Publications with PHASER
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- Evaluation of Leaf-Derived Extracts as an Environmentally Sustainable Source of Essential
Oils by Using Gas Chromatography-Mass Spectrometry and Enantioselective Gas Chromatography-Olfactometry
Barbara d´Acampora Zellner, Maria Lo Presti, Lauro Euclides Soares Barata, Paola Dugo, Giovanni Dugo and Luigi Mondello. Anal. Chem. 2006, 78, 883-890<< Read Abstract >>In consideration of the world´s present environmental situation and the threat of species extinction, investigations concerning alternative sustainable sources of natural substances represent an extremely important issue. In this respect, the present research is focused on the analytical evaluation of Brazilian rosewood (Aniba rosaeodora Ducke) leaves, as an alternative source (with respect to wood) of rosewood essential oil and, as such, of natural linalool, which is extensively used in perfumery. Enantioselective-gas chromatography-olfactometry (Es-GC-O) was used as a tool for the simultaneous stereodifferentiation and olfactive evaluation of the volatile optically active components present in the analyzed samples. In addition to Es-GC-O analyses, direct olfactive analyses were also performed, enabling the evaluation of the global aroma exerted by each sample and the influence of each linalool antipode, as also other minor compounds. The samples were also submitted to gas chromatography-mass spectrometric analysis, thus establishing their chemical profiles. The assessment of enantiopure chiral compounds through Es-GC-O, along with direct olfactive analyses, confirmed that the leaves are a potential substituent for wood in the extraction of Brazilian rosewood essential oil, representing a sustainable nonwood source of natural linalool.
- Odour fingerprint acquisition by means of comprehensive two-dimensional gas chromatography-olfactometry and comprehensive two-dimensional
gas chromatography/mass spectrometry
Barbara d´Acampor Zellner, Paola Dugo, Giovanni Dugo, Luigi Mondello. Journal of Chromatography A, 1141 (2007) 279-286<< Read Abstract >>The analysis of complex matrices, such as perfumes, by means of gas chromatography-olfactometry (GC-O) can be rather imprecise due to the co-elutions, leading to a possible masking of odour-active trace-level compounds by major interferences or agglomeration of olfactive impressions resulting in unreliable olfactive characterization. To overcome these limits an innovative technique, comprehensive two-dimensional gas chromatography-olfactometry (GCxGC-O), was applied, revealing several relevant co-elutions, as in the linalool and linalyl acetate zones. A total of 177 compounds, out of these 135 odour-active, were detected by GC-O, while about 481 out of 818 compounds presented odour-activity through GCxGC-O analyses. In addition, GC/mass spectrometry (GC/MS) and GCxGC/MS analyses were also performed. Peak assignment was achieved by means of different information sources, such as GC/MS, GCxGC/MS, LRI, injection of standards and olfactive impressions.
- Identification of New, Odor-Active Thiocarbamates in Cress Extracts and Structure-Activity Studies on Synthesized Homologues
Katharina Breme, Xavier Fernandez, Uwe J. Meierhenrich, Hugues Brevard, and Daniel Joulain. J. Agric. Food Chem. 2007, 55, 1932-1938<< Read Abstract >>New, odorant nitrogen- and sulfur-containing compounds are identified in cress extracts. Cress belongs to the botanical order Brassicales and produces glucosinolates, which are important precursors of nitrogen- and sulfur-containing compounds. Those compounds often present low perception thresholds and various olfactive notes and are thus of interest to the flavor and fragrance chemistry. When the study of organonitrogen and organosulfur compounds is undertaken, Brassicale extracts are one of the matrices of choice. Cress extracts were studied by analytical (GC-MS, GC-FPD) and chemical (fractionation) means to identify new interesting odorant compounds. Two compounds that have never been reported in cress extracts, containing both nitrogen and sulfur, were discovered: N-benzylO-ethyl thiocarbamate and N-phenethyl O-ethyl thiocarbamate. These two molecules being of organoleptic interest, their homologues were synthesized and submitted to organoleptic tests (static and GC sniffing). Their odors evolve from garlic and onion over green, mushroom- and cress-like to fresh, spearmint-like. This paper presents the origin, chemical synthesis, and organoleptic properties of a series of O-alkyl thiocarbamates.
