•Metabolic profiling approach to determine phenolic compounds of olive oil.•Possibility of implementing direct injection of olive oil into the LC.•Exhaustive optimization and evaluation of possible ...matrix effect.•21 compounds (belonging to different chemical classes) were determined.
A LC–MS method involving direct injection of extra-virgin olive oil (EVOO) – after a simple dilution – for determining its phenolic compounds has been developed. Optimization of the most appropriate solvent for sample dilution, selection of the optimum oil/solvent ratio, and establishment of column cleaning strategy and maximum number of injections were some of the most relevant steps. Then, the analytical parameters of the method were evaluated, establishing LOD (from 3.3 to 31.6µg/L) and LOQ, precision (RSD values for inter-day repeatability were found between 3.49 and 6.12%), and trueness (within the range 89.9–102.3% for 1.0mg/L) and checking possible matrix effect (which was no significant). Three kinds of calibration were used: external standard, standard addition and calibration in a phenols-free matrix, which was subsequently applied to quantify the phenolic compounds in 16 EVOOs (from 6 cultivars). A total of 21 compounds were determined without the need of using any extraction protocol.
► Resolution liquid chromatography. ► Mass spectrometry. ► Olive oil. ► Phenolic compounds.
The phenolic compounds present in seven samples of olive fruits were analysed by a rapid and resolutive ...LC–ESI-TOF MS method. All samples were collected during the normal picking period for olive oil production, in central and south Tunisia, and were obtained from the Oueslati variety cultivated in different olive growing areas.
In the Tunisian samples, 22 compounds have been characterised by LC–ESI-TOF MS analysis. Results showed no qualitative differences in the phenolic fractions between virgin olive oils from different geographical region. However, significant quantitative differences were observed in a wide number of phenolic compounds. These results permit to use the phenolic fractions as an indicator of each region.
In this research, a full rehabilitation study (retrofit) of an isolated villa in a Mediterranean climate was carried out in order to show how a retrofit of a building with a combination of simple ...passive and active strategies can improve the sustainability, energy efficiency and the thermal comfort. This is performed thanks to the design of a methodology of using a thermal simulation tool with experimental measurements based on a low-cost open source hardware platform in order to evaluate the energy saving measures and analyse the thermal comfort and energy savings. To accomplish this, a study of the housing needs is performed a priori to later design the different actions in the rehabilitation, using if possible, ecological materials in its development. Basically, walls and ceilings are insulated, three solar air collectors are included to heat the air ventilation and decrease the heating demand, and two pellet stoves are installed. Finally, the refurbished house is modeled and simulated in EnergyPlus and compared with the indoor air temperature and relative humidity measurements, made using an Open-Source Monitoring System (OSMS) developed for this research in Arduino, obtaining results with no significant differences without the need to calibrate the system. The results of thermal comfort, heating and cooling demand and heating energy consumption of the house before and after the renovation are compared providing a decrease in thermal demand of 66% and a decrease in heating energy consumption of 50% in the winter season, where 60% of the energy consumed is contributed from renewable sources. In terms of thermal comfort, the comparison of the PPD and PMV values shows an improvement in the house in heating and cooling season.
•A study of the retrofit of a villa in the south of Spain was planned, executed and measured.•Walls and ceilings are insulated, three solar air collectors supply hot air ventilation and two pellet stoves are installed.•The refurbished house is modeled and simulated in EnergyPlus and compared with the measurements made with Arduino.•A decrease in demand of 66% and a decrease in energy consumption of 50% in the winter season is obtained.
The purpose of this work was to evaluate some new filtration systems in relation to the quality of extra-virgin olive oil (EVOO). Filtration processes were undertaken using a polypropylene filter bag ...and two different inert gas flows as filter aids (argon and nitrogen). Qualitative and quantitative variations of the glyceride composition, antioxidant and pro-oxidant compounds, and water content were correlated with the oxidative stability to establish the effect on EVOO shelf life. The influence on physicochemical and sensorial properties was also evaluated. After filtration, the oxidative stability was reduced. The behavior of the polyphenols and water content on the filtration process could explain the lowest oxidative stability of filtered EVOO. Moreover, the results of the sensorial analysis confirmed that filtration using inert gases did not decrease the intensity of the main positive sensory attributes. The results could help olive-oil producers to improve EVOO quality and establish optimal storage conditions.
