Headspace Aroma Research Articles

Valorization of Citrus peels: GC/MS-based metabolites profiling, multivariate analysis, and antiaging potential.

Aging and agro-waste are major challenges. Natural ingredients are preferred in skincare. This study intended to isolate the essential oils (EO) from the leftover peels obtained from three commonly edible Citrus species fruit peels, namely Citrus paradisi (grapefruit), Citrus sinensis (sweet orange), and Citrus deliciosa (mandarin). Gas chromatography/mass spectrometry analysis identified volatile constituents in EO and headspace aroma. Multivariate analysis distinguished between the three species. The antiaging effects of Citrus EO were assessed in vitro and in silico, studying volatile interactions with target enzymes. C. sinensis peels had the highest oil yield, rich in monoterpenes. C. paradisi and C. deliciosa contained sesquiterpenes. Limonene dominated the hydrodistilled EO: 94.50% in C. paradisi, 96.80% in C. sinensis, and 80.66% in C. deliciosa. Unsupervised multivariate analysis of Citrus species revealed that d-limonene, γ-terpinene, and β-pinene are the key phytochemical markers contributing to their diverse chemical composition. C. paradisi exhibited the highest enzyme inhibitory activity, with IC50 values of 12.82, 27.58, and 18.16 µg/mL for tyrosinase, elastase, and collagenase, respectively. In silico studies showed that the volatiles can inhibit the tested antiaging enzymes. According to these findings, the investigated agro-waste might slow aging in skin care.

Production of Syrups from Corinthian Currant Industrial Finishing Side-Stream: Quality Evaluation and Volatilome

The industrial finishing side-stream (FSS) of premium-quality Corinthian currants was used to produce syrups with/without pigment- and tartrate-reduction treatments. The chemical composition, total titratable acidity (TTA; % w/w as tartaric acid), volatile acidity (VA; % w/w as acetic acid), total phenolic content (TPC; as gallic acid, GA), antioxidant capacity (AC; as ascorbic acid, AA), volatilome (SPME GC-MS), sensory properties, and microbial stability were compared. All syrups had similar average sugar content (65.4–69.4% w/w), and no sucrose. Those not treated for tartrate reduction were more acidic (pH ~4.5) than those treated (pH > 5.6), while all syrups had higher pH than similar commercial products (3.0–4.5). On the other hand, the FSS syrups had similar TTA (<1.2 ± 0.3%) despite the applied treatment, and had low VA (0.08–0.27%). The blonde syrups had a lower average TPC (134–143 mg GA/100 g) and AC (0.90–1.0 mg AA/100 g) than the brown syrups (185–213 and 0.3–0.6, respectively), due to the removal of phenolics in the clarification treatments. Totally 144 headspace aroma volatiles were identified, deriving either from the grapes or the raisin-drying process. HMF was not detected. The sensory, microbiological, and VA analyses indicated that FSS can be used to produce high-quality, preservable, and added-value syrups.

Geographical-based variations in white truffle Tuber magnatum aroma is explained by quantitative differences in key volatile compounds.

The factors that vary the aroma of Tuber magnatum fruiting bodies are poorly understood. The study determined the headspace aroma composition, sensory aroma profiles, maturity and bacterial communities from T.magnatum originating from Italy, Croatia, Hungary, and Serbia, and tested if truffle aroma is dependent on provenance and if fruiting body volatiles are explained by maturity and/or bacterial communities. Headspace volatile profiles were determined using gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and aroma of fruiting body extracts were sensorially assessed. Fruiting body maturity was estimated through spore melanisation. Bacterial community was determined using 16S rRNA amplicon sequencing. Main odour active compounds were present in all truffles but varied in concentration. Aroma of truffle extracts were sensorially discriminated by sites. However, volatile profiles of individual fruiting bodies varied more within sites than across geographic area, while maturity level did not play a role. Bacterial communities varied highly and were partially explained by provenance. A few rare bacterial operational taxonomical units associated with a select few nonodour active volatile compounds. Specificities of the aroma of T.magnatum truffles are more likely to be linked to individual properties than provenance. Some constituents of bacteria may provide biomarkers of provenance and be linked to nonodour active volatiles.

Key Odor-Active Compounds in Raw Green and Red Toona sinensis (A. Juss.) Roem. and Their Changes during Blanching.

