Key Aroma Compounds Research Articles

Characterization of key aroma compounds in flat peach juice based on gas chromatography-mass spectrometry-olfactometry (GC-MS-O), odor activity value (OAV), aroma recombination, and omission experiments

The aroma profiles of fresh flat peach juice (FPJ) samples obtained from four different cultivars (RP1), (ZLP), (RP18), and (ZP) were characterized by gas chromatography-Mass spectrometry-olfactometry (GC-MS-O). Totally, 32 aroma-active compounds in FPJs were identified by GC-MS-O and further quantified. Of these, 14 aroma-active compounds presented odor activity values (OAVs) greater than 1, with several lactones and aldehydes contributing as key aroma-active components of FPJs. Partial least-squares regression (PLSR) revealed that RP18 was greatly related to “fruity”, “sweet” and “peach-like” attributes, while ZLP was highly correlated with “floral” and “green and grassy” attributes, confirming the quantitative describe analysis (QDA) results. In addition, an aroma recombination experiment was conducted to mimic the aroma profile of flat peach juice based on the actual concentrations of RP18. Omission experiments indicated that lactones were very highly significant for the characteristic aroma of FPJ.

Characterization of volatiles in Allium tenuissimum L. flower by headspace-gas chromatography-olfactometry-mass spectrometry, odor activity values, and the omission and recombination experiments

Volatiles in four Allium tenuissimum flower samples were detected and characterized by headspace-gas chromatography-olfactometry-mass spectrometry, and odor activity values. The key aroma compounds were determined by combining the sensory analysis with the omission and recombination experiments. The results illustrated that a total of 36 volatiles were identified and divided into six types, including sulfur-containing compounds, aldehydes, alcohols, ketones, nitrogen-containing compounds, and others. The sulfur-containing compounds and aldehydes were the two most abundant compounds in A. tenuissimum flower. The volatiles were quantified through authentic reference compounds, and the contents of these compounds in four A. tenuissimum flower samples were obtained. Five key aroma compounds of A. tenuissimum flower were confirmed as dimethyl disulfide, dimethyl trisulfide, linalool, 2-methylbutanal, and nonanal. Among these, the predominant compounds dimethyl disulfide and dimethyl trisulfide having strong onion and sulfur aroma, significantly contributed to the aroma of A. tenuissimum flower. The main aroma profiles of A. tenuissimum flower were onion, sulfur, flower, green and burnt. The closer the geographical location and environment of A. tenuissimum flower growth are, the more similar their chemical composition.

Comparative characterization of key odorants of French fries and oils at the break-in, optimum, and degrading frying stages

Flavor is a significant factor determining the popularity of French fries (FFs). The frying process of soybean oil (SO) showed three obvious stages—break-in, optimum, and degrading. Further, in order to distinguish the key aroma compounds in each stage, the FFs prepared in SO with total polar compounds (TPC) of 6.5% (FF7), 16.37% (FF16), and 26.5% (FF27), and their corresponding oils (SO7, SO16, SO27) were chosen for sensory-directed analysis. In the break-in stage (6.50–13.50% of TPC), the flavor of the FFs was light and undesirable due to the lower content of (E,E)-2,4-decadienal. Then at the optimum stage (15.43–22.70% of TPC), the FFs obtained a higher sensory score, mainly owing to the increase of (E,E)-2,4-decadienal with a strong, deep-fried odor. However, in the degrading stage (over 22.70% of TPC), high level of four acids (hexanoic, heptanoic, octanoic, and nonanoic acid), benzeneacetaldehyde and trans-4,5-epoxy-(E)-2-decenal resulted in flavor deterioration in FF27.