Herewith, the potential of an approach based on the combination of the determination of phenolic compounds and the use of chemometric treatments has been evaluated to establish, for the first time, ...promising models to authenticate the provenance of Moroccan monovarietal olive oils produced under different geographical origin indication systems. To achieve this purpose, 136 commercial extra virgin olive oil samples from three diverse production areas (Meknès territory; the Protected Geographical Indication Ouazzane; and the Protected Designation of Origin Tyout-Chiadma) were collected over two consecutive crop seasons (2012/2013 and 2013/2014). Their phenolic fraction composition was investigated by using high performance liquid chromatography coupled to mass spectrometry (HPLC-ESI-IT MS). The results showed that geographical provenance and harvest season had a marked influence on the content of identified phenolic compounds. Principal components analysis (PCA) and linear discriminant analysis (LDA) were applied to test the potential of the determined compounds as geographical discriminant features, achieving a noticeable discrimination among the three evaluated regions. The contribution of each analyte to the statistic model has been evaluated in depth.
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•Quali-quantitative characterization of olive oil phenolic comp. from PDO-oils.•A LDA model for geographical classification of samples was constructed.•A perfect discrimination between studied samples was achieved.•Authenticating origin of Moroccan EVOOs under geographical indication labels.
•An UFAD consisting of a radiant floor cooling with a rotational diffuser is presented.•The plume generated has been compared with the CFD results from smoke visualizations.•Numerical and ...experimental Nusselt against Reynolds are compared.•A non-linear fitting determines the scaling laws governing heat transfer in the system.•The change from DV to MV is controlled by inertia, not by temperature differences.
In this research, we explore the characteristics of an HVAC system consisting of a rotational floor diffuser with an underfloor plenum, coupled with a radiant floor cooling. Numerical simulations are performed using two different meshes. Firstly, we solve the diffuser outflow entering into the room by means of a very detailed mesh.
Secondly, the whole room with the radiant floor using as input the flow obtained from the former diffuser mesh. Besides, we analyze the flow visualizations that emerge near the rotational diffuser, and we demonstrate that there are two different regimes depending on the flow rate: (i) displacement ventilation that works as a radial flow, and (ii) a vertical jet with a very active mixing process for low or high flow rates, respectively. We calculate the Nusselt number versus the Reynolds number and collapse into a linear fit with different slopes below and above the Reynolds number 16,000, a limit that coincides with the previously observed change in flow patterns. Therefore, the type of flow patterns created near the diffuser only affect the level of heat transfer, but not its linear dependence. Finally, we propose another non-linear general adjustment of the Nusselt number as a function not only of Reynolds number but of the temperature ratios for all cases considered (isothermal and non-isothermal). This last non-linear regression model shows us that only inertia controls heat transfer and independence on the temperature ratio for Reynolds numbers lower than 16,000.
Herewith the development of a rapid and powerful LC methodology (with three different detectors) is presented to determine triterpenic acids and dialcohols in extracts from Olea europaea tissues ...(olive skin, pulp and leaves). After the proper optimization of the LC, DAD and MS conditions and the comprehensive characterization of the behavior of each analyte in ESI and APCI (with accurate m/z signals and, in ESI, with MS/MS data too), the method was fully validated. DAD, ESI-IT MS and APCI-QTOF MS were used as detection systems to give different alternatives to carry out the accurate determination of these analytes, evaluate their analytical performance, advantages and drawbacks, and check whether the quantitative results achieved by the three platforms were in good agreement. ESI-IT MS gave the lowest detection limits (3–455μg/L) followed by APCI-QTOF MS (22–408μg/L); in contrast, DAD (83–600μg/L) had the widest dynamic range. The RSD values for inter-day repeatability were found below 11.82% in all the cases. No statistically significant differences were found among the quantitative results from the three detectors. Olive leaves showed the highest concentration levels of ursolic acid (1.8mg/g), erythrodiol (1.6mg/g) and uvaol (1.2mg/g), whereas the olive skin was the richest matrix in terms of maslinic (80mg/g), betulinic (0.20mg/g), and oleanolic (26mg/g) acids. Concentration values of triterpenic acids were established by first time for skinless olive pulp, and were found around 65, 1.2, 55 and 4.4μg/g for maslinic, betulinic, oleanolic and ursolic acids, respectively.
