Analysis of Volatile Markers for Virgin Olive Oil Aroma Defects by SPME-GC/FID: Possible Sources of Incorrect Data

Abstract

The need to explain virgin olive oil (VOO) aroma descriptors by means of volatiles has raised interest in applying analytical techniques for trapping and quantitating volatiles. Static headspace sampling with solid phase microextraction (SPME) as trapping material is one of the most applied solutions for analyzing volatiles. The use of an internal standard and the determination of the response factors of the main volatiles seem to guarantee the correct determination of volatile concentrations in VOOs by SPME-GC/FID. This paper, however, shows that the competition phenomena between volatiles in their adsorption to the SPME fiber, inherent in static headspace sampling, may affect the quantitation. These phenomena are more noticeable in the particular case of highly odorant matrices, such as rancid and vinegary VOOs with high intensity of defect. The competition phenomena can modify the measurement sensitivity, which can be observed in volatile quantitation as well as in the recording of internal standard areas in different matrices. This paper analyzes the bias of the peak areas and concentrations of those volatiles that are markers for each sensory defect of VOOs (rancid, vinegary, musty, and fusty) when the intensity and complexity of aroma are increased. Of the 17 volatile markers studied in this work, 10 presented some anomalies in the quantitation in highly odorant matrices due the competition phenomena. However, quantitation was not affected in the concentration ranges at which each volatile marker is typically found in the defective oils they were characteristic of, validating their use as markers.

Volatile compounds of Algerian extra-virgin olive oils: Effects of cultivar and ripening stage

“…However, quantification tests of heptane showed a nonlinear trend in our calibration curve, indicating a competition phenomenon against other compounds during adsorption on SPME fiber. Indeed, Oliver-Pozo et al [41] highlighted anomalies in the volatiles' markers quantification in highly odorant VOO due to competition phenomena between volatiles that are molecule-specific. Many literature authors semi-quantified heptane in Chemlal and Blanquette Algerian olive varieties, [14] French VOO of the Cailletier variety [26] , and Tunisian VOO of Chemlali and Chétoui varieties.…”

Exploring multiple‐cumulative trapping solid‐phase microextraction for olive oil aroma profiling

“…Forty‐nine compounds were selected over the entire chromatogram covering a wide range of polarity and volatility, focusing mainly (but not exclusively) on previously reported compounds in extra‐virgin olive oil aroma characterization [11,22,31–33].…”

Development of a robust HS-SPME-GC-MS method for the analysis of solid food samples. Analysis of volatile compounds in fresh raw beef of differing lipid oxidation degrees

“…In the present work, solid phase microextraction (SPME) sampling combined with gas chromatography and mass spectrometry (GC-MS) was selected to collect volatiles in the headspace (HS), because this technique provides information most closely matching what happens when a package of raw beef is opened. Although the limitations of SPME are known --such as competition phenomena between volatiles in their adsorption of the SPME fibre, that may affect quantification (Met & Yesilcubuk, 2017;Oliver-Pozo, Aparicio-Ruiz, Romero, & Garcia-Gonzalez, 2015) --it is a recognized technique for the analysis of volatile and semivolatile compounds in beef (Acevedo, Creixell, Pavez-Barra, Sanchez, Albornoz, & Young, 2012;La Storia, Ferrocino, Torrieri, Di Monaco, Mauriello, Villani, et al, 2012;Machiels & Istasse, 2003;Saraiva, Oliveira, Silva, Martins, Ventanas, & Garcia, 2015) due to its many advantages: it is simple, cost-efficient, solventfree, user-friendly; easily automated and implemented, and of high sensitivity. Moreover, because a low extraction temperature can be used, SPME gives a better estimation of the aroma profile as perceived by the human nose (Brunton, Cronin, Monahan, & Durcan, 2000).…”