- Gas chromatography-olfactometry in food flavour analysis
Barbara d´Acampor Zellner, Paola Dugo, Giovanni Dugo, Luigi Mondello. Journal of Chromatography A, 1186 (2008) 123-143<< Read Abstract >>The application of gas chromatography-olfactometry (GC-O) in food flavour analysis represents to be a valuable technique to characterise odour-active, as well as character impact compounds, responsible for the characterizing odour of a food sample. The present article briefly reviews the use of GC-O in the flavour investigation of dairy products (milk and cheese), coffee, meat and fruits. Particular attention has been devoted to extraction techniques, GC-O hardware commonly utilised and olfactometric assessment methods, which can be applied to food analysis.
- Influence of decomposed chemical emissions from PVC flooring on perceived air quality
Satoko Chino1, Shinsuke Kato, Janghoo Seo and Yuji Ataka1. Indoor Air 2008, August 17-23, 2008, Copenhagen, Denmark<< Read Abstract >>2-Ethyl-1-hexanol (2E1H) is sometimes detected indoors in relatively high concentrations because ester compounds in building materials hydrolyze. This study addresses 2E1H emission from flooring, and its influence on perceived air quality. Some PVC floorings are attached on top of moisture-containing SL materials with adhesive, and it is these 2E1H emission rates that are measured. In addition, odorous compounds from PVC floorings attached to SL materials are identified and characterized using gas chromatography-flame ionization detection-olfactometry (GC-FID-O). 2E1H emission rates also change, depending on the type of flooring material. The diffusion coefficients of the chemical substances in the material are affected by the material´s characteristics. The quantity and character of odorous chemical compounds from building materials differs. It is considered that the perceived air quality and emission rate are affected by the chemical reaction in the building materials and moisture content of the floor slabs.
- Successful application of Thermal Desorption-Gas Chromatography/Olfactometry/Mass Spectrometry
(TD-GC/O/MS) technique to the identification of main odorants in complex mixtures of volatile compounds
Maurizio Benzo, Gianluca Gilardoni<< Read Abstract >>A GC/MS system equipped with a thermal desorber and a sniffing port has been set up and used for identification of main odorants in complex mixtures of volatile compounds. Emissions were sampled from the soil in a former refinery plant in LaSpezia during remediation, and have been analyzed with TD-GC/O/MS technique; headspace samples of the soil have been tested in the same way. Samples had a strong disturbing odour but their chromatograms were covered by a great number of peaks of saturated, branched and cyclic hydrocarbons. Aromagrams allowed to individuate as main odorants (garlic-like odour) small peaks of linear and cyclic olefins; their identification has been confirmed by peak disappearance after oxidation of the emission bubbling through a permanganate solution. Other trace odorants were found analyzing the water after scrubbing of the emission through a Drechsel bottle; water was extracted using SBSE technique, and aromagram showed very small peaks identified as cyclic thioeters (broccoli-like odour): their presence was confirmed by peak disappearance after addition of hydrogen peroxide and oxidation to sulfoxide. Aromagram allowed to individuate also a few aromatic hydrocarbons (grass-like, gasoline-like odour) as responsible of the whole odour of the emission.