Characterization of key aroma compounds in Xinjiang dried figs (Ficus carica L.) by GC–MS, GC–olfactometry, odor activity values, and sensory analyses

Xinjiang is the main production area of figs in China. In this work, three different methods (SDE, SAFE, and SPME) were employed to extract the volatile compounds from Xinjiang dried figs. The exactions were then analyzed using aroma extract dilution analysis (AEDA) based on gas chromatography-mass spectrometry (GC−MS) and gas chromatography–olfactometry (GC−O). Seventy-five aroma-active compounds were identified with flavor dilutions (FD) factors ranging from 1 to 2187. Aroma compounds with odor activity value (OAV) greater than 10 were subsequently used in aroma reconstitution and omission experiments. Based on instrumental analysis and sensory evaluation, 22 compounds were identified as the key aroma compounds and eight of these were evaluated as the most important aroma contributors of Xinjiang dried figs, including heptanal, nonanal, linalool, benzyl benzoate, styrene, eugenol, 2-methoxy-4-vinylphenol, and vanillin. Moreover, three volatile components, including 2-methoxy-4-methylphenol, 2-methoxy-4-vinylphenol and ortho-guaiacol, were identified as key aroma compounds of dried figs and have not been reported previously.

Microwave pretreatment of camellia (Camellia oleifera Abel.) seeds: Effect on oil flavor

Microwave is a new pretreatment technology, and microwave processing time of camellia seeds is a factor affecting the flavor of camellia seed oil (CSO). Therefore, this study on the characteristic volatile compounds of CSO from microwaved seeds with different processing time was carried out by electronic nose (E-nose), headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). The results of E-nose show that W1W, W2W and W5S were the main sensors to distinguish the flavor profile of CSOs. Through HS-SPME-GC-MS and odor activity value analysis, 80 volatile compounds were detected and 22 key aroma compounds were screened in CSOs. Compared with HS-SPME-GC-MS, 44 volatile compounds were detected by HS-GC-IMS, including 9 identical compounds and 35 different compounds. In general, the volatile compounds of 0, 2 and 3 min CSOs were mainly alcohols and esters, while the 4, 5 and 6 min CSOs were mainly heterocycles and aldehydes.

Profiling Volatile Compounds in Blackcurrant Fruit using Headspace Solid-Phase Microextraction Coupled to Gas Chromatography-Mass Spectrometry.

There is an increasing interest in measuring volatile organic compounds (VOCs) emitted by ripe fruits for the purpose of breeding varieties or cultivars with enhanced organoleptic characteristics and thus, to increase consumer acceptance. High-throughput metabolomic platforms have been recently developed to quantify a wide range of metabolites in different plant tissues, including key compounds responsible for fruit taste and aroma quality (volatilomics). A method using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) is described here for the identification and quantification of VOCs emitted by ripe blackcurrant fruits, a berry highly appreciated for its flavor and health benefits. Ripe fruits of blackcurrant plants (Ribes nigrum) were harvested and directly frozen in liquid nitrogen. After tissue homogenization to produce a fine powder, samples were thawed and immediately mixed with sodium chloride solution. Following centrifugation, the supernatant was transferred into a headspace glass vial containing sodium chloride. VOCs were then extracted using a solid-phase microextraction (SPME) fiber and a gas chromatograph coupled to an ion trap mass spectrometer. Volatile quantification was performed on the resulting ion chromatograms by integrating peak area, using a specific m/z ion for each VOC. Correct VOC annotation was confirmed by comparing retention times and mass spectra of pure commercial standards run under the same conditions as the samples. More than 60 VOCs were identified in ripe blackcurrant fruits grown in contrasting European locations. Among the identified VOCs, key aroma compounds, such as terpenoids and C6 volatiles, can be used as biomarkers for blackcurrant fruit quality. In addition, advantages and disadvantages of the method are discussed, including prospective improvements. Furthermore, the use of controls for batch correction and minimization of drift intensity have been emphasized.

Key Aroma Compounds in Roasted White Kołuda Goose.

