration. Hormonal profiling revealed that olive fruit growth involves a lowering of auxin (IAA), cytokinin (CKs), and jasmonic acid (JA) levels as well as a rise in salicylic acid (SA) levels from the endocarp lignification to the onset of fruit ripening in both cultivars. During olive fruit ripening, both abscisic acid (ABA) and anthocyanin levels rose, while JA levels fell, and SA levels showed no significant changes in either cultivar. By contrast, differential accumulation patterns of gibberellins (GAs) were found between the two cultivars during olive fruit growth and ripening. GA1 was not detected at either stage of fruit development in ‘Arbequina’, revealing a specific association between the GA1 and ‘Picual’, the cultivar with large sized, elongated, and fast-ripening fruit. Moreover, ABA may play a central role in regulating olive fruit ripening through transcriptional regulation of key ABA metabolism genes, whereas the IAA, CK, and GA levels and/or responsiveness differ between olive cultivars during olive fruit ripening. Taken together, the results indicate that the relative absence or presence of endogenous GA1 is associated with differences in fruit morphology and size as well as in the ripening duration in olives. Such detailed knowledge may be of help to design new strategies for effective manipulation of olive fruit size as well as ripening duration.
... HT is derived as a hydrolysis product of more complex compounds such as of oleuropein either during ripening of olive fruits or with time after olive oil production and storage. 3 Many factors affect the HT content of olive oil, including olive variety, region microclimate, soil quality (factors that define oil quality) 5 and the olive oil extraction process. 6 Thus, the concentration of HT in olive oil vary, ranging from 0.2 ± 004 to 29.0 ± 0.42 mg/kg. ...
This study explores the biological effects of hydroxytyrosol (HT), produced by the metabolic engineering of Escherichia coli, in a series of in vitro and in vivo experiments. In particular, a metabolically engineered Escherichia coli strain capable of producing HT was constructed and utilized. HEK293 and HeLa cells were exposed to purified HT to determine non-toxic doses that can offer protection against oxidative stress (activation of Nrf2/HO-1 signaling pathway). Male CD-1 mice were orally supplemented with HT to evaluate (1) renal and hepatic toxicity, (2) endogenous system antioxidant response, and (3) activation of Nrf2/HO-1 system in the liver. HT protected cells from oxidative stress through the activation of Nrf2 regulatory network. Activation of Nrf2 signaling pathway was also observed in the hepatic tissue of the mice. HT supplementation was safe and produced differential effects on mice's endogenous antioxidant defense system. HT biosynthesized from genetically modified Escherichia coli strains is an alternative method to produce high-quality HT that exerts favorable effects in the regulation of the organism's response to oxidative stress. Nonetheless, further investigation of the multifactorial action of HT on the antioxidant network regulation is needed.
... Virgin olive oil has α-, β-, and γ-tocopherols. α-Tocopherol represents more than 95% of total tocopherols ranging from 50 to 300 mg/Kg (Beltrán et al., 2010) and contributes to its oxidative stability (Blekas, Tsimidou, & Boskou, 1995). The vitamin E content of olive oil is highly dependent on the cultivar (89-1410 mg of tocopherol/Kg of oil) . ...
Edible oils are essential energy providers in human diets. However, these oils are also a natural source of bioactive compounds and phytonutrients. This chapter will provide an overview of the bioactive lipids from olive, palm, and fish oils. The nutritional and health benefits of these oils are well documented and frequently associated with their minor lipids, which exhibit significant positive effects on human health. Each oil displays a unique set of lipid families, called lipidome, with bioactive lipids belonging to different classes and with diverse structures and functions. Bioactive lipids, such as polar lipids, prenol lipids, or polyunsaturated fatty acids, have been reported to have health benefits and to prevent the onset of several disorders. The knowledge of the bioactive compounds present in these edible oils is used to develop novel biotechnological applications that incorporate these lipids into functional foods, cosmetic or pharmaceutical innovations to improve human health and well-being.
... As expected, the values of FA composition, OSI, phenolic and volatile compounds, as well as the sensory profile, varied among the oils according to variety and olive maturation, which is in agreement with the previous knowledge [36][37][38][39][40][41]. ...
During storage, premium extra virgin olive oils (PEVOO), which are oils of exceptional sensory quality, may lose the organoleptic characteristics that define them. This study assessed the effect of applying modified atmospheres and low temperatures (refrigeration and freezing) on the quality of 4 PEVOO for 24 months. Also, the effect of two freezing methods was studied (in the freezer at − 20 °C and in a bath of liquid nitrogen), along with the impact of freezing on the quality of the oils after thawing and storing at room temperature. Official quality parameters, organoleptic assessment, phenolic compounds, volatile compounds and oxidative stability index were measured periodically. While no significant effect of headspace composition was found, the oils stored at − 20 °C maintained their initial quality better than the oils stored at room temperature. Physicochemical quality parameters remained unchanged throughout the 24 months at − 20 °C. Polar phenolic and volatile compounds associated with green and fruity aromas were better preserved at − 20 °C, which translated into a minimum change in the sensory profile of the oils. While no significant difference was observed regarding oxidative parameters, freezing at − 20 °C maintained the initial volatile and sensory profile of the oils better than freezing with liquid nitrogen. Lastly, quality of thawed oils showed no significant differences compared to control oils during storage at room temperature. In conclusion, storage at − 20 °C maintains the quality of PEVOO, especially their sensory profile, and does not compromise their quality after thawing.
... An increase in water availability was negatively correlated with total phenolic concentration in fresh olive fruit and the extracted oil [113]. Olive oils produced in years characterized by low precipitations showed the highest tocopherol content depending on the cultivar [114]. Tura et al. [115] observed that a warm ripening season and sufficient rain in spring and autumn positively affected the content of volatile compounds as well as the overall sensorial evaluation of the oils. ...
The changes in the state of the climate have a high impact on perennial fruit crops thus threatening food availability. Indeed, climatic factors affect several plant aspects, such as phenological stages, physiological processes, disease-pest frequency, yield, and qualitative composition of the plant tissues and derived products. To mitigate the effects of climatic parameters variability, plants implement several strategies of defense, by changing phenological trends, altering physiology, increasing carbon sequestration, and metabolites synthesis. This review was divided into two sections. The first provides data on climate change in the last years and a general consideration on their impact, mitigation, and resilience in the production of food crops. The second section reviews the consequences of climate change on the industry of two woody fruit crops models (evergreen and deciduous trees). The research focused on, citrus, olive, and loquat as evergreen trees examples; while grape, apple, pear, cherry, apricot, almond, peach, kiwi, fig, and persimmon as deciduous species. Perennial fruit crops originated by a complex of decisions valuable in a long period and involving economic and technical problems that farmers may quickly change in the case of annual crops. However, the low flexibility of woody crops is balanced by resilience in the long-life cycle.
... EVOO composition, both minor and major fractions, is extensively affected by the agronomic and technological factors (Olmo-Cunillera et al., 2021). Triglycerides (Sánchez-Rodríguez et al., 2020), vitamin E (Beltrán et al., 2010), carotenoids (Lazzerini & Domenici, 2017), phenolic compounds (López-Yerena et al., 2019), and volatile compounds (Sánchez-Rodríguez et al., 2019) are affected by the olive cultivar, the harvest date, and the technical extraction procedures, among others. ...