- Characterization of olive paste volatiles to predict the sensory quality of virgin olive oil
Diego L. García-González, Noelia Tena, Ramón Aparicio. Eur. J. Lipid Sci. Technol. 109 (2007) 663-672<< Read Abstract >>One of the main challenges that virgin olive oil producers face today is an accurate prediction of the sensory quality of the final product prior to the milling of the olives. The possibility that olive paste aroma can be used as a predictive measurement of virgin olive oil quality is studied in this paper. The study was centered on distinguishing the aroma of olive pastes that produced virgin olive oils without sensory defects from the aroma of olive pastes the virgin olive oils of which showed sensory defects. Olive pastes were analyzed by solid-phase microextraction-gas chromatography and a sensor system based on metal oxide sensors. Forty-four volatile compounds were identified in olive pastes, all of them being also present in virgin olive oil. Six volatile compounds - acetic acid, octane, methyl benzene, (E)-2-hexenal, hexyl acetate and 3- methyl-1-butanol - distinguished both kinds of pastes with only five misclassified samples. Five metal oxide sensors were able to classify the olive pastes with only two erroneous classifications.
- First Identification of O,S-Diethyl Thiocarbonate in Indian Cress Absolute and Odor Evaluation of Its
Synthesized Homologues by GC-Sniffing
Katharina Breme, Nadine Guillamon, Xavier Fernandez, Pascal Tournayre, Hugues Brevard, Daniel Joulain, Jean Louis Berdagu´ E, and Uwe J. Meierhenrich J. Agric. Food Chem. 2009, 57, 2503-2507<< Read Abstract >>Indian cress (Tropaeolum majus L.) absolute was studied by GC-olfactometry (VIDEO-Sniff method) in order to identify odor-active aroma compounds. Because of its fruity-sulfury odor note, a compound that has never been identified in plant extracts before stood out: O,S-diethyl thiocarbonate, present at 0.1% (percentage of the total GC/FID area) in the extract. GCxGC-TOFMS allowed for a clean mass spectrum to be obtained, and isolation by preparative GC followed by NMR studies allowed its identification. Here, we report on the first detection of O,S-diethyl thiocarbonate in Indian cress absolute by GC-olfactometry/VIDEO-Sniff and on its isolation and identification. The synthesis and odor evaluation of its homologues are presented.
- GC-MS, GC-O and enantio-GC investigation of the essential oil of Tarchonanthus camphoratus L.
Rosaria Costa, Barbara d´Acampora Zellner, Maria L. Crupi, Maria R. De Fina, Maria R. Valentino, Paola Dugo, Giovanni Dugo and Luigi Mondello J. Agric. Food Chem. 2009, 57, 2503-2507<< Read Abstract >>The volatile fraction of Tarchonanthus camphoratus L. has been studied by means of gas chromatography- mass spectrometry (GC-MS) and GC-FID, leading to the determination of 90 components whose major were à -pinene (14.7 g/100 g), eucalyptol (14.8 g/100 g) and fenchyl alcohol (12.2 g/100 g). Gas chromatography-olfactometry (GC-O) has been applied to the evaluation of the olfactive notes and their intensity. Also, the enantiomeric distribution of some relevant constituents has been assessed by enantio-GC through the use of a chiral cyclodextrin-based stationary phase.
- Gas chromatography-olfactometry
Conor M. Delahunty, Graham Eyres, Jean-Pierre Dufour. J. Sep. Sci. 2006, 29, 2107-2125<< Read Abstract >>GC-olfactometry (GC-O) refers to the use of human assessors as a sensitive and selective detector for odour-active compounds. The aim of this technique is to determine the odour activity of volatile compounds in a sample extract, and assign a relative importance to each compound. Methods can be classified into three types: detection frequency, dilution to threshold and direct intensity. Dilution to threshold methods measure the potency of odour-active compounds by using a series of extract dilutions, whereas detection frequency and direct-intensity methods measure odouractive compound intensity, or relative importance, in a single concentrated extract. Factors that should be considered to improve the value of GC-O analysis are the extraction method, GC instrument conditions, including the design and operation of the odour port, methods of recording GC-O data and controlling the potential for human assessor bias using experimental design and a trained panel. Considerable emphasis is placed on the requirement for multidimensional GC analysis, and on best practice when using human assessors.
