Gas Chromatography-olfactometry Research Articles

Construction of aroma association network of cooked rice based on gas chromatography–mass spectrometry (GC–MS) and sensory analysis

AbstractThe aroma of cooked rice is a key factor in the evaluation of taste quality for rice grading, which greatly affects consumer acceptance. Combining the results of instrumental analysis and sensory evaluation to comprehensively analyse the aroma of cooked rice is a new strategy. The aroma characteristics of fifteen cooked rice varieties were analysed by gas chromatography–mass spectrometry (GC–MS) and descriptive sensory analysis. Based on the aroma descriptors obtained by gas chromatography‐olfactometry (GC‐O) analysis and the odour activity value (OAV) of aroma compounds, the aroma profiles of cooked rice were preliminarily explained by bipartite network and aroma fingerprint. The Pearson correlation coefficients between the OAV results of aroma compounds and sensory data were calculated to construct the aroma association network. The results showed that the aroma attributes of cooked rice were significantly correlated with certain aroma compounds identified by GC–MS, such as aldehydes and heterocycles. The aroma attributes of cooked grain, popcorn, grassy, nutty, and fruity could be well explained by the results of GC–MS analysis. The purpose of the study is to better understand the relationship between aroma characteristics and chemical composition, as well as to provide a theoretical basis for evaluating and predicting the aroma of cooked rice using GC–MS analysis.

Effect of shaking manners on floral aroma quality and identification of key floral-aroma-active compounds in Hunan black tea

Shaking is a key process effecting the floral aroma of Hunan black tea (HBT). In this study, the aroma composition of HBTs shaken in the early withering stage (ES1, ES1 + LS1, and ES2), shaken in the late withering stage (LS1), and not shaken (NS), and the identification of main floral aroma compounds were analyzed using sensory evaluation combined with gas chromatography-mass spectrometry (GC–MS), gas chromatography–olfactometry (GC-O), and aroma recombination experiments. Sensory evaluation results showed that the floral aroma of HBT shaken in the early withering stage was with high intensity, whereas HBT shaken in the late withering stage had low-intensity floral aroma. GC–MS identified a total number of 81 differential volatile compounds in HBT, including 30 esters, 18 aldehydes, 15 alcohols, 12 terpenes, 4 ketones, and 2 nitrogen-containing compounds. Further screening of important floral aroma differential compounds was performed using sensory-guided, odor activity value (OAV), and GC-O analysis, which identified three critical floral aroma differential compounds. Eventually, absolute quantification analysis and aroma recombination experiments confirmed that indole and methyl jasmonate were the most critical compounds of HBT determining floral aroma intensity. The findings of this study provide valuable guidance for the production of HBT with rich floral aroma attributes.

Aroma Comparison between Plant-based Hamburgers and Traditional Beef Hamburgers

The aim of the study was to investigate the differences in aroma in the many plant-based hamburger analogues in the market today when compared with traditional beef hamburger. For that purpose, we investigated the aroma components using headspace gas chromatography-olfactometry and gas chromatography coupled to mass spectrometry analytical methods. The lipid-derived aldehydes and Maillard reaction compounds were key contributors to the characteristic aroma of a beef hamburger. And that most of the plant-based burgers in the market today were unable to replicate that profile. The plant-based meat analogues displayed a more roasted odor character with higher pyrazine levels and then many show evidence to the addition of other flavor compounds and spices to give the perception of a flavored meat analogue. These approaches resulted in higher flavor intensity; however, the result was something very sensorially different than the sweet, juicy, buttery, and meaty character of beef hamburger. Based on these findings, replication of the characteristic aroma of beef hamburger is complex. This work provides new insights into the key aroma contributors of beef hamburgers and the challenges that exist in trying to replicate it with plant-based meat analogues.