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•Fast and sensitive method to determine triterpenoids in Olea europaea tissues.•Basic pH and both MS polarities to determine the 6 analytes under study.•Evaluating complementarity of three detectors coupled to LC in food metabolomics.•Comparison of triterpenoids concentration levels in different tissues of olive tree.
•Rapid and reliable LC-MS method to determine triterpenic acids and dialcohols in VOO.•First tangible alternative to widely used GC–MS to evaluate triterpenoids in VOO.•UAE-based method for efficient ...triterpenic compounds isolation from VOO.•Direct injection (after VOO dilution in acetone) into the LC-MS.•Comparison of triterpenic compounds concentration levels in different VOO cultivars.
Pentacyclic triterpenes are minor, but very relevant compounds found in virgin olive oil (VOO). A rapid and reliable LC-MS method for determining the triterpenic acids and dialcohols (after ultrasound assisted extraction) from VOO has been developed, giving an alternative to the widely used GC (FID/MS) methodologies. The analytical parameters of the proposed method were exhaustively checked, establishing limits of detection (from 1 to 95µg/l) and quantification, precision (RSD values for inter-day repeatability were found between 4.2 and 7.3% considering area values), trueness (within the range 92.7 and 100.5%) and evaluating possible matrix effect (which was no significant). The method was applied to the analysis of six triterpenic compounds in 11 monovarietal VOOs and the results compared with the quantitative GC–MS data. Moreover, the direct injection (after a simple dilution) of the samples into the LC-MS system was also tested, in an attempt to proffer an even simpler sample treatment.
Roots and aerial parts of
Cistaceae have been used since ancient times in the Mediterranean cultures for its medicinal properties. In this study, phenolic and tannin content of
C. ladanifer and
C. ...populifolius leaves aqueous extracts were determined and their antioxidant and antimicrobial activity were fully studied by several
in vitro assays. Their major compounds were identified and quantitated by high-performance liquid chromatography with diode array detection coupled to electrospray ion-trap mass spectrometry. Cytotoxicity on a panel of human cancer cells was also determined.
C. populifolius extract was stronger antioxidant than
C. ladanifer extract in electron transfer reaction based assays but
C. ladanifer extract was more effective to inhibit peroxyl radicals. The major compounds in both extracts were ellagitannins, especially punicalagins derivatives, showing
C. populifolius a higher content.
C. ladanifer showed noteworthy antibacterial activity against
Staphylococcus aureus, whereas
C. populifolius was effective against
Escherichia coli, with MICs values of 154 and 123
μg/mL, respectively. Last, both extracts showed a notorious capacity to inhibit the proliferation of M220 pancreatic cancer cells and MCF7/HER2 and JIMT-1 breast cancer cells. The leaves of these plants suppose a source for water-soluble ellagitannins-enriched polyphenolic extracts with antioxidant and antimicrobial activities. Their cytotoxic activity against several cancer cells may deserve further attention.
For the first time, a multi-class GC–MS method was applied to perform the quantitative-profiling of the minor fraction of VOOs (considering >40 compounds) in a single run. This comprehensive ...methodology has demonstrated a remarkable profiling ability on five groups of compounds (phenolic and triterpenic compounds, tocopherols, sterols and free fatty acids) with wide range of polarities/volatilities and chemical entities. After the complete analytical validation of the method, 32 VOO samples from eight different cultivars (some of them very scarcely studied before) were analyzed and the quantitative results were subjected to both non-supervised and supervised multivariate statistics for testing the capability of the determined VOO minor compounds to discriminate the varietal origin of the samples. Typical compositional profiles were defined for each cultivar and promising potential varietal markers were pointed out. The models built to discriminate Cayon and Maurino samples from the rest exhibited the best quality parameters. The relative levels of tocopherols together with characteristic concentration of luteolin, β-sitosterol and tyrosol were, for instance, the most specific features of Cayon VOOs.
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•A GC–MS multi-class method was applied to the analysis of virgin olive oil samples.•Comprehensive quantitative characterization of samples was achieved.•>40 compounds (5 different chemical classes) were determined in a single run.•PLS–DA models were established to discriminate among the 8 studied olive cultivars.•Potential varietal markers for each cultivar were pointed out.