Application of aroma extract dilution analysis and headspace aroma dilution analysis revealed 51 odorants in raw green Toona sinensis and 54 odorants in raw red T. sinensis in the flavor dilution factor range of 8-4096. (E,E)-2,4-Decadienal, nonanal, 2,3,5-trimethylpyrazine, (E,Z)- and (Z,Z)-di-1-propenyl trisulfide, 2-methoxyphenol, and 4-ethylphenol were first identified as key odorants of T. sinensis. Clear differences between green and red T. sinensis in aroma profiles, flavor dilution factors, quantitative data, and odor activity values verified that (E,E)-, (E,Z)-, and (Z,Z)-di-1-propenyl disulfide, (E,E)-, (E,Z)- and (Z,Z)-di-1-propenyl trisulfide, cis- and trans-2-mercapto-3,4-dimethyl-2,3-dihydrothiophene, and dimethyl sulfide caused the distinct sulfury odor note of each variety. Further, hexanal, (E)-2-hexenal, (E)-2-hexen-1-ol, and (E,Z)-2,6-nonadienal led to the green odor note in green T. sinensis, while 2-methoxyphenol and 4-ethylphenol contributed to the intense phenolic aroma note in red T. sinensis. Quantitation experiments and triangle tests in blanched T. sinensis verified that the quick loss of the abovementioned sulfur-containing compounds, aldehydes, the alcohol (E)-2-hexen-1-ol, and phenols was responsible for the changes in the overall aroma profile during blanching.

Cork powder as a new natural and sustainable fining agent to reduce negative volatile phenols in red wine

In red winemaking, especially those aged in wood barrels, the contamination and growth ofDekkera/Brettanomycesyeasts results in the formation of 4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG). These volatile phenols (VPs) are responsible for negative aromatic notes like horsy, barnyard, smoky and medicine, decreasing significantly red quality and its commercial value. In this work, cork powder waste was especially prepared and used to remove these negative volatile phenols (4-EP and 4-EG) from spiked red wine. The optimisation of cork powder performance by removal of dichloromethane and ethanol cork extractives, air removal and ethanol impregnation, allowed to obtain 41 to 62% of 4-ethylphenol and 50 to 53% of 4-ethylguaiacol removal from VPs spiked red wine applied at 250 g/hL. There was no significant impact on phenolic acids and monomeric anthocyanins, although being observed a decrease in the headspace aroma abundance (40%). This optimised cork powder allowed to decrease significantly the wine negative phenolic character, bitterness and astringency, recovering the positive fruity and floral sensory attributes. Results show that optimised cork powder can be a good solution for VPs removal, presenting a great potential to be a new oenological fining agent, contributing to the wine industry sustainability.

Reduction of 4-ethylphenol and 4-ethylguaiacol in red wine by activated carbons with different physicochemical characteristics: Impact on wine quality.

Activated carbon (AC) could be a solution to remove 4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG) off-flavours from Dekkera/Brettanomyces contaminated red wines. The relation between AC physicochemical characteristics and removal efficiency of these compounds is unknown. The impact of ACs characteristics on 4-EP and 4-EG removal, phenolic and headspace aroma composition was studied. All ACs reduced significantly 4-EP and 4-EG levels (maximum 73%). Their efficiency was related to their surface area and micropores volume. A higher surface area of mesopores and total pore volume were detrimental for anthocyanins and colour intensity, while a higher surface area and micropores volume were important for removing phenolic acids. Volatile phenols reduction was more important for the positive fruity attribute perception than the abundance of headspace aroma compounds. With an optimal selection of the AC physicochemical characteristics it was possible to remove efficiently the volatile phenols without impacting negatively on the wine sensory quality.

Odor-Active Components of Luo Han Guo (Siraitia grosvenorii)

The volatile components -of the dried fruit of Luo Han Guo (Siraitia grosvenorii Swingle) belonging to the family Cucurbitaeae were analyzed by AROMASCOPE® technique using MonoTrap® DCC 18 as an absorbent. A total of 124 volatile components were identified from the headspace aroma solvent extract. The major components were ethanol, butan-l-ol, pentanal, 2-methylbutanal, hexanal, furfural, pent-3-en-2-one, acetic acid, propionic acid, 3- methylbutanoic acid, hexadecanoic acid, and so on. Among them, acetic acid, 3-methylbutanoic acid, and 3-hydroxy-4,5-dimethylfuran-2(5H)-one (sotolon) strongly contributed to the overall aroma of the fruit. Besides, sotolon and 5-ethyl-3-hydroxy-4-methylfuran-2(5H)-one (maple furanone) were responsible for - the characteristic molasses-like aroma of the fruit.