Unveiling improval changes in fried chicken flavor by glucose-curing treatment based on molecular sensory science

To gain insight into the improved flavor changes, the volatile flavor composition of fried chicken with glucose curing (500 mg/100 g meat) (FCWG), exhibiting the strongest meaty and roasted aromas, and that without curing (FCWOG) were comparatively analyzed. Solvent-assisted flavor evaporation combined with gas chromatography–mass spectrometry (GC–MS) and aroma extract dilution analysis by gas chromatography–olfactometry (GC–O), accurate quantitation, and odor-activity values (OAVs) calculation were performed. Both GC–MS or GC–O results revealed that levels of most aroma compounds were increased by the glucose-curing treatment. GC–MS results suggested that the glucose-curing treatment caused increased formation of the flavors via the Maillard reaction and lipid degradation, while the lipid degradation pathway was modified. In addition, GC–O results indicated a higher increase in the formation of the aroma compounds via the Maillard reaction by the glucose-curing treatment. Furthermore, quantitation and odor active values (OAVs) calculation showed glucose-curing had increased formation of the key odorants (OAV ≥ 1) (e.g., bis(2-methyl-3-furyl)disulfide, 2-acetylthiophene, 2-acetylthiazole, (E,E)− 2,4-decadienal, and methional), of which 2-acetylthiophene, bis(2-methyl-3-furyl)disulfide, and (E,E)− 2,4-decadienal are vital in fried chicken flavor. The results can provide guidance for improving fried chicken flavor by marination.

How anaerobic treatment is controlling the volatile components and key odorants of purple-colored leaf tea

Special purple-colored leaf tea products rich in γ-aminobutyric acid (GABA) have recently gained popularity. Although anaerobic treatment could effectively increase the GABA content in tea products, it also imparted an unknown unpleasant aroma. This study aimed to elucidate the dynamic effects of anaerobic treatment on volatile components during the purple-colored leaf tea processing and reveal the key aroma-active components. A total of 112 volatile components were identified, and it was found that anaerobic treatment could facilitate the accumulation of 2-heptanol, (E)− 2-hexenal, ethyl salicylate, phenylethyl alcohol, and (E,E)− 2,4-decadienal, but inhibited the formation of (Z)− 3-hexenyl acetate and methyl jasmonate. Moreover, 17 potent odorants including (E)-β-ionone, linalool, hexanal, 2-heptanol, (Z)− 3-nonen-1-ol, and (E,E)− 2,4-decadienal were distinguished as the key odorants of purple-colored leaf tea products rich in GABA based on gas chromatography–olfactometry and odor activity value analysis. These results provide new insights into the effect of anaerobic treatment on tea volatile metabolites.

Characterization of the key aroma compounds in soy sauce by gas chromatography-mass spectrometry-olfactometry, headspace-gas chromatography-ion mobility spectrometry, odor activity value, and aroma recombination and omission analysis.

Most previous studies on volatile compounds in soy sauce were performed by gas chromatography-mass spectrometry (GC-MS). In this study, the volatile compounds of high-salt liquid-state fermentation soy sauce (HLFSS) were analyzed qualitatively and quantitatively by GC-MS and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). One hundred and seventy-four substances were detected using the two instruments, 87 by HS-GC-IMS and 127 by GC-MS. Aldehydes (26), ketones (28), esters (29), and alcohols (26) were the main compounds in HLFSS. In addition, ethyl pyruvate, (E)-2-pentenal and diethyl propanedioate were detected by HS-GC-IMS, which were previously not detected in HLFSS. Forty-eight aromatics including 34 key ones were identified by gas chromatography-olfactometry. Phenylacetaldehyde, methional, 2-methylbutanal, 1-octen-3-ol, ethyl acetate, 2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone, 4-hydroxy-2,5-dimethyl-3(2H)-furanone and 4-ethyl guaiacol were identified as the main aroma compounds in HLFSS by aroma recombination and omission test. This study laid foundation for developing flavor assessment standards for soy sauce.

GC–MS, GC–O, and sensomics analysis reveals the key odorants underlying the improvement of yellow tea aroma after optimized yellowing

An optimized yellowing process for yellow tea (YT) was recently developed. The study found that the optimized yellowing process caused a significant increase in sweet and floral aromas by 31.3% and 24.0%, respectively. A total of 21 aroma-active compounds were identified using gas chromatography-mass spectrometry (GC–MS) and gas chromatography–olfactometry (GC-O) combined with sensomics analysis. Quantification of the 15 aroma-active compounds and calculation of odor activity values (OAVs) showed that the OAVs of sweet and floral aroma compounds increased significantly by 986.2% and 46.4%, respectively, after the optimized yellowing process. Sensory-directed aroma reconstitution and omission experiments confirmed that dimethyl sulfide, 3-methylbutanal, β-ionone, β-damascenone, geraniol, phenylacetaldehyde, and linalool were the key odorants in YT after the optimized yellowing process. Odorant addition tests further demonstrated that β-damascenone (OAV 590.4) was the main odorant for YT sweet aroma enhancement, while β-ionone (OAV 884.6) was the main odorant for YT floral aroma enhancement.