- Character impact odorants from Brassicaceae by aroma extract dilution analysis (AEDA): Brassica cretica and Brassica insularis
Katharina Breme, Stéphane Langle, Xavier Fernandez, Uwe J. Meierhenrich, Hugues Brevard, Daniel Joulain Flavour Frag. J. 2009, 24, 88-93<< Read Abstract >>Volatile extracts of two wild cabbages, Brassica cretica and Brassica insularis, were studied by GC-MS, GC/FID, and GC-olfactometry/aroma extract dilution analysis (GC-O/AEDA). Major compounds were 3-butenyl cyanide (70% of the total GC/FID area) and 3-butenyl isothiocyanate (29%) in B. cretica and 2-phenylethyl cyanide (53%) and 2-phenylethyl isothiocyanate (21%) in B. insularis. AEDA revealed the impact of five heteroatomic trace compounds (diacetyl, methional, furfuryl thiol, 1-octen-3-one and skatole) with moderate to high flavour dilution (FD) factors that were detected only due to GC-O analyses
- Identification of Odor Impact Compounds of Tagetes minuta L. Essential Oil: Comparison of Two GC-Olfactometry Methods
Katharina Breme, Pascal Tournayre, Xavier Fernandez, Uwe J. Meierhenrich, Hugues Brevard, Daniel Joulain and Jean Louis Berdagué J. Agric. Food Chem., 2009, 57 (18), pp 8572-8580<< Read Abstract >>Odor impact compounds of Tagetes minuta L. essential oil were studied by gas chromatography (GC)-olfactometry using aroma extract dilution analysis (AEDA) and vocabulary-intensity-duration of elementary odors by sniffing (VIDEO-Sniff). AEDA was conducted by direct injection and revealed the presence of 43 odorant zones. Highest flavor dilution (FD) values were obtained for ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, (E)-ocimenone, two tentatively identified thiols, and two yet unknown compounds. VIDEO-Sniff was realized by dynamic headspace sampling (D-HS) combined with 8W-GC-olfactometry where eight sniffers simultaneously detect volatile compounds obtained from a single chromatographic separation and revealed the presence of 42 odorant zones. Odorant trace compounds detected by GC-O that were present in quantities inferior to the GC-qMS system´s detection limit and those subject to coelutions were identified by GCxGC-time-of-flight mass spectrometry (TOFMS). A total amount of 37 odorant components could be identified by VIDEO-Sniff, and the strong influence of the fruity notes of numerous esters stood out. Highest olfactory signals were obtained for ethyl 2-methylpropanoate, ethyl 2- and 3-methylbutanoate, and oct-1-en-3-one. Both methods hence come to the conclusion that ethyl 2-methylpropanoate and ethyl 2- and 3-methylbutanoate are among the main odorants in Tagetes minuta L. essential oil. Differences, advantages, and drawbacks of both GC-O methods are discussed.
- Quality Evaluation of Olive Oil by Statistical Analysis of Multicomponent Stable Isotope Dilution Assay Data of Aroma Active Compounds
Georg Dierkes, Annette Bongartz, Helmut Guth and Heiko Hayen. dx.doi.org/10.1021/jf203406s | J. Agric. Food Chem., 2012, 60 (1), pp 394-401<< Read Abstract >>An instrumental method for the evaluation of olive oil quality was developed. Twenty-one relevant aroma active compounds were quantified in 95 olive oil samples of different quality by headspace solid phase microextraction (HS-SPME) and dynamic headspace coupled to GC-MS. On the basis of these stable isotope dilution assay results, statistical evaluation by partial least-squares discriminant analysis (PLS-DA) was performed. Important variables were the odor activity values of ethyl isobutanoate, ethyl 2-methylbutanoate, 3-methylbutanol, butyric acid, E,E-2,4-decadienal, hexanoic acid, guaiacol, 2-phenylethanol, and the sum of the odor activity values of Z-3-hexenal, E-2-hexenal, Z-3-hexenyl acetate, and Z-3-hexenol. Classification performed with these variables predicted 88% of the olive oils´ quality correctly. Additionally, the aroma compounds, which are characteristic for some off-flavors, were dissolved in refined plant oil. Sensory evaluation of these models demonstrated that the off-flavors rancid, fusty, and vinegary could be successfully simulated by a limited number of odorants.
