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1.
Phenolic compounds are of fundamental importance to the quality and nutritional properties of virgin olive oils. In this paper, the high-performance liquid chromatographic analysis of simple and complex olive oil phenols in the streams generated in the two-phase extraction system was carried out using Arbequina and Picual olives. The malaxation stage reduced the concentration of orthodiphenols in oil ca 50–70%, while the concentration of the nonorthodiphenols remained constant, particularly the recently identified lignans 1-acetoxypinoresinol and pinoresinol. Oxidation of orthodiphenols at laboratory scale was avoided by malaxing the paste under a nitrogen atmosphere. Phenolic compounds in the wash water used in the vertical centrifuge were also identified. Hydroxytyrosol, tyrosol, the dialdehydic form of elenolic acid linked to hydroxytyrosol were the most representative phenols in these waters. Hence, phenolic compounds in the wash waters came from both the aqueous and the lipid phases of the decanter oily must.  相似文献   

2.
The effect of extraction systems on the phenolic composition of virgin olive oils obtained from two different Italian cultivars (Coratina and Oliarola) was determined. The oils extracted using two-phase centrifugation showed in all cases higher phenolic concentration in comparison to oils obtained from three-phase centrifugation. In particular, the highest differences were observed for aglykone derivatives of oleuropein (3,4-DHPEA-EDA and 3,4-DHPEA-EA) that are the most concentrated antioxidant phenolic compounds of virgin olive oil. These results were confirmed by the autoxidation stability of the oils examined.  相似文献   

3.
The purpose of this investigation was to study differences in the chlorophyll, carotenoid, and phenolic fractions of virgin olive oils from the Arbequina variety cultivated in different olive growing areas of Spain. Virgin olive oil from Lleida was less heavily pigmented, and these oils showed more negative values for the ordinate a* (of the CIELAB colorimetric system). Pheophytin a was the major chlorophyll pigment, and lutein was the major component of the carotenoid fraction in all oils analyzed. The chlorophyll a concentration in virgin olive oils from Lleida was 700 μg kg−1, but was 175 μg kg−1 in oils from Jaén, and 200 μg kg−1 in oils from Tarragona. Finally, the chlorophyll a/chlorophyll b ratio was 9 in oils from Lleida and around 0.6 in the other two Arbequina olive oils. In relation to the phenolic fraction, the hydroxytyrosol and tyrosol contents were significantly higher in olive oils from Jaén (grown at higher altitude and precipitation rates). The secoiridoid derivatives showed a significantly higher concentration in olive oils from Tarragona, probably due to the low altitude where they grow, and finally the ratio of (dialdehydic form of elenolic acid linked to tyrosol)/lignans had a value of 1.4 in olive oils from Lleida, whereas this value was around 0.7 in the other Arbequina olive oils.  相似文献   

4.
A characterization study of the main olive oil cultivars of southwest Spain (Picual, Arbequina, and Verdial) has been performed in order to establish logistic regression models. Several quality characteristics (free acidity, peroxide value, K232, K270, oxidative stability index) and chemical data (fatty acids, sterols, erythrodiol–uvaol composition) were measured. Logit regressions were used to evaluate the correlation of the parameters and to create models that allow saving costs on identifying oils as Arbequina, Picual, or Verdial type. Multiple logit regression models were developed: one for Arbequina, three models for Picual, and two models for Verdial cultivar, allowing in this way to minimize the cost for classifying oil samples. Practical application: The olive oil marketing is increasingly focused on the chemical differentiation and characterization of the product because the chemical composition of these virgin oils is responsible for their valuable sensory and nutritional properties. Here we present a characterization study (quality characteristics and chemical data) from the main olive oil cultivars of southwest Spain, Picual, Arbequina, and Verdial, as a first step for the traceability of these three types of monocultivar virgin olive oils. The results may be used as a training to create models for other olive oil cultivars.  相似文献   