The health benefits of extra virgin olive oil (EVOO) are far proven. However, considering that this oil is consumed also cooked, this work aimed to evaluate the impact of different cooking techniques on human colorectal adenocarcinoma cells (Caco-2) exposed to in vitro digested EVOO. In particular, the effect of different cooking methods, namely sauteing, deep-frying, and Roner®, was assayed and compared to a raw EVOO sample. The Caco-2 cell lysates were analyzed through an untargeted lipidomics approach, and multivariate statistics were used to identify the marker compounds of the differences in cells' lipidomic signatures. Despite representing the cooking at the lowest temperature (but longer time), cells exposed to Roner® cooked EVOO presented the most distinguished lipidomic profile. The markers of differences in Caco-2 could be related to oxidative stress-related compounds such as oxidized glutathione, diketogulonic acid, ceramides, and diglycerides. Taken together, our findings indicate that the differences in EVOO composition determined by cooking could impose significant lipidomic perturbation on the human intestinal cells.
... The determination of α-tocopherol levels in olive oil can be useful to detecting adulteration. Tocopherol content of olive oil depends on the type of olive and to a lesser extent on its ripeness and the climate 14 . In the research of Baiano et al. 15 , tocopherols varied with were found, but were not affected by geographical origin 16 . ...
The aim of this study was to examine olive oils purchased in Poland for their compliance with label declarations and EEC criteria. Statistical analysis was used to compare the olive oils in terms of their content and composition of essential constituents and color parameters. Fifty olive oils (extra virgin, bioextra virgin, cold-pressed, refined, and pomace) from different countries (Spain, Italy, Greece, Portugal, Germany, France, Israel, and the European Union), were purchased commercially in Poland. The contents of triacylglycerols, sterols, and tocopherols, the fatty acid composition, and the color parameters were determined using chromatographic and spectrophotometric methods. Statistical methods were used to divide the olive oils into clusters. Our results show that the composition and color parameters of olive oils available commercially in Poland, excluding pomace olive oils, are similar. It can thus be concluded that, irrespective of the type of olive oil stated on the label, their quality is the same or very similar.
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... Figure 4 shows the content of tocopherols and chlorophylls in the oil extracted both from the fresh Itrana cultivar olives and from the processed olives. Tocopherols are important in daily nutrition and disease prevention and their content is mainly influenced by the variety but also by other factors [21,22]. The total tocopherols content in fresh Itrana cultivar olives was 248.7 mg/kg, while it decreased after fermentation in all jars at a rate of about 30% less: jar A 171.8, jar B 171.3, jar C 171.5, and jar D 170.8 mg/kg. ...
In this study, four different kinds of table olive fermentations belonging to Olea europaea L. Itrana cultivar were evaluated: A, spontaneous fermentation; B, fermentation with a single inoculum (Lactiplantibacillus plantarum B1); C, fermentation with multiple inoculum (L. plantarum B1 + L. plantarum B51 + L. plantarum B124, 1:1:1); and D, fermentation with mixed (bacterium + yeast) inoculum (L. plantarum B1 + Candida boidinii). This research focuses on the correlation between the different mixes of inoculations and their effect under the chemical, sensorial, and textural profiles in the final products (olives) for potential applications on table olive fermentation. During the fermentation, some specific parameters were monitored: chemical characterization of oil fraction (pigments, tocopherols, fatty acids, alkyl esters, and sterol composition), Texture Profile Analysis (TPA), determination of olive color, and sensory evaluation of the final products. The use of LAB starters (single and multiple inocula) compared to spontaneous process revealed a greater performance in preventing the spoilage process and in developing favorable physico-chemical conditions during the fermentation. In fact, the highest values of fatty acid alkyl esters were reached in spontaneous fermentation (~480 mg/kg in jar A). The presence of C. boidinii as inoculum in jar D was involved in table olive softening: the fermented olives showed the lowest values of the parameters related to consistence of fruit as hardness (~2300 g) and gumminess (~990 g) and high value of fatty acid methyl esters (~110 mg/kg).
... α-Tocopherol is the most common form of vitamin E with the highest biological activity, representing 95% of the total tocopherol content in olive oil. The content of tocopherols is shown to be cultivar dependent and significantly affected by the harvesting system, fruit ripeness, crop year, the storage temperature and the storage time [39,43,46,96]. ...
Cold storage of olive fruit has been the subject of study for over more than 50 years. From the 1990s on, an increasing amount of knowledge is build-up about the impact of the conservation on the physiological response of the fruit as well as on the quality of the extracted oil therefrom. This review offers a comprehensive synopsis of this research, discusses the most important influential factors and summarizes the results on the influence of the studied parameters on both the fruit and the oil. Currently, changing climatic conditions, new harvesting techniques and a more demanding consumer market are triggering the need to broaden this strict focus on conservation. A more dynamic view on the effects of temperature from the moment the fruit is harvested up to the oil extraction process, reveals the necessity to manage this crucial influential factor more diversely. An overview of how this management can take form is structured through a focus on the different phases of the postharvest processing and the widely different harvesting scales. Future prospects of research are presented based on the actual state of the art of cold storage research as well as on the necessities that come forward from a broader fruit temperature management perspective.
... The composition and content of these substances depend on several agronomic factors, such as, olive processing conditions and storage quality. [29][30][31][32] EVOO is one of the foods richest in vitamin E (tocopherols), with the most representative ⊍-tocopherol, which accounts for about 90% of the total tocopherols with vitaminic and antioxidant actions. ...
BACKGROUND
Single cultivar ‘Olivastro di Bucchianico’ extra virgin olive oil is obtained from olives cultivated in a narrow area of the Abruzzo region, Italy. This cultivar is mostly present in the municipality of Bucchianico and in some neighbouring municipalities in the province of Chieti. There is very little research in the literature describing the morphological and chemical characteristics of this cultivar.
RESULTS
A morphological characterization of the plant and the fruit was carried out. In addition, we characterized the chemical, physical‐chemical and sensory properties of the extra virgin olive oil. The following analyses were conducted: free acidity, peroxide value, ultraviolet spectrophotometric indices, contents in fatty acid ethyl esters, waxes, tocopherols, fatty acids, triglycerides, sterols, alcohols, phenolic substances, volatile compounds and sensory profile. The analysis of the volatile compounds was performed using a headspace‐gas chromatography‐ion mobility spectrometry (HS‐GC‐IMS) instrument connected to a nitrogen generator for carrier/drift gas production.
CONCLUSION
The results of the chemical analyses showed good levels of nutraceutical components in the oils, which were found to be organoleptically well balanced with medium values of fruity, bitter and pungent. The HS‐GC‐IMS method based on the analysis of 15 volatile molecules might be a useful tool for a chemometric discrimination of the varietal origin for the oils under investigation. © 2021 Society of Chemical Industry.
... In addition to a high-energy value in food intake, it provides an abundant resource of monounsaturated fatty acids, which confers a multitude of benefits to human health (Covas et al., 2009). The main biological effect of olive oil has been attributed to the diversity of its minor fraction (Beltr an et al., 2010), which involves a mixture of different amounts of vitamins, phytosterols, and polyphenols, characterized as bioactive compounds responsible for the sensory quality and oxidative stability of olive oil (Cicerale et al., 2009). However, the composition and concentration of these different components of olive oil appear to be particularly sensitive to the variations of agronomic, technological, and climatic factors (Dabbou et al., 2009;Desouky et al., 2009). ...
