scholarly journals High-Throughput Chemometric Quality Assessment of Extra Virgin Olive Oils Using a Microtiter Plate Reader

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4169
Author(s):  
Huihui He ◽  
Weiying Lu

A commercially available microtiter plate reader was applied as a high-throughput counterpart of ultraviolet-visible (UV–Vis) spectrophotometer to identify the producing location of extra virgin olive oils (EVOOs). Multiplicative scatter correction and the first derivative was used to denoise the UV–Vis spectra and eliminate the effects of background drift. The spectra were analyzed using chemometrics methods including the principal component analysis (PCA) and the partial least squares-discriminant analysis (PLS-DA). The PLS-DA model on full spectra using 5 latent variables showed a classification accuracy of 97.92% by cross-validation. The overall results demonstrated that the use of a UV–Vis spectrophotometer based on the microtiter plate reader combined with chemometrics can be applied to the quality assessment of EVOOs. It is demonstrated that the microtiter plate reader can be a high-throughput tool in the quality assessment of food ingredients.

Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 330 ◽  
Author(s):  
Deborah Pacetti ◽  
Maria Chiara Boarelli ◽  
Rita Giovannetti ◽  
Stefano Ferraro ◽  
Paolo Conti ◽  
...  

Chemical and sensory peculiarities of monovarietal extra virgin olive oils (MEVOOs) from the cultivars (cvs.) Ascolana tenera (ASC), Coroncina (COR), Mignola (MIG), Piantone di Mogliano (MOG), and Raggia (RAG) from Marche region (Italy) are investigated. Their polar phenolic substances and α-tocopherol are analysed through high performance liquid chromatography with different detectors. Volatile substances, fatty acid composition, and squalene are analysed by gas chromatography coupled to mass spectrometry (MS) and to the flame ionization detector, respectively. Total antioxidant activity and sensory analysis were also performed. MOG showed high squalene content (on average 0.88 ± 0.16 g/100 g), high relative amount of α-copaene among volatiles, and the highest oleic acid percentage. MIG had high α-tocopherol content (on average 350.0 ± 57.6 mg kg−1) and high α-farnesene in the volatile fraction. ASC showed the highest sensory quality and the lignan pinoresinol with higher concentration as compared to the other MEVOOs (p < 0.05), which resulted in a possible chemical marker for this cv. RAG was characterized by the sensory note of almond, which corresponds to its highest (E)-2-hexenal percentage. Sensory analysis and an antioxidant activity assay performed on a set of industrial extra virgin olive oils purchased in supermarkets, highlighted MEVOOs’ superiority from these points of view. Principal component analysis displays the main characteristics of the cvs. investigated.


2020 ◽  
Vol 18 (1) ◽  
pp. e0901
Author(s):  
Karima Benamirouche-Harbi ◽  
Sonia Keciri ◽  
Zohir Sebai ◽  
Hicham Benamirouche ◽  
Lilya Boudriche

Aim of study: To evaluate the effect of cultivar and year of harvest on the content of mineral elements of Algerian extra virgin olive oils.Area of study: Technical Institute of Arboriculture of Fruits and Vine (TIAFV), Bejaia, Algeria.Material and methods: The mineral contents of extra virgin olive oils from ten cultivars during two consecutive campaigns 2014/2015 and 2015/2016 were determined using atomic absorption spectrometry and absorption in a graphite furnace after microwave-assisted acid digestion. Principal component analysis was applied to correlate the mineral content with cultivar type and year of harvest.Main results: Mean concentrations for Fe, Zn, Cu, Na, K, Mg, As and Co in samples were observed in the range of 1.640-13.213, 1.546-32.866, 1.375-3.337, 19.666-104.720, 4.573-117.133, 0.120-2.560, 0.006-0.146 and 0.002-0.051 μg g-1, respectively. The first three principal components retained 76.25% of the variance. The determinants of the effect of cultivar type and year of harvest were Fe and Na; Mg, Co and As, respectively.Research highlights: The study showed that mineral composition of the olive oils was mainly determined by the cultivar and the year of harvest.


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.