5.
The evaluation and characterization of segregating populations is a critical step in olive breeding programs. In this work, phenolic profiles of virgin olive oils (VOOs) from segregating populations obtained by cross breeding in Cordoba (Spain) have been evaluated. Genotypes obtained from open pollination of the cultivar Manzanilla de Sevilla, and from crosses between the cultivars Arbequina × Arbosana, Picual × Koroneiki and Sikitita × Arbosana were tested. The phenolic composition was determined after liquid–liquid extraction with 60:40 v/v methanol–water and subsequent chromatographic analysis with ultraviolet (UV) detection of both absorption and fluorescence in a sequential configuration. Results for all studied compounds showed high degree of variability between genotypes, with a higher range of variation than the observed for the genitors. Most of the observed variability was attributable to differences in genotypes within crosses rather than among crosses. Some issues related to breeding strategies are discussed. Practical applications: Phenolic compounds are considered to be of paramount importance for the assessment of virgin olive oil quality due to their contribution to the nutraceutical and sensory profile of this natural food. This study focuses on the evaluation of the content of phenolic compounds in olive oils originated from cross breeding in an olive breeding program (Cordoba, Spain). This step is crucial to determine the range of variation of phenolic compounds and the selection of interesting genotypes with higher composition in total phenols or in an individual phenol targeted at a breeding program.  相似文献   

6.
Virgin olive oil has high levels of phenolic compounds that are highly bioavailable; these compounds are receiving considerable attention for their antioxidant activity, closely related to the prevention of non‐communicable chronic diseases. The aim of this work was to characterize the phenolic profile and antioxidant capacity of monovarietal olive oils cvs. Arauco, Arbequina, Farga and Empeltre produced in Argentina. This study focused on the relationship between the single molecules or classes of molecules quantified by SPE‐CZE, the corresponding Folin‐Ciocalteu results, and antioxidant capacity using three different tests. Fifteen compounds were simultaneously determined: tyrosol, vinylphenol, oleuropein, hydroxytyrosol, rutin, catechin, naringenin, cinnamic acid, chlorogenic acid, syringic acid, luteolin, apigenin, vanillin acid, quercetin, and caffeic acid. The phenolic contents of the monovarietal olive oils show significant differences between different varieties (p < 0.05), with positive and significant Pearson's correlation found between Folin–Ciocalteu and CZE. Besides, the correlation between the content of total polyphenols and antioxidant capacity was high for all the antioxidant assays performed. When analyzing the correlation coefficients of the different families of phenolic compounds studied, simple phenols and cinnamic acid derivatives show a higher correlation with antioxidant capacity. Thus, findings obtained in this study demonstrated that Arauco olive oil, autochthonous for Argentina, possesses the highest antioxidant/free‐radical scavenging properties, which are very likely due to the presence of high contents of phenolic compounds.  相似文献   

7.
Fifteen genotypes coming from crosses between the cultivars Arbequina, Frantoio and Picual were selected on the basis of their agronomic characteristics in a breeding program initiated in 1991. In the present work, the main components of the olive oil of these 15 advances selections have been characterized and compared to their genitors. A wide range of variation was observed for all the fatty acids, minor components and related characteristics evaluated, with significant differences between genotypes for all of them except for β‐tocopherol content. These results confirm the strong genetic influence on olive oil quality previously reported on olive oil cultivar evaluations. The values obtained in the selections have extended the range of variation of their three genitors for all the characters evaluated, except for γ‐tocopherol. Selections UC‐I 7‐8, UC‐I 5‐44 and UC‐I 2‐68 showed the highest average values for tocopherols, polyphenol and C18:1 contents, respectively. Finally, multivariate analysis allowed the classification of genotypes in four groups according to their olive oil composition. Practical applications: Olive oil composition is considered one of the most important objectives in breeding programs aiming at obtaining new olive cultivars. In the last decades olive breeding programs are being carried out in the main olive‐producing countries and several new cultivars and advanced selections have been described. The results of this work provide an initial characterization of virgin olive oils of advanced selections coming from crosses between the cultivars Arbequina, Frantoio and Picual and suggest a strong genetic influence on fatty acid composition, several minor components and related characteristics. These results, together with the agronomic characterization of these selections previously reported, will be used for the final selection of the best genotypes to be registered as new cultivars.  相似文献   