Aroma-active compounds in the roasted leg meat of White Kołuda goose were assayed by gas chromatography-olfactometry, using aroma extract dilution analysis and solvent-assisted flavor evaporation. Quantitation, recombination-omission tests, and sensory evaluation were carried out. Thirty aroma compounds, for which odor activity values (OAVs) were calculated and for which the flavor dilution factors were greater than or equal to 1, were identified. The concentration of aroma compounds ranged from 0.06 to 633 (μg/kg). The highest OAVs (>1024) were for 2-furfurylthiol, 2-acetyl-1-pyrroline, and 1-octen-3-one. Nine key aroma compounds were: 2-furfurylthiol, 2-acetyl-2-thiazoline, 1-octen-3-one, 2-phenylethanethiol, 4,5-dimethyl-3-hydroxy-2(5H)-furanone, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, (E,E)-2,4-decadienal, 2-acetyl-1-pyrroline, and 3-(methylthio)propanal. The intensity of the dominating roasted, meaty/broth, and fatty notes in the recombination model consisting of the key odorants were rated (10-point scale) at 4.6-5.8 points, relative to the original roasted goose (5.2-6.2). The aroma compounds defined predominantly the meaty, roasted, and fatty flavors during the descriptive sensory evaluation of the roasted goose meat.

Aroma characteristics of traditional Huangjiu produced around Winter Solstice revealed by sensory evaluation, gas chromatography–mass spectrometry and gas chromatography–ion mobility spectrometry

Traditional Huangjiu (a kind of traditional Chinese rice wine) produced around Winter Solstice has higher quality and a more harmonious aroma than those produced during other periods. To determine the specific differences in aroma characteristics, sensory evaluation, gas chromatography–mass spectrometry (GC–MS) and gas chromatography–ion mobility spectrometry (GC–IMS) were used to analyze the volatile profiles of the traditional Huangjiu samples produced under different ambient temperature conditions. The sensory evaluation results showed that the aroma attributes of wheat, sweet, ester, alcoholic and sauce were stronger for the samples fermented near Winter Solstice than those for the other samples. GC–MS combined with heatmap analysis showed that with the decrease in average ambient temperature, the contents of esters such as diethyl succinate and ethyl butanoate gradually increased, and the contents of alcohols such as phenylethyl alcohol, 2-methylpropanol and 3-methylbutanol gradually decreased. Some key aroma compounds, such as ethyl butyrate (OAV: 97–151), nonanal (OAV: 189–200), ethyl octanoate (OAV: 859–1134) and ethyl phenylacetate (OAV: 307–353), were more abundant in the samples fermented near Winter Solstice than the other samples. The visualization of GC–IMS suggested that isoamyl acetate, 2-methylpropyl acetate, ethyl 3-methylbutyrate, and ethyl 2-methylbutanoate were enriched near Winter Solstice. Together, the results suggested that the traditional Huangjiu produced around Winter Solstice contained more flavor volatiles and had better aroma quality than those produced during other periods.

Formation of Diastereomeric Dihydromenthofurolactones by Cystostereum murrayi and Aroma Dilution Analysis Based on Dynamic Headspace Extraction.

Submerged cultures of the basidiomycota Cystostereum murrayi emit an intensive coconut-like, sweetish, and buttery smell. For identification of the key aroma compounds, an aroma dilution analysis using dynamic headspace was performed by adjusting the split ratio of the GC inlet system. Flavor dilution (FD) factors varied from 22 up to ≥218, whereby the largest class of compounds represented terpenoids, including two rare stereoisomers of 3,6-dimethyl-2,3,3a,4,5,7a-hexahydrobenzofuran (dill ether, ee ≥ 99.9). By means of nuclear magnetic resonance spectroscopy, the substances with the highest FD factors (29, 212, and 218) were identified as diastereomers of 3,6-dimethyl-3a,4,5,6,7,7a-hexayhydro-3H-1-benzofuran-2-one (dihydromenthofurolactone) and as its corresponding C3-unsaturated lactone. The latter two compounds have not been described for Cystostereum murrayi or for any other basidiomycota previously. Supplementation studies using 2-13C-d-glucose indicated that these lactones as well as the two stereoisomers of dill ether and other terpenoids were formed de novo by the fungus.

