Oil quality parameters and quantitative measurement of major secoiridoid derivatives in Neb Jmel olive oil from various Tunisian origins using qNMR

2016 ◽  
Vol 96 (13) ◽  
pp. 4432-4439 ◽  
Author(s):  
Amir Ben Mansour ◽  
Boutheina Gargouri ◽  
Eleni Melliou ◽  
Prokopios Magiatis ◽  
Mohamed Bouaziz
Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 674
Author(s):  
Nawaf Abu-Khalaf

An electronic nose (EN), which is a kind of chemical sensor, was employed to check olive oil quality parameters. Fifty samples of olive oil, covering the four quality categories extra virgin, virgin, ordinary virgin and lampante, were gathered from different Palestinian cities. The samples were analysed chemically using routine tests and signals for each chemical were obtained using EN. Each signal acquisition represents the concentration of certain chemical constituents. Partial least squares (PLS) models were used to analyse both chemical and EN data. The results demonstrate that the EN was capable of modelling the acidity parameter with a good performance. The correlation coefficients of the PLS-1 model for acidity were 0.87 and 0.88 for calibration and validation sets, respectively. Furthermore, the values of the standard error of performance to standard deviation (RPD) for acidity were 2.61 and 2.68 for the calibration and the validation sets, respectively. It was found that two principal components (PCs) in the PLS-1 scores plot model explained 86% and 5% of EN and acidity variance, respectively. PLS-1 scores plot showed a high performance in classifying olive oil samples according to quality categories. The results demonstrated that EN can predict/model acidity with good precision. Additionally, EN was able to discriminate between diverse olive oil quality categories.


2021 ◽  
Vol 10 (1) ◽  
pp. 39
Author(s):  
Omar H. Dib ◽  
Christophe B. Y. Cordella ◽  
Rita Yaacoub ◽  
Hussein Dib ◽  
Nathalie Locquet ◽  
...  

The impact of harvest period on the quality parameters, polyphenols, fatty acids, sterols, and volatile compounds of Lebanese olive oil from the Soury variety was investigated in this study. Two groups of olive oil were compared, each with a specific harvest date. HD1 was harvested in October, whereas HD2 was picked in November. The analysis of both olive oil categories showed that HD2 witnessed a significant increase in all quality parameters except K270 and a decrease in total polyphenol content from 138 mg/mL to 44 mg/mL. Oleic and linoleic acids had an inverse relation, where the former decreased and the latter increased with the harvest date’s advancement. Palmitic acid in both groups was higher than the standards set for extra virgin olive oil. The relative amount of β -Sitosterol was mainly found to decrease, while those of stigmasterol, ∆5,24 -stigmastadienol, ∆7 -stigmastenol, and ∆7 -avenasterol increased with delaying harvest time. As for the volatile compounds, principle component analysis was used on the flash GC data to differentiate HD1 from HD2. Ethanol was found mostly characterizing HD2, whereas HD1 was influenced by 1-hexanol and (E,E)-2,4-decadienal. It can be concluded that the Soury variety should be harvested early, and a delay would result in the declassification of Lebanese olive oil quality from extra virgin to virgin olive oil.


2019 ◽  
Vol 11 (9) ◽  
pp. 2611 ◽  
Author(s):  
Andrea Casson ◽  
Roberto Beghi ◽  
Valentina Giovenzana ◽  
Ilaria Fiorindo ◽  
Alessio Tugnolo ◽  
...  

The olive oil industry is a significant productive sector in the European Union and the related production process is characterised by practices and techniques associated with several adverse effects on the environment. In the literature, many works on the environmental impact assessment of the olive oil chain have been carried out but the effects of the analytical analyses procedures were considered to be negligible. Currently, the reduction of solvents and of energy consumption in the laboratory has become a crucial aspect to be investigated. In this scenario, non-destructive optical methods based on visible/near-infrared (vis/NIR) spectroscopy represent a simple, rapid, and easy-to-use method to predict olive and olive oil quality parameters. Therefore, the aim of the work was to evaluate the environmental impact of the use of optical vis/NIR technologies for analytical assessment in comparison to chemical analyses on olive oil. The life cycle assessment method (LCA) was used. The functional unit defined for this study was the analysis and a “from cradle to grave” approach was applied. The vis/NIR technology results were distinctly better, by 36 times on average, than the chemical methods. Attention must be paid to the calibration phase of the vis/NIR instrumentation: In this case, the two methods must coexist for this initial procedure to obtain the required reference data for a reliable chemometric model. In conclusion, the vis/NIR spectroscopy gives very reliable results and can be considered a green technology, representing a choice among applications of low environmental impact analytical technologies.


2021 ◽  
Author(s):  
Annalisa Rotondi ◽  
Gianpaolo Bertazza ◽  
Barbara Faccini ◽  
Giacomo Ferretti ◽  
Lucia Morrone

