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Volatile Composition (volatile + composition)
Selected AbstractsElectronic Nose Technology in Quality Assessment: Predicting Volatile Composition of Danish Blue Cheese During RipeningJOURNAL OF FOOD SCIENCE, Issue 6 2005Jeorgos Trihaas ABSTRACT This work describes for the 1st time the use of an electronic nose (e-nose) for the determination of changes of blue cheeses flavor during maturation. Headspace analysis of Danish blue cheeses was made for 2 dairy units of the same producer. An e-nose registered changes in cheeses flavor 5, 8, 12, and 20 wk after brining. Volatiles were collected from the headspace and analyzed by gas chromatography-mass spectrometry (GC-MS). Features from the chemical sensors of the e-nose were used to model the volatile changes by multivariate methods. Differences registered during ripening of the cheeses as well as between producing units are described and discussed for both methods. Cheeses from different units showed significant differences in their e-nose flavor profiles at early ripening stages but with ripening became more and more alike. Prediction of the concentration of 25 identified aroma compounds by e-nose features was possible by partial least square regression (PLS-R). It was not possible to create a reliable predictive model for both units because cheeses from 1 unit were contaminated by Geotrichum candidum, leading to unstable ripening patterns. Correction of the e-nose features by multiple scatter correction (MSC) and mean normalization (MN) of the integrated GC areas made correlation of the volatile concentration to the e-nose signal features possible. Prediction models were created, evaluated, and used to reconstruct the headspace of unknown cheese samples by e-nose measurements. Classification of predicted volatile compositions of unknown samples by their ripening stage was successful at a 78% and 54% overall correct classification for dairy units 1 and 2, respectively. Compared with GC-MS, the application of the rapid and less demanding e-nose seems an attractive alternative for this type of investigation. [source] Screening of Volatile Composition of Lavandula hybridaReverchon II Honey Using Headspace Solid-Phase Microextraction and Ultrasonic Solvent ExtractionCHEMISTRY & BIODIVERSITY, Issue 3 2009Igor Jerkovi Abstract The volatiles of unifloral Lavandula hybridaReverchon II honey were isolated by means of headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) and analyzed by gas chromatography and mass spectrometry (GC, GC/MS). A total of 23 compounds were identified in the headspace with hexan-1-ol, hexanal, acetic acid, hotrienol, and 2-phenylacetaldehyde as the principal components. Three solvents of different polarity were used for USE, and a total of 53 compounds were identified. The extracts with pentane/Et2O 1,:,2 (v/v) were the most representative for USE method containing the majority of the honey floral origin compounds and potential biomarkers (hexanol, acetic acid, butane-1,3-diol, butane-2,3-diol, benzoic acid, coumarin, and 2-phenylacetic acid). The total number of identified compounds (USE and HS-SPME) was 59. In general, the comparison with volatiles of other lavandin honeys of different geographic origins indicated several similarities, while acetic and formic acids were identified with high percentages in L. hybridaReverchon II honey. [source] Volatile composition and olfactory profile of pennyroyal (Mentha pulegium L.) plantsFLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2007M. Consuelo Díaz-Maroto Abstract The composition of volatile oil extracts of pennyroyal (Mentha pulegium L.) plants was investigated by gas chromatography,mass spectrometry. Those volatiles responsible for the characteristic minty and pungent aroma of this plant were determined by gas chromatography,olfactometry. Volatile oil extracts were found to be rich in oxygenated monoterpenes, mainly pulegone and piperitone oxide, followed by isopulegol, piperitone and piperitenone. Major monoterpenes hydrocarbons were limonene and , -pinene, while sesquiterpenoids were detected in low levels. With respect to the aroma characteristics, pulegone was found to have an intense mint, balsamic and pungent aroma. Other compounds with minty notes were isopulegone, piperitol and 1,8-cineole. Copyright © 2006 John Wiley & Sons, Ltd. [source] Volatile composition of the laksa plant (Polygonum hydropiper L.), a potential source of green note aroma compoundsFLAVOUR AND FRAGRANCE JOURNAL, Issue 5 2005J. Jiang Abstract Volatile compounds were extracted from laksa plant (Polygonum hydropiper L.) by three isolation techniques,dynamic headspace sampling, simultaneous distillation and extraction (SDE) and liquid,liquid extraction with dichloromethane (DCM). In the GC,MS analysis of the volatile extracts, a total of 46 compounds were identi,ed, including 14 carbonyls, 14 alcohols, 10 hydrocarbons, four esters, two furans, one acid and one base. Carbonyls (aldehydes/ketones) and