Black garlic is a new garlic product produced through fermentation of fresh garlic and is very popular in Asia countries due to its health benefits. Its key aroma-active compounds were characterized ...by gas chromatography–olfactometry–mass spectrometry (GC-O-MS), gas chromatography–time-of-flight mass spectrometry (GC-TOFMS), and sensory evaluation. In total 52 aroma compounds were identified, and 15 of them with high flavor dilution (FD) factors based on aroma extract dilution analysis (AEDA) were selected and quantitated. Finally, 9 key aroma-active compounds, including acetic acid (sour), allyl methyl trisulfide (cooked garlic), Furaneol (caramel), diallyldisulfide (garlic), diallyltrisulfide (sulfur), (E,Z)-2,6-nonadien-1-ol (cucumber), 3-methylbutanoic acid (sweat), 5-heptyldihydro-2(3H)-furanone (apricot), and diallyl sulfide (garlic), were determined through aroma recombination and omission experiment. In addition to the sulfur-containing compounds, heterocyclic compounds were the major aroma contributors in black garlic. Sensory evaluation revealed that the flavor profile of black garlic mainly consisted of sulfur, sour, sweet, fresh, sauce, gasoline, and roasted odors.
Sensory evaluation revealed that traditional high-salt liquid-state soy sauce (THLS), a popular seasoning in China, has a caramel-like/sweet, roasted, nutty, cooked potato-like, and spicy/burnt ...aroma. As a comparative sample, commercial high-salt liquid-state soy sauce (CHLS) showed a similar aroma profile; however, the aroma intensity was stronger and richer in THLS. Gas chromatography−olfactometry−mass spectrometry and aroma extract dilution analysis of the aroma concentrates, prepared by solvent-assisted flavor evaporation, revealed the presence of over 70 odor-active compounds. Among them, methional had the highest flavor dilution factor. Maltol, 4-ethylguaiacol, and phenylacetaldehyde were detected with a higher flavor dilution factor in THLS than in CHLS. Quantitative analysis indicated that the concentrations of 11 key aroma compounds were higher in THLS than in CHLS. The sensory evaluation suggested that the aroma profile of the aroma recombination sample was similar to that of THLS. HEMF, 2-acetyl-1-pyrroline, methional, HDMF, 4-ethylguaiacol, phenylacetaldehyde, 2,3-diethylpyrazine, 2-phenylethanol, furfuryl alcohol, 2,3-butanediol, and maltol imparted the overall aroma profile to THLS.
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•Chinese traditional soy sauce has a sweet, roasted, nutty, cooked potato-like, spicy aroma.•Aroma intensity of traditional soy sauce is stronger than those in other commercial ones.•Eleven key aroma compounds were identified by GC-O-MS, AEDA and sensory evaluation.•The aroma profile of aroma recombinate was similar to that of traditional soy sauce.
•The aroma compounds in Hanyuan Zanthoxylum bungeanum were identified by GC × GC-O-MS.•72 volatile compounds were identified by GC-O-MS, of which 28 were aroma-active.•116 volatile compounds were ...identified by GC × GC-O-MS, 43 of which were aroma-active.•23 important aroma-active compounds with FD ≥ 27 were identified by AEDA.•Compounds were quantified by external standard curves and OAV.
The present study sought to characterize the composition of volatile aroma compounds and key aroma-active compounds of dried Hanyuan Zanthoxylum bungeanum. The volatile aroma compounds were analyzed by the solid-phase microextraction (SPME) combined with gas chromatography–olfactometry-mass spectrometry (GC-O-MS) and two-dimensional comprehensive gas chromatography–olfactometry-mass spectrometry (GC × GC-O-MS). The key aroma-active compounds were analyzed by the aroma extract dilution analysis and odor activity value. A total of 72 volatile compounds were identified by GC-O-MS, of which 28 were aroma-active. Meanwhile, 116 volatile compounds were identified by GC × GC-O-MS, of which 43 were aroma-active. These results revealed that myrcene, (+)-limonene, (E)-β-ocimene, β-cubebene, Germacrene D, cineole, linalool, and linalyl acetate were the key aroma-active compounds of dried Hanyuan Zanthoxylum bungeanum.