8.
Storage conditions influence the maximum time for which the composition and sensory characteristics of olive oils can be guaranteed. The purpose of this research was to study the quality and phenol content of extra virgin olive oil (EVOO) after storage for 1 year in different types of containers under darkness or light. Three Spanish cultivars with quantitatively different phenol contents were selected for the study. Storage under light conditions impaired the physicochemical and sensorial properties of the three cultivars, and reduced total phenolics, but there was an increase in hydroxytyrosol and tyrosol concentrations. It also markedly decreased their total phenolic content, especially when kept in polyethylene containers exposed to light, with reductions ranging from 4.28% for vanillic acid in Picual oils stored in dark glass containers under dark conditions to 97.82% for ferulic acid in Arbequina oils stored in polyethylene containers under light conditions. There was a reduced concentration of flavonoid and lignan concentrations after 1 year of storage, with the greatest decrease (98.01% of initial content) being observed for in the flavonoid apigenin. These results indicate that EVOO should be stored in dark glass containers under dark conditions for the optimal preservation of its quality and phenol content.  相似文献   

9.
The presence of different bioactive compounds in virgin olive oil affects its nutritional, oxidative and sensorial properties. Phenolic compounds are olive endogenous bioactive compounds highly susceptible to degradation. Olive endogenous oxidoreductases, mainly polyphenol oxidases (PPO) and peroxidases (POD), may play an important role on the profile of bioactive compounds in olive oil by promoting oxidation of phenolic compounds. The aim of this study was to evaluate if changes on PPO and POD activities in olive fruits from two Portuguese cultivars (Olea europaea, cv ‘Cobrançosa’ and cv ‘Galega Vulgar’) are related with the composition of their olive oils, especially phenolic compounds. Pattern recognition techniques [principal component analysis (PCA), cluster analysis (CA), and discriminant analysis (DA)] were used for multivariate data analysis. Olive oils characterized by their FA composition were grouped by cultivar. When olive oils were characterized by their phenolic composition, green pigments, and enzymatic activities in fruits, they could be discriminated by olive ripening stage. Along ripening, PPO activity was only detected in the fruit mesocarp of both cultivars and POD activity was mainly detected in the seeds. The POD activity, as well as vanillin and gamma‐tocopherol contents in olive oil increased with the ripening index. Conversely, higher PPO activity in fruits at early ripening stages together with higher levels of total phenols, green pigments, beta‐tocopherol, hydroxytyrosol and p‐coumaric acid in olive oils were observed. The ripening stage of fruits showed to be a key factor on the amount and profile of bioactive compounds of olive oil.  相似文献   

10.
Fatty acids, tocopherols, and phenolic compounds biogenesis from two major Spanish olive cultivars (Arbequina and Manzanilla) were analyzed for the function of the thermal regime during the fruit ontogeny in a non‐Mediterranean environment. Bilinear models characterized the dynamics of fatty acid biogenesis. Regressions between the accumulated thermal time (TT) and the levels of both oleic and linoleic acids showed different responses to temperature of each olive cultivar. After reaching similar absolute maximum oleic acid contents at similar TT, the levels of this fatty acid decreased markedly in cv. Arbequina and its final concentration was 10 % lower than that found in cv. Manzanilla. In both cultivars, concentrations of all tocopherol isoforms were negatively associated with the TT accumulated over the entire oil accumulation period. Dynamics of phenolic compounds biogenesis showed no clear tendencies with TT. Nevertheless, and whatever the stage of fruit development, secoiridoids were the major phenolic components. Results suggest greater sensitivity of fatty acid metabolism to temperature in cv. Arbequina. This fact points out the necessity of appropriate evaluation of the ambient thermal characteristics before introducing this cultivar into new growing environments.  相似文献   

