scholarly journals Volatile Compounds, Profiles of Virgin Olive Oils Produced In the Eastern Morocco: Oxidative Stability and Sensory Defects

2012 ◽  
Vol 1 (4) ◽  
pp. 194 ◽  
Author(s):  
Karima Tanouti ◽  
Hanae Serghini-Caid ◽  
Marianne Sindic ◽  
Jean-Paul Wathelet ◽  
Amina Bouseta ◽  
...  

<p>Studies on flavor profiles of virgin olive oil (VOO) are becoming more and more numerous. The VOO aromas are determined by a mixture of chemicals in olive oil, which influence its quality. Various studies around the world have shown that the volatile compounds in VOO depend on the climate, cultivation and process.</p> <p>The present work is a first approach to compare volatile profiles of VOO largely produced in eastern of Morocco after 6 months of storage at ambient temperature in darkness. Oxidative stability measured by Rancimat method at 101C was also determined. VOO volatile profiles were examined using the solid-phase micro extraction fibre method (SPME) in conjunction with gas chromatography/mass spectrometer (GC/ MS). 84 volatile compounds were identified; they belong to various chemical classes, such as aldehydes, alcohols, esters, ketones, carboxylic acids and hydrocarbons. The main volatile compounds present in olive oil samples were compounds with 6 carbon atoms (C6) such as Hexanal, (E)-hex-2-enal, Z-3-Hexen-1-ol and 1-Hexanol. Ethanol and Z-3, 7-dimethyl-1, 3, 6-octatriene, methyl acetate and ethyl acetate were also found. In general, these compounds have been identified in all VOO analyzed samples. The chemical compositions of the analyzed virgin olive oil headspaces evidenced that the most representative compounds In Isly and Kenine were carboxylic acids accounted for 59.24%-49.7% respectively, whereas the volatile fraction of the oil from Achajara almoubaraka showed significantly higher amounts of the alcohols (46%). Concerning oxidative stability, Isly and Kenine OO, have lower stability values compared to Achajara almoubaraka. Their potential oxidative susceptibility is therefore much higher than Achajara almoubaraka.</p>

Author(s):  
Bechir Baccouri ◽  
Imene Rajhi

The volatile profiles of Tunisian virgin olive oils were established by solid phase micro-extraction (SPME) and gas chromatography (GC), using flame ionisation and mass spectrometer detectors. Terpenes compounds were identified and characterized. Limonene, the main terpene compound extracted by SPME, characterized the studied olive oil. Significant differences in the proportions of terpenes constituents from oils of different maturity index were detected. The results demonstrated that the accumulation of the terpenes compounds in the studied oils obtained from different ripeness stage was strictly connected with the ripeness stage.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Mokhtar Guerfel ◽  
Mohamed Ben Mansour ◽  
Youssef Ouni ◽  
Flamini Guido ◽  
Dalenda Boujnah ◽  
...  

The present study focused on the comparison the chemical composition of virgin olive oil samples obtained from fruits of the main Tunisian olive cultivar (Chemlali) grown in four planting densities (156, 100, 69, and 51 trees ha−1). Despite the variability in the triacylglycerols and volatile compounds composition, the quality indices (free fatty acids, peroxide value, and spectrophotometric indices K232and K270) all of the virgin olive oils samples studied met the commercial standards. Decanal was the major constituent, accounting for about 30% of the whole volatiles. Moreover, the chemical composition of the volatile fraction of the oil from fruits of trees grown at the planting density of 156, 100, and 51 trees ha−1was also characterised by the preeminence of 1-hexanol, while oils from fruits of trees grown at the planting density of 69 trees ha−1had higher content of (E)-2-hexenal (20.3%). Our results confirm that planting density is a crucial parameter that may influence the quality of olive oils.


Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1672
Author(s):  
Ioanna S. Kosma ◽  
Michael G. Kontominas ◽  
Anastasia V. Badeka

In the present study, volatile compound analysis of olive oil samples belonging to ten Greek cultivars was carried out. A total of 167 olive oil samples collected from two consecutive harvest years were analyzed by Head Space-Solid Phase Microextraction-Gas Chromatography/Mass Spectrometry (HS-SPME-GC/MS). Volatile compound data were combined with chemometric methods (Multivariate Analysis of Variance (MANOVA) and Linear Discriminant Analysis (LDA)) with the aim not only to differentiate olive oils but also to identify characteristic volatile compounds that would enable differentiation of botanical origin (marker compounds). The application of Stepwise LDA (SLDA) effectively reduced the large number of statistically significant volatile compounds involved in the differentiation process, and thus, led to a set of parameters, the majority of which belong to compounds that are highly dependent on variety. In addition, the use of these marker compounds resulted in an increased correct classification rate (85.6%) using the cross-validation method indicating the validity of the model developed despite the use of a large number of dependent variables (cultivars).


Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2379 ◽  
Author(s):  
Lorenzo Cecchi ◽  
Maria Bellumori ◽  
Filomena Corbo ◽  
Gualtiero Milani ◽  
Maria Lisa Clodoveo ◽  
...  