Characterization of odor-active compounds in Dahongpao Wuyi Rock Tea (Camellia sinensis) by sensory-directed flavor analysis

Different methods for extraction and analysis of odor-active compounds in Dahongpao (DHP) Wuyi Rock Tea (WRT) were compared. The results showed that two-dimensional gas chromatography–olfactometry–mass spectrometry (GC×GC–O–MS) is a better method than GC–O–MS, stir bar sorptive extraction (SBSE) can extract more odor-active compounds. Aroma extraction dilution analysis (AEDA) and odor activity value (OAV) further indicated that 15 compounds were the most important odor-active compounds in DHP: phenethyl alcohol, (E)-β-ionone, nonanal, linalool, hexanal, geraniol, benzaldehyde, α-ionone, methyl salicylate, 6-methyl-5-hepten-2-one, geranylacetone, benzyl alcohol, tea pyrrole and hexyl hexanoate. The roasting process affected the overall odor characteristics of DHP, and appropriate roasting would enhance the sensory quality of DHP. As the roasting temperature increases, the contribution of compounds such as tea pyrrole, 2-ethyl-6-methylpyrazine, and 2,6-dimethylpyrazine to the roasted and burnt odor of the samples gradually increase, and the concentration of typical floral compounds such as phenethyl alcohol, (E)-β-ionone, α-ionone and linalool increase decidedly under light fire roasting, which was consistent with the sensory evaluation results. This study is helpful to further guide the production process of DHP.

Quantification of odorous and potentially harmful substances in acrylic paint

Within this study sixteen odour active substances (1-butanol, butyl acetate, 3-methyl-4-heptanone, butyl acrylate, styrene, ethylbenzene, propylbenzene, cumene, sec-butylbenzene, benzaldehyde, 2-ethylhexyl acrylate, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1,2-dimethylnaphthalene, 1,7-dimethylnaphthalene), that have previously been identified in acryl paints were quantified in ten black acrylic paint samples using GC-GC-MS (heart-cut two-dimensional gas chromatography-mass spectrometry) after prior extraction and purification via solvent assisted flavour evaporation. In this case, the preceding analysis of the most abundant odour active volatiles via GC-O (gas chromatography-olfactometry) provided indications on which smell properties might be linked with elevated and concerning levels of possibly harmful substances. Based on that work, four samples raised attention due to their mainly repelling or unpleasant odour with mainly aromatic, solvent-like, mothball-like or geranium-like smell impressions. The remaining samples either showed fruity/fermented, fruity/apple juice-like, mushroom-like or cocoa-like/earthy odour qualities. The repelling and unpleasant odour was generally linked to naphthalene or benzene derivatives that are of concern with regard to being potential carcinogens. With concentrations ranging as high as from 3.75 mg/kg to 143.41 mg/kg, n-butanol was found to be the odour active substance with the highest concentrations in all but one paint sample. The results showed that all paints contain different and specific patterns of the analysed odour active substances and volatiles. Whereas only two samples revealed no elevated concentration of any of the quantified substances, two samples (A9 and A10) showed elevated levels for all or nearly all substances. The concentrations for single substances were generally lower than the recommended exposure limit and therefore unlikely to cause any adverse effects with regards to toxicity and irritation as single constituents. However, as a group of substances these might exert adverse health effects due to combined or synergistic effects. Based on these observations, the occurrence of combinations of potentially carcinogenic substances in products which are occupationally used on a daily basis or are in direct skin contact should thus be regarded with care in the future.

Characterization of the key odorants in fresh Amomum tsao-ko Crevost et Lemaire fruit by gas chromatography-olfactometry, quantitative analysis and aroma reconstitution

To decode key odorants (KOs) in fresh Amomum tsao-ko Crevost et Lemaire fruit (FAF) and investigate the effect of isolation methods on KOs and enantiomer ratios, volatiles were isolated using both direct solvent extraction combined with solvent-assisted flavor evaporation (DSE-SAFE) and hydrodistillation (HD) and analyzed by gas chromatography‒mass spectrometry/olfactometry. In total, 55 odor-active compounds with flavor dilution factors between 1 and 8192 were identified, of which 36 and 39 odorants were detected in the SAFE and HD isolates, respectively. By quantitative analysis and odor activity value calculation, 22 odorants in the SAFE isolate and 25 odorants in the HD isolate were determined to be FAF KOs. The differences in the concentrations and the number of KOs caused the two isolates to have different odor characteristics. The recombination experiment further confirmed the results. Among the three studied chiral odorants, including linalool, 4-terpenol, and α-terpineol, the (S)-(−)-enantiomer was dominant, and the (S)-(−)-enantiomer inverted into the (R)-(−)-enantiomer during HD.