This work aimed to investigate the combined effect of harvest time and crop altitude on the fruit and oil quality of two autochthonous Algerian olive cultivars, Chemlal and Azeradj. Fruit morphological characteristics, oil quality parameters, fatty acids and triacylglycerols composition, pigments, tocopherols and oxidative stability were determined. Olives were harvested at four different ripening stages in orchards located at 110, 320 and 490 m altitude, in the olive‐growing region of Kabylia, northern Algeria. Results showed a good discrimination between varieties, which were characterized by specific triacylglycerols and fatty acids profile. Different chemometric analyses carried out on the oil data highlighted the strong influence of variety in relation to the factors studied. Moreover, Principal Component Analysis performed on both fatty acids and triacylglycerols profile allowed correlating the distinct composition with the different varietal sensitivities to changes in crop attitude and ripening stage. Tocopherols showed a remarkable decrease with the ripening progress. Oxidative stability was positively correlated with variations in tocopherols and monounsaturated fatty acids during maturation and altitude changes.
... Alpha tocopherol content of olive oils was determined between 12.00 to 98.35 mg/kg. This value was similar with Kiritsakis (1998) (11.4 to 142.5 mg/kg) and Boskou (1996) (47.5-285 mg/kg) but lower than Beltrán et al. (2010) (80-439 mg/kg). Tocopherol content was reported up to 300 mg/kg for high quality olive oil and 5 mg/kg or less for poor quality olive oils (Gümüskesen 1999). ...
This is the first study evaluated oil characteristic of 23 olive cultivar candidates, which obtained by cross breeding and later selection among 492 olive genotypes. In this research, oil characteristics such as alfa tocopherol, total phenol, antioxidant activity, oxidative stability and sensory analysis were determined. Olive oils of standard ‘Gemlik’ and ‘Ayvalık’ cultivars were also included analysis to compare candidates. Significant genetic influence was determined on nutritional, oxidative stability and sensory characteristics of oils. Oils of GT009, LE003 and LT019 genotypes had highest both total phenol content and antioxidant activity so that they had remarkable characters from nutritional physiology perspective. GE363 showed longest induction time and LE003, GE417 and GE363 showed longest shelf life. Highest alpha tocopherol content was determined in oils of BK013 and ‘Gemlik’ olives. According to sensory evaluation, oil of GU429 was classified as well balanced oil and oils of GE067, GE110, GE366, GU247, GU320, GU323 and GU434 classified as mild oil. These results will be used to give decision for their final selection and register the selected best cultivar candidates.
... sylvestris from Tunisia was found to be close to that obtained by Baccouri et al. [35] (309.5-781.8 mg/kg) and higher than that obtained from Algerian wild olive (170-320 mg/kg) [36] and cultivated olive trees (84-463 mg/kg) [37]. It should be noted that the climatic conditions can also influence the tocopherol content especially α-tocopherol and β-tocopherol for ssp. ...
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.
... It can be concluded that the tocopherol content, mainly a-tocopherol, is higher in VOO obtained from regions where the weather is warm compared to those originating from cold-weather regions. 35 Fig. 2b shows that the VOO from Languedoc Picholine, Moroccan Picholine, and Arbozana presented similar trends, while Arbequina VOO presented a different trend. Furthermore, the Languedoc Picholine samples showed the highest FI in the 320-330 nm range, while Arbequina VOO exhibited the lowest FI in the same spectral range. ...
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.
... [65,66] Similarly, ripening, harvest date, and agronomical factors were linked to the variability of tocopherol. [67] Bassi et al [2] noted AsA variability in apple peel and pulp even though the same cultivation, storage, and sampling conditions were used for all cultivars. Therefore, we concluded that the biological variability noted in this and the other cited studies reflects the cultivar-specific content and stability of AsA in response to the external factors. ...
This study aimed to analyze the most important apple vitamin, L-ascorbic acid (AsA), and the most abundant fat-soluble one, α-tocopherol, in the pulp of 24 cultivars from harvest season 2010 and in six cultivars collected over three consecutive years (2008–2010). All cultivars were grown and stored under identical conditions and identified as ‘true to type’ by molecular genetic tools. The two vitamins were analyzed using high performance liquid chromatography with diode array detection (HPLC-DAD), involving two rapid methods with excellent recovery, linearity, precision, and sensitivity. Results showed an intriguing diversity of AsA contents and, to a lesser extent, of α-tocopherol in biological replicates, between cultivars and harvest years. Nevertheless, cultivar-specific relative vitamin contents can be deduced from this study. Among the 24 cultivars, a minimum AsA content of 0.43 ± 0.13 mg/100 g fresh weight (FW) and a maximum of 6.22 ± 1.06 mg/100 g FW have been found in ‘Gala’ and ‘Freiherr von Berlepsch,’ respectively. α-tocopherol ranged from 0.13 ± 0.02 mg/100 g FW to 0.33 ± 0.04 mg/100 g FW for ‘Freiherr von Berlepsch’ and ‘Brixner Plattling,’ respectively. The results of the present study suggest a potential of some old cultivars as a component of a healthy, vitamin-rich diet.
... The results of tocopherol analysis confirmed this trend; indeed, TR presented a higher content than MR. The amount of α-tocopherol was significantly higher in TR samples, while the content of the sum of β-and γ-tocopherols was found in a small amount and without significant differences between the samples, as expected (Beltrán et al., 2010). Regarding carotenoids and chlorophylls, it was observed a similar behaviour ( Table 2). ...
Malaxation represents a critical and deeply studied step of the virgin olive oil extraction process due to its influence on yield and quality. Nonetheless, few experimental works have been focused on the mechanical aspects of the malaxer machine itself, with the aim of increasing its performance. In this framework, we investigated the effects of design changes of the rotating parts of the malaxer machine on the oil yield and on the virgin olive oil quality, antioxidants and volatile compounds.
The modified reel determined a significant increase in extraction yield, respect to the traditional one, as a consequence of the decrease in consistency index of the olive paste. By the qualitative point of view the extracted oil could be categorized as extra virgin. However, malaxer modification brought to a decrease of the antioxidants and an increase of the oxidative phenomenon, as showed by volatiles originated from oxidative degradation and by the enzymatic activities in olive paste. Nonetheless, the outcomes suggested that a possible reduction of malaxation time by the modified reel could be useful to increase the work capacity and to possibly preserve oil quality.
... Although 'Picual' oils have higher tocopherol content, in this work similar concentrations were found in both oils. It can be explained for the influence of other agronomic factors, such as the fruit ripeness [74]. As expected, the α-tocopherol was the major tocopherol detected in both oil varieties. ...
In this work, the effects of high power ultrasound treatment (40 kHz) on virgin olive oil (VOO) for different times (0, 15, 30 minutes) were studied, in order to verify if extent modifications in their chemical composition and thermal properties. The effects of the different ultrasound treatments on VOOs were determined considering the following parameters: quality index (free acidity, K232 and K270), lipid profile (fatty acids and triglycerides composition) minor components (phenols, tocopherols, pigments and volatiles) and thermal properties (crystallization and melting) by Differential Scanning Calorimetry (DSC).
During the ultrasound treatments, bubbles growth was present in the VOO due to the phenomenon of cavitation and a slight increase of the temperature was observed. In general, the ultrasound treatments did not cause alterations on VOO parameters evaluated (oxidation state, lipid profile, minor components and thermal profiles). However, a slight decrease was observed in some volatile compounds.
... However, studies have shown that other oily plants promote tocopherol synthesis under water stress [75,76], and that tocopherol is slightly higher in a water deficit environment. In olive oil, the total tocopherols and α-tocopherol are highly influenced by crop-year rainfalls, with the highest concentration being found during the driest year [77]. The increase in tocopherol content might contribute to the prevention of plant oxidative damage in drought conditions [78]. ...