Delineating the extra-virgin olive oil aroma blueprint by multiple headspace solid phase microextraction and differential-flow modulated comprehensive two-dimensional gas chromatography

Comprehensive two-dimensional gas chromatography with parallel mass spectrometry and flame ionization detection (GC × GC-MS/FID) enables effective chromatographic fingerprinting of complex samples by comprehensively mapping untargeted and targeted components. Moreover, the complementary characteristics of MS and FID open the possibility of performing multi-target quantitative profiling with great accuracy. If this synergy is applied to the complex volatile fraction of food, sample preparation is crucial and requires appropriate methodologies capable of providing true quantitative results.In this study, untargeted/targeted (UT) fingerprinting of extra-virgin olive oil volatile fractions is combined with accurate quantitative profiling by multiple headspace solid phase microextraction (MHS-SPME). External calibration on fifteen pre-selected analytes and FID predicted relative response factors (RRFs) enable the accurate quantification of forty-two analytes in total, including key-aroma compounds, potent odorants, and olive oil geographical markers.Results confirm good performances of comprehensive UT fingerprinting in developing classification models for geographical origin discrimination, while quantification by MHS-SPME provides accurate results and guarantees data referability and results transferability over years. Moreover, by this approach the extent of internal standardization procedure inaccuracy, largely adopted in food volatiles profiling, is measured. Internal standardization yielded an average relative error of 208 % for the fifteen calibrated compounds, with an overestimation of + 538% for (E)-2-hexenal, the most abundant yet informative volatile of olive oil, and a -89% and -80% for (E)-2-octenal and (E)-2-nonenal respectively, analytes with a lower HS distribution constant.Compared to existing methods based on 1D-GC, the current procedure offers better separation power and chromatographic resolution that greatly improve method specificity and selectivity and results in lower LODs and LOQs, high calibration performances (i.e., R2 and residual distribution), and wider linear range of responses.As an artificial intelligence smelling machine, the MHS-SPME-GC × GC-MS/FID method is here adopted to delineate extra-virgin olive oil aroma blueprints; an objective tool with great flexibility and reliability that can improve the quality and information power of each analytical run.

Characterization of key aroma compounds in pixian broad bean paste through the molecular sensory science technique

The Pixian broad bean paste (PBBP) is widely welcomed by consumers in China due to its unique aroma. The objective of this study was to characterize the key aroma of PBBP. The aromas of PBBP were fractionated by normal phase-liquid chromatography (NP–LC) and detected and identified by gas chromatography-olfactory (GC–O) coupled with gas chromatography-mass spectrometry (GC–MS), and quantitated by stir bar sorptive extraction (SBSE). The results showed that 58 aroma-active compounds were identified in PBBP, of which acids and phenolics had the highest concentration, and 39 odorants were demonstrated as important odorants. Besides, aroma recombination tests and statistical analysis showed that the original PBBP and recombinant have no significant difference in sweat/sour, roasted, and floral attributes, proving that this study successfully simulated the typical aroma of PBBP. The omission tests demonstrated 4-ethylguaiacol and 4-vinylguaiacol as the key odorants and revealed the significance of sotolon, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), the entire class of phenolics, and the entire class of acids, particularly acetic acid, 3-methylbutanoic acid, 4-methylpentanoic acid may have a synergistic effect, for the overall aroma of the PBBP.