Aroma generation in sponge cakes: The influence of sucrose particle size and sucrose source.

The influence of sucrose source and particle size was investigated in relation to the volatile and aromatic properties of sponge cakes. Six sponge cake formulations were studied using two sucrose sources (sugarbeet and sugarcane), at two particle sizes (large and small) with controls. Volatiles profiles and odour active compounds were identified by gas chromatography mass spectrometry and olfactometry. Sixty two volatile compounds were identified, incorporating twenty five odour active compounds/co-eluting compounds, with 5 odours perceived without any corresponding volatile. Particle size had the greatest impact on volatile abundance, with particle size especially influencing pyrazine abundance. Five odour active volatiles (methional, furfural, 2,3-dimethylpyrazine, heptanal and (E)-2-octenal) contributed most to the aroma of these sponge cakes. Small particle size particularly from sugarbeet yielded higher levels of some Maillard and caramelisation reaction compounds, such as furfural (spicy/ bready), where larger particle size supressed volatile abundance in comparison to the control.

Comparison Study of the Physicochemical Properties, Amino Acids, and Volatile Metabolites of Guangdong Hakka Huangjiu.

The physicochemical properties, amino acids, and volatile metabolites of 20 types of Guangdong Hakka Huangjiu were systematically compared in this study. Lower sugar contents were detected in LPSH, ZJHL-1, and GDSY-1, but the total sugar contents of the other types of Guangdong Hakka Huangjiu were more than 100 g/L (which belonged to the sweet type). Among them, a lower alcohol content was found in GDSY-1 (8.36 %vol). There was a significant difference in the organic acid and amino acid composition among the 20 Guangdong Hakka Huangjiu samples, especially the amino acid composition. However, bitter amino acids as the major amino acids accounted for more than 50% of the total amino acids. A substantial variation in volatile profiles was also observed among all types of Guangzhou Hakka Huangjiu. Interestingly, MZSK-1 had different volatile profiles from other Guangzhou Hakka Huangjiu samples. According to gas chromatography olfactometry (GC-O), most of the aroma-active ingredients identified in Guangdong Hakka Huangjiu were endowed with a pleasant aroma of "fruity".

Effect of extrusion on the structural and flavor properties of oat flours

As widely consumed functional grain worldwide, oats have received increasing attention due to numerous health benefits. Compared to the traditional multistep baking methods (saturated steam and kiln drying), extrusion offered economic and practical advantages in time and energy savings, as well as consumer product quality. With the purpose of discovering potentially new products, this study investigated the impact of extrusion on starch structural and flavor profiles (volatile and non-volatile) in oat flour. The high temperature, high pressure, and high shear in the extrusion process changed the intimate texture of the oat flour into irregular, spongy texture, which forms V-type crystal structure. Extruded oat flour's gelatinization temperature was significantly lower than unextruded. Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry demonstrated significant increases in aldehydes and heterocycles after extrusion of oat flours. The odorants in raw oat flours, identified by gas chromatography-olfactometry and odor activity value changed from green to pleasant nutty, grass and bean fragrance in extruded flours. Furthermore, umami amino acid contents increased, while bitter amino acid contents decreased significantly. This study identified the structural and flavor differences in extruded oat flours and provided clues that could improve potential in the development of ready-to-eat cereals and snack foods.

Evaluation of the Chemosensoric Properties of Commercially Available Dog Foods Using Electronic Sensors and GC-MS/O Analysis.