Effect of Sourdough, Bakery Yeast and Sodium Bicarbonate on Volatile Compounds, and Sensory Evaluation of Lavash Bread

The process of dough preparation is an important stage in the production of bread, which has a significant effect on quality of the end product. Bakery yeast (Saccharomyces cerevisiae) and sourdough are used for dough fermentation worldwide and are very important for bread quality. Flavor and aroma of bread are important factors for acceptance of bread, which can be affected by the method of dough production. The effect of sourdough, bakery yeast, sodium bicarbonate and combination of bakery yeast and sodium bicarbonate for the production of flat bread (Lavash), on volatile compounds and sensory properties of bread, was studied. The changes in the headspace aroma volatiles were assessed using solid-phase micro-extraction (SPME) GC–MS analysis. A total of 31 compounds were identified in the samples. The obtained results showed differences in the volatile composition of the different types of bread. Bread produced by the combination of bakery yeast and sodium bicarbonate had most volatile compounds. The abundant volatile compounds identified in bakery yeast-raised bread were butanal-3-methyl,butanol-3-methyl and hexanal, in the sourdough bread, they were ethanol, furan-2-metyhl and pentan, in the sodium bicarbonate bread, they were benzene-1,3-dimethyl, 2,4 nonadiene and limonene and in the combination of sodium bicarbonate and bakery yeast bread, they were furan-2-methyl, butanol-3-methyl and hexanal. Practical Applications The present study evaluated the effect of sourdough, bakery yeast, sodium bicarbonate and combination of yeast and sodium bicarbonate on the volatile compounds of Lavash bread. Some of the volatile compounds were found in the four samples. The number of volatile compounds in bread produced from the combination of yeast and sodium bicarbonate was higher than that of other samples. The sensory evaluation of samples (shape, upper and beneath surface, odor, flavor, color, firmness and softness of texture and chewing ability) showed that bread produced from the combination of yeast and sodium bicarbonate has higher score than other samples based on the scoring of a panelist group.

Analytical and sensory characterization of ‘Pesca di Leonforte’ (Prunus persica Batsch)

‘Pesca di Leonforte’ is a Protected Geographical Indication (PGI) product cultivated in the Southern Sicily (Italy). The application for PGI status for ‘Pesca di Leonforte’ is justified by its particular firmness and late ripening characteristic. This research aimed to characterize ‘Pesca di Leonforte’ by quantification of its aroma compounds and the sensory profile. Head-space aroma volatiles were extracted and analyzed by SPME-GC-MS. A large number of compounds have been identified; most of these are well-known in peach fruits, but others have been here identified for the first time. Alcohols, esters and lactones were the most representative chemical classes. The sensory profile of ‘Pesca di Leonforte’ was also defined by a trained panel which assigned high values to peach odor and flavor descriptors. The quantitative data were correlated to the odor descriptors allowing the sensorial characterization of the product. In the samples analyzed esters and lactones prevailed with their sensory descriptors of fruity and peach odor.

Sensory analysis and head-space aroma volatiles for the characterization of capers from different geographic origin

Characterization of capers (Capparis spinosa L. Capparaceae) was achieved by measurement of aroma compounds and sensory descriptors. Different capper samples (the floral buds of the plants) coming from Pantelleria and Salina Islands (Italy) were analyzed. Head-space aroma volatiles were extracted and analyzed by SPME-GC-MS. In all, more than one-hundred volatile compounds were identified and the quantitative results have been expressed as percentage of total peak area. Aliphatic acids and aldehydes were the most abundant chemical classes in all the samples whereas aromatic alcohols distinguish the samples from different origin. Among sulfur compounds, methyl-isothiocyanate was the major one, followed by benzyl-isothiocyanate. The sensory profile of capers was defined by a trained panel, measuring the intensity of nineteen descriptors. All the data were statistically correlated. Multivariate analysis applied to the volatile and sensory data allowed distinguishing the samples in relation to the area of origin.

Influence of olive oil phenolic compounds on headspace aroma release by interaction with whey proteins.