<p>During the growing season, the use of foliar treatments based on fine grained geomaterial to reduce the negative impact of environmental stresses and protect the olives from insect pests is a well-known approach; however, while kaolin powders have been widely employed, zeolitite-based materials are much less known and exploited.</p><p>The aim of this study is to assess the effect of the two different treatments (zeolitite and kaolin) on the chemical and sensory qualities of the oils produced.</p><p>The study was carried out during two consecutive crop seasons in a 15 year old commercial olive orchard (Olea europaea), cv Correggiolo, located on the Appennine hills near Bologna (Italy). Foliar treatments were distributed during summer, until olive harvest. Ripening index, weight, oil and water content were measured on olive fruits. Olive productions were transformed in oils using a low scale continuous mill, quality parameters (free acidity, peroxide numbers, K232, K270, total phenols, fatty acids) were evaluated according to the official methods described in Regulation EC 2568/91 and subsequent amendments. Phenolic compounds, vitamins and pigments were determined by HPLC-DAD. Sensory analysis was performed by the panel of Agency for Agrofood Sector Services of Marche region (ASSAM), a fully-trained analytical taste panel recognized by the International Olive Oil Council (IOC) of Madrid, Spain, and by the Italian Ministry for Agriculture, Food, and Forestry Policy.</p><p>Olives treated with zeolite showed higher oil contents with respect to the other treatments. Oils produced by plants treated with zeolite particle film exhibited higher contents of total phenols, tyrosol, oleuropein and secoiridoids than to the oils produced by other treatments. Oils produced from olives treated with kaolin had sensory profiles characterized by sweet notes ascribable to ripe fruits, the tasters perceived notes of berries that are not typical of the Correggiolo cultivar.</p><p>The sensory taint test revealed a statistically significant difference between oils produced from olives treated with kaolin and the control, whereas no difference emerged between oils obtained from olives treated with zeolite and the control.</p><p>Particle film can influence some physiological plant parameters (photosynthesis, transpiration, water use efficiency) and, by consequence, it has also an influence on olive and oil quality. Olive plants treated with zeolite produced oils with higher antioxidant endowment, while oils produced from plants treated with kaolin were characterized by lower phenolic contents. Moreover, the kaolin treatment significantly affected the organoleptic properties of oils.</p>


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Samira Saffar Taluri ◽  
Seid Mahdi Jafari ◽  
Akbar Bahrami

AbstractChilling and freezing injuries of olives harvested in geographically high elevated locations may affect the quality of olive, and subsequently lead to oil with a poor quality. This study was aiming to investigate the influence of whether changes and freezing condition on the quality of extracted olive oil. The olive Koroneiki cultivar obtained from two origins was stored at three different temperatures (20, 5 and −18 °C) before oil extraction and common analyses (oil yield, acidity, peroxide value, thiobarbitorik acid value, total phenolics level, and color) were carried out in different time intervals (0, 20, 40, and 60 days) in order to assess the olive oil quality. Our data revealed that longer storage times significantly (P < 0.05) decreased the quality of olive oil. The fruits remained at 20 °C provided the lowest oil quality in all parameters. For example, the acidity of olive oil at 20 °C was 177% higher than samples kept at 5 °C after 20 days of olive storage. The general trend for comparing the quality parameters of extracted oils from olives kept at different temperatures was −18 > 5 > 20 °C. No significant negative effect (P < 0.05) was found for the samples kept at −18 °C, compared to 5 °C. Also, the geographical source of olive had a statistically significant influence (P < 0.05) on the quality of olive oil.


2019 ◽  
Vol 10 (1) ◽  
pp. 114 ◽  
Author(s):  
Antonia Tamborrino ◽  
Stefania Urbani ◽  
Maurizio Servili ◽  
Roberto Romaniello ◽  
Claudio Perone ◽  
...  

The aim of this study was to evaluate the ability of pulsed electric field (PEF) technology to improve the extractability and enhance the oil quality in an industrial olive oil extraction process. Using a PEF device on olive pastes significantly increased the extractability from 79.5% for the control, up to 85.5%. The PEF system did not modify the primary legal quality parameters or total concentrations of phenols, aldehydes, and esters. On the contrary, the non-thermal treatment slightly enhanced the dialdehydic forms of decarboxymethyl elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA) and tyrosol (p-HPEA-EDA), and decreased the total saturated and unsaturated C5 and C6 alcohols of the PEF EVOO (Extra Virgin Olive Oil) compared to the control test. This study confirmed that PEF technology can improve olive oil extraction and quality.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Alfonso M. Vidal ◽  
Sonia Alcalá ◽  
Antonia de Torres ◽  
Manuel Moya ◽  
Francisco Espínola

Centrifugation, storage, and filtration of olive oil were evaluated in an oil mill to determine their effect on the final quality of virgin olive oil. The main functions of these processes are to clarify the olive oil by removing water, solids, and other possible suspended particles. Although some changes were detected in the oil quality parameters after these processes, all the samples were extra virgin olive oil. The phenolic and volatile compound content of the olive oil was influenced by vertical centrifugation processing. Significantly, vertical centrifugation led to a 53% reduction in ethanol content. Oil storage before filtration resulted in a significant increase of around 30% in the peroxide index, while the antioxidant capacity decreased by 78%. Comparison of the results for filtered and unfiltered oil samples revealed that the most significant change was the reduction in the photosynthetic pigment content, with a decrease of around 50% in chlorophyll. Due of all this, the conditions applied in vertical centrifugation and the time of storage of the olive oils should be further controlled, enabling cleaning and decantation but avoiding the reduction of the antioxidant capacity and the content of phenolics compounds.


2016 ◽  
Vol 12 (33) ◽  
pp. 537
Author(s):  
Benaziza Abdelaziz ◽  
Semad Djamila

The cultivation of olive trees in the pre-Saharan areas of Algeria showed yields that are satisfactory and has acceptable values of oil quality. In the context of improvement of culture and order to respond to international norms for a particular exporting oil extra virgin, she should have a lower 0.8% acidity required by the economic operators. For enhanced characterization and valorization some local of olive oil varieties introduced, this work falls under this objective and is articulated primarily on six varieties. It is based essentially on oil quality parameters.


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