scholarly journals Physico-chemical and sensory evaluation of virgin olive oils from several Algerian olive-growing regions

OCL ◽  
2021 ◽  
Vol 28 ◽  
pp. 55
Author(s):  
Malika Douzane ◽  
Mohamed-Seghir Daas ◽  
Amel Meribai ◽  
Ahmed-Hani Guezil ◽  
Abdelkrim Abdi ◽  
...  

Olive cultivar diversity is rich in Algeria but most remain unexplored in terms of quality traits. This work aimed to evaluate the physicochemical and organoleptic quality of twenty olive oil samples belonging to four Algerian cultivars (Chemlal, Sigoise, Ronde de Miliana and Rougette de Mitidja) collected throughout the national territory. Physical-chemical and sensory results showed that 60% of the oils belong to the extra virgin category, while 40% were classified as “virgin olive oil”. The results of the principal component analysis (PCA) revealed a great variability in fatty acids composition between the samples depending on the cultivar and origin. Oleic acid was the most abundant and varied between 64.84 and 80.14%. Extra virgin olive oils with quality attributes are eligible for a label. Rougette de Mitidja, Ronde de Miliana and Sigoise from Oran showed great potential.

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1870
Author(s):  
Ramón Aparicio-Ruiz ◽  
Sara Barbieri ◽  
Tullia Gallina Toschi ◽  
Diego L. García-González

Sensory assessment of virgin olive oil (“panel test”) is the only sensory method included in international regulations of edible oils and its application is compulsory. Even if its application has been a success in quality control, improving the quality of virgin olive oils over the last 30 years, at present, there is no reference material (RM), in the strict sense of the term, to be used as a validated standard for sensory defects of virgin olive oil with which tasters can be trained. Usually, real samples of virgin olive oils assessed by many panels for the International Olive Council (IOC) ring tests are used as materials of reference in panel training and control. The latter are highly representative of the main perceived defects, but availability is limited, samples are not homogeneous year after year, and other secondary defects can be present. Thus, in order to provide solutions, this work describes an analytical procedure for implementing olfactory formulations that emulate rancid and winey-vinegary defects found in virgin olive oils with the aim of providing reproducible RMs that can be prepared on demand. A strategy for designing RMs for aroma is presented and the optimization process to obtain the best formulation is described. Under the criteria of representativeness, verified with the advice of the IOC, aroma persistence, and simplicity in formulation, two RMs for winey-vinegary and rancid were obtained by diluting acetic acid and ethanol (winey-vinegary defect) and hexanal (rancid defect) together with other compounds that are used to modify aroma and avoid non-natural sensory notes.


2018 ◽  
Vol 28 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Carmen Mena ◽  
Alejandra Z. González ◽  
Raúl Olivero-David ◽  
María Ángeles Pérez-Jiménez

The production of high-quality virgin olive oil from traditional olive (Olea europaea L.) varieties with peculiar and differential characteristics is of great interest for the olive oil market. ‘Castellana’ is an autochthonous variety mainly located in the center of Spain. The aims of this study were 1) the characterization of ‘Castellana’ virgin olive oils and 2) the evaluation of the influence of fruit ripening degree on the oil quality to establish an optimum harvest time for ‘Castellana’ olives. A wide range of physicochemical and sensorial quality parameters were assayed in oils produced at four harvest times during three crop seasons. ‘Castellana’ oils could be classified into the extra virgin category at all ripening degrees studied. This variety provides well-balanced oils from the sensorial point of view with an optimum chemical composition. Nevertheless, fruit maturation had a strong effect in various quality parameters, especially total phenol content, total tocopherol content, sensorial quality, and to a lesser extent in fatty acid composition. Loss of antioxidants and decrease in sensorial quality take place during olive ripening, reducing the nutritional, sensorial, and commercial quality of virgin olives oils as the harvest is delayed. Results suggest that the production of optimal extra virgin olive oil requires that ‘Castellana’ olives should be harvested from the middle of November to the middle of December, coinciding with a ripening index between 3.1 and 4.1. These results are of great importance to the olive oil industry for improving the quality of virgin olive oils produced from ‘Castellana’.


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.


Author(s):  
Konstantoula Akrida Demertzi ◽  
Christos Roukos ◽  
Panagiotis Demertzis

In the present study the qualitative characteristics such as peroxide number, absorption coefficients (K232, K270), acidity, total phenols, a-tocopherols, chlorophylls and composition of fatty acids were determined in 19 virgin olive oil samples of “Lianolia” variety cultivated in Corfu and “Kalinioti” variety cultivated in South Albania, harvested in the crop year 2013/2014. Obtained results indicate that all olive oil samples show chemical and physicochemical parameters included in the limits established for virgin olive oils and some of them in the limits for “extra” virgin olive oils. Moreover it was found that the qualitative characteristics of olive oil samples are affected by variety, fruit treatment and the method of olive harvesting (in Corfu olives are collected by hands from plastic nets under the trees, whereas in Albania they are basically collected by hand after falling on the ground). The results of the present study are a first indication of the olive oil quality produced in Corfu and South Albania.


Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 95
Author(s):  
Emin Yilmaz ◽  
Şahin Demirci

This study aimed to prepare and evaluate virgin olive oil (VOO) oleogels enriched with thyme and cumin spices with sunflower wax (SW) organogelator. Common physico-chemical, structural, thermal, and rheological analyses were completed. Furthermore, aromatic volatiles composition, sensory descriptive analysis, and consumer tests were provided. Results indicated that spice addition does not interfere with gel formation, stability, and gelation time. The oleogels’ color values were affected by the color of the VOO and the spices. The free fatty acidity and peroxide values were within the acceptable limits for virgin olive oils. There were β’ crystal polymorphs, and melting peak temperatures were around 62 °C. Rheological analyses proved that the oleogels were fairly stable under moderate frequencies, maintained their gelled state until around 52 °C, and recovered their shear induced structural loss after force cessation. There were 22 aromatic volatiles quantified in the samples, which originated from the VOO and spices used as ingredients. A trained panel defined the samples using 13 sensory descriptors. Consumer tests proved that the new oleogels were liked by consumers. Overall, this study provided information and the possibility of spice-enriched and spreadable VOO oleogels to enhance per capita consumption of olive oils with new consumption habits.


Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 155 ◽  
Author(s):  
Vasiliki Skiada ◽  
Panagiotis Tsarouhas ◽  
Theodoros Varzakas

The qualitative characteristics and chemical parameters were determined for 112 virgin olive oil samples of the two dominant olive cultivars in the southern region of Peloponnese, cv. Koroneiki and cv. Mastoides. As no relevant data exist for this geographical area, yet one of the most important olive-growing regions in Greece, this study aimed to evaluate and evidence the differences on specific chemical characteristics of the oils because of their botanical origin. Olive oils of Koroneiki variety were characterized by a three-fold lower concentration in heptadecanoic and heptadecenoic acid compared to oils of cv. Mastoides. In addition, Mastoides oils exhibited higher β-sitosterol and total sterols concentration and lower Δ-5-avenasterol and total erythodiol content compared to Koroneiki olive oils Analysis of variance and principal component analysis of the GC-analyzed olive oil samples showed substantial compositional differences in the fatty acid and sterolic profile between Koroneiki and Mastoides cultivars. Hence, results demonstrate that the fatty acid and sterolic profile can be used as exceptional compositional marker for olive oil authenticity.


Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1457 ◽  
Author(s):  
Abbatangelo ◽  
Núñez-Carmona ◽  
Duina ◽  
Sberveglieri

Extra virgin olive oil (EVOO) is characterized by its aroma and other sensory attributes. These are determined by the geographical origin of the oil, extraction process, place of cultivation, soil, tree varieties, and storage conditions. In the present work, an array of metal oxide gas sensors (called S3), in combination with the SPME-GC-MS technique, was applied to the discrimination of different types of olive oil (phase 1) and to the identification of four varieties of Garda PDO extra virgin olive oils coming from west and east shores of Lake Garda (phase 2). The chemical analysis method involving SPME-GC-MS provided a complete volatile component of the extra virgin olive oils that was used to relate to the S3 multisensory responses. Furthermore, principal component analysis (PCA) and k-Nearest Neighbors (k-NN) analysis were carried out on the set of data acquired from the sensor array to determine the best sensors for these tasks and to assess the capability of the system to identify various olive oil samples. k-NN classification rates were found to be 94.3% and 94.7% in the two phases, respectively. These first results are encouraging and show a good capability of the S3 instrument to distinguish different oil samples.


2021 ◽  
Author(s):  
Hicham Zaroual ◽  
El Mestafa El Hadrami ◽  
Romdhane Karoui

This study examines the feasibility of using front face fluorescence spectroscopy (FFFS) to authenticate 41 virgin olive oil (VOO) samples collected from 5 regions in Morocco during 2 consecutive crop seasons.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2298
Author(s):  
Pablo Cano Marchal ◽  
Chiara Sanmartin ◽  
Silvia Satorres Martínez ◽  
Juan Gómez Ortega ◽  
Fabio Mencarelli ◽  
...  

The organoleptic profile of a Virgin Olive Oil is a key quality parameter that is currently obtained by human sensory panels. The development of an instrumental technique capable of providing information about this profile quickly and online is of great interest. This work employed a general purpose e-nose, in lab conditions, to predict the level of fruity aroma and the presence of defects in Virgin Olive Oils. The raw data provided by the e-nose were used to extract a set of features that fed a regressor to predict the level of fruity aroma and a classifier to detect the presence of defects. The results obtained were a mean validation error of 0.5 units for the prediction of fruity aroma using lasso regression; and 88% accuracy for the defect detection using logistic regression. Finally, the identification of two out of ten specific sensors of the e-nose that can provide successful results paves the way to the design of low-cost specific electronic noses for this application.


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1677
Author(s):  
Biagi Angelo Zullo ◽  
Giulia Venditti ◽  
Gino Ciafardini

Filtration is a widely used process in the production of extra virgin olive oil. We studied the influence of filtration performed with cotton filters and cellulose filter press on the biotic components of the oily mass containing probiotic traits in two freshly produced monocultivar extra virgin olive oils. The concentration of bacteria was reduced from 100% to 28%, while that of fungi was reduced from 100% to 44% after filtration, according to the filtration system and the initial contamination of the original monocultivar extra virgin olive oil. Compared with the control, the yeast content in the oil samples filtered with cotton filters was reduced from 37% to 11% depending on the cultivar. In the oil filtered with cellulose filter press, the yeast content reduced from 42% to 16%. The viable yeast that passed through the oily mass during the filtration process with cellulose filter press, unlike all the other samples, were unable to survive in the oil after a month of storage. The possible health benefits of compounds from both the biotic and abiotic fraction of the oil, compared to the control, were significantly low when filtered with the cellulose filter press.


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