The release of volatile compounds in an oil-in-water model system obtained from olive oil-whey protein (WP) pairing was investigated by considering the effect of phenolic compounds. Human saliva was used to simulate mouth conditions by retronasal aroma simulator (RAS) analysis. Twelve aroma compounds were quantified in the dynamic headspace by SPME-GC/MS. The results showed significant influences of saliva on the aroma release of virgin olive oil (VOO) volatiles also in the presence of WP. The interaction between WP and saliva leads to lower headspace release of ethyl esters and hexanal. Salivary components caused lower decrease of the release of acetates and alcohols. A lower release of volatile compounds was found in the RAS essay in comparison to that in orthonasal simulation of only refined olive oil (without addition of saliva or WP), with the exception of hexanal and 1-penten-3-one, where a significantly higher release was found. Our results suggest that the extent of retronasal odor (green, pungent) of these two volatile compounds is higher than orthonasal odor. An extra VOO was used to verify the release in model systems, indicating that WP affected aroma release more than model systems, while saliva seems to exert an opposite trend. A significant increase in aroma release was found when phenolic compounds were added to the system, probably due to the contrasting effects of binding of volatile compounds caused by WP, for the polyphenol-protein interaction phenomenon. Our study could be applied to the formulation of new functional foods to enhance flavor release and modulate the presence and concentrations of phenolics and whey proteins in food emulsions/dispersions.

Effect of destoned olive cake on the aromatic profile of cows’ milk and dairy products: comparison of two techniques for the headspace aroma profile analysis

The aim of this study, carried out within the NOVOROD project (PSR Campania 2007-2013 Misura 124 HC), was to evaluate the aromatic profile of milk and dairy products of dairy cows supplemented with destoned olive cake (DOC). Two techniques for the headspace aroma profile analysis: the thermal desorption by gas chromatography with a mass selective (GC/MS) detector and the electronic nose were compared. The trial was performed into a dairy cow farm. Ten dairy cows were allotted into two homogenous groups: control and experimental. Animals received the same diet, while in the experimental group the concentrate supplementation (15% dry matter) was replaced with DOC. After two weeks of adaptation, animals were fed with the experimental diet for other 15 days. During the experimental period, the milk was collected and cumulatively processed in Caciotta cheese (a soft cheese, 25 days ripened) and in Semicotto cheese (hard cheese, 3 months ripened) for 13 times for each group. Milk and cheese volatile organic compounds (VOCs) were extracted and concentrated with dynamic headspace method and determined by GC/MS. Statistical analysis of data, expressed in arbitrary units (a.u.=peak area × 10–6) and allotted in compound classes, was carried out by ANOVA. All data collected of VOCs were processed with principal component analysis (PCA). Milk and cheese samples were comparatively analysed with the electronic nose, fitted with a tenmetal oxide sensors electronic device. PCA has been used for the evaluation of the pattern data. Our results show that the use of DOC, as an unconventional feed for livestock, has no effect on the aromatic profile of both milk and dairy products. In fact, no significant differences were found in both milk and dairy products between the two groups using the GC/MS method. Also the discriminating analysis carried out by electronic nose did not show significant differences between the two groups. The two compared techniques seem to lead to the same result.

Identification of aroma-active volatiles in banana Terra spirit using multidimensional gas chromatography with simultaneous mass spectrometry and olfactometry detection

Fruit spirits have been produced and consumed throughout the world for centuries. However, the aroma composition of banana spirits is still poorly characterised. We have investigated the aroma-impact compounds of the banana Terra spirit for the first time, using multidimensional gas chromatography (MDGC and GC×GC) in a multi-hyphenated system – i.e., coupled to flame ionisation detection (FID), mass spectrometry (MS), and olfactometry (O). Solid-phase microextraction (SPME) was used to isolate the headspace aroma compounds of the banana spirit. The detection frequency (DF) technique was applied and aroma regions, detected in the first column separation at >60% Nasal Impact Frequency (NIF), were screened as target potent odour regions in the sample. Using a polar/non-polar phase column set, the potent odour regions were further subjected to MDGC separation with simultaneous O and MS detection for correlation of the aroma perception with MS data for individual resolved aroma-impact compounds. GC–O analysis enabled 18 aroma-impact regions to be located as providing volatiles of interest for further study; for example, those comprising perceptions of flower, whisky, green, amongst others. Compounds were tentatively identified through MS data matching and retention indices in both first and second dimensions. The principal volatile compounds identified in this work, which are responsible for the characteristic aroma of the banana spirit, are 3-methylbutan-1-ol, 3-methylbutan-1-ol acetate, 2-phenylethyl acetate and phenylethyl alcohol. This is the first such study to reveal the major aroma compounds that contribute to banana spirit aroma.