Pet owners think of their animals as part of their family, which further promotes the growth of the pet food market, encouraging pet owners to select nutritious, palatable, and high-quality foods for pets. Therefore, the evaluation of taste and volatile compounds in pet foods is essential to improve palatability. In this study, the sensory characteristics of taste and odor compounds in 10 commercially available dry dog foods were investigated using electronic tongue (E-tongue), electronic nose (E-nose), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O). Dry dog foods were separated based on the sensory properties of taste and volatile compounds through the multivariate analysis of integrated results of the E-tongue and E-nose. A total of 67 odor active compounds were detected through GC-MS and GC-O, and octanal, nonanal, 2-pentyl furan, heptanal, and benzaldehyde were identified as key odor compounds which may have positive effects on food intake. The multivariate analysis was used to classify samples based on key odor compounds. Volatile compounds responsible for aroma properties of samples were evaluated using GC-O and multivariate analysis in this present study for the first time. These results are expected to provide fundamental data for sensory evaluation in producing new dog foods with improved palatability.

A Study of Key Aroma Compounds in Hurood Cheese and Their Potential Correlations with Lactic Acid Bacteria

Hurood cheese (namely Hurood) is a traditional acid-coagulated cheese in China. This work investigated key aroma compounds and their potential correlations with dominant species of Hurood sampled from three distinct geographical origins. Key aroma compounds were determined according to Gas chromatography–mass spectrometry (GC–MS), gas chromatography–olfactometry (GC–O), and relative odor active values (ROAVs) analyses. In addition, 16S rDNA sequencing was used to identify the dominant species. Furthermore, Pearson correlation analysis was used to determine the potential relationships between key aroma compounds and dominant species. A total of 31 key aroma compounds were identified in the Hurood samples from three regions. Lactobacillus paracasei, Lactobacillus crispatus, and Leuconostoc citreum were found to be significantly correlated with the key aroma compounds (p < 0.05) and were identified as the core species. This study shows the link between the presence of presumptive functional core microbes and the unique aroma profiles of this traditional dairy product.

The characteristic of the key aroma-active components in white tea using GC-TOF-MS and GC-olfactometry combined with sensory-directed flavor analysis.

White tea has become more and more popular with consumers due to its health benefits and unique flavor. However, the key aroma-active compounds of white tea during the aging process are still unclear. Thus, the key aroma-active compounds of white tea during the aging process were investigated using gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS) and gas chromatography-olfactometry (GC-O) combined with sensory-directed flavor analysis. A total of 127 volatile compounds were identified from white tea samples with different aging years by GC-TOF-MS. Fifty-eight aroma-active compounds were then determined by GC-O, and 19 of them were further selected as the key aroma-active compounds based on modified frequency (MF) and odor activity value (OAV). Aroma recombination and omission testing confirmed that 1-octen-3-ol, linalool, phenethyl alcohol, geraniol, (E)-β-ionone, α-ionone, hexanal, phenylacetaldehyde, nonanal, (E, Z)-(2,6)-nonadienal, safranal, γ-nonalactone and 2-amylfuran were the common key aroma-active compounds to all samples. Cedrol, linalool oxide II and methyl salicylate were confirmed peculiar in new white tea, while β-damascenone and jasmone were peculiar in aged white tea. This work will offer support for further studies on the material basis of flavor formation of white tea. © 2023 Society of Chemical Industry.

Reutilization of berry press residues in minced Baltic herring (Clupea harengus membras) – Effect on lipid oxidation and sensory characteristics during cold storage

Lipid oxidation is one of the main causes of quality deterioration in dark-muscled fish. This study investigated the effect of berry side streams of juice pressing or oil extraction at different concentrations on lipid oxidation and sensory quality of minced Baltic herring (Clupea harengus membras) stored at 1 °C. Lipid oxidation was assessed by determining the peroxide value and volatile secondary oxidation products. Generic descriptive analysis and gas chromatography-olfactometry were used to investigate the odor, flavor, and odor-active compounds of minces. Based on the peroxide value and formation of hexanal, 1-penten-3-ol, and 3,5-octadien-2-one, a concentration of 1.5 g/100 g of lingonberry-bilberry juice press residue and sea buckthorn juice press and oil extraction residue was sufficient to retard and reduce the extent of oxidation. Furthermore, the addition of these residues inhibited the formation of fishy odors during 3 days of storage. The control mince stored for 3 days showed the highest number and intensities of oxidation products such as (Z)-4-heptenal, 2,3-pentanedione, and (E,Z)-2,6-nonadienal, while their formation was retarded in the mince containing press residue from sea buckthorn. Berry press residues were efficient in controlling lipid oxidation of minced Baltic herring during storage and have the potential to mask potentially unpleasant fishy odor and flavor.