Hazelnut (Corylus avellana L.) is a popular tree nut worldwide, and in recent years, the production of hazelnuts has increased in many countries due to large investments improving agricultural techniques and the selection of new cultivars. Turkey, the leader of global hazelnut production, has shown that supply can strongly fluctuate, which leads to peak prices and market instability. In this review, an overview of the morphological traits, nutritional value, fatty acid composition, tocopherols, and future prospects of hazelnut production are described. Furthermore, information regarding hazelnuts from different geographical origins (Chile, Croatia, Iran, Italy, Oregon (US), Poland, Portugal, Serbia, Spain, and Turkey; total of 22 cultivars) to enhance the utilization of hazelnut cultivars from newly producing orchards and origins is comprehensively summarized.
... In this sense, the predicted climate warming, that could specially affect the Mediterranean climate (Lionello, 2012), could greatly affect the olive oil composition and, therefore, its quality. For instance, an increase of temperature could decrease C18:1 content while low temperature increases the C18:1 content (Rondanini et al., 2011;Mousavi et al., 2019); besides, drier seasons could be related with an increase of total tocopherols (Beltran et al., 2010). ...
Olive oil is highly valued by its nutritious and healthy function mainly due to its chemical composition. Oil chemical components are highly influenced by the cultivar and the environment, resulting in some cases in levels out of the limits set by the International Olive Council. In the present research, we used a multi-environment trial with five different agro-climatic conditions of Andalusia to evaluate how genetic and environmental factors and their interactions influence some of the most important olive quality components. Most of variation for olive components according to ANOVA was attributed to genetic effect, which was supported using principal component analysis and linear discriminant analysis. For the fatty acids, ‘Arbequina’ showed oils with the highest C16:0 and C18:2 values, and the lowest C18:1. Contrarily, an advanced breeding selection, Selection 2, and ‘Picual’ showed high C18:1 and low C16:0 and C18:2. The minor components varied depending of the genotype, underlining very high squalene values in ‘Carrasqueño’. Even so, the environment and the G x E interactions also resulted highly significant, with some genotype-environment combination unfavourable for oil composition as ‘Arbequina’-Gibraleón. The significant interactions were analysed separately by additive main effects and multiplication interaction to identify the most stable genotypes and adaptations to specific environments. For instance, ‘Arbequina’ showed low stability for C18:1 and C18:2, but very high stability for total tocopherol content and squalene content. These results underline the relevance of using multi-environment trials for adequate characterization of genotypes for oil components.
... the olive varieties also differ in the characteristics of the fruit that limit or enhance multiple uses [114] and in the quality of the olive oil. namely in its stability and chemical composition [115,116]. Since the quality of the final products are an added value for the sector. ensuring its authenticity is imperative. ...
Worldwide sustainable development is threatened by current agricultural land change trends, particularly by the increasing rural farmland abandonment and agricultural intensification phenomena. In Mediterranean countries, these processes are affecting especially traditional olive groves with enormous socioeconomic costs to rural areas, endangering environmental sustainability and biodiversity. Traditional olive groves abandonment and intensification are clearly related to the reduction of olive oil production income, leading to reduced economic viability. Most promising strategies to boost traditional groves competitiveness-such as olive oil differentiation through adoption of protected denomination of origin labels and development of value-added olive products-rely on knowledge of the olive varieties and its specific properties that confer their uniqueness and authenticity. Given the lack of information about olive varieties on traditional groves, a feasible and inexpensive method of variety identification is required. We analyzed leaf spectral information of ten Portuguese olive varieties with a powerful data-mining approach in order to verify the ability of satellite's hyperspectral sensors to provide an accurate olive variety identification. Our results show that these olive varieties are distinguishable by leaf reflectance information and suggest that even satellite open-source data could be used to map them. Additional advantages of olive varieties mapping were further discussed.
... The obtained crude oil was used for the vitamin analysis. The vitamin compounds of the oil samples were investigated according to the procedure of Beltrán et al. (2010). According to the method, 1.5 g of oil was dissolved in the mobile phase (10 mL) and the chromatographic separation was performed using HPLC (Agilent, 1260) equipped with a UV-Vis detector. ...
In this study, 36 different ornamental pumpkin (Cucurbita pepo L. var. ovifera (L.) Alef.) genotypes were analyzed in terms of detailed morphological parameters, molecular properties, and some nutritional features. In this regard, high morphological diversity among the genotypes was observed in terms of plant, leaf and fruit characteristics. Molecular results showed that the genotype which is farthest from the other genotypes of 55% of the difference was determined and fourteen ISSR primers produced, on average, 121 bands in the accessions examined, of which 88 (73%) were polymorphic and Jaccard’s similarity coefficient ranged from 0.45 to 0.96. Nutritional analysis showed that C. pepo var. ovifera seeds are rich in potassium (K) and phosphorus (P) with the concentrations of 8490–21,798 mg/kg and 13,902–28,686 mg/kg, respectively. It was also determined that the pumpkin seed oils had alpha and gamma tocopherols and no β-tocopherols. All samples had β-carotene with the range of 19.63–150.88 mg/kg oil.
... The concentrations of pigments, tocopherols, and squalene in olive oil tend to differ depending on the geographical origin, the variety of the olive fruit, the cultivation parameters, the fruit maturation stage during ripening, and the oil production parameters (oil press system, centrifugation system, addition of water during malaxation of olive paste, malaxation time, malaxation temperature) [11][12][13][14][15]. In the literature, many studies have reported the connection of the quality of olive oil with the concentration of these compounds (pigments and antioxidants), thus it is of great value to be able to determine the levels of these compounds with a fast, cheap, and effective methodology. ...
A new facile and fast method was developed in this study for the determination of pigments (chlorophylls and carotenoids), tocopherols (α-, sum of (β + γ), and δ), and squalene in olive oil. This method consisted of a dilution of olive oil in 2-propanol, followed by reversed phase-high-pressure liquid chromatography equipped with a diode array detector (RP-HPLC-DAD). Chromatographic separation was performed using a C18 column, while the mobile phase consisted of acetonitrile and methanol using a gradient elution program. The methodology was optimized, validated, and applied to the analysis of 452 samples of Extra Virgin Olive Oil (EVOOs) and Virgin Olive Oil (VOOs) originated from five islands of the Northeastern Aegean Region, in Greece. From the obtained results, it was indicated that the carotenoid, tocopherol, and squalene content was relatively high, while the chlorophyll content was low. Furthermore, the acquired results were studied and compared in order to obtain useful information about the correlation of the concentration levels of these compounds in olive oil to different cultivation and olive oil production parameters. Several parameters were found to play a significant role on the pigment and antioxidant content of olive oil, such as the olive tree variety, geographical origin, fruit maturation stage during harvesting, and addition of water during malaxation, while other parameters such as the altitude of cultivation, the type of farming (organic or conventional), and the type of olive mill did not seem to affect the levels of these compounds.
A new non-destructive index of absorbance difference (IAD), calculated with different wavelengths as references, near the chlorophyll absorbance peak or that for anthocyanin, has been used to determine the fruit ripening of several fruit species using portable devices such as Standard DA-Meter® and Kiwi-Meter®. In this study, for the first time, the application of the IAD was evaluated on single, intact olives of the Leccino cultivar, as a single non-destructive maturity index to follow ripening in the field, directly on the tree. The IAD determined by both devices was found to be useful for monitoring the olive ripening, however, better performance was achieved with the Kiwi-Meter®. In fact, the IAD determined by this device was more effective at measuring all the studied olive ripening parameters in the calibration and validation datasets with acceptable accuracy. Specifically, better performance of the IDA by Kiwi-Meter® was observed in estimation of the color index (R2 = 0.817, DRMSEC = 0.404 and RPIQ = 3.863 for calibration and R2 = 0.752, DRMSECV = 0.574 and RPIQ = 3.244 for validation), confirming its potential for evaluating the degree of olive ripeness. This novel index has significant applicative possibilities, since it would allow rapid, on-site screening of the best harvesting time to improve the olive production in terms of both yield and quality.