Bioactives and nutraceutical phytochemicals naturally occurring in virgin olive oil. The case study of the Nocellara del Belice Italian olive cultivar

This work reports on the composition and bionutritional value of organic virgin olive oil from the Nocellara del Belice variety, one cultivated in the olive areas of the Sicily region, Italy. Destoned oils obtained by processing olives with a destoning-based procedure were compared with conventional oils. This innovative technique, consisting in removing the stone from fruits prior to processing, strongly enhanced the already high-quality level of the conventional product. An in-depth analytical investigation from 2008 to 2010 showed how this innovative olive extraction process led to an excellent peculiar final product, mainly attributable to the improved biophenol and volatile composition, as well as higher concentrations of the lipophilic and vitamin antioxidants (tocopherols and tocotrienols). It had higher levels of oleocanthal (p-HPEA-EDA), a nutraceutical compound exerting actions against COX1 and COX2 (cycloxygenases). Its head-space aroma displayed new volatile phytomolecules and also had higher levels of green volatiles from the lipoxygenase (LOX)-pathway (one having as precursors the polyunsaturated fatty acids containing a cis–cis-1,4-pentadiene system). Among the other bioactives, we highlight its significant levels of trans-β-carotene and xanthophylls (lutein, violaxanthin, neoxanthin and other carotenoids). Its enhanced nutritional value was also attributable to the increased intensity of valuable tasting notes.

Concentrations of Bioactives and Functional Factors in Destoned Virgin Olive Oil: The Case Study of the Oil from Olivastra di Seggiano Cultivar

This work reports on the composition and bionutritional value of destoned (vs. whole) virgin olive oil from Olivastra di Seggiano cultivar, one having wild features, which is cultivated in olive areas of Tuscany Region, Italy. Removal of the stone from fruit before processing is an innovative technique that strongly enhanced the already high quality level of this oil variety. There was for this product marked interaction between genetic background and destoning. An in-depth analytical investigation from 2008 to 2010 showed how the innovated olive extraction process led to an improved product standing out for its peculiar features, related mainly to the improved biophenol and volatile composition, as well as to higher concentrations of the lipophilic and vitamin antioxidants (tocopherols and tocotrienols). It had slowly higher levels of oleocanthal (p-HPEA-EDA), which was found to be a nutraceutical factor. Its head-space aroma even displayed new volatile phytomolecules and also had higher levels of green volatiles from the LOX-pathway (having as precursors the polyunsaturated fatty acids containing a cis-cis-1,4-pentadiene system). Among the other bioactives are to be highlighted the significant levels of trans-β-carotene and xanthophylls (lutein, violaxanthin, neoxanthin and other minor carotenoids), whose amount however was not higher with respect to reference oil. Its enhanced bionutritional value was confirmed by the increased intensity of valuable tasting notes, among which stood out the artichoke flavour. Finally it showed higher resistance to autoxidation and longer shelf-life.

Chemometric Discrimination of Philippine Civet Coffee Using Electronic Nose and Gas Chromatography Mass Spectrometry

This study presents a practical and promising approach to profile the headspace aroma attributes of Philippine civet coffee using electronic nose (E-nose) and gas chromatography mass spectrometry (GCMS). Chemometric pattern method was applied to enhance the discrimination of civet coffee against its control coffee beans (not eaten by civet animal). E-nose analysis revealed that aroma characteristic is one of the most important quality indicators of civet coffee. The result was supported by GCMS analysis. The chromatographic fingerprints indicated that civet coffee differed with their control beans in terms of composition and concentration of individual volatile constituents. Chemometric discrimination of E-nose and GCMS data demonstrated a clearly separated civet from their control coffees indicating that cultivar and geographic origins dictate the aroma and volatiles variations in coffee.

A PTR-MS-Based Protocol for Simulating Bread Aroma During Mastication

The sampling parameters to simulate retronasal aroma during the mastication of white bread has been optimized using a retronasal aroma simulator (RAS) to compare the retronasal bread aroma with the conventional headspace aroma. The volatile composition in breath was compared with that in the effluent from a RAS using proton transfer reaction mass spectrometry, and the optimized RAS parameters were as follows: 2.5 g of bread sample, 250 mL of buffer, 1 L/min of N2 gas stream, 350 rpm of rotating speed, and 38 °C of water jacket temperature. The increased sensitivity and high reproducibility of RAS enabled detailed measurements of flavor release in the mouth during the mastication of bread. The simulated retronasal aroma was compared with the conventional headspace aromas by gas chromatography/olfactometry (GC/O), and the results demonstrated that the caramel note odorant of 2,5-dimethyl-4-hydroxy-3(2H)-furanone was found to show the highest contribution to the headspace aroma; however, it showed little contribution to the simulated retronasal aroma. These differences appeared to be caused by the volume of buffer added in RAS experiments. The odorant concentrations in the RAS effluent were found to decrease with the increase of the buffer volume, and the decreasing rates appeared to be associated with the chemical types of odorants. Flavor release of typical odorants in a RAS was measured at various ratios of buffer volume, and the results indicated that flavor release in mouth appeared to be influenced by the physicochemical properties of odorants. The results would help flavor chemists to make better prediction of bread aroma in mouth during the mastication.