Characterization of key aroma compounds and enantiomer distribution in Longjing tea

By comparing the enantiomers of authentic Longjing tea, the authenticity of Longjing tea can be effectively distinguished. In this study, 18 enantiomers were identified using a chiral column. At the same time, the unique enantiomer ratio (ER) of Longjing tea (LG1, LG2, LG3, LG4, LG5) of different grades and origins was determined. The ER can provide a theoretical basis for distinguishing Longjing tea of different grades and origins, and for identifying the authenticity of Longjing tea. The ER ratio of (R)-(-)-1-octen-3-ol and (S)-(+)-1-octen-3-ol can be used to identify LG1 (71:29). The ER ratio of (S)-(+)-α-ionone and (R)-(-)-α-ionone can be used to identify LG2 (65:35). The ER ratio of (R)-(-)-dihydroactinidiolide to (S)-(+)-dihydroactinidiolide (71:29) can also be used to detect LG3. The ER ratio of (R)-(+)-Limonene and (S)-(-)-limonene can be used to identify LG4 (20:80). The ER ratio of (R)-(-)-linalool to (S)-(+)-linalool (12:83) was available to identify LG5.

Use of headspace GC/MS combined with chemometric analysis to identify the geographic origins of black tea

Some black teas demand high market prices. Black tea samples (306) collected from 10 geographic origins, including China (Guxi, Likou, Jinzipai, Guichi, Dongzhi, Changning, Wuyishan, Shaowu), India (Darjeeling), and Sri Lanka (Kandy), were analyzed using headspace volatilization followed by GC/MS (HS-GC/MS). Forty-eight volatile compounds were identified. The aroma compounds were mainly identified as alcohols, aldehydes, ketones, and esters. Analysis of either full-spectrum data or 22 tea compounds shared among the samples with k-Nearest Neighbor (k-NN) and Random Forest (RF) models discriminated all origins at 100% using KNN and 95% with RF using either data set. The discrimination rates using 2 key aroma compounds (linalool and geraniol) by k-NN were 100% for nine origins, with the rate for Guxi area at 89%, because 3 samples were classified to Jinzipai. The findings support the use of HS-GC/MS combined with chemometrics as a tool to identify the origin of black tea.

Characterization of the Key Aroma Compounds in Fresh Leaves of Garden Sage (Salvia officinalis L.) by Means of the Sensomics Approach: Influence of Drying and Storage and Comparison with Commercial Dried Sage.

The overall aroma profiles of commercial dried sage differ significantly from the profile of macerated fresh leaves. To clarify changes in the key aroma compounds, first an aroma extract dilution analysis was applied on an extract/distillate prepared from the fresh leaves of Italian garden sage cultivated in a green house in Germany. Among the 39 aroma active compounds characterized, (Z)-3-hexenal, 1,8-cineol, borneol and eugenol showed the highest flavor dilution (FD) factors. Odorants identified with FD factors between 64 and 8192 were quantitated to calculate odor activity values (OAV; ratio of concentration to odor threshold). The highest OAVs were determined for myrcene, (Z)-3-hexenal, (1S,2R,4S)-borneol and 1,8-cineol. A mixture of 22 key reference aroma compounds in the same concentrations as determined in the fresh sage leaves successfully mimicked the overall aroma profile of the spice. To get insight into changes induced by drying, all key aroma compounds were quantitated in sage leaves from the same plant by drying at 50 °C. While all monoterpenes remained nearly unchanged during drying, in particular highly volatile compounds such as dimethyl sulfide or 2- and 3-methylbutanal were decreased. Almost a total loss occurred for 3-(methylthio)propanal, phenylacetaldehyde, and (Z)-3-hexenal. By contrast, storage of the dried leaves for 12 months at room temperature in the dark did not much effect the concentrations of selected key odorants, thus indicating that drying is the most important factor for the changes in aroma compounds. Sensory profiling of six commercial sage samples showed different aroma profiles, which also clearly differed from the profile of the sage dried in lab scale, which was rated to elicit the most typical sage aroma. In addition, the concentrations of selected key aroma compounds as well as the total amount of volatiles were clearly lower in all commercial samples.

Characterization of the Key Aroma Compounds in a Commercial Fino and a Commercial Pedro Ximénez Sherry Wine by Application of the Sensomics Approach.