Beer is a popular alcoholic beverage worldwide. However, limited research has been conducted on identifying key odor-active components in lager-type draft beers for the Chinese market. Therefore, ...this study aims to elucidate the odor characteristics of the four most popular draft beer brands through a sensory evaluation and an electronic nose. Subsequently, the four draft beers were analyzed through solid-phase microextraction and liquid–liquid extraction using a two-dimensional comprehensive gas chromatography–olfactometry–mass spectrometry analysis (GC×GC–O–MS). Fifty-five volatile odor compounds were detected through GC×GC–O–MS. Through an Aroma Extract Dilution Analysis, 22 key odor-active compounds with flavor dilution factors ≥ 16 were identified, with 11 compounds having odor activity values > one. An electronic nose analysis revealed significant disparities in the odor characteristics of the four samples, enabling their distinct identification. These findings help us to better understand the flavor characteristics of draft beer and the stylistic differences between different brands of products and provide a theoretical basis for objectively evaluating the quality differences between different brands of draft beer.
YE (yeast extract) has been widely used in the flavor industry as the source to produce the high-quality meaty and umami flavors. It is because YE is rich in the savory and mellow constituents and is ...important precursors to generate aromas via thermal treatment. This study aims to investigate the change of meaty aroma and umami taste in the hydrolyzed YE during the thermal treatment. In this study, gas chromatography–olfactometry-mass spectrometer (GC-O-MS) was employed to detect the aroma-active compounds, and systematic approaches was used for the taste-active umami proteolytics separation and detection. The reaction conditions of two optimal samples, YE-A and YE-B, were as follows: the reaction time (A) was 90 min, the reaction temperature (B) was at 115 °C, the concentration of YE solution (C) was 0.4 g/mL, and pH (D) was 5.5 and 6.0, respectively. The GC-O-MS results show YE-A contains 31 and YE-B contains 29 key aroma-active compounds, and the priorities of four factors are both C > B > D > A. The key aroma-active compounds that contributed to meaty flavor were both 3-(methylthio)propanal (cooked potato-like), dihydro-5-pentyl-2(3H)-furanone (coconut-like, peach-like), 2-ethyl-3,5-dimethyl pyrazine (potato-like) etc
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with OAVs greater than 1. The Q-TOF–MS/MS results show that YE-A contained five umami peptides, which were Ala-Asp-Ala, Pro-Gly-Asp, Glu-Met-His, Gln-Pro-Ser and Val-Glu-His; whereas YE-B contained four umami peptides, which were Glu-Asp, Pro-Ser-Gly, Ala-Glu-Ala, and Gly-Gly-Pro-Gly.
Gas chromatography-olfactometry-mass spectrometry (GC-O-MS) is a combination of gas chromatography-olfactometry (GC-O) and gas chromatography–mass spectrometry (GC–MS). GC-O-MS technique is a ...powerful tool to study food flavors and it has been widely applied for aroma and flavor analysis of various food items. In combination with different technologies, GC-O-MS can be applied to solve many flavor problems in the food industry such as quick mapping of aroma-active compounds, identification of key aroma-active compounds, cluster analysis based on the aroma-active compounds, relationship between odorants and sensory properties, and clarification of formation mechanism of important odorants. The newly proposed “molecular sensory science” concept (or sensory-directed flavor analysis) provides a much deeper research for the GC-O-MS application. Here, we have reviewed the operation, advantages and applications of GC-O-MS technique. Qualitative/quantitative analysis methods and sampling methods of aroma-active compounds have been described to introduce the different application areas of GC-O-MS. Case studies based on existing papers and our research have been discussed.
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•GC-O-MS (gas chromatography-olfactometry-mass spectrometry) is combination of GC-O and GC–MS.•The advantage of GC-O-MS was quicker and more accurate.•The application of GC-O-MS was reviewed.•The prospective of GC-O-MS technique was outlined.
