An overview of recent developments in volatile compounds analysis from edible oils: Technique‐oriented perspectives

Abstract

The analysis of the volatile compounds from edible oils is a tool used for the evaluation of aroma compounds, the quantitative determination of contaminants or the study of oil degradation and represents a major analytical challenge. This review deals with the recent evolution of methods for vapor phase sampling of the headspace of edible oils combined with gas chromatography. Non‐selective sampling methods, such as static headspace (SHS), sampling techniques with adsorbents, including direct thermal desorption (DTD) and dynamic headspace (DHS), and high concentration capacity headspace techniques (HCC‐HS), as headspace solid phase microextraction (HS‐SPME) and headspace sorptive extraction (HSSE), are presented. Advantages, drawbacks, and applications to edible oils are critically discussed. HS‐SPME is shown to be the most popular technique for the volatile fraction sampling of edible oils. Finally, other promising in‐tube sorptive extraction techniques that are not yet applied to edible oils are also described. Practical applications: The analysis of the volatile compounds from edible oils is a major analytical challenge and is applied in many fields. An overview of different sampling techniques with a critical point of view can be useful to determine the best technique to apply in a specific context. The composition of the headspace of edible oils can provide different information related to the evaluation of aroma compounds, the quantitative determination of contaminants, or the study of oil degradation. Several techniques can be considered to respond to this challenge with different advantages and drawbacks, such as static headspace, solid phase microextraction, dynamic headspace, or headspace sorptive extraction.

Identification of Volatile Oxidation Compounds as Potential Markers of Walnut Oil Quality

“…During the last two steps, unstable primary oxidation products known as hydroperoxides are formed and easily degrade into a complex mixture of volatile oxidation compounds (VOCs). The compositions of the VOC mixture have been widely studied and used to indicate the degree of oxidation in vegetable oils, based on methodologies such as headspace solid‐phase microextraction (HS‐SPME) followed by gas chromatography coupled to mass spectrometry (GC‐MS) (Jeleń, Obuchowska, Zawirska‐Wojtasiak, & Wasowicz, ; Sghaier et al., ). The aldehydes, especially hexanal, were considered to be adequate oxidation indicators for types of oil products (Ha, Seo, Chen, Hwang, & SHIM, ; Ma et al., ; Panseri, Soncin, Chiesa, & Biondi, ).…”

Comparative Fingerprint Changes of Toxic Volatiles in Low PUFA Vegetable Oils Under Deep‐Frying

“…Extraction of volatiles is known to be enhanced by sample agitation, with magnetic stirring widely used by other authors [14], usually around 200 rpm [18,24,25]. A special reference should be made to the stir bars used, because the usual Teflon coated ones might retain some components from the oil matrix, introducing an external source of error and contamination (data not shown).…”

“…Headspace solid-phase micro extraction combined with gas chromatography and mass spectrometry (HS-SPME/GC-MS) has been widely used to extract, separate and identify volatile compounds from edible oils [14]. HS-SPME is a solvent-free extraction technique, with rapid sampling and low cost and it can be easily automated [15].…”

Static headspace gas chromatographic determination of hexanal as a marker of lipid oxidation in fat-rich food

“…As a consequence, intermediate oxidation products hydroperoxides are formed. Later on, they decompose to volatile secondary oxidation products such as alkanes, alkenes, aldehydes, ketones, alcohols, esters, acids and hydrocarbons [1,2]. Oxidation occurs during storage and especially during heat treatment.…”