GC MS Olfactometry Research Articles

Flavoromic determination of lactones in cheddar cheese by GC–MS–olfactometry, aroma extract dilution analysis, aroma recombination and omission analysis

To systematically identify and quantify the γ- and δ-lactones in Cheddar cheeses, 20 samples from three sources (Ireland, the UK and the USA) were analysed by gas chromatography–mass spectrometry (GC–MS), gas chromatography–olfactometry (GC–O), aroma extract dilution analysis, aroma recombination analysis, and aroma addition/omission analysis. Nine lactones were detected in these samples, and one of these lactones, γ-undecalactone, was identified in Cheddar cheese for the first time. The quantitative results showed that the concentration of lactones in these cheeses usually increased as the length of their maturity period increased. γ-Octalactone, γ-undecalactone, γ-dodecalactone, δ-octalactone, δ-decalactone and δ-dodecalactone were identified as aroma-active substances based on their odour activity values and aroma extract dilution analysis, with flavour dilution factors ranging from 2 to 128. Aroma recombination and omission experiments based on a newly developed deodorised Cheddar matrix further validated the important contributions of these lactones to the overall aroma of Cheddar cheeses. The addition of each lactone to aroma recombination models reduced the aroma intensity of sour and rancid properties to various extents and improved the acceptability of the overall flavour.

Fingerprint of aroma-active compounds and odor activity values in a traditional Moroccan fermented butter “Smen” using GC–MS–Olfactometry

Smen is a fermented Moroccan butter highly regarded for its unique flavor characteristics. For the first time, this study aimed to evaluate the suitability and complementary performance of purge-and-trap extraction (PTE) and solvent-assisted flavor evaporation (SAFE) extraction methods prior to gas chromatography–mass spectrometry–olfactometry (GC–MS–O) in order to characterize key compounds in Smen. According to the representativeness tests, both SAFE and PTE aromatic extracts gave satisfactory similarity and intensity scores and were representative aromatic extracts, being similar to the Smen reference odor. Thirty-four volatile compounds were identified in Smen including acids, alcohols, esters, and ketones. Aroma extract dilution analysis (AEDA) was applied to characterize potent odorants, and odor activity values (OAVs) were calculated to authenticate these compounds. Twenty-two and nineteen aroma-active compounds were revealed by SAFE and PTE methods, respectively, with flavor dilution (FD) factors ranging from 4 to 4096, and OAVs between 1 and 3359. Ethyl butanoate, ethyl lactate, ethyl hexanoate, butanoic acid, and hexanoic acid were the main potent odorants in Smen, producing fruity-rose, creamy-whey, overripe fruit, ripened cheese, and rancid buttery/soapy odors, respectively. Therefore, SAFE and PTE methods were not only representative, but also complementary for elucidating potent aroma compounds of Smen.

Characterization of aldehydes and hydroxy acids as the main contribution to the traditional Chinese rose vinegar by flavor and taste analyses.

The volatile aroma compounds of traditional Chinese rose vinegar were identified by headspace solid-phase micro extraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) and GC-MS-olfactometry (GC-MS-O), and the metabolites were identified by silylation-GC-MS in this study. A total of 48 and 76 kinds of flavors and metabolites, respectively were detected in this study. Quantitative analysis showed that aldehydes and acids were present in relatively high amounts. Furthermore, the data colleted by the calculated odor activity values (OAVs) suggested that aldehydes are likely to contribute greatly to the aroma of traditional Chinese rose vinegar, especially, nonanal (OAV: 133, rose), 3-methyl-butanal (OAV: 57, apple-like), decanal (OAV: 23, orange peel), heptanal (OAV: 17, fruity), and dodecanal (OAV: 4-9, violet scents). Moreover, among the detected nonvolatile acids, 14 kinds of hydroxy acids, such as lactic acid, citric acid, 3-phenyllactic acid (PLA) and d-gluconic acid were detected in rose vinegar. The acids provide a well buffer system, not only greatly reduce the irritation of acetic acid, but also improve the flavor of rose vinegar. This study suggests that the fragrance and sour notes in rose vinegar are from aldehydes and hydroxy acids.

