Implementing Dynamic Headspace With SPME Sampling of Virgin Olive Oil Volatiles: Optimization, Quality Analytical Study, and Performance Testing

Abstract

Competition and interaction phenomena among volatiles during their adsorption process by solid phase microextraction (SPME) fibers in static headspace sampling procedure (SHS) cast doubt on its ability to quantify virgin olive oil volatiles. SPME fibers being excellent traps, their use was analyzed with a new device allowing the concentration of volatiles in a dynamic headspace sampling procedure (DHS). A central composite experimental design optimized the main variables of the device (4 g sample weight, 40 °C temperature, 150 mL/min flow rate, 50 min adsorption time), while values of the analytical quality control parameters of the method (repeatability, limits of detection and quantification, working range, sensitivity, and resolution) were compared with those ones from static headspace. DHS shows better precision results for aldehydes and alcohols than SHS and allowed analyzing higher concentrations with no problem of saturation. In 19 of 28 compounds analyzed in 50 samples the chromatographic areas were higher when running DHS. The concentration values of volatile compounds in these samples after applying SHS and DHS are discussed together with the ability of the new method for distinguishing virgin olive oil by their categories (extra virgin, virgin, and lampante) by the volatiles quantified in commercial oils.

Tracking Sensory Characteristics of Virgin Olive Oils During Storage: Interpretation of Their Changes from a Multiparametric Perspective

“…The identification of the volatiles was carried out with standards [29]. Additionally, the identification was checked by analyzing the samples with mass spectrometry (GC7820-MSD5975, Agilent Technology, Santa Clara, CA, USA) following the strategy described in previous works [38,50]. Thus, the information from mass spectra, and their comparison with standards in the FID chromatograms, and linear retention indexes (LRIs) were considered for a full identification.…”

Does Authenticity of Virgin Olive Oil Sensory Quality Require Input from Chemistry?

“…The experiment was repeated with two sets of official reference samples of VOO sensory defects corresponding to two successive years. Results show the great divergence in the odor thresholds obtained in these two different years …”

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].…”

“…Oliver‐Pozo et al. [22] developed a dynamic HS sampling system to facilitate analytes accumulation into the SPME fiber. Another interesting alternative was presented by Lipinski [23] using multiple cumulative direct immersion‐SPME to enhance the sensitivity for analysis of pesticides in water; a stop‐flow approach was used to focalize the compounds at the front of the cool GC column (40°C) before the GC separation.…”