Crude palm oil (CPO) is a vegetable oil that came from a palm tree bunch. Palm oil tree was known as highest vegetable oil yield. It was grown across Equatorial County, especially in Malaysia and Indonesia. The greenish red color on CPO was came from carotenoid antioxidant, which could be extracted and use widely as functional food and other purposes as antioxidant source such on the biodiesel posttreatment to prevent biodiesel oxidation. Another antioxidant that also found in CPO is tocopherol. The aim of the research work is to find antioxidant activity on CPO comparing to the synthetic antioxidant that available in a market. On this research work, antioxidant was extracted by using a mixture of acetone and n. hexane, while activity of the antioxidant extract was determined by DPPH method. Antioxidant activity of the extracted compound has better performance compare to pure tocopherol. While the solvent mixture does not influence on the antioxidant activity.
The olive tree represents a symbol of the Mediterranean basin where it originated. It is a species characterized by a wide genetic diversity, the germplasm of which is very large and constantly evolving. The management of olive tree genetic resources as well as genetic improvement are challenges that may be easier to be faced using advanced genomics tools. This chapter describes the olive tree biodiversity as a primary source for breeding programs aimed at improving the oil quality, the currently available genomic tools to support these programs, and the state of the art about the current progress of molecular research in relation to the discovery of key genes and their expression regulation underlying the olive oil quality, crucial for the improvement of nutraceutical properties.
The present study was conducted to determine the quality parameters, fatty acid profile, minor compounds (pigments, tocopherols, phenolic compounds, squalene and total sterols) and volatile compounds of olive oils from four common olive cultivars (cv. ‘Koroneiki’, ‘Coratina’, ‘Frantoio’ and ‘Arbequina’) planted in China. The effect of maturation stage on the characteristics of the oils was also evaluated. All samples were classified as extra virgin according to the standards established by IOC. Statistically significant differences (p < 0.05) were observed in the most analytical indicators of the oils among the cultivar and ripening. Coratina oils contained the highest contents of carotenoids, chlorophylls, tocopherols, phenolic compounds and high level of volatiles, demonstrating their excellent nutritional qualities and pleasant flavors. Whereas, Koroneiki oils contained the highest contents of oleic acid and squalene. Further, high levels of total sterols were found in Frantoio and Arbequina oils. Phenolic compounds and volatiles decreased with increase of ripe degree, which indicated the oils from green olive fruits possess better quality and flavor.
Edible oils and fats play an important role regarding human nutrition, consequently human health. Oils and fats are considered as one of the food products which are characterized with high energy content. It contains also relative high level of essential fatty acids and soluble fat vitamins (A, D, E, K). Moreover, it gives different food products its desired and accepted sensory properties, such as taste, odour, colour, flavour, consistency...etc.
Extra virgin olive oil (EVOO) has unique nutritional and sensory characteristics. The importance of EVOO is mainly attributed to its high content of oleic acid and its richness in phenolic compounds, which act as natural antioxidants. On the other hand, EVOO is expensive owing to the hard and time-consuming tasks involved in the cultivation of olive trees, the harvesting of the fruits, and the extraction of the oil. For these reasons, adulterations of EVOO with olive oils of lower quality are occasionally detected.
Adulteration EVOO, either by adding lower-grade olive oils or adding other less expensive oils such as sunflower (SO), corn (CO), sesame and soybean oils.
The adulteration practice in oils is difficult to detect, when the oil adulterant has close similarity in terms of chemical composition and color to that of the original oil. The development of a fast and reliable technique for qualitative and quantitative analyses of high value oils like EVOO is one of the interest aspects for researchers.
The present study aims to carried out by blending the EVOO with the less expensive oils commonly used for cheating, such as SO and CO, where the EVOO was obtained by extracting it using the methods approved from the fresh olive fruits, while the other oils were purchased after making sure of their conformity to the correct storage conditions and from then prepare binary mixtures (w / w) of olive oil and SO in similar proportions to the expected cheat levels (5, 15 and 25%) and binary mixtures of olive and CO in the same proportions. Each samples were analyzed for important physical and chemical properties such as: unsaponifiable matter%, , color, refractive index, viscosity, specific weight, acidity%, peroxide value, iodine value,
saponification number, total phenols, flavonoids and tocopherols,
fatty acid profile and oxidative stability then comparing the data
obtained with data previously known by Codex Alimentarius
Standard, The Egyptian Standards, and IOC. Applications of UV
at wavelengths 274, 266, 270, 232 nanometer and calculation ΔK
and FTIR spectroscopy to assess the adulteration of EVOO with
SO and CO.
The obtained results can be summarized as follows:
1- Fatty acid profile:
Results shown that the most prevalent fatty acids in EVOO were C16:0 (12.95%), C18:1 (70.42%) and C18:2 (13.13%). The percentage of total saturated fatty acids of EVOO were (14.80%).
The palmitic acid as a major saturated fatty acid, followed by stearic acid their percentages were (12.95 and 1.55%), respectively. While, the percentage of total unsaturated fatty acids were (85.20%), it is clear that oleic acid (C18:1) was the most common unsaturated fatty acid (70.42%) followed by linoleic acid (C18:2) (13.13%).
Adulterations EVOO with SO by addition of different concentrations 5, 15 and 25% from SO with to EVOO showed remarkable changes in the main constituents and the predominant saturated fatty acids and unsaturated fatty acids composition of EVOO. The concentration level of C16:0 and C18:1 was gradual decreased corresponding with increasing the SO content in the oil blends. The blend samples for EVOO and SO (95:5%), (85:15%) and (75:25 %) recorded 12.67, 12.14 and 11.24% for palmitic acid, respectively, while oleic acid were 67.88, 64.0 and 58.49%, respectively. Linoleic acid had a lesser percentages in EVOO (13.13%), but with added SO showed a gradual increase with increasing the SO concentrations. The adulterations EVOO with SO ratios (95:5%), (85:15%) and (75:25 %) recorded 16.28, 20.61 and 27.18% linoleic acid, respectively.
On the other hand, the addition of different concentrations 5, 15 and 25% from CO (as adulterations oil) to EVOO showed slight changes in the main constituents and the predominant saturated fatty acids and unsaturated fatty acids composition of EVOO. The concentration level of C16:0 and C18:1 was slight decreased with increasing the CO content in the oil blends. The blend samples for EVOO and CO (95:5%), (85:15%) and (75:25%) recorded 12.92, 12.80 and 12.60% for palmitic acid, respectively, while oleic acid were 65.05, 60.90, and 56.63%
respectively. Also, can noted that linoleic acid had a lesser percentages in EVOO (13.13%), but with added CO showed a gradual increase with increasing the CO concentrations. The blends for EVOO and CO (95:5%), (85:15%) and (75:25 %) recorded 19.20, 23.40 and
27.20% linoleic acid respectively, because CO contained higher levels of linoleic acid (57.84%).
Total unsaponifiable matter (%):
From the obtained results it is noticed that EVOO was the highest total unsaponifiable matter among the authentic oils. The addition of different concentrations 5, 15 and 25% from SO and CO to EVOO showed remarkable changes in total unsaponifiable matter of EVOO. The blend various concentrations of EVOO with SO and EVOO with CO recorded (0.60, 0.50 and 0.40%) and (0.60, 0.50, and 0.48%) for concentrations 5, 15 and 25%, respectively.
