scholarly journals Study of the Evolution of Pigments from Freshly Pressed to ‘On-the-Shelf’ Extra-Virgin Olive Oils by Means of Near-UV Visible Spectroscopy

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1891
Author(s):  
Eleonora Borello ◽  
Daniele Roncucci ◽  
Valentina Domenici

Spectroscopic non-destructive methods have high potentialities as fast, cheap and easy-to-be-used approaches to address olive oil quality and authenticity. Based on previous research where near-UV Visible spectroscopy was used to investigate extra-virgin olive oils (EVOOs) and their main pigments’ content (i.e., β-carotene, lutein, pheophytin a and pheophytin b), we have implemented the spectral deconvolution method in order to follow the EVOO’s life, from ‘freshly pressed’ to ‘on-the-shelf’ EVOO samples at different storage time. In the first part of the manuscript, the new implemented deconvolution spectroscopic method aimed to quantify two additional pigments, namely chlorophyll a and chlorophyll b, is described and tested on ‘ad hoc’ samples with known concentrations of chlorophylls. The effect of light exposure and acidification was investigated to test the reliability and robustness of the spectral deconvolution. In the second part of the work, this approach was used to study the kinetic of pigments’ degradation in several monocultivar fresh EVOO samples under optimal storage’s conditions. The results here reported show that this spectroscopic deconvolution approach is a good method to study fresh EVOOs too; moreover, the proposed method revealed to be sensitive to detect eventual stresses of olive oil samples stored in not-good conditions.

Foods ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 18 ◽  
Author(s):  
Eleonora Borello ◽  
Valentina Domenici

The colour of olive oil is due to the presence of natural pigments belonging to the class of carotenoids, chlorophylls, and their derivatives. These substances, other than being responsible for the colour, an important qualitative feature of the oil, have antioxidant and, more generally, nutraceutical properties and their quantification can be related to the product’s quality and authenticity. In this work, we have quantified the total amount of carotenoids and chlorophylls’ derivatives in several virgin and extra-virgin olive oils produced in Italy, by using two different methods that are based on near-ultraviolet-visible absorption spectroscopy. The first method defines two indexes, K670 and K470, related to absorbance values of oil at wavelengths of 670 and 470 nm, respectively. The second method is based on the mathematical deconvolution of the whole absorption spectrum of the oil to obtain the concentrations of four main pigments present in olive oils: β-carotene, lutein, pheophytin A, and pheophytin B. The concentrations of the total carotenoids and total chlorophylls’ derivatives, as obtained by the two spectroscopic methods, are compared and the results are discussed in view of the practical usefulness of spectroscopic techniques for a fast determination of pigments in olive oil.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Aimen El Orche ◽  
Mustapha Bouatia ◽  
Siham Yanisse ◽  
Houda Labjar ◽  
Mouad Mouhsin ◽  
...  

One of the most important challenges in the authentication of olive oil is the determination of the geographical origin of virgin olive oil. In this work, we evaluated the capacity of two spectroscopic techniques, UV-Visible and ATR-FTMIR, coupled with chemometric tools to determine the geographical origin of olive oils. These analytical approaches have been applied to samples that have been collected during the period of olive oil production, in the Moroccan region of Beni Mellal-Khenifra. To develop a rapid analysis tool capable of authenticating the geographical origin of virgin olive oils from five geographical areas of the Moroccan region of Beni Mellal-Khenifra, UV-Visible and ATR-FTMIR spectral data were processed by chemometric algorithms. PCA was applied on the spectral data set to represent the data in a very small space, and then discrimination methods were applied on the principal components synthesized by the PCA. The application of the PCA-LDA method on the spectral data of UV-Visible and ATR-FTMIR shows a good ability to classify olive oils according to their geographical origin with a percentage of correct classification that represents 90.24% and 85.87%, respectively, and the processing of the spectral data of UV-Visible and ATR-FTMIR by PCA-SVM allows differentiating correctly between five olive oils with a correct classification rate of 100% and 97.56, respectively. This study demonstrated the feasibility of UV-Visible and ATR-FTMIR fingerprinting (routine technique) for the geographical classification of olive oils in the Moroccan region of Beni Mellal-Khenifra. Such developed methods can be proposed as alternative and complementary methods to authenticate the geographical origin of virgin olive oil.