Dry Red Wine Making Using Yeast Immobilized on Cork Pieces

The commercial Saccharomyces cerevisiae Uvaferme 299 wine yeast was immobilized on cork pieces to produce a biocatalyst for use in dry red wine making. The immobilized biocatalyst was suitable for clarified and non-clarified grape must fermentation at ambient and low temperatures (0-25 degrees C). Fermentation times were low and very low amounts of residual sugar were detected, showing suitability for dry wine production. The presence of suspended solids in the non-clarified must did not affect the activity of the immobilized cells. Complete fermentation of sugars at 0 degrees C was possible with immobilized Uvaferme 299, although not a cryotolerant strain, indicating a cryoprotective effect of cork. The presence of cork did not affect the composition of major volatiles with methanol and acetaldehyde kept at low levels. Reduction of amyl alcohols on total volatiles was also observed in wines fermented at low temperatures. Differences in the headspace aroma profile in wines produced by immobilized and free cells were found by GC-MS analysis, but no cork taint compounds were detected.

Analysis of Freshly Brewed Espresso Using a Retronasal Aroma Simulator and Influence of Milk Addition

Abstract: A quick (headspace: 1 min and retronasal aroma simulator (RAS): 2 min) sampling method for capturing volatiles released from coffee drinks by solid-phase microextraction (SPME) (fiber type; divinylbenzene (DVB)/carboxen/polydimethylsiloxane (PDMS)) has been applied to freshly brewed espresso and cafe latte (espresso and milk). Headspace volatiles and volatiles in the RAS effluent were collected from espresso and cafe latte, and examined by gas chromatography/mass spectrometry (GC/MS) and GC/olfactometry (GC/O, CharmAnalysis™). When milk was added to espresso in 60% by weight, aroma release (odor activities) was generally suppressed, both in headspace and RAS aromas. The relative charm value of sweet-caramel odor increased in the headspace aroma, while the phenolic odor increased markedly and the smoke-roast odor decreased in the RAS aroma. These results suggested that milk addition had different effects on the headspace and RAS aromas.

Characterization of Headspace Aroma Compounds of Freshly Brewed Arabica Coffees and Studies on a Characteristic Aroma Compound of Ethiopian Coffee

A sampling method to isolate headspace volatiles of freshly brewed drip coffee using a solid-phase microextraction fiber (fiber type: divinylbenzene/carboxen/polydimethylsiloxane) in a short time (2 min) immediately after extraction has been developed. Volatile compounds and potent odorants obtained from each headspace aroma of various arabica coffee extracts (3 production countries: Ethiopia, Tanzania, and Guatemala; 3 roasting degrees for each country: L26, L23, and L18) using the sampling method were examined by gas chromatography/mass spectrometry (GC/MS) and GC/olfactometry (GC/O, CharmAnalysis). The results of principal component analysis (PCA) using the data of GC/O analysis showed that the aroma profile of Ethiopian coffee was discriminately different from those of Tanzanian coffee and Guatemalan coffee. In addition, it was suggested from the factor loading of the PCA that 4-(4'-hydroxyphenyl)-2-butanone (raspberry ketone; sweet-fruity odor) characterized the aroma profile of freshly brewed Ethiopian coffee. Therefore, the 4-(4'-hydroxyphenyl)-2-butanone was quantified in the 9 kinds of coffee extracts. Ethiopian coffee extract of the lightly roasted degree (roasting degree: L26) contained the highest amount of this component, while it was only a little over the reported threshold. In the sensory test, the headspace aromas of Tanzanian and Guatemalan coffees in which 4-(4'-hydroxyphenyl)-2-butanone was added were, respectively, discriminated from not added samples, and "sweet" odor was selected as an odor description that assessors found similarity between the added Tanzanian or Guatemalan coffee aroma and the Ethiopian coffee aroma. It was suggested that 4-(4'-hydroxyphenyl)-2-butanone made some detectable change on total aroma profile even though the added amount was only near threshold level.