Keywords: methyl salicylate, Fusarium, tomato, spider mite, predatory mite.
- Contribution of beef base to aroma characteristics of beeflike process flavour
assessed by descriptive sensory analysis and gas chromatography olfactometry
and partial least squares regression
Shiqing Song, Xiaoming Zhang, Khizar Hayat, Meigui Huang, Ping Liu, Eric Karangwa, Fenglin Gu, Chengsheng Jia, Shuqin Xia, Zuobing Xiao, Yunwei Niu. | Journal of Chromatography A, 1217 (2010) 7788-7799<< Read Abstract >>Descriptive sensory analysis and gas chromatography-mass spectrometry (GC-MS) analysis were conducted to investigate changes in aroma characteristics of beeflike process flavours (BPFs) prepared from enzymatically hydrolyzed beef (beef base) of different DH (degree of hydrolysis) with other ingredients. Five attributes (beefy, meaty, simulate, mouthful and roasted) were selected to assess BPFs. The results of descriptive sensory analysis confirmed that BPF2 from beef base of moderate DH 29.13% was strongest in beefy, meaty and simulate characteristics; BPF4 and BPF5 from beef base of higher DH (40.43% and 44.22%, respectively) were superior in mouthful and roasted attributes respectively; while BPF0 without beef base gave weaker odour for all attributes. Twenty six compounds from GC-MS were selected as specific compounds to represent beef odour based on their odour-active properties assessed by a detection frequency method of GC-O and correlation of their contents with sensory attributes intensity. Correlation analysis of molecular weight (MW) of peptides, odour-active compounds and sensory attributes through partial least squares regression (PLSR) further explained that beef base with DH of 29.13% was a desirable precursor for imparting aroma characteristics of beeflike process flavour.
Keywords: Beef base, Beeflike process flavour, Descriptive sensory analysis, GC-O, PLSR
- Identification of the Compounds Responsible for the Sweat-Like Odor
in Hop (Humulus lupulus L.) Volatile Oil
Hironari Miyazato. URL: http://dx.doi.org/10.5539/jfr.v2n5p34 | Journal of Food Research; Vol. 2, No. 5; 2013<< Read Abstract >>The aroma of hop volatile oil contains a sweat-like odor. We studied the odorous volatile compounds responsible for the sweat-like odor in the volatile oil extracted from Hallertau Perle hop (Humulus lupulus L.) pellets. The combined use of gas chromatography-mass spectrometry/olfactometry (GC-MS/O), aroma extract dilution analysis (AEDA) by GC-MS/O (an odor dilution technique), and heart-cut multidimensional GC-MS (heart-cut MDGC-MS) equipped with the polar (1D) and apolar (2D) capillary columns revealed seven sweat-like odor producing compounds: methyl-branched saturated and unsaturated aliphatic acids, such as 3-methylbutanoic acid (sweaty/rancid/cheese-like), 2-methylbutanoic acid (sweaty/rancid/cheese-like), 4-methyl-3-pentenoic acid (sweaty/urine-like/malodor in laundry), and (E)-4-methyl-3-hexenoic acid (sweaty/urine-like/malodor in laundry), as well as others, such as an unknown compound (sweaty), methyl (E)-4-methyl-3-hexenoate (sweaty/malodor in laundry/fruity), and S-methyl (E)-4-methyl-3-hexenethioate (sweaty/rubber). The reference substances were synthesized stereoselectively using for the identification procedures. In this study, (E)-4-methyl-3-hexenoic acid, methyl (E)-4-methyl-3-hexenoate, and S-methyl (E)-4-methyl-3-hexenethioate were identified for the first time in hop volatile oil.