The use of innovative systems, such as the heat exchanger, for production of extra virgin olive oil should allow maintenance of the same quality of those oils derived from traditional processes, and presents specific advantages. The performance of this system was evaluated by (i) determining the parameters directly measurable by the olive millers (i.e., end-user validation based on the production yields when the plant is located in different processing lines) and (ii) assessing the product quality through estimation of the content of phenolic and volatile compounds. The phenols were determined by High Performance Liquid Chromatography with Diode Array Detector (HPLC–DAD) before and after acidic hydrolysis while the volatile fraction was studied by Head-Space Solid-Phase-Micro-Extraction Gas-Chromatography with Mass Detector (HS–SPME–GC–MS). The use of the sono-heat-exchanger presents several advantages: it is a flexible machine, able to interface with all devices of the world’s leading manufacturers of the Extra Virgin Olive Oil (EVOO) extraction plant, and it guarantees shorter processing times and energy savings. Our results also pointed out its capability to increase the oil yields up to 5.5%, particularly when it extracts oil from unripe fruits, which in traditional processes yield oils with higher phenolic contents, but with lower oil yields. Overall, the quality of virgin olive oils was maintained, avoiding decreases of phenolic content or detrimental effects on the sensory characteristics.


Separations ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 34 ◽  
Author(s):  
Federico Stilo ◽  
Chiara Cordero ◽  
Barbara Sgorbini ◽  
Carlo Bicchi ◽  
Erica Liberto

The study explores the complex volatile fraction of extra-virgin olive oil by combining high concentration-capacity headspace approaches with comprehensive two-dimensional gas chromatography, which is coupled with time of flight mass spectrometry. The static headspace techniques in this study are: (a) Solid-phase microextraction, with multi-polymer coating (SPME- Divinylbenzene/Carboxen/Polydimethylsiloxane), which is taken as the reference technique; (b) headspace sorptive extraction (HSSE) with either a single-material coating (polydimethylsiloxane—PDMS) or a dual-phase coating that combines PDMS/Carbopack and PDMS/EG (ethyleneglycol); (c) monolithic material sorptive extraction (MMSE), using octa-decyl silica combined with graphite carbon (ODS/CB); and dynamic headspace (d) with either PDMS foam, operating in partition mode, or Tenax TA™, operating in adsorption mode. The coverage of both targeted and untargeted 2D-peak-region features, which corresponds to detectable analytes, was examined, while concentration factors (CF) for a selection of informative analytes, including key-odorants and off-odors, and homolog-series relative ratios were calculated and the information capacity was discussed. The results highlighted the differences in concentration capacities, which were mainly caused by polymer-accumulation characteristics (sorptive/adsorptive materials) and its amount. The relative concentration capacity for homologues and potent odorants was also discussed, while headspace linearity and the relative distribution of analytes, as a function of different sampling amounts, was examined. This last point is of particular interest in quantitative studies where accurate data is needed to derive consistent conclusions.


Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 368
Author(s):  
Paula Garcia-Oliveira ◽  
Cecilia Jimenez-Lopez ◽  
Catarina Lourenço-Lopes ◽  
Franklin Chamorro ◽  
Antia Gonzalez Pereira ◽  
...  

Extra virgin olive oil (EVOO) is one of the most distinctive ingredients of the Mediterranean diet. There are many properties related to this golden ingredient, from supreme organoleptic characteristics to benefits for human health. EVOO contains in its composition molecules capable of exerting bioactivities such as cardio protection, antioxidant, anti-inflammatory, antidiabetic, and anticancer activity, among others, mainly caused by unsaturated fatty acids and certain minor compounds such as tocopherols or phenolic compounds. EVOO is considered the highest quality vegetable oil, which also implies a high sensory quality. The organoleptic properties related to the flavor of this valued product are also due to the presence of a series of compounds in its composition, mainly some carbonyl compounds found in the volatile fraction, although some minor compounds such as phenolic compounds also contribute. However, these properties are greatly affected by the incidence of certain factors, both intrinsic, such as the olive variety, and extrinsic, such as the growing conditions, so that each EVOO has a particular flavor. Furthermore, these flavors are susceptible to change under the influence of other factors throughout the oil's shelf-life, such as oxidation or temperature. This work offers a description of some of the most remarkable compounds responsible for EVOO’s unique flavor and aroma, the factors affecting them, the mechanism that lead to the degradation of EVOO, and how flavors can be altered during the shelf-life of the oil, as well as several strategies suggested for the preservation of this flavor, on which the quality of the product also depends.


Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 75
Author(s):  
Alexandra Nanou ◽  
Athanasios Mallouchos ◽  
Efstathios Z. Panagou

Olives are characterized by a wide variety of volatile compounds, which are primarily products of microbial metabolism that contribute to the organoleptic characteristics of the final product and especially to its flavor. The volatilome in Spanish-style processed green olives of Conservolea and Halkidiki cultivars were analytically characterized. A solid phase micro-extraction (SPME) technique was used for the extraction of volatile components from the olive samples that were further identified and quantified by gas chromatography coupled to mass spectrometry (GC–MS). Eighty-eight (88) compounds were identified, including several aldehydes, ketones, acids, terpenes, but mainly esters and alcohols. Results showed that there were no significant differences in the qualitative composition of the volatile profiles between the two varieties. Acetic and propanoic acids, thymol, ethanol, 2-butanol, 1-propanol, ethyl acetate as well as ethyl propanoate were the most dominant compounds found in both cultivars. However, some quantitative differences were spotted between the two varieties regarding some of the identified volatile compounds. The quantity of 2-butanol was higher in the Halkidiki variety, while propanoic acid ethyl ester was found in higher amounts in the Conservolea variety. Furthermore, differences in the quantities of some volatile compounds over time were observed. Most of the identified compounds presented an increasing trend during storage.


Sign in / Sign up

Export Citation Format

Share Document