11.
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, are 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 are 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 is influenced by both cultivar and harvest year. EVOO produced in 2018 has 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 are the variables whose contents most contributed to the differentiation of oils by cultivar in both harvest years. Chemical characterization analyses allow 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 shows high quality, and is especially rich in phenolic compounds. Although harvest year influences oil composition, oil from both harvests meet EVOO standards and cultivar specific metabolic markers are observed. This study provides the foundation for olive producers in Southern Brazil to seek authentication of the geographical origin of olive oil.  相似文献   

12.
The use of an emulsifier to stabilize the phenolic compounds added in the preparation of an enriched olive oil was evaluated. Two emulsifiers, lecithin and monoglyceride, were studied. The results showed lecithin to be the most convenient, due to the increase in the value of the oxidative stability of the phenol‐enriched oils in relation to the enrichments prepared with monoglycerides. After that, the shelf life of the prepared oils was evaluated during a period of 256 days of storage at 25°C in the dark. Oil quality parameters, total phenolic content, bitterness index and oxidative stability were studied during the storage period. Additionally, the phenolic composition and antioxidant capacity (by using the ORAC assay) were evaluated at the end of the storage. The phenolic enrichment of the oils allowed the shelf life of the oils to be extended compared with the control (virgin olive oil without phenol addition), delaying the appearance of peroxides and improving their oxidative stability. In addition, the higher content of phenolic compounds in the oils at all stages of storage is desirable in order to increase the intake of these beneficial compounds. Practical applications : The preparation of phenol‐enriched olive oils with a higher phenolic content than the commercial virgin olive oils is of special interest to increase the ingestion of these healthy compounds the daily intake of which is limited due to the high caloric value of olive oil. There are two key points in the development of this product: (i) the dispersion and stabilization of the phenol extract in the oil matrix and (ii) the stability of the phenols in the prepared oils to guarantee the phenol concentration during their shelf life. It is important to study the use of emulsifiers to determine if they allow an improvement in the dispersion of the phenolic extract, and their stabilization in the final product. In addition, the emulsifiers could mask the bitter taste of the enriched oils, which is desirable to increase consumer acceptance of the enriched oil.  相似文献   

13.
Phenolic compounds are of fundamental importance to the shelf life of virgin olive oils because of their antioxidative properties. In this paper, the evolution of simple and complex olive oil phenols during 18 mon of storage is studied by high-performance liquid chromatography (HPLC) analysis. The olive oils under examination were from various olive cultivars, harvested in two sectors in the same region at different stages of ripeness. The findings indicate that it is not the variety but rather the ripeness of the olives and the soil and climate that influence the phenol composition of virgin olive oil. In addition, a positive correlation was found between the age of the oils and the tyrosol to total phenols ratio. Lastly, gas chromatography-mass spectrometry analysis confirmed that the unidentified peaks detected by HPLC were of a phenolic nature.  相似文献   

14.
“Sikitita” is a relatively new olive cultivar obtained from crossbreeding between “Picual” and “Arbequina” that can be trained into the super-high-density orchard system. The impact of harvest time and crop season (2017 and 2018) on fruit parameters, oil quality, and minor compounds was assessed for super-high-density “Sikitita” in California, USA. Maximum olive fruit oil content (~49% on a dry basis) was reached between the first and second weeks of November. Quality parameters were within limits for extra virgin classification for all harvest times during both crop seasons. While total phenols were affected by harvest time, crop year, and their interaction, total volatile content was mainly influenced by harvest time. Both phenolic and volatile compounds reached a maximum concentration by the first week of October, suggesting that harvesting at the beginning of October would lead to a richer oil in terms of minor components. However, oil yield can be maximized if the harvest takes place in November. Our results demonstrated fruit parameters, oil quality, and minor compounds of super-high-density “Sikitita” followed a similar pattern and reached comparable values in both years, despite an earlier maturation in 2018. “Sikitita” has potential as a viable cultivar for growers and processors who are looking to expand on the traditional super-high-density cultivars.  相似文献   