2002 ◽  
Vol 56 (10) ◽  
pp. 1268-1274 ◽  
Author(s):  
Francesca Apruzzese ◽  
Ramin Reshadat ◽  
Stephen T. Balke

The objective of this work was to examine the application of various multivariate methods to determine the composition of a flowing, molten, immiscible, polyethylene–polypropylene blend from near-infrared spectra. These spectra were acquired during processing by monitoring the melt with a fiber-optic-assisted in-line spectrometer. Undesired differences in spectra obtained from identical compositions were attributed to additive and multiplicative light scattering effects. Duplicate blend composition data were obtained over a range of 0 to 100% polyethylene. On the basis of previously published approaches, three data preprocessing methods were investigated: second derivative of absorbance with respect to wavelength (d2), multiplicative scatter correction (MSC), and a combination consisting of MSC followed by d2. The latter method was shown to substantially improve superposition of spectra and principal component analysis (PCA) scores. Also, fewer latent variables were required. The continuum regression (CR) approach, a method that encompasses ordinary least squares (OLS), partial least squares (PLS), and principle component regression (PCR) models, was then implemented and provided the best prediction model as one based on characteristics between those of PLS and OLS models.


2017 ◽  
Vol 100 (6) ◽  
pp. 1804-1813 ◽  
Author(s):  
Habib Shirzad ◽  
Vahid Niknam ◽  
Mehdi Taheri ◽  
Hassan Ebrahimzadeh

Abstract The present study investigated variations in extra virgin olive oils in relation to fatty acid (FA) composition and the characteristics of 10 olive cultivars. The findings demonstrated that their oil yield properties, including refractive index, acid value, peroxide value, saponification value, iodine value, and composition, were significantly different. Moreover, based on GC-MS analysis, the presence of oleic acid [C18:1(9)] was identified as one of the major components. The highest amount of 18:1(9) was found in four major varieties of cultivars, namely Zard, Roghani, Karidolia, and Korfolia. Hierarchical cluster analysis of principal component analysis revealed two distinct categories of cultivars based on their FAs. The first category (cluster I), consisted of Arbequina, Karydolia, Roghani, and Zard cultivars, which can be considered cultivars with good commercial cultivation potential due to their high contents of unsaturated FAs and oil quantities produced.


2010 ◽  
Vol 76 (13) ◽  
pp. 4136-4142 ◽  
Author(s):  
Michael R. Benoit ◽  
Carolyn G. Conant ◽  
Cristian Ionescu-Zanetti ◽  
Michael Schwartz ◽  
A. Matin

ABSTRACT Control of biofilms requires rapid methods to identify compounds effective against them and to isolate resistance-compromised mutants for identifying genes involved in enhanced biofilm resistance. While rapid screening methods for microtiter plate well (“static”) biofilms are available, there are no methods for such screening of continuous flow biofilms (“flow biofilms”). Since the latter biofilms more closely approximate natural biofilms, development of a high-throughput (HTP) method for screening them is desirable. We describe here a new method using a device comprised of microfluidic channels and a distributed pneumatic pump (BioFlux) that provides fluid flow to 96 individual biofilms. This device allows fine control of continuous or intermittent fluid flow over a broad range of flow rates, and the use of a standard well plate format provides compatibility with plate readers. We show that use of green fluorescent protein (GFP)-expressing bacteria, staining with propidium iodide, and measurement of fluorescence with a plate reader permit rapid and accurate determination of biofilm viability. The biofilm viability measured with the plate reader agreed with that determined using plate counts, as well as with the results of fluorescence microscope image analysis. Using BioFlux and the plate reader, we were able to rapidly screen the effects of several antimicrobials on the viability of Pseudomonas aeruginosa PAO1 flow biofilms.


Author(s):  
Fatma Chtourou ◽  
Enrico Valli ◽  
Amir Ben Mansour ◽  
Alessandra Bendini ◽  
Tullia Gallina Toschi ◽  
...  

AbstractSeveral compositional parameters (fatty acids, tocopherols, polar phenols and volatiles) in virgin olive oils from varieties located at the center of Tunisia, namely Baldi, Chemchali, Neb Jmel, Tounsi and Besbessi from Gafsa and Chemchali and Sehli cultivated in Sidi Bouzid, were studied. To the best of our knowledge, this is the first study focusing on the chemical composition of virgin olive oils (VOO) from Sidi Bouzid. Significant differences were found between varieties from Sidi Bouzid and Gafsa in monounsaturated saturated fatty acid levels, some volatile compounds and γ-tocopherol amounts. Notably, Tounsi and Baldi VOOs showed the highest six carbon atoms alcohol contents, whereas Neb Jmel VOO revealed the highest aldehyde six carbon atoms content. Fatty acid composition, as well as tocopherol content, showed differences among different VOO. Principal component analysis and hierarchical component analysis on polar phenols, fatty acids, tocopherols and volatiles data evidenced a good discrimination among oils from the different investigated varieties.


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.


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