Keywords: hop (Humulus lupulus L.), sweaty odor, gas chromatography-mass spectrometry/olfactometry (GC-MS/O), aroma extract dilution analysis (AEDA), multidimensional gas chromatography-mass spectrometry (MDGC-MS), organic synthesis
- Volatile and Amino Acid Profiling of Dry Cured Hams from Different Swine Breeds and Processing Methods
Diego L. García-González, Ramón Aparicio and Ramón Aparicio-Ruiz. | Molecules 2013, 18, 3927-3947; doi:10.3390/molecules18043927<< Read Abstract >>The flavor of dry cured ham explains the high appreciation of this product and it determines consumer acceptance. Volatile compounds provide valuable information about the odor and sensory quality of dry cured hams. Since amino acids are the origin of some volatile compounds of dry cured ham, the volatile and amino acid compositions of forty-one dry cured hams from Spain and France were determined to establish associations between them. The samples included different pig breeds (non Iberian vs. Iberian), which were additionally affected by different maturation times and feeding types (acorn vs. fodder). Results showed that 20 volatile compounds were able to distinguish Iberian and non Iberian hams, and 16 of those had relevant sensory impact according to their odor activity values. 3-Methylbutanol, 2-heptanol and hexanal were among the most concentrated volatile compounds. In the case of non-volatile compounds, the concentrations of amino acids were generally higher in Iberian hams, and all the amino acids were able to distinguish Iberian from non Iberian hams with the exception of tryptophan and asparagine. A strong correlation of some amino acids with volatile compounds was found in the particular case of alcohols and aldehydes when only Iberian hams were considered. The high correlation values found in some cases proved that proteolysis plays an important role in aroma generation.
Keywords: dry-cured ham; volatile compounds; amino acids; aroma; HS-GCMS; HPLC
- Odor-Active (E)-4-Methyl-3-hexenoic Acid in Roasted Coffee Generated in the Maillard Reactions of L-Isoleucine with Sugars
Hironari Miyazato, Michiaki Nakamura, Seiji Hashimoto and Shuichi Hayashi. | Advance Journal of Food Science and Technology 5(10): 1367-1374, 2013<< Read Abstract >>This study describes a novel odor-active unsaturated aliphatic acid in roasted Brazilian Arabica coffee. (E)-4-Methyl-3-hexenoic acid ((E)-4M3H), which is responsible for a sweaty odor, was identified for the first time using Gas Chromatography-Mass Spectrometry/Olfactometry (GC-MS/O), Aroma Extract Dilution Analysis (AEDA) and Multidimensional Gas Chromatography-Mass Spectrometry (MDGC-MS); its (Z)-isomer was also determined. Additionally, we conducted a model formation experiment to detect the presence of 4M3H in coffee and found that it may be produced nonstereoselectively in the Maillard reactions of L-isoleucine with sugars (xylose, fructose, glucose, rhamnose and sucrose). We also found that 2-methylbutanal derived from L-isoleucine and sugar degradation compounds such as α-dicarbonyl compounds (glyoxal, 2-oxopropanal, 2, 3-butanedione and 2, 3-pentanedione) and α-hydroxy ketones (1-hydroxy-2-propanone and 3-hydroxy-2-butanone) are key factors in the formation of 4M3H. Based on these results, we propose a series of potential nonstereoselective formation pathways for 4M3H.
Keywords: AEDA, Arabica coffee, formation pathway, MDGC-MS, odorant
- Investigation of the Aroma Profile of Green Tea Leaves Using Organic Synthesis and Conventional Analytical Techniques
Toshio Hasegawa, Takashi Fujita, Yasutsugu Tsukumo, Takashi Fujihara, Daisuke Jingu, Atsushi Takahashi and Kenta Nakajima. | Journal of Food Science and Engineering 4 (2014) 10-20<< Read Abstract >>Although many aroma components have been identified in green tea leaves, the aroma compounds contributing to green tea’s characteristic odor have not yet been reported. The authors recently reported that aroma components with a matcha-like odor are present in both green tea and black tea prepared from the Sayamakaori tea cultivar. This matcha-like odor is similar to the odor of commercial available matcha (high-quality powdered green tea), and is a specific odor feature of green tea leaves. At present, the green-tea odor is thought to arise from the combination of a large number of constituents. Recent reports indicate that a complex interaction between olfactory receptors and odorants is important for the evaluation of the odors. Taking into consideration these findings, the authors investigated the aroma profile of green tea, focusing on the characteristic molecular structures of the constituents that give matcha-like odor. Using a combination of organic synthesis and gas chromatography-mass spectrometry plus gas chromatography-olfactometry, the authors identified aroma components with matcha-like odors in five other tea cultivars. This investigation also revealed that several compounds with a formyl group were important constituents of the aroma of green tea leaves, although the odor of each constituent was not individually similar to the tea’s overall aroma. The authors found for the first time a group of key components that have the matcha-like odor.