2021 ◽  
Vol 8 (2) ◽  
pp. 20-29
Author(s):  
Ayca Akca Uckun

In this context, aim of this study is to determine the effect of Çekişte olive oils in different locations and show differences on geographical locations while taking geographical indication label. Çekişte olive oil variety which cultivated in six different locations (Birgi, Bademli, Beyazit, Yeniceköy, Zeytinlik, Uzumlu) were evaluated the effects of geographical locations on the chemical characterization of in the southwest of Turkey. The agricultural ecological map of each location was created using GIS. Olive oil samples were analyzed fatty acid, sterol and phenolic. Moreover, LC IMS Qtof spectrometer and Progenesis QI software were used to determine the geographical fingerprints of olive oil samples in different locations. Results showed that oil qualities of some locations differ significantly depending on olive growing area (p <0.05), some of them not. The Principal Component Analysis of the different locations analyzed revealed that "geographical location" factor significantly affects the olive oil quality.


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.


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.


ACTA IMEKO ◽  
2016 ◽  
Vol 5 (1) ◽  
pp. 22 ◽  
Author(s):  
Milena Bucar-Miklavcic ◽  
Terezija Golob ◽  
Vasilij Valencic ◽  
Erika Bester ◽  
Bojan Butinar ◽  
...  

The olive variety 'Istrska belica' is well known for its numerous positive properties, such as resistance to low temperature and high oil content. The aim was to determine the variations in the levels of phenolic compounds and sensory properties during storage of 'Istrska belica' virgin olive oil. The profile of the phenolic compounds and sensory properties of 'Istrska belica' olive oil were further compared with those for other varieties, including 'Leccino' and 'Maurino'. The content of phenolic compounds of the olive oils decreased after 1 year and 2 years of storage. After 2 years of storage, the levels of oleuropein and the ligstroside derivates significantly decreased, while the end-stage compounds tyrosol and hydroxytyrosol increased. These data show that after 1 year of storage, the 'Istrska belica' olive oil preserves similar intensities for bitterness and pungency, and similar oleuropein and ligstroside derivates levels. In contrast to the other oils analysed, the intensities of bitterness and pungency of 'Istrska belica' olive oil decreased greatly only after 2 years of storage. Moreover, the phenolic compounds content, and oleuropein and ligstroside derivates levels, and the intensities of bitterness and pungency were the highest in fresh 'Istrska belica' olive oil, compared to the other olive oils analysed. Overall, 'Istrska belica' olive oil has important advantages over olive oil from other varieties that are grown in the Istria region.


Metabolites ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 60 ◽  
Author(s):  
Chiara Roberta Girelli ◽  
Laura Del Coco ◽  
Samanta Zelasco ◽  
Amelia Salimonti ◽  
Francesca Luisa Conforti ◽  
...  

According to Coldiretti, Italy still continues to hold the European Quality record in extra virgin olive oils with origin designation and protected geographical indication (PDO and PGI). To date, 46 Italian brands are recognized by the European Union: 42 PDO and 4 PGI (Tuscan PGI, Calabria PGI; Tuscia PGI and PGI Sicily). Specific regulations, introduced for these quality marks, include the designation of both the geographical areas and the plant varieties contributing to the composition of the olive oil. However, the PDO and PGI assessment procedures are currently based essentially on farmer declarations. Tuscan PGI extra virgin olive oil is one of the best known Italian trademarks around the world. Tuscan PGI varietal platform is rather wide including 31 specific olive cultivars which should account for at least 95% of the product. On the other hand, while the characteristics of other popular Italian extra virgin olive oils (EVOOs) cultivars from specific geographical areas have been extensively studied (such as those of Coratina based blends from Apulia), little is still known about Tuscan PGI EVOO constituents. In this work, we performed, for the first time, a large-scale analysis of Tuscan PGI monocultivar olive oils by 1H NMR spectroscopy and multivariate statistical analyses (MVA). After genetic characterization of 217 leaf samples from 24 selected geographical areas, distributed all over the Tuscany, a number of 202 micro-milled oil samples including 10 PGI cultivars, was studied. The results of the present work confirmed the need of monocultivar genetically certified EVOO samples for the construction of 1H-NMR-metabolic profiles databases suitable for cultivar and/or geographical origin assessment. Such specific PGI EVOOs databases could be profitably used to justify the high added value of the product and the sustainability of the related supply chain.


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