15.
The effects of the contents of lipids, pigments, α-tocopherol and phenols were studied in relation to the antioxidant capacity of five virgin olive oils obtained from five olive cultivars planted in Tunisia (Arbequina, Koroneiki, Leccino, Oueslati and Chemchali). The antioxidant capacities were evaluated by two different radical scavenging activities: radical scavenging activity by the DPPH assay (RSA-DPPH) and total antioxidant status by the ABTS test (TAA-ABTS). The highest contents of antioxidant compounds (75.96, 10.34, 6.32, 15.39 and 241.52 mg kg−1 for oleic acid, O/L ratio, carotenes, chlorophylls and total phenols, respectively) were found for the Koroneiki cultivar except for α-tocopherol and o-diphenols, which had the highest contents (369 and 160.7 mg kg−1, respectively) in the Leccino and Chemchali cultivars (cvs). Furthermore, the highest antioxidant capacity in virgin olive oil was observed in the Koroneiki cultivar (0.24 mmol TE kg−1) followed by the Chemchali and Leccino cvs (0.22 and 0.13 mmol TE kg−1) for the TAA-ABTS test. However, the RSA-DPPH activity was higher for the Chemchali cultivar (19.9%) than for the Koroneiki and Leccino cvs (18.4 and 13.5%, respectively). Correlation between these capacities and the oil composition revealed that they were mainly influenced by the carotene content, followed by chlorophyll and phenolic contents where the ABTS test was more pronounced. Then, the antioxidant capacity of the virgin olive oils was correlated with polar components and the lipid profile which are important for its shelf life.  相似文献   

16.
Extra virgin olive oils were extracted from six different major olive cultivars (Gemlik, Ayvalik, Domat, Akhisar, Memecik, Arbequina) cultivated in the Aegean region of Turkey. Fatty acid, sterol and tocopherol compositions were analyzed and the results were compared by multivariate statistical analysis. Olive samples were collected from the same orchard in order to limit the contribution of parameters such as climate, soil quality and agricultural practices to the total variance of chemical composition of olive oils. Principal component analysis (PCA) showed that cultivars can be clearly distinguished on the basis of fatty acid and sterol composition. It is of interest to note that palmitoleic acid content of Arbequina, a Spanish cultivar, is significantly (p < 0.05) higher than the local Turkish cultivars in question and it is the only olive sample whose palmitoleic acid concentration is higher than that of the stearic acid concentration, exhibiting a divergent composition from the local Turkish cultivars. β‐Sitosterol and Δ5‐avenasterol contents of the oils are significantly correlated (r = ?0.989, p < 0.05) and this results in a discriminative axis on the PCA loading plot. Tocopherol composition was relatively insufficient in discriminating the olive varieties. Regarding tocopherol compositions Gemlik cultivar is distinguished from other cultivars with its γ‐tocopherol content, which is in average two times higher than that of other cultivars. The result of the present compositional study provides important data which can be used for olive oil authenticity studies in Turkey.  相似文献   

17.
The purpose of this investigation was to evaluate and compare the differences in the phenolic fractions and antioxidant properties of virgin olive oils from the Nizip yaglik and Kilis yaglik olive varieties cultivated in native and different olive growing areas of Turkey. The phenolic composition of olive oils was carried out by HPLC-DAD and identifications were made by LC–MS. Fourteen phenolic compounds were identified and among these compounds elenolic acid, tyrosol and hydroxytyrosol were the most dominant. Based on the results, there was no difference in distribution of phenolic compounds, but the total phenolic content in oil from native regions was higher than in oil from Bornova regions. The antioxidant capacity of olive oil extracts was determined by two different methods, including DPPH and ABTS. In both methods, antioxidant capacity values were higher in oil from native regions.  相似文献   