Characterization of Ayran Aroma Active Compounds by Solvent-Assisted Flavor Evaporation (SAFE) with Gas Chromatography–Mass Spectrometry–Olfactometry (GC–MS–O) and Aroma Extract Dilution Analysis (AEDA)

The aroma compounds of ayran were isolated using solvent-assisted flavor evaporation (SAFE) resulting in a more representative extract of ayran odor compared to liquid–liquid extraction (LLE), solid-phase extraction (SPE), and simultaneous distillation–extraction (SDE). The aromatic extract was subjected to sensory analysis and identified and quantified by gas chromatography–mass spectrometry (GC–MS). A total of 19 volatile compounds were detected that included alcohols, aldehyde, acids, esters, ketones, and terpenes. However, the compounds present at the highest concentrations were ethyl lactate, ethanol, 2,3-butanediol, acetoin, and acetic acid. The key odorants for the ayran drinks were detected using aroma extract dilution analysis (AEDA) and GC–MS–olfactometry (GC–MS–O). A total of 14 aroma-active compounds were determined for the first time. The flavor dilution (FD) factors ranged between 4 and 512 while their odor activity values (OAVs) were from 1.35 to 1126.99. Ethyl lactate (FD of 512 whey/creamy), 2-methylbutanal (FD of 512, fruity), acetoin (FD of 256, buttery creamy), and butanoic acid (FD of 256, cheesy-sweet) were the strongest aroma-active components of the Ayran drink.

Characterization of key aroma compounds in fresh and roasted terebinth fruits using aroma extract dilution analysis and GC–MS-Olfactometry

Aroma, key aroma compounds, and their odor activity values of fresh and roasted P. terebinthus fruits were studied. Aroma compounds were extracted by the solvent-assisted flavor evaporation technique and analyzed by GC–MS-Olfactometry for the first time. A total of 64 different aroma compounds were detected (57 in fresh and 62 in roasted samples), including terpenes (34), acids (8), aldehydes (4), ketones (4), pyrazines (5), alcohols (5), pyrrole (1), furan (1), lactone (1) and ester (1). Terpenes were the predominant group followed by acids. Aroma profiles of both samples were quite analogous. Nonetheless, pinocarvone and dodecanoic acid were detected only in fresh fruits, while pyrazine class, 5-methylfurfural and γ-butyrolactone were emerged only in roasted fruits. Aroma extract dilution analysis (AEDA) was applied for the first time and revealed 31 key aroma compounds. Among them, the most powerful key aroma compounds with the greatest FD factors were α-pinene and β-myrcene.

Characterization of odor-active compounds of chicken broth and improved flavor by thermal modulation in electrical stewpots

The influence of high temperature modes (cooking in traditional clay stewpot (TS) and cooking in commercial ceramic electrical stewpot (CS)) and low temperature modes (cooking in electrical stewpot with Temperature Modulations, TM1-TM6) on chicken broth sensory evaluation and flavor profile was studied. Sensory evaluation results showed that chicken broth processed using TM1 had the best flavor with higher chicken meat-like and lower off-flavor scores. Gas chromatography-mass spectrometry (GC-MS) and GC-MS/olfactometry (GC-MS/O) results revealed that the TM1 samples had the most abundant odorants. The umami-taste components from TM1 samples such as umami free amino acids and inosine 5′-monophosphate (IMP) had the highest amount, 20.0 ± 0.10 mg/g chicken broth and 17.19 ± 0.58 μg/g chicken broth respectively. The relationship between sensory evaluation and odor-active compounds were evaluated by Partial Least Squares Regression (PLSR), and the PLSR analysis indicated that heptanal, benzaldehyde, (Z)-2-decenal, (E,E)-2,4-decadienal, 1-pentanol, 2-undecanone, 2-pentyl-furan and one unknown compound were significantly and positively correlated with chicken meat-like note. Whereas, fatty aroma were significantly and positively correlated with octanal, (E,E)-2,4-decadienal and 1-pentanol. (E,E)-2,4-Decadienal and 2-undecanone had a significant and negative correlation with off-flavor attribute.

The contribution of aromatic components in Katsuobushi to preference formation and reinforcement effect.