Following the sensomics approach, the key aroma compounds of a commercial Fino and Pedro Ximénez sherry were identified, quantitated, and validated through recombination experiments. In Fino sherry, 31 compounds were determined in concentrations above their odor detection thresholds, with the fruity/green smelling 1,1-diethoxyethane displaying the highest odor activity value ((OAV); the ratio of the concentration to the odor threshold) of 8970, followed by ethyl (2S,3S)-hydroxy-3-methylpentanoate (853) and 2- and 3-methylbutanal (448). In the Pedro Ximénez sherry, 23 compounds were present in concentrations exceeding their odor thresholds, and the malty smelling 2- and 3-methylbutanal were found with the highest OAV (1006), followed by 1,1-diethoxyethane (808) and methylpropanal (561). The results were compared to those characterized previously by us in an Amontillado sherry revealing that in all three sherry wines, 1,1-diethoxyethane, 2- and 3-methylbutanal, methylpropanal, ethanol, ethyl (2S,3S)-2-hydroxy-3-methylpentanoate, acetaldehyde, and 3-(methylthio)propanal, as well as the fruity-smelling ethyl 2-methylbutanoate, ethyl hexanoate, ethyl octanoate, and ethyl 3-methylbutanoate ranked among the 15 odorants with the highest OAVs. But, although most odorants were identical in the three sherries, their amounts differed significantly. The results are discussed considering the different winemaking processes and the different aroma profiles.

Characterization of the Key Aroma Compounds in the Fruit of Litsea pungens Hemsl. (LPH) by GC-MS/O, OAV, and Sensory Techniques

The key aroma compounds in the fruit of Litsea pungens Hemsl. (LPH) were concentrated through solvent-assisted flavor evaporation (SAFE) and characterized by gas chromatography-mass spectrometry-olfactometry (GC-MS/O), quantitative descriptive analysis (QDA), odor activity values (OAVs), and addition test. The results showed that LPH contained 31 aroma-active compounds (flavor dilution, FD = 9). Among them, 30 odorants were quantified by the standard curve method. The OAV analysis results showed that 25 odorants had OAVs ≥ 1, which could be considered as the potent odorants. D-Limonene and 3,7-dimethyl-2,6-octadienal had the highest OAVs (OAV = 9803 and 8399), followed by (Z)-3,7-dimethylocta-2,6-dienal (OAV = 1893), β-myrcene (OAV = 1798), (E)-3-phenyl-2-propenoic acid ethyl (OAV = 1603), and β-caryophyllene (OAV = 1129). Addition experiments further confirmed that 3,7-dimethyl-2,6-octadienal, (Z)-3,7-dimethylocta-2,6-dienal, and D-limonene contributed to lemon attribute, β-myrcene contributed to green attribute, citronellal contributed to mint and fresh note, and eucalyptol contributed to eucalyptus-like note were the key odorants.

Microbial communities succession and flavor substances changes during Pixian broad-bean paste fermentation

Pixian broad-bean paste (PXDB) is a traditional Chinese fermented condiment with a distinct flavor. The flavors stems from its strong relationship to local microorganisms. This study analyzed changes in key aroma compounds, organic acids, free amino acids (FAA), and the microbial community during different fermentation stages in order to study the correlation between flavors and microbes. Results indicated that the presence of key aroma compounds and organic acids initially increased, then decreased. Changes in total FAA content were divided into two stages due to the addition of chili pepper, however, both stages displayed an increase in FAA levels as fermentation time increased. High-throughput sequencing was used to study the microbial community and succession. Lactobacillus, Prevotella 9, Ruminococcaceae ucg-014, Lysinibacillus, Enterococcus, Weissella, Escherichia-Shigella, Sphingomonas, Aspergillus, Zygosaccharomyces, Candida, and Pichia presented as the primary microorganism during fermentation process. Simultaneously, it was found that bacteria genera indicated a stronger potential correlation with flavors, versus fungi genera. Escherichia-Shigella, Leuconostoc, Acetobacter, Chromohalobacter, Candida, Mortierella, Plectosphaerella, Podoscypha, and Podospora displayed a significant correlation with flavors (isoamyl alcohol, 2,5-dimethylpyrazine, phenethyl alcohol, 2,3,5,6-tetramethylpyrazine, citric acid, serine, asparagine, glutamate, etc.). This study provides an improved understanding on formation mechanisms of flavors, and guidance for screening PXDB fermentation strains.