18.
The effect of filtration and dehydration on the stability and quality of virgin olive oil during storage at room temperature (25 °C) and under accelerated conditions (40 °C) was studied. Different types of monovarietal olive oil, namely unfiltered (UF), filtered (F) and filtered‐dehydrated (FD), were obtained from Arbequina, Colombaia, Cornicabra, Picual and Taggiasca cultivars. Results showed that filtration and dehydration decreased the rate of hydrolysis of the triacylglycerol matrix, especially at the higher temperature and in oils with a higher initial free acidity (e.g. free acidity of 0.82% and 0.63% in UF and FD Colombaia samples, respectively, after 8 months of storage), and delayed the appearance of rancid defects (e.g. UF and FD Arbequina samples lost extra‐virgin grade after 10 and 12 months of storage, respectively). The formation of simple phenols due to the hydrolysis rate of their secoiridoid derivatives was also greater in unfiltered olive oils (e.g. 174 μmol/kg and 137 μmol/kg in UF and FD Picual samples, respectively, after 8 months of storage). Thus, filtration and especially dehydration could help to prolong the shelf life of high‐quality and less stable olive oils like those obtained from the Arbequina and Colombaia varieties.  相似文献   

19.
The factors influencing the oxidative stability of different commercial olive oils were evaluated. Comparisons were made of (i) the oxidative stability of commercial olive oils with that of a refined, bleached, and deodorized (RBD) olive oil, and (ii) the antioxidant activity of a mixture of phenolic compounds extracted from virgin olive oil with that of pure compounds andα-tocopherol added to RBD olive oil. The progress of oxidation at 60°C was followed by measuring both the formation (peroxide value, PV) and the decomposition (hexanal and volatiles) of hydroperoxides. The trends in antioxidant activity were different according to whether PV or hexanal were measured. Although the virgin olive oils contained higher levels of phenolic compounds than did the refined and RBD oils, their oxidative stability was significantly decreased by their high initial PV. Phenolic compounds extracted from virgin olive oils increased the oxidative stability of RBD olive oil. On the basis of PV, the phenol extract had the best antioxidant activity at 50 ppm, as gallic acid equivalents, but on the basis of hexanal formation, better antioxidant activity was observed at 100 and 200 ppm.α-Tocopherol behaved as a prooxidant at high concentrations (>250 ppm) on the basis of PV, but was more effective than the other antioxidants in inhibiting hexanal formation in RBD olive oil.o-Diphenols (caffeic acid) and, to a lesser extent, substitutedo-diphenols (ferulic and vanillic acids), showed better antioxidant activity than monophenols (p- ando-coumaric), based on both PV and hexanal formation. This study emphasizes the need to measure at least two oxidation parameters to better evaluate antioxidants and the oxidative stability of olive oils. The antioxidant effectiveness of phenolic compounds in virgin olive oils can be significantly diminished in oils if their initial PV are too high.  相似文献   

20.
The time of exposure of olive pastes to air contact (TEOPAC) during malaxation was studied as a processing parameter that could be used to control endogenous oxidoreductases, such as polyphenoloxidase, peroxidase, and lipoxygenase, which affect virgin olive oil quality. Phenolic and volatile compounds were analyzed in the oils obtained using progressive TEOPAC at three ripening stages of olives. Multivariate statistical analysis was applied to the raw data. The phenolic concentration of virgin olive oil progressively decreased with increasing IEOPAC. On the contrary, a positive relationship was found with the concentration of several volatile compounds responsible for virgin olive oil aroma. The effect of TEOPAC, however, was strictly related to fruit ripening.  相似文献   

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