Katsuodashi, a dried bonito broth, is very basic and indispensable in Japanese cuisine and contains taste-exhibiting components and unique aroma. We previously reported that its unique aroma contributes to the preference and reinforcement effect associated with dried bonito. This study aims to elucidate the contribution of aromatic components in Katsuobushi to preference formation and reinforcement effect. Volatile components obtained from dried bonito were fractionated and the fractions were subjected to two-bottle choice test. The fractionation test suggested that the component responsible for the preference is not one but comprises multiple components. In the GC-MS analysis/reconstruction test, solution with aromatic flavor narrowed down to 125 compounds had preference, and also had reinforcement effect. Moreover, GC-MS-olfactometry analysis narrowed down the candidate components to 28 out of 125. Mice showed preference for the test solution with aromatic flavor reconstructed with 28 components but did not show reinforcement behavior.

Volatile and key odourant compounds of Turkish Berberis crataegina fruit using GC-MS-Olfactometry

This research was conducted to identify the aroma and aroma-active compounds of Berberis crataegina for the first time. Volatile profile of B. crataegina was obtained using the purge and trap extraction method with dichloromethane. Gas chromatography was coupled to mass spectrometry (GC–MS) allowed the quantitative and qualitative detection of 22 compounds in the sample. Aldehydes were the main chemical group in the sample and followed by aromatic alcohols and lactone. Aroma extract dilution analysis was implemented for the specification of key odourants of B. crataegina. In total, eight key odourants were detected in the extract of the sample, using GC–MS–Olfactometry and aldehydes were the leading chemical group. The key odourants, found to be contributing to the overall aroma in B. crataegina, were nonanal (FD = 1024; green, flowery), hexanal (FD = 512; green) and linalool (FD = 256; flowery, rose) because of high FD factors.

Characterization of key aroma compounds in a representative aromatic extracts from citrus and astragalus honeys based on aroma extract dilution analyses

The aroma and aroma-active compounds of astragalus and citrus honeys were determined by GC-MS-olfactometry (GC-MS-O). The honey extracts were obtained by two different extraction techniques including liquid–liquid extraction (LLE) and solid phase extraction (SPE), and compared to determine the more representative odour aromatic honey extract. According to sensory analysis, the aromatic extract (40 g honey with 22 mL water) obtained by LLE was the most similar of honey odour. The amount of aroma compounds of citrus honey (14391.6 µg kg−1) was higher than astragalus honey (4270.1 µg kg−1). Terpenes and acids in citrus honey and esters and aldehydes in astragalus honey were the most dominant aroma compounds. Aroma extract dilution analysis (AEDA) was used to determine the aroma-active compounds of honey samples. By application of AEDA on the aromatic extracts isolated by LLE, 12 aroma-active compounds in astragalus honey and 23 in citrus honey could be detected within a flavour dilution (FD) factor range of 8–128. On the basis of the FD factor, phenylethyl alcohol in both honeys was the most powerful key compound and was described as the flowery odour.

GC-MS/Olfactometric characterisation and aroma extraction dilution analysis of aroma active compounds in Polygonum minus essential oil

Polygonum minus Huds. is an aromatic plant with potential anti-inflammatory, antiulcer and diuretic properties. Although the volatile compounds from the essential oil of P. minus have been extensively studied, knowledge of the aroma-active compounds is still incomplete. Hence, the aim of this study is to investigate and to characterise the aroma-active compounds that contribute to the potent odour of P. minus. Essential oil was extracted from the leaves of kesum (P. minus) using hydrodistillation and was analysed by gas chromatography-mass spectrometry (GC-MS) to identify the volatile constituents. The important aroma-active compounds were further analysed by GC-MS/Olfactometry (GC-MS/O) and aroma extraction dilution analysis (AEDA). The GC-MS analysis using Kovats retention indices detected 39 volatile compounds in the essential oil. Aldehydes represented the major class of compounds, encompassing 75.43% of the total peak area, followed by sesquiterpenes (13.19%), alcohols (8.07%) and organic acids (0.83%). The dominant components of the kesum essential oil were dodecanal (54.25%) and decanal (18.27%) in the aldehyde group. The sesquiterpenes that were detected include β-farnesene (1.74%), α-caryophyllene (1.72%), β-caryophyllene oxide (1.51%) and βselinene (1.36%). In this study, GC-MS/O and AEDA analysis identified dodecanal, decanal, farnesol, 1-nonanal and α-bergamotene as the main contributors to the characteristic fragrance of this plant. This is the first olfactometric study on the essential oil of P. minus, and it is important for our understanding of the biosynthesis of volatile compounds in this medicinal herb. Moreover, the characterisation of aromatic compounds that contributed to the potent odour of P. minus can be further applied in the flavour and fragrance industries.

