348
Estimation of the aroma compounds in wine is usually performed by gas chromatography/mass spectrometry (GC/MS), as a highly efficient separation technique
for volatiles’ analysis. Moreover, GC/MS is also suitable for quantification purposes, using polar column for separation of the components, since it is more sensitive for analysis of components present in a low concentration, as well as in a
complex matrices, as wine. The volatile compounds are usually extracted by different methods, such as solid-phase extraction, solid-phase microextraction, stir bar
sorptive extraction, or liquid-liquid extraction methods using organic solvents
before the gas chromatographic analysis (Ivanova et al. 2012, 2013; Ivanova
Petropulos et al. 2014a).
Gas chromatography (GC) is the technique of choice for the analysis of fatty acids
in edible oils, usually coupled with a flame ionization detector (FID) or for the analysis of volatile compounds (Ivanova-Petropulos et al. 2015; Murkovic et al. 1996). GC
or HPLC in combination with mass spectrometry, as sophisticated techniques allowing structural identification and quantification by single-ion monitoring (SIM) or
multiple-ion monitoring (MIM) of different classes of compounds, is used for the
analysis of different classes of compounds present in the oils. Recently, a headspace
comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (headspace GC × GC-TOF/MS) was used for the classification of volatiles from
vegetable oils in order to build a statistical model that should help to identify adulteration of oils (Hu et al. 2014).
11.8 Application of MALDI-TOF-MS
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
(MALDI-TOF-MS) is a powerful new technique that has a great potential in food
analysis, as well as on wine and grape analysis (Sugui et al. 1998; Wang et al. 1999;
Reed et al. 2005; Ivanova et al. 2011b; Ivanova Petropulos et al. 2014a, b). This
technique allows successful determination of the molecular weights in complex
samples directly from ion abundances in the mass spectrum without previous isolation or cleanup of the sample (Ivanova et al. 2011b). MALDI-MS has also been
applied to carbohydrates (Mock et al. 1991) and fructooligosaccharides in plants
and food samples (Wang et al. 1999), and it has proved to be highly suited for the
analysis of highly polydisperse and heterogeneous proanthocyanidins (Monagas
et al. 2010). In addition, MALDI-TOF-MS has been used for the identification of
wine and grape anthocyanins and confirmation of the dominant anthocyanin compounds such as malvidin and its derivatives, using different matrices
(2,5- dihydroxybenzoic acid (2,5-DHB), α-cyano-4-hydroxycinnamic acid (CHCA),
and sinapic acid (SA)), as well as C70 fullerene applied for the first time for this
purpose, without sample preparation (Ivanova et al. 2011b).
Coupling of MALDI with one of the simplest mass analyzers, time-of-flight
(TOF), allowed sensitive and efficient technique with high sensitivity, ease of use,
speed of analysis, good tolerance toward contaminants, and, the most important, the
V. I. Petropulos and B. Balabanova
Estimation of the aroma compounds in wine is usually performed by gas chromatography/mass spectrometry (GC/MS), as a highly efficient separation technique
for volatiles’ analysis. Moreover, GC/MS is also suitable for quantification purposes, using polar column for separation of the components, since it is more sensitive for analysis of components present in a low concentration, as well as in a
complex matrices, as wine. The volatile compounds are usually extracted by different methods, such as solid-phase extraction, solid-phase microextraction, stir bar
sorptive extraction, or liquid-liquid extraction methods using organic solvents
before the gas chromatographic analysis (Ivanova et al. 2012, 2013; Ivanova
Petropulos et al. 2014a).
Gas chromatography (GC) is the technique of choice for the analysis of fatty acids
in edible oils, usually coupled with a flame ionization detector (FID) or for the analysis of volatile compounds (Ivanova-Petropulos et al. 2015; Murkovic et al. 1996). GC
or HPLC in combination with mass spectrometry, as sophisticated techniques allowing structural identification and quantification by single-ion monitoring (SIM) or
multiple-ion monitoring (MIM) of different classes of compounds, is used for the
analysis of different classes of compounds present in the oils. Recently, a headspace
comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (headspace GC × GC-TOF/MS) was used for the classification of volatiles from
vegetable oils in order to build a statistical model that should help to identify adulteration of oils (Hu et al. 2014).
11.8 Application of MALDI-TOF-MS
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
(MALDI-TOF-MS) is a powerful new technique that has a great potential in food
analysis, as well as on wine and grape analysis (Sugui et al. 1998; Wang et al. 1999;
Reed et al. 2005; Ivanova et al. 2011b; Ivanova Petropulos et al. 2014a, b). This
technique allows successful determination of the molecular weights in complex
samples directly from ion abundances in the mass spectrum without previous isolation or cleanup of the sample (Ivanova et al. 2011b). MALDI-MS has also been
applied to carbohydrates (Mock et al. 1991) and fructooligosaccharides in plants
and food samples (Wang et al. 1999), and it has proved to be highly suited for the
analysis of highly polydisperse and heterogeneous proanthocyanidins (Monagas
et al. 2010). In addition, MALDI-TOF-MS has been used for the identification of
wine and grape anthocyanins and confirmation of the dominant anthocyanin compounds such as malvidin and its derivatives, using different matrices
(2,5- dihydroxybenzoic acid (2,5-DHB), α-cyano-4-hydroxycinnamic acid (CHCA),
and sinapic acid (SA)), as well as C70 fullerene applied for the first time for this
purpose, without sample preparation (Ivanova et al. 2011b).
Coupling of MALDI with one of the simplest mass analyzers, time-of-flight
(TOF), allowed sensitive and efficient technique with high sensitivity, ease of use,
speed of analysis, good tolerance toward contaminants, and, the most important, the
V. I. Petropulos and B. Balabanova