Keywords: Aroma profile, green tea leaves, matcha-like odor, formyl group, aldehyde, complex odor.
- Unravelling the Scent of Vetiver: Identification of Character-Impact Compounds
Emilie Belhassen, Nicolas Baldovini, Hugues Brevard, Uwe J. Meierhenrich, and Jean-Jacques Filippi | CHEMISTRY & BIODIVERSITY - Vol. 11 (2014)<< Read Abstract >>Vetiver oil is a highly esteemed basic ingredient of modern perfumery, but the nature of the constituents that really impart its typical and most sought woody-earthy scent has remained controversial. Indeed, vetiver oil is considered as one of the most complex essential oils, being mostly composed of several hundreds of sesquiterpene derivatives with a large structural diversity. Its complexity has hindered the direct identification of its odoriferous components. We thus aimed at using a combination of GCxGC/MS and GC-Olfactometry in order to identify most of its odor-impact constituents. The olfactory analysis of vetiver oil and vetiveryl acetate revealed a huge variety of odors in both products. While khusimone has almost unanimously been recognized as the most characteristic vetiver odorant, we have identified several even more important contributors to the typical vetiver character.
- Changes in the bound aroma profiles of ‘Hayward’ and ‘Hort16A’ kiwifruit (Actinidia spp.) during ripening and GC-olfactometry analysis
Coralia V. Garcia, Ralph J. Stevenson, Ross G. Atkinson, , Robert A. Winz, Siew-Young Quek | Food Chemistry - Volume 137, Issues 1-4, 15 April 2013, Pages 45-54<< Read Abstract >>Bound volatiles are recognised as a potential source of aroma compounds in fruits. In this study, the bound volatiles of Actinidia deliciosa Hayward and A. chinensis Hort16A were studied at three different ripening stages. The bound volatile content tended to increase as the fruit ripened from under-ripe to ripe, and then decreased in over-ripe fruit. Glycosides of (Z)-3-hexen-1-ol and hexanol (green-note volatiles) were present in considerable amounts. ß-Glucosidase activity in Hayward and Hort16A remained fairly constant throughout ripening. GC-olfactometry analysis of the hydrolysates of ripe Hayward and Hort16A revealed the presence of 2-phenylethanol, ß-damascenone, vanillin and 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF). This is the first report of DMHF in Haywar kiwifruit. For both Hayward and Hort16A, the odour-active compounds found in the bound volatile extracts were different from those reported as contributors to the aroma of the ripe fruit, suggesting that bound volatiles are probably not significant contributors to the aroma of ripe kiwifruit.
- Effects of different commercial lipases on the volatile profile of lipolysed milk fat
Bei Wang and Shiying Xu | Flavour and Fragrance Journal - Volume 24, Issue 6, pages 335-340, November/December 2009<< Read Abstract >>Keywords:
lipolysed milk fat;lipase;sensory analysis;GC-MS;GC-O;flavour
The effect of four different commercial lipases on the flavour profiles (sensory and analytical data) of lipolysed milk fat was examined in this study. Gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O) were used to determine the most potent volatiles resulting from lipolysis. Forty-six volatile compounds were determined and semi-quantified by GC-MS. Nineteen volatile compounds were considered to be major contributors to the characteristic flavour of the lipolysed samples. Based on sensory and analytical data, Palatase 20000 L was selected as the preferred lipase to produce a lipolysed milk fat to be used in the production of dairy flavourings. The key aroma compounds (hydrolytic products) resulting from the use of this lipase are butanoic acid, hexanoic acid, d-dodecalactone, 2-nonanone, 2-undecanone and hexanal.
