Page 79 - FoodFocusThailand No.219 June 2024

STRONG QC & QA

2) Mechanical analysis substances, constituting an integral component of gas
Gas chromatography (GC) is a method employed for chromatography (GC). A specific type of physical examination
analyzing volatile organic compounds present in food is typically employed when assessing odorous substances.
products. For successful application of this technique, the This involves the utilization of a device resembling the
substance or sample under scrutiny must possess the dimensions of the human nose, enhancing the capacity to
capacity to readily evaporate. GC functions by separating measure odor and thereby facilitating a convergence between
mixtures into their components through their movement in instrumental analysis and sensory perception. The operational
the gaseous state. This separation process is predicated on principle of the GC-O system entails the injection of the sample
disparities in solubility properties and adsorption capacities into a gas chromatography system for mixture separation.
among the various substances within the mobile and Subsequently, the separated sample is bifurcated into two
stationary phases. The operational mechanism of a GC streams. The first stream is directed into the detector of the
machine involves injecting the sample into a column, where gas chromatography system to quantify the signal intensity
it vaporizes and is carried through the column by a carrier generated by distinct substances. Simultaneously, the second
gas acting as the mobile phase. The individual components stream enters the olfactometry system, allowing human
of the sample undergo separation within distinct tubes or evaluators to perceive and record the olfactory signals elicited
columns functioning as the stationary phase. Subsequently, by the sample. This concurrent measurement approach
the separated substances are sequentially eluted from the enables a continuous comparison between the outputs of the
column and measured using an appropriate detector to two detectors.
record their retention time and signal magnitude. This data Flavor represents a crucial attribute in food sensory
is then depicted in the form of a chromatogram. GC machines perception, significantly influencing consumer satisfaction and
can be categorized into three types based on their operational purchase intentions. Hence, flavor analysis holds paramount
principles: importance within the food industry, facilitating various
2.1) Gas Chromatography-Mass Spectrometry (GC- aspects of food product processing, including quality control
MS): GC-MS involves a hybrid approach combining gas and product development. In contemporary times, an array of
chromatography and mass spectrometry. This method entails flavor analysis techniques has been employed for testing
analyzing compounds and assessing their similarity (match) purposes. These encompass both human-based evaluations
with spectra stored in a database to predict the substance and mechanical methodologies, such as GC-E-Nose.
type and its likelihood. Notably, this analysis does not Nevertheless, the selection of an appropriate testing
necessitate the use of standard substances for comparing method should be carefully considered, taking into account
retention time to identify the substance type or for the complex sensory nature of the product. Furthermore,
qualitative analysis, as the database enables comparison of exploring comparisons with artificial intelligence (AI)
substances. presents an intriguing avenue, given AI’s remarkable accuracy
2.2) Gas Chromatography Flame Ionization Detector and its ability to closely approximate consumer sensory
(GC-FID): Gas chromatography with a flame ionization perceptions.
detector (FID) is utilized for the analysis of the quantity of
active ingredients present in the product. The sample solution
injected into the instrument is carried by a gas stream into
a separation tube referred to as the “column,” with helium or
nitrogen commonly used as the carrier gas. Inside the More Information Service Info C010
column, the various components undergo separation. To
measure a sample with an unknown concentration, a
standard sample with a known concentration is also injected เอกสารอ้างอิง / References
into the instrument. The retention time and area of the peak Auvray, M. and Spence, C., 2008. The multisensory perception of
in the standard sample are then compared to those of the flavor. Consciousness and cognition, 17(3), pp.1016-1031.
test sample to calculate the concentration. Brattoli, M., Cisternino, E., Dambruoso, P.R., De Gennaro, G.,
2.3) Gas Chromatography Electronic Nose (GC- Giungato, P., Mazzone, A., Palmisani, J. and Tutino, M., 2013.
E-Nose): An electronic nose, often referred to interchangeably Gas chromatography analysis with olfactometric detection (GC-O)
as a mechanical bridge, olfactory sensing system, odor is a useful methodology for the chemical characterization of
control system, or electronic odor control system, mimics odorous compounds. Sensors, 13(12), pp.16759-16800.
the olfactory capabilities of humans. This device elucidates Buettner, A., Beer, A., Hannig, C., Settles, M. and Schieberle, P.,
the properties and composition of odor components 2002. Physiological and analytical studies on flavor perception
dynamics as induced by the eating and swallowing process. Food
through GC-E-Nose, a technique combining gas Quality and Preference, 13(7-8), pp.497-504.
chromatography with flame ionization (FID) analysis. By Harrison, J., McNutt, W. and Lundgren, R., 2021. The Determination
employing this method in conjunction with a comprehensive of Response Factors for Reaction Monitoring by Gas
dataset (library) and conducting similarity analyses, Chromatography.
it becomes possible to identify the substances present in the Picó, Y. and Barceló, D., 2020. Pyrolysis gas chromatography-mass
analyzed sample. Furthermore, the utilization of FID spectrometry in environmental analysis: Focus on organic matter
facilitates the quantification of these substances, enabling and microplastics. TrAC Trends in Analytical Chemistry, 130,
precise determination of both the presence and quantity of p.115964.
sample components. Wardencki, W., Chmiel, T. and Dymerski, T., 2013. Gas
3) Coupled between mechanical analysis and sensory chromatography-olfactometry (GC-O), electronic noses (e-noses)
and electronic tongues (e-tongues) for in vivo food flavour
analysis by trained panelist measurement. Instrumental assessment of food sensory quality,
Gas Chromatography Olfactometry (GC-O): GC-O is pp.195-229.
a specialized technique utilized to separate mixed

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