Natural antioxidants content of virgin olive oil:-
From the obtained results noticed that EVOO the highest value of total phenols, flavonoids and tocopherols content among the authentic SO and CO samples were recorded (850, 70 and 45 mg/kg.), (230, 25 and 20 mg/kg) and (10.2, 6.8 and 6.4 mg/kg), respectively.
The binary admixtures from (EVOO and SO) and (EVOO and CO) showed remarkable changes in the natural antioxidants content of EVOO as follows:
- Total phenols content of blend samples gradual decrease with increase the addition of SO and CO at 5, 15 and 25% ratio recorded (810, 730 and 650 mg/kg) and (808, 720 and 640 mg/kg) respectively.
- Total flavonoids content of blend samples gradual decrease with increase the addition of SO and CO at 5, 15 and 25% ratio recorded (220, 200 and 180 mg/kg) and (220, 190 and 175 mg/kg), respectively
- Total tocopherols values of blend samples decrease with increase the addition of SO and CO at 5, 15 and 25% ratio recorded and (10.3, 9.7 and 9.1 mg/kg) and (9.5, 8.7 and 7.7 mg/kg), respectively.
The physical properties of oils samples
Colour index:
The EVOO extracted from authentic olive fruit was superior in their colour measurements which were found (10, 1 and 0.2 in the yellow, red and blue Lovibond scale), when compared with the colour units for the SO, CO were (8, 0.8) and (10, 1.1), respectively.
The colour metrics for the binary admixtures showed stability with increase SO and CO, it is also noted the appearance of the blue color in EVOO and its disappearance completely from all mixtures, this is due to EVOO showed the highest values among the authentic oils and the disappearance of the blue color from both authentic oils.
Refractive index
EVOO was the lowest value of the refractive index among the authentic oils. The refractive index for EVOO, SO and CO were 1.4675, 1.4723 and 1.4711, respectively.
The refractive index for oil blends at different concentrations 5, 15 and 25% from (SO to EVOO) and (CO to EVOO) were (1.4681, 1.4685 and 1.4693) and (1.4677, 1.4684 and 1.4689), respectively. The refractive index value of EVOO showed gradual increase with increase the of SO and CO up to 5%.
Viscosity
EVOO was the highest viscosity value among the authentic oils. The viscosity values of EVOO, SO and CO were 61, 40 and 42 cp., respectively. The addition of different concentrations 5, 15 and 25% from SO and CO to EVOO showed gradual decrease with increase the of SO and CO which recorded in the binary admixtures (EVOO and SO)
60, 55 and 50 cp. respectively, while, recorded in the binary admixtures (EVOO and CO) 60, 57 and 55 cp., respectively.
Specific gravity:
As for the specific weight, when applied to both authentic oils and their dual mixtures, it has been proven that it may play a role in detecting fraud in olive oil, but with less sensitivity if compared to some other tests, where fraud can be detected when there is SO and CO, starting from the ratio of 5% and by applying this test to randomized commercial olive oil samples, it was proven effective in detecting fraud, as it gave a positive result and gave readings outside the range specified in the standard specifications for olive oil.
The chemical properties of oils samples
Free fatty acid % (as oleic acid):
Free fatty acid % for samples of EVOO, SO and CO were 0.261, 0.036 and 0.085%, respectively. The addition of different concentrations 5, 15 and 25% from SO and CO to EVOO showed gradual decreased in free fatty acid% with increase the of SO and CO ratio, which recorded (0.250, 0.227 and 0.205%) and (0.252, 0.235 and 0.217%) for both of binary admixtures for oils under study.
Peroxide value
Peroxide values for samples of EVOO, SO and CO were 4.8, 0.2 and 0.2 meqO2/kg oil, respectively. EVOO was the highest peroxide value among the authentic oils under study; this is may be due to was not conducted refining process to EVOO such as refining SO and CO. The addition of different concentrations 5, 15 and 25% from SO and CO to EVOO showed gradual decreased in peroxide value with increase the of SO and CO ratio, which recorded (3.7, 2.5 and 2.3 meqO2/kg oil) and (4.8, 3.2 and 2.4 meqO2/kg oil) for both of binary admixtures for
oils under study.
Iodine value
Iodine values for samples of EVOO, SO and CO were 84, 129 and 121 gI2/100g oil respectively. The addition of different concentrations 5, 15 and 25% from SO and CO to EVOO showed gradual increased in iodine value with increase the SO and CO ratio, which recorded (86.2, 90.7 and 95.2 gI2/100g oil,) and (85.8, 89.5 and 93.2 gI2/100g oil) respectively, for both of binary admixtures for oils under study.
Oxidative stability (rancimat induction period)
The oxidative stability values of EVOO, SO and CO were 43.5, 16.4 and 25.1 (hr) respectively. the oxidative stability of the blends SO and CO with olive oil decreased with the increase of SO and CO at different concentrations 5, 15 and 25% were recorded (38.5, 32.4 and 25.5 hr) and (42.2, 39.3 and 35.8 hr), respectively.
Ultraviolet (UV) Spectroscopic Characteristics
Results revealed that the adulteration will be detected easily by UV absorbance at 270 nm because SO showed a shift out of the permitted range at 15% upward higher concentrations added to EVOO. Also, CO will be detected if present in 15% upward higher concentrations in blends with EVOO. The calculated ΔK allowed the detection of adulteration in EVOO at the concentration of 15% upward higher concentrations of adulterant SO and CO; and this is the lowest detectable value in adulterated EVOO.
Fourier Transform Infrared
A band around 2925 cm-1 along with its intensity (assigned to C–O stretching and symmetric stretching vibration of the aliphatic CH2 group) along with a very strong band along with its intensity located at 1743 cm-1 (assigned to the C=O stretching vibration of the ester group) were important to detect concentration of 5% adulterants SO and CO in EVOO.
Conclusion:
The present work successfully achieved its aim included in the applications of UV and FTIR spectroscopy as rapid, cheap, nondestructive, authenticity measuring tools to assess the adulteration of extra virgin olive oil with other edible oils such as corn and sunflower oils in detection limit 15% for UV and 5% for FTIR spectroscopy. Library searching in the FTIR region is a well established and powerful way which was used in comparison and matching of measured spectra.
The health benefits of extra virgin olive oil (EVOO) are associated to its fatty acids profile (with predominance of oleic acid) and to the minor components that include phenols, among others. Phenols are responsible for the only health claim of olive oil reported in the Commission Regulation (EU) 432/2012. Here, we have applied a LC–MS/MS method to determine the most abundant phenols included in the health claim (with special emphasis on secoiridoids) in 1239 EVOO samples produced in two consecutive agronomical seasons. The predominant cultivars in Spain (“Picual”, “Arbequina”, “Hojiblanca” and “Cornicabra”) were evaluated. We also studied the influence of harvesting date and orchards location on the EVOO phenolic concentration. A great variability in phenolic content, from 1 to 2850 mg/kg, was found in these EVOOs and not all of them (4.6 and 23.1% in the two seasons) reported a concentration above 250 mg/kg to certify the health claim.