The key aroma compounds and sensory characteristics of commercial Cheddar cheeses

To study the key aroma components and flavor profile differences of Cheddar cheese with different maturity and from different countries, the flavor components of 25 imported commercial Cheddar cheese samples in the China market were determined by gas chromatography-mass spectrometry. The quality and quantity of 40 flavor compounds were analyzed by gas chromatography-olfactometry among 71 aroma compounds determined by gas chromatography-mass spectrometry. Combined with odor activity value calculation, principal component analysis (PCA) was conducted to analyze the relationship among 26 flavor compounds with odor activity values >1 and the maturity of Cheddar cheese. The PCA results showed significant differences between the group of mild Cheddar cheese and the groups of medium Cheddar cheese and mature Cheddar cheese, and no significant differences were observed between medium Cheddar cheese and mature Cheddar cheese. According to the results of PCA and consumers' preference test, representative Cheddar cheese samples with different ripening times were selected for the flavor profile analysis. Partial least squares regression analysis was conducted to obtain the relationship between sensory properties and flavor compounds of different Cheddar cheeses. Based on partial least squares regression analysis, 1-octen-3-one, hexanal, acetic acid, 3-methylindole, and acetoin were positively correlated with milky, sour, and yogurt of mild Cheddar cheese. Dimethyl trisulfide, phenylacetaldehyde, ethyl caproate, octanoic acid, and furaneol and other compounds were positively correlated with fruity, caramel, rancid, and nutty notes of the medium and mature Cheddar cheeses.

Occurrence, Formation, Stability, and Interaction of 4-Hydroxy-2,5-dimethyl-3(2H)-furanone

4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), one of the most important volatile compounds from the 3(2H)-furanone family, makes vitally important contributions to aromas related to various foods. Because of the relatively low threshold itself, HDMF is especially considered as a potent aroma compound and greatly appreciated by the food industry. Substantial progress has been made to elucidate its formation pathways both in natural fruits and in thermal processes with respect to biosynthesis and the Maillard reaction, respectively. Interaction with sulfur-containing amino acids also generates characteristic meaty flavors. HDMF easily reacts with other compounds in food systems, being affected by parameters under different conditions and showing strong antioxidant activities. Nevertheless, unstable properties may also make its evolution possible in various and complex reaction cascades, leading to different key aroma compounds. This review is based on the sensory significance of HDMF to discuss its formations, stability, and interactions in flavor generation.

Variations in the key aroma and phenolic compounds of champignon (Agaricus bisporus) and oyster (Pleurotus ostreatus) mushrooms after two cooking treatments as elucidated by GC–MS-O and LC-DAD-ESI-MS/MS

Volatiles, key odorants, phenolics and antioxidant properties of raw, boiled and oven-cooked champignon and oyster mushrooms were investigated. Total concentration of the volatiles was drastically reduced by both cooking treatments and the lowest contents were found in the oven-cooked sample. Alcohols and terpenes were the dominant aroma groups in the raw champignon and oyster sample, respectively. The highest FD factor (FD = 2048) was found for 1-octen-3-one and methional in raw and boiled champignon samples while the same FD factor was determined in 1-octen-3-ol and methional in raw and boiled oyster samples. It was determined that the phenolics were more abundant in champignon samples than the oyster samples and that the boiling process caused a decrease while oven-cooking resulted in an increase in the amount of phenolics in both varieties. It was revealed that cooking was a crucial factor for the key odorants and phenolics in champignon and oyster mushrooms.