- Influence of Pulsed Electric Field Treatments on the Volatile Compounds of Milk in Comparison with Pasteurized Processing
Sha Zhang, Ruijin Yang, Wei Zhao, Xiao Hua, Wenbin Zhang and Zhong Zhangu | Journal of Food Science - Volume 76, Issue 1, pages C127-C132, January/February 2011<< Read Abstract >>Keywords:
GC-MS;GC-O;milk;pulsed electric field;volatile compounds
Effects of pulsed electric field (PEF) treatments on the volatile profiles of milk were studied and compared with pasteurized treatment of high temperature short time (HTST) (75°C, 15 s). Volatile compounds were extracted by solid-phase micro-extraction (SPME) and identified by gas chromatography/mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). A total of 37 volatile compounds were determined by GC-MS, and 19 volatile compounds were considered to be major contributors to the characteristic flavor of milk samples. PEF treatment resulted in an increase in aldehydes. Milk treated with PEF at 30 kV/cm showed the highest content of pentanal, hexanal, and nonanal, while heptanal and decanal contents were lower than in pasteurized milk, but higher than in raw milk. All the methyl ketones detected in PEF milk were lower than in pasteurized milk. No significant differences in acids (acetic acid, butanoic acid, hexanoic acid, octanoic acid, and decanoic acid) , lactones, and alcohols were observed between pasteurized and PEF-treated samples; however, 2(5H)-furanone was only detected in PEF-treated milk. Although GC-MS results showed that there were some volatile differences between pasteurized and PEF-treated milk, GC-O data showed no significant difference between the 2 samples.
- Characterization of Artemisia arborescens L. (Asteraceae) leaf-derived essential oil from Southern Italy
M. Lo. Presti, M. L. Crupi, B. d'A. Zellner, G. Dugo, L. Mondello, P. Dugo & S. Ragusa | Journal of Essential Oil Research - Volume 19, Issue 3, 2007<< Read Abstract >>Leaf-derived essential oils isolated from Artemisia arborescens L. (Asteraceae) were analyzed by using GC/MS and GC-FID (for compound quantification); a total of 82 components were determined. The oils were derived from plants collected at the vegetative stage and originating from three locations in southern parts of Italy: Calabria, Sicily and the island of Lipari (Eolian Islands). In general, the chemical compositions were rather similar with some major differences regarding, in particular, the amounts of oxygenated compounds, such as camphor, chamazulene and a- and ß-thujones. The research work was extended to the determination of a series of chiral compounds, as also the olfactive analysis of the aroma-active compounds, with the aim of acquiring an enlargened view on this specific sample-type.
- Qualitätsbewertung von Olivenöl als alternativer Ansatz zur Sensorik
Bergische Universität Wuppertal | http://www.git-labor.de/<< Read Abstract >>Die Einordnung von Olivenölen in die Kategorien nativ und nativ extra erfolgt derzeit über eine organoleptische Qualitätsbewertung. Da diese sensorische Charakterisierung sehr zeit- und personalaufwendig ist, besteht Bedarf an einer schnellen und objektiven instrumentellen Analysenmethode. Die Analyse des Aromastoffprofils mittels Gaschromatographie in Kombination mit einer chemometrischen Datenanalyse hat sich als leistungsstarkes Verfahren zur Klassifizierung von Olivenölen herausgestellt.
- The impact of Whisky blend matrices on the sensory perception of Peaty flavours
International Centre for Brewing and Distilling School of Life Sciences | Tao Yang, thesis<< Read Abstract >>Tao Yang
A thesis submitted for the degree of Doctor of Philosophy