Tocopherols are compounds with high biological activity, beneficial for human health that can be found in vegetable oils like olive oil, contributing for its resistance to oxidation. In this work, the tocopherol contents of olive oils extracted from centenarian olive trees of six cultivars (cvs. Lentisca, Madural, Rebolã, Redondal, Verdeal, and Verdeal Transmontana) were evaluated during five consecutive crop seasons (2013–2017). Three tocopherol isoforms (α‐, β‐ and γ‐tocopherols) were detected in all analyzed olive oils, and their content varied significantly with the cultivar and year of production. The highest amounts were found in cv. Lentisca (456 ± 122 mg/kg olive oil), while the lowest were observed in cv. Verdeal (179 ± 45 mg/kg olive oil). Crop year was the most influential factor, with the highest contents observed in 2013 and lowest in 2014. Principal component analysis and hierarchical clustering analysis helped differentiate olive oils according to cultivar or production year. These data suggest that tocopherol composition may serve as a chemical marker to distinguish the subject cultivar olive oils from centenarian trees either by olive cultivar or by crop year, being some cultivars identified as potential candidates for guaranteeing the production of olive oils rich in these compounds.
The results obtained in this work explain how can affect the clarification systems to the conservation of virgin olive oils (VOOs) during the storage step. The evolution of the quality and sensory properties during the storage of VOOs clarified by different systems, vertical centrifugal separator (VCS) with minimal water addition and conical bottom settling tank (CBST), were studied at industrial scale for two different crop years. In general, VCS oils showed a slight higher moisture and solid impurities content at the end of the storage step due to a higher emulsion grade (because of the emulsion generated) caused by the rotating movement of . For the studied clarification systems, no remarkable differences were observed between the oils during their storage for quality indexes. However, these systems showed differences regarding to oil sensory properties. The VOOs clarified by VCS were characterized by a higher presence of phenol components, higher positive sensory attributes intensity and higher “LOX” aldehydes content during their storage. VOOs from CBST showed lower phenol content, a higher “non‐LOX” volatiles content and the presence of sensory defects during storage. Practical applications: The results obtained in this work are very important in order to provide specific recommendations and scientific support based on objective data to improve the VOOs quality. As described in this study, the VCS with a minimal water addition could be a better option to produce VOO of improved quality. This clarification system is an efficient and quick operation that reduces the contact between oil and the remaining water and impurities during the storage step. The minimal water addition used in this clarification system allows obtaining VOOs with higher phenol content and positive sensory notes. This leads to prolong VOO shelf‐life and conservation during the storage stage, due to preservation of the quality indexes and minor components with antioxidant activity. Besides, this clarification system reduces the water consumption during oil clarification and generates a lower wastewater volume regarding to conventional vertical centrifugation, and therefore can be considered more environmentally friendly. This article is protected by copyright. All rights reserved
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.
The composition of olive oil is primarily triacylglycerols (~99%) and secondarily free fatty acids, mono- and diacylglycerols, and an array of lipids such as hydrocarbons, sterols, aliphatic alcohols, tocopherols, and pigments. A plethora of phenolic and volatile compounds are also present. Some of these compounds contribute to the unique character of the oil. Fatty acids present in olive oil are palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0), oleic (C18:1), linoleic (C18:2), and linolenic (C18:3). Myristic (C14:0), heptadecanoic, and eicosanoic acids are found in trace amounts. This chapter discusses some classes of minor constituents that are present only in the crude oil. Filtration reduces the initial levels to a great extent whereas refining results in their removal. © 2006 AOCS Press Published by Elsevier Inc. All rights reserved.
The lipid-soluble antioxidants alpha-tocopherol and carnosic acid were studied in field-grown rosemary (Rosmarinus officinalis L.) plants subjected to drought. During summer in the Mediterranean region, the predawn water potential decreased to -3 MPa and the relative water content to 42%, which caused a depletion of the maximum diurnal CO(2) assimilation rate by 80%. Meanwhile, the maximum efficiency of photosystem II photochemistry and the chlorophyll content of leaves remained unaltered, indicative of the absence of photooxidative damage. The concentration of alpha-tocopherol increased by 15-fold and that of carotenoids by approximately 26% in response to water stress. Enhanced formation of the highly oxidized abietane diterpenes isorosmanol (by 25%) and dimethyl isorosmanol (by 40%) was observed during the summer as result of the oxidation of carnosic acid, which decreased by 22%. The large amounts of carnosic acid, alpha-tocopherol, and carotenoids present in rosemary leaves might contribute to the prevention of oxidative damage in plants exposed to drought.
alpha-Tocopherol (alpha-T) has been identified, using gas chromatography-mass spectroscopy and (1)H- and (13)C-nuclear magnetic resonance, in senescing leaves of Melia azedarach L. The content of alpha-T increased concomitantly with the breakdown of chlorophyll in senescing Vinca and Melia leaves. An increase in alpha-T was found also in detached Melia leaves, senescing in either light or darkness and in senescing, ethylene-treated orange leaves and fruit. The possibility that phytol, which is released from chlorophyll by chlorophyllase is utilized for the biosynthesis of alpha-T is discussed. Senescing leaves of the low chlorophyllase plants, parsley and tobacco, did not contain alpha-T in measureable amounts.
The lipid-soluble antioxidants α-tocopherol and carnosic acid were studied in field-grown rosemary (Rosmarinus officinalis L.) plants subjected to drought. During summer in the Mediterranean region, the predawn water potential decreased to −3 MPa and the relative water content to 42%, which caused a depletion of the maximum diurnal CO2 assimilation rate by 80%. Meanwhile, the maximum efficiency of photosystem II photochemistry and the chlorophyll content of leaves remained unaltered, indicative of the absence of photooxidative damage. The concentration of α-tocopherol increased by 15-fold and that of carotenoids by approximately 26% in response to water stress. Enhanced formation of the highly oxidized abietane diterpenes isorosmanol (by 25%) and dimethyl isorosmanol (by 40%) was observed during the summer as result of the oxidation of carnosic acid, which decreased by 22%. The large amounts of carnosic acid, α-tocopherol, and carotenoids present in rosemary leaves might contribute to the prevention of oxidative damage in plants exposed to drought.
A new method for the production of tocopherols by safflower (Carthamus tinctorius) cell culture has been developed. The main tocopherol produced is α-tocopherol which has the strongest vitamin E activity among tocopherol analogues. In a time course experiment tocopherol production showed a secondary metabolic pattern rather than a primary one. Better cell lines in terms of both growth rate and amounts of tocopherols produced were obtained by selection using various growth regulators and media additives. In addition, tocopherol production was effectively stimulated by administration of biosynthetic precursors. In particular, phytol increased the total tocopherol content by some 18-fold, i.e. 63.6 mg per 100 g dry weight, and the α-tocopherol content by some 11- fold i.e. 28.8 mg per 100 g dry weight.
During the ripening cycle of Frantoio and Leccino olive varieties, the respiration rate of drupes was measured, giving the respiratory curve of fruits. This curve, for both varieties, dropped to a minimum point towards the end of November (a few days earlier for the Leccino variety) followed by a rise up to a maximum. This phase of the ripening process of olives corresponds to the climacteric crisis of the fruits. In this period the oil extracted from drupes gave the best analytical characteristics and was rich in tocopherols, phenols and aromatic volatile substances, components closely related to the shelf-life and the organoleptic quality of the product. The climacteric phase of drupes therefore corresponds to the optimal ripening stage of fruits and the harvesting of olives should be carried out during this period, in order to obtain oils of elevated quality. The respiration rate of drupes is therefore proposed as a new ripening index for drupes. © 1998 SCI.
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.