Characterization of odor-active compounds of various pea preparations by GC-MS, GC-O, and their correlation with sensory attributes

Pea preparations (flours, concentrates, and isolates) are increasingly used in plant-based products, but their characteristic odor is often causing problems. Advanced knowledge of the aroma profile of pea preparations could improve understanding of how pea-based ingredients affect sensory properties of foods.This study investigated the aroma profiles of different pea preparations using solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O), and descriptive sensory analysis. The GC-MS analysis included MRM detection of methoxypyrazines, which significantly contribute to the flavor of pea preparations.More than 100 volatile compounds were identified in pea preparation samples by GC-MS, aldehydes being the main molecules, and 39 aroma-active compounds were registered by GC-O assessors. Sensory attributes of pea protein preparations were compared with analytical data to find the characteristic aroma-active compounds. Sensory panel evaluation showed noticeable differences between the pea preparations. Unsaturated aldehydes, which impart green odor, and methoxypyrazines, with pea-like and beany notes, enhance the sensory perception of green and pea-like characteristics in pea preparations. Methanethiol increased sulfur-like odor in pea protein isolate A. β-Damascenone had high modified frequency in pea protein isolate C, enhancing honey-like attributes. Methanethiol and β-damascenone were not reported previously as odor-active compounds in pea protein preparations.

Impact of frying methods on colours, morphological properties, and aroma compounds of arrowhead (Sagittaria latifolia) corm chips

Arrowhead is a starchy vegetable with a unique taste and many health promoting effects. To diversify the usage and increase the consumption of arrowhead, the effects of different frying methods on the morphology and aroma compounds of arrowhead corm chips were studied. The analysis of aroma compounds by accelerated solvent extraction coupled with high-vacuum flavour extraction analysis (ASE-HVFEA), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O) of deep- and air-fried arrowhead corm chips was conducted. The aim was to understand the variability and abundance of aroma compounds between deep- and air-fried arrowhead chips. In addition, the colours and morphological characteristics of the corm chips were also studied. Twenty-three aroma compounds were identified in the differently fried chips. The predominant aroma compounds were the Strecker-aldehydes, in which 2-methylbutanal, (E)-2-heptenal, hexanal, and (E,E)-2,-4-decadienal were identified as the major aroma constituents of the fried chips. This was followed by the pyrazines. Results of the odour activity values (OAVs) revealed significant (p < 0.05) differences in the aroma profiles of the differently fried chips. Deep-fried chips produced more potency for the baked-like, 2-3-diethyl-5-methylpyrazine, potato-like, methional, deep-fried, (E,E)-2,4-decadienal, roasty, 2-ethyl-3,5-dimethylpyrazine, malty, and 2-methylbutanal. However, air-fried chips exhibited similar but lower potency for the same compounds. Whilst there was no significant (p ≥ 0.05) difference in the external appearance of the differently fried chips, deep-frying significantly (p < 0.05) altered the cell walls of the deep-fried chips more than the air-fried chips. These results would serve as a guidance for aroma flavour evaluation, improvement, and quality control during oil- and air-frying of chips.

Identification of Important Aroma Components and Sensory Profiles of Minimally Processed (Unroasted) and Conventionally Roasted Dark Chocolates.

Roasting is an important unit operation for the development of characteristic chocolate aroma during manufacturing. However, there is an increase in interest in minimally processed chocolate products due to their potential positive health benefits. The odor-important compounds and sensory characteristics of minimally processed (unroasted) and conventionally roasted dark chocolates were determined by gas chromatography-olfactometry, aroma extract dilution analysis (AEDA), and stable isotope dilution analysis (SIDA). Except for acetic acid, all odorants had higher odor-activity values (OAVs) in roasted chocolate. Acetic acid, developed during fermentation and drying, had the highest OAV in both chocolates but was better preserved in unroasted chocolate. Compounds making a greater aroma impact on roasted chocolate compared with unroasted chocolate included dimethyl trisulfide, 2-ethyl-3,5-dimethylpyrazine, and 3-methylbutanal. Nine significant sensory attributes in unroasted and roasted chocolates were identified. Vinegar (aroma) and roasted (aroma and aroma by mouth), sweet (taste), and hardness (texture) attributes differed between unroasted and roasted chocolates. The results of this study enforce the embracement of low thermal processes to showcase the inherent flavor potential of cacao beans but also to support the concept of chocolate "terroir" by potentially preserving important aroma compounds developed during fermentation.