scholarly journals 13C Nuclear Magnetic Resonance Spectroscopic Detection of the Adulteration of Extra Virgin Olive Oils Extracted from Different Cultivars with Cold-Pressed Hazelnut Oil

2009 ◽  
Vol 92 (6) ◽  
pp. 1747-1754 ◽  
Author(s):  
Giovanna Vlahov
Keyword(s):  
Nmr Spectroscopy ◽  
Olive Oil ◽  
13C Nmr ◽  
Acyl Chain ◽  
13C Nmr Spectroscopy ◽  
Hazelnut Oil ◽  
Virgin Olive Oils ◽  
Olive Oils ◽  
13C Nuclear Magnetic Resonance ◽  
Cold Pressed

Abstract 13C NMR spectroscopy was applied to detect the adulteration of olive oils with hazelnut oil. Considering that the linolenate chain and the squalene hydrocarbon were absent in hazelnut oil, unlike olive oil, a 13C NMR spectroscopy method was developed to measure in addition to the triglyceride normal chains (i.e., saturated, oleate, and linoleate chains), the resonances of the linolenate chain and of squalene hydrocarbon. Acyl chain and squalene resonances highly discriminated olive oil samples by cultivars. Nevertheless, the hazelnut oil percentage factor prevailed over the cultivar factor, thus correctly classifying 86 of the authentic and adulterated olive oil samples according to the hazelnut oil percentages. In particular, 85.7, 73.7, and 100.0 of the authentic olive oil samples, and the samples adulterated with 5 and 20 of hazelnut oil, were correctly classified through cross-validation.

Intracellular pH determination by 13C-NMR spectroscopy

1993 ◽  
Vol 264 (3) ◽  
pp. C755-C760 ◽  
Author(s):  
V. P. Chacko ◽  
R. G. Weiss
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Intracellular Ph ◽  
13C Nmr ◽  
Nonlinear Least Squares ◽  
13C Nmr Spectroscopy ◽  
31P Nmr Spectroscopy ◽  
Rat Hearts ◽  
13C Nuclear Magnetic Resonance ◽  
Wide Range

A noninvasive method for the determination of pH by the 13C-nuclear magnetic resonance (NMR) chemical shift of the C-3 carbon of sn-glycerol 3-phosphate is described. Nonlinear least-squares analysis of the chemical shift variation of the C-3 resonance of sn-glycerol 3-phosphate with pH at 37 degrees C in solutions and in perchloric acid extracts of tissue yielded a pKa of 6.2, making it a very sensitive indicator of pH in the approximate range of 5-7. Intracellular pH determined by the present 13C-NMR method correlated well with simultaneous measurements of pH by 31P-NMR spectroscopy over a wide range during normal perfusion and ischemic conditions in intact rat hearts. These findings indicate that this approach is particularly suited for quantification of intracellular pH over the physiological range in intact tissues and that observed in ischemic myocardium.

A preliminary study on the potential of front face fluorescence spectroscopy for the discrimination of Moroccan virgin olive oils and the prediction of their quality

2021 ◽  
Author(s):  
Hicham Zaroual ◽  
El Mestafa El Hadrami ◽  
Romdhane Karoui
Keyword(s):  
Fluorescence Spectroscopy ◽  
Olive Oil ◽  
Virgin Olive Oil ◽  
Front Face ◽  
Virgin Olive Oils ◽  
Olive Oils ◽  
Preliminary Study

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.

scholarly journals (2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol

Molbank ◽  
10.3390/m1140 ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. M1140
Author(s):  
Jack Bennett ◽  
Paul Murphy
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
13C Nmr ◽  
Conjugate Addition ◽  
13C Nmr Spectroscopy ◽  
One Pot ◽  
1H And 13C Nmr ◽  
Esi Mass Spectrometry ◽  
The One

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by 1H and 13C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring.

scholarly journals Prediction of Fruity Aroma Intensity and Defect Presence in Virgin Olive Oil Using an Electronic Nose

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2298
Author(s):  
Pablo Cano Marchal ◽  
Chiara Sanmartin ◽  
Silvia Satorres Martínez ◽  
Juan Gómez Ortega ◽  
Fabio Mencarelli ◽  
...  
Keyword(s):  
Olive Oil ◽  
Low Cost ◽  
Virgin Olive Oil ◽  
General Purpose ◽  
Quality Parameter ◽  
Lasso Regression ◽  
Virgin Olive Oils ◽  
Electronic Noses ◽  
Olive Oils ◽  
Instrumental Technique

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.

scholarly journals Effects of the Filtration on the Biotic Fraction of Extra Virgin Olive Oil

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1677
Author(s):  
Biagi Angelo Zullo ◽  
Giulia Venditti ◽  
Gino Ciafardini
Keyword(s):  
Olive Oil ◽  
Virgin Olive Oil ◽  
Extra Virgin Olive Oil ◽  
Filter Press ◽  
Filtration Process ◽  
Virgin Olive Oils ◽  
Olive Oils ◽  
Filtration System ◽  
Cellulose Filter ◽  
Initial Contamination

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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