There is a growing body of evidence to suggest that the dietary intakes of vitamin E are insufficient to protect against the long-term health risks associated with oxidative stress. Traditional plant breeding and food processing technologies have not concerned themselves with maximising the levels of the tocopherols in the diet, and supplementation is necessary both for nutritive reasons and for the protection of fat-rich foods against oxidative rancidity. The paper reviews the potential for improving the tocopherol levels in the diet, particularly alpha-tocopherol. Genetic technologies have already demonstrated the potential to enhance tocopherol levels by up-regulation of the final steps in the biosynthetic pathway. Other strategies for the enhancement of the vitamin E content of plant foods are considered both from the perspective of improved bioavailability and the levels in processed foods. Finally some priorities for future research in the field are described. (C) 2000 Society of Chemical Industry.
The olive tree is generally grown under rain-fed conditions. However, since the yield response to irrigation, even with low amounts of water, is great there is increasing interest in irrigated agriculture. The main goal of this study was therefore to optimize sustainable irrigation conditions in the Cornicabra olive cultivar grown in Castilla-La Mancha, a region where the aquifers are over-exploited, and to study the effect of different irrigation strategies on the composition and quality of Cornicabra virgin olive oil. Different irrigation treatments, based on regulated deficit irrigation (RDI), 100% ETc, 125% ETc, and rain-fed as control, were applied to a traditional olive orchard (cv Cornicabra) in a randomized complete-block design with four replications. The average olive production of the trees grown under rain-fed conditions was much lower, about 35%, than that obtained by applying the different irrigation treatments studied, between which practically no difference were observed. The total phenol content, which affected the sensory bitterness in the oils, decreased significantly as the amount of supplied water increased. This is very relevant, as high levels of phenols, typical of Cornicabra virgin olive oils, may decrease consumer preference. Notably, one of the RDI strategies produced olive oil similar in composition and quality to that obtained by 100% ETc but with reduced water usage.
Work was carried out on the characterisation of virgin olive oils from the main Italian cultivars, `Frantoio' and `Leccino', grown in two different locations in Andalusia: Mengibar (Jaén) and Cabra (Córdoba), with important differences in altitude. The study was carried out during the crop years 1999/2000 and 2001/2002. There were significant differences between the oils from both cultivars when grown in the different environments, Cabra close to the hills and Mengibar in the open at 280 m height. At higher altitude, the oils showed a greater content of oleic acid and higher stability, while in the open the oils had higher tocopherol and linoleic acid contents. For the phenolic compounds, the environment influenced each cultivar in different ways. Sensorial characteristics, showed significant differences between the oils from each cultivar and location. In general, the oils from Andalusia had higher levels of natural antioxidants, greater oxidative stability and more marked sensorial characters.
To study the relationship between drought and oxidative stress and mechanisms of photo- and antioxidative protection in strawberry tree (Arbutus unedo L.), the endogenous concentrations of xanthophyll cycle pigments, α-tocopherol and reduced and oxidized ascorbate were measured in 2-year-old plants exposed to a combination of water deficit, high light and high temperatures in Mediterranean field conditions. Under moderate stress (relative leaf water content [RWC] of ca. 68%), levels of photosynthetic pigments (chlorophylls and carotenoids) and ascorbate were kept constant, while α-tocopherol levels increased by ca. 50%. Under severe stress (RWC of ca. 53%): (i) α-tocopherol levels remained high, (ii) zeaxanthin concentrations increased by 75%, (iii) ascorbate increased by 54% and its redox state shifted towards its oxidized form, and (iv) chlorophylls, lutein and β-carotene decreased by ca. 63, 61 and 75%, respectively. These results are consistent with the contentions that drought causes oxidative stress in A. unedo plants, and that mechanisms of photo- and antioxidative protection contribute to withstand drought-induced oxidative stress in this Mediterranean plant species.
The effect of fruit ripeness on the antioxidant content of `Hojiblanca' virgin olive oils was studied. Seasonal changes were monitored at bi-weekly intervals for three consecutive crop years. Phenolic content, tocopherol composition, bitterness index, carotenoid and chlorophyllic pigments and oxidative stability were analysed. In general, the antioxidants and the related parameters decreased as olive fruit ripened. The phenolics and bitterness, closely related parameters, did not present significant differences among years. Although in general, the tocopherols decreased during olive ripening γ-tocopherol increased. Differences between crop years were found only for total tocopherols and α-tocopherol, which showed higher content in low rainfall year oils. The pigment content decreased during ripening, chlorophyll changing faster. For low rainfall years, the level of pigments was higher, reaching significant differences between yields. Significant differences among years were found for oil oxidative stability; higher values were obtained for drought years. A highly significant prediction model for oxidative stability has been obtained.
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.
Our understanding of the role of vitamin E in human nutrition, health, and disease has broadened and changed over the past two decades. Viewed initially as nature's most potent lipid-soluble antioxidant (and discovered for its crucial role in mammalian reproduction) we have now come to realize that vitamin E action has many more facets, depending on the physiological context. Although mainly acting as an antioxidant, vitamin E can also be a pro-oxidant; it can even have nonantioxidant functions: as a signaling molecule, as a regulator of gene expression, and, possibly, in the prevention of cancer and atherosclerosis. Since the term vitamin E encompasses a group of eight structurally related tocopherols and tocotrienols, individual isomers have different propensities with respect to these novel, nontraditional roles. The particular beneficial effects of the individual isomers have to be considered when dissecting the physiological impact of dietary vitamin E or supplements (mainly containing only the alpha-tocopherol isomer) in clinical trials. These considerations are also relevant for the design of transgenic crop plants with the goal of enhancing vitamin E content because an engineered biosynthetic pathway may be biased toward formation of one isomer. In contrast to the tremendous recent advances in knowledge of vitamin E chemistry and biology, there is little hard evidence from clinical and epidemiologic studies on the beneficial effects of supplementation with vitamin E beyond the essential requirement.
Inhibiting oxidation Antioxidants in Food
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Vitamin E: an introduction The Antioxidant Vitamins C and E
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Pigmentos clorofilicos y carotenoides responsables del color del aceite de oliva virgen
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In: Standard Methods of Analyses of Oils Fats and Deri-vatives Nutritional and health aspects of olive oil
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IUPAC, 1992. Determination of tocopherols and tocotrienols in vegetable fats by HPLC. Method 2432. In: Standard Methods of Analyses of Oils Fats and Deri-vatives, Blackwell, Oxford, UK. Lenart, E.B., Willet, W.C., Kiritsakis, A.K., 1998. Nutritional and health aspects of olive oil. In: Kiritsakis, A.K. (Ed.), Olive Oil. Food and Nutrition Press, Trumbull (USA), pp. 299–322.
Olive oil composition Olive Oil Chemistry and Technology
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Boskou, D., 1996. Olive oil composition. In: Boskou, D. (Ed.), Olive Oil Chemistry and Technology. AOCS Press, Champaing (USA).
La caratterizzazione dell'olio extra virgene 'Tipico toscano'. II. Anno di recerca
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Cimato, A., 1991. La caratterizzazione dell'olio extra virgene 'Tipico toscano'. II. Anno di recerca. C.R.O.E.V.O.T.T, Firenze, Italy.
Informe sobre la utilizació n del analizador de rendimiento Abencor
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Martí, J.M., Muñ oz, E., Alba, J., Lanzó n, A., 1975. Informe sobre la utilizació n del analizador de rendimiento Abencor. Grasas y Aceites 26, 379–385.
Informe sobre la utilización del analizador de rendimiento Abencor
- Martínez
Vitamin E: an introduction
- Packer
Determination of tocopherols and tocotrienols in vegetable fats by HPLC. Method 2432
- IUPAC
Nutritional and health aspects of olive oil
- Lenart
Pigmentos clorofilicos y carotenoides responsables del color del aceite de oliva virgen
- Garrido