Comparison of the nutritional as well as the volatile composition of in-season and off-season Hezuo 903 tomato at red stage

The influence of the planting season on the nutritional as well as the aromatic composition of Hezuo 903 tomato was investigated by combining use of nutrition analysis, sensory evaluation, electronic nose and electronic tongue analysis, gas chromatography–mass spectrometry (GC–MS) and GC–MS–olfactometry (GC–MS–O) method. The results suggested that in-season tomato contained higher levels of reducing sugar, vitamin C and lycopene than off-season tomato. In-season tomato showed a better overall flavor and acceptability than off-season tomato. Significant difference was observed in both composition and concentration of the typical volatile and aroma-active compounds in two samples. E-2-Hexenal and methyl salicylate were only found in off-season tomato, and phenylacetaldehyde detected merely in in-season tomato. In addition, significantly higher levels of 6-methyl-5-hepten-2-one (P < 0.01) and 2-isobutylthiazole (P < 0.01) were detected in off-season tomato than in-season tomato, which showed a negative effect on the overall flavor of tomato. Our result indicated that the planting season affected the composition and concentration of both non-volatile and volatile compounds of tomato fruit.

Characterization of off-odor compounds of collagen peptides from tilapia scale using GC-MS-olfactometry

Off-odor compounds were identified from marine collagen peptide (MCP) and gelatin collagen peptide (GCP) by using solid phase microextraction (SPME) and solvent assisted flavor evaporation (SAFE) combined with GC-MS-olfactometry (GC-MS-O). Methional, dimethyl trisulfide, and dimethyl tetrasulfide were detected as characteristic off-odor compounds of MCP and GCP. Unknown compounds with sulfurous, cool/refreshing, and medicinal odors also contributed to the off-odors of MCP and GCP. Volatile compounds of MCP and GCP increased gradually as manufacturing process proceeded, indicating that activated carbon deodorization was ineffective in eliminating off-odor compounds. Sulfur-containing compounds, such as methanethiol, dimethyl disulfide, dimethyl trisulfide, and dimethyl tetrasulfide increased as manufacturing process continued. Current study suggested that the fermentation by Lactobacillus plantarum deodorized off-odors of MCP most effectively.

Characterization of aroma-active volatiles in three Chinese bayberry (Myrica rubra) cultivars using GC–MS–olfactometry and an electronic nose combined with principal component analysis

Chinese bayberry (Myrica rubra Sieb. et Zucc.) is one of the most popular and valuable fruits in China because of its unique and exquisite flavor. In this study, headspace solid-phase micro-extraction (HS-SPME) coupled with gas chromatography–mass spectrometry and olfactometry (GC–MS–O) analyses were used to characterize the aroma-active profiles of the fruits from three different bayberry cultivars. The aim was to differentiate the bayberry cultivars by their aroma. Fifty-five volatile components, composed of aldehydes (10), alcohols (9), esters (8), terpenes (17), and others (11), were identified by optimized HS-SPME/GC–MS. Meanwhile, 36 aroma-active compounds were detected by olfactometry using detection frequency analysis (DFA). Hexanal (grass-like), (E)-2-hexenal (green), nonanal (fruit, flower), 1-hexanol (flower), and isocaryophillene (wood) were identified in all three cultivars. Further principal component analysis (PCA) of the active aromas revealed their contributions to the odor differences among the bayberry cultivar groups. The BQ bayberry was characterized by having a stronger “herb” odor, which is mainly caused by benzoic acid and methyl ester. DK bayberry had a stronger “grass” odor, which is mainly caused by 2,6-dimethyl-2,4,6-octatriene, while FHZ bayberry had a stronger “pine” odor, which is caused mainly by α-pinene. The GC–MS–O and electronic nose techniques, when combined with PCA, could be used to successfully distinguish between different bayberry cultivars.

Characteristic odor components of volatile oil from the cultivation medium of Lactobacillus acidophilus.