Green tea is a popular beverage around the world and possesses a unique flavor. The flavor qualities of green tea are closely related to its grade and this relationship has not yet been studied. ...Three baked green teas with similar flavor were studied, namely, Huangshan Maofeng, Taiping Houkui, and Shucheng Xiaolanhua. A total of 34 odor compounds were identified by solid phase microextraction (SPME) combined with two-dimensional comprehensive gas chromatography-olfactometry-mass spectrometry analysis (GC×GC-O-MS). The results of the clustering analysis showed that the content of D-limonene and linalool in the high-grade (Grade A) tea was much higher than the content in other grades, so they were identified as odor markers of Grade A baked green tea. The taste components of different grades of green tea infusion were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS) and HPLC. A combination of clustering analysis, principal component analysis (PCA), and orthogonal partial least squares discrimination analysis (OPLS-DA) indicated that galloylglucose, digalloylglucose, trigalloyglucose, strictinin, and gallic acid could be used as taste markers of Grade A baked green tea. Therefore, the results in this paper reveal the substances responsible for the odor and taste markers of high-grade baked green tea.
Guangdong, Guangxi and Yunnan are the three provinces in China that yield the most brown sugar, a brown-red colored solid or powdered sugar product made from sugar cane. In the present study, the ...differences between odor compounds of brown sugar from Guangdong, Guangxi, and Yunnan provinces in China were compared and analyzed by gas chromatography-olfactometry-mass spectrometry (GC-O-MS). A total of 80 odor compounds, including 5 alcohols, 9 aldehydes, 8 phenols, 21 acids, 14 ketones, 5 esters, 12 pyrazines, and 6 other compounds, were detected. The fingerprint analysis of the brown sugar odor compounds showed 90% similarity, indicating a close relationship among the odor properties of brown sugar in each province. Moreover, the orthogonal partial least squares discriminant analysis (OPLS-DA) was performed to identify the compounds contributing to the volatile classification of the brown sugar from three provinces, which confirmed that OPLS-DA could be a potential tool to distinguish the brown sugar of three origins.
► In this study, the pathways of key meat flavour compounds were analysed by using carbon module labelling technique. ► LC/TOF MS used to analyse the non-volatiles may be a new attempt in the study ...of Maillard reaction. ► This study was helpful for investigating the role of peptides as precursors in the generation of meat flavour compounds.
The formation mechanism of meat flavours formed from a glutathione–xylose Maillard reaction was studied using a group of model reactions with 13C5 xylose/xylose (1:1), heated at 132°C for 90min. Volatiles, especially the aroma-active compounds, and non-volatiles were analysed respectively with GC-O-MS and LC-TOF-MS. Analysis of the mass spectra showed that furfural, 2-furfurylthiol and thiophene were 13C5-labelled and hence stem from xylose, whereas 2-methyl-3-furanthiol, 2-methyl-thiophene and 2-pentyl-thiophene, which showed similar formation patterns with only unlabelled compounds, may be from thiamine and/or cysteine carbons. In the process of Maillard reactions, GSH can be capable of cleaving in the position of glutamyl and cysteinyl, and then form 5-oxoproline or pyroglutamic acid (PCA), cysteine, and Cys-Gly dipeptide, which can form cyclic (Cys-Gly).
Boiling, the most frequent edible way to hotpot seasoning (HS), exerts a significant impact on the aroma of HS. The present study employed, for the first time, a novel switchable system between ...GC-O-MS and GC×GC-O-MS (SGC/GC×GC-O-MS) to study the aroma compounds of HS and hotpot seasoning boiling liquid (HSBL). A total of 79 aroma compounds and 56 aroma-active compounds were identified. The aroma extract dilution analysis (AEDA) was used to analyze the differences between the key aroma-active components in the HS and HSBL. The results showed that 13 aroma-active components were significantly affected by boiling, such as D-limonene, methional, and linalool. Moreover, a total of 22 key aroma-active components were identified through the odor activity values (OAVs) calculation. Of them, (E)-2-octenal (fatty) and linalool showed a significant difference, suggesting them to be the most critical aroma-active compounds in the HSBL, and HS, respectively. Finally, the correlation between key aroma-active compounds and the sensory properties of HS and HSBL was studied. These results demonstrated that the OAVs of key aroma-active compounds could characterize the real information of samples through bidirectional orthogonal partial least squares (O2PLS). The analysis results were consistent with the sensory evaluation results.
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