Volatile oils obtained from both the liquid medium after incubation (MAI) and liquid medium before incubation (MBI) in the cultivation process of Lactobacillus acidophilus were isolated by hydrodistillation (HD) and analyzed to investigate the utility of the liquid waste. The composition of the volatile oils was analyzed by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). In total, 46 and 19 compounds were detected in the volatile oils from MAI (MAI oil) and MBI (MBI oil), respectively. The principle components of MAI oil were fatty acids, including pentanoic acid (12.75%), heptanoic acid (14.05%), and nonanoic acid (14.04%). The important aroma-active compounds in the oils were detected by GC-MS/Olfactometry (GC-O), and their intensity of aroma were measured by aroma extraction dilution analysis (AEDA). Pyrazines were determined as key aroma components; in particular, 2-ethyl-5-methylpyrazine was the most primary aroma-active compound in MAI oil. In addition, as the characteristic aroma-active compounds, 3-(methylthio)-propanal, trimethylpyrazine, and pentanoic acid were also detected in MAI oil. These results imply that the waste medium after incubation of L. acidophilus may be utilized as a source of volatile oils.

Volatile Components of Essential Oil from Cultivated Myrica gale var. tomentosa and Its Antioxidant and Antimicrobial Activities

Aromatic components in the essential oil prepared from the leaves of cultivated Myrica gale var. tomentosa were compared with those from oil derived wild plants by using gas chromatography-mass spectroscopy (GC/MS). We found that essential oils from both the wild and cultivated plants contained similar aromatic components such as β-elemenone, selina 3,7(11)-diene, myrcene, limonene, cymene, 1,8-cineole, and β-pinene, but the content ratio of the oil was significantly different, which might yield differences in the aromatic properties. The aroma impact components of the essential oils were also determined using GC/MS-Olfactometry (GC/MS-O) and aroma extract dilution analysis. Eight aromatic compounds, including linalool, limonene, and 1,8-cineole, were shown to contribute to the aromatic properties of cultivated M. gale var. tomentosa. The strongest aromatic note was defined as linalool, followed by limonene, 1,8-cineole, and β-elemenone. The essential oil, ethanol (EtOH), 1,3-butylene glycol (BG), and 1,3-propanediol (PD) extracts prepared from the leaves of cultivated M. gale var. tomentosa also showed antioxidant and antimicrobial activities, that is, they demonstrated scavenger activity against hydroxyl and superoxide radicals in the aqueous phase, and showed inhibitory effects on lipid peroxidation. The essential oil extracts also exhibited antimicrobial activity against gram-positive bacteria, with the lowest minimum inhibitory concentration value against Bacillus subtilis. In conclusion, the essential oil and solvent extracts from cultivated M. gala var. tomentosa have a potential for utilization as food and cosmetic ingredients.

Character Impact Odorants of Wild Edible Plant-Cacalia hastata L. var. orientalis-Used in Japanese Traditional Food

The chemical composition of the essential oil of Cacalia hastata L. var. orientalis has been investigated by GC and GC-MS. Important odor-active compounds were detected in the oil by GC-MS/Olfactometry (GC-MS/O) and aroma extraction dilution analysis (AEDA). Fifty-one compounds were identified in the oil by GC-MS. The major components of the essential oil were (+)-(4S)-cacalohastine (48.8%), germacrene D (11.4%), and myrcene (10.2%). GC-MS/O and AEDA showed that γ-terpinene, hexanol, and p-mentha-2,4(8)-diene were the most characteristic aroma compounds of the oil. It seems that these components are responsible for the fresh odor of C. hastata L. var. orientalis.

Identification of green note compounds in malt whisky using multidimensional gas chromatography

AbstractWe studied green note compounds in malt whisky using multidimensional GC–MS–olfactometry (MDGC–MS–O). Two aldehydes and three alcohols were shown to contribute to the green note: E,Z‐2,6‐nonenal and E‐2‐nonenal, and 1‐octen‐3‐ol, 4‐hepten‐1‐ol and nonan‐2‐ol, respectively. Malt whiskies with high green note scores organoleptically contained more of the aldehydes and nonan‐2‐ol than those with low scores. This is the first time that E,Z‐2,6‐nonadienal, 1‐octen‐3‐ol, and 4‐hepten‐1‐ol have been identified in malt whisky. These compounds are related to lipid oxidation and degradation, and formation may be due to the action of lipoxygenase. In addition, MDGC–MS–O was effective in examining small amounts of compounds in malt whisky, which contains many volatiles, since this method enables the volatiles in a complicated matrix to be highly resolved without the influence of large amounts of volatiles. Copyright © 2002 John Wiley &amp; Sons, Ltd.