alcohols are the predominant classes of volatile compounds, accounting for almost 90% (or above) of the total volatiles extracted from the plant. The major compounds include dodecanal (3,40%), (E)-2-hexenal (20,35%), decanal (4,22%), (Z)-3-hexen-1-ol (4,31%), hexanal (1.7,5.1%) and , -caryophyllene (1.7,2.3%). Signi,cantly high levels of both (E)-2-hexenal (leaf aldehyde) and (Z)-3-hexen-1-ol (leaf alcohol) may make the weed plant become a potential source of green note aroma componds. More (Z)-3-hexen-1-ol was found in the stem while more (E)-2-hexenal was detected in the leaf. The laksa stem appeared to contain more decanal and dodecanal but less esters than the leaf. Different isolation techniques produced volatile extracts with different proportions of the major volatile components. Copyright © 2005 John Wiley & Sons, Ltd. [source] Volatile composition and proteolysis in traditionally produced mature Kashar cheeseINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2009Ali Adnan Hayaloglu Summary Twelve samples of raw milk mature Kashar cheese at different stages of ripening were collected from retail outlets. The average pH, moisture, fat-in-dry matter, protein, salt-in-dry matter and titratable acidity contents of the samples were 5.33, 39.39%, 45.20%, 27.33%, 6.62% and 0.65% (as lactic acid), respectively. Indices of proteolysis varied from 10.72% to 23.75% and 7.09% to 12.26% for pH 4.6-soluble and 12% trichloroacetic acid-soluble nitrogen fractions, respectively, and total free amino acid concentrations ranged from 6.36 to 36.03 mg Leu g,1 of cheese. The cheeses were analysed for volatile compounds by Solid Phase Microextraction and Gas Chromatography-Mass Spectrometry (GC-MS). A total of 113 compounds were detected and identified belonging to the following chemical groups: acids (eleven), esters (sixteen), ketones (sixteen), aldehydes (six), alcohols (twenty-seven), sulphur compounds (seven), terpenes (seven) and miscellaneous compounds (twenty-three). The potential effect of each compound on the flavour profile of Kashar cheese is discussed. Acids, esters, ketones and alcohols were found at considerable levels in the samples. Kashar cheeses obtained from different retail outlets displayed some differences in terms of chemical composition, proteolysis and patterns of aroma compounds; and may be attributed to their production technologies and age-related variations. [source] Volatile compositions of two Asteraceae from the north-east of Brazil: Ageratum conyzoides and Acritopappus confertus (Eupatorieae)FLAVOUR AND FRAGRANCE JOURNAL, Issue 6 2005Mary Anne Sousa Lima Abstract Essential oils obtained by hydrodistillation of leaves from specimens of Ageratum conyzoides and Acritopappus confertus were investigated by GC,MS. The leaf essential oil of A. conyzoides consisted exclusively of the chromenes precocene I (95.4%) and II (4.5%). The essential oil of A. confertus consisted predominantly of monoterpenes, representing 81.0% of the total. The main component was myrcene (52.0%), with reasonable amounts of , -pinene (16.8%) and limonene (8.2%). The essential oil of A. conyzoides from the north-east of Brazil has been reported as the major source of precocene I to date. Copyright © 2005 John Wiley & Sons, Ltd. [source] Aroma of minor tropical fruitsFLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2005M. R. B. Franco Abstract Publications on the volatile composition of some minor tropical fruits, i.e. acerola, cupuaçu, soursop, bacuri, genipap, umbu-cajá, araçá-boi, camu-camu, umbu, murici and cashew apple, are reviewed. Differences observed in the volatile composition of a same fruit could be due to the methodology and[sol ]or to different cultivars or geographical regions. Bound volatiles can also be liberated during the extraction procedures under drastic conditions. Copyright © 2005 John Wiley & Sons. Ltd. [source] The essential oil of Anemia tomentosa (Savigny) Sw. var. anthriscifolia (Schrad.) MickelFLAVOUR AND FRAGRANCE JOURNAL, Issue 6 2004Hector R Juliani Abstract The essential oil composition of the aerial parts of Anemia tomentosa var. anthriscifolia (Anemiaceae) was characterized by GC,MS. Total volatile oil yield extracted by steam distillation was 0.2% dry weight basis. The volatile oil was composed mainly of sesquiterpenes (75%, as the relative percentage of the total essential oil) with lower amounts of monoterpenes (15%); no phenylpropanoids were detected. The sesquiterpenes were composed mainly of oxygenated components (67%), including , -bisabolol (51%), spathulenol (1%), caryophyllene oxide (3%), , -bisaboloxide (1%) and 14-hydroxy-9-epi-(E)-caryophyllene (1%). The monoterpenes were dominated by neral (5%) and geranial (7%), with lower amounts of , -pinene, camphene, 6-methyl-5-hepten-2-one, 1,8-cineole and pinocarveol. This is the ,rst report of the essential oil accumulation (0.2%) and volatile composition in the aromatic fern A. tomentosa. Copyright © 2004 John Wiley & Sons, Ltd. [source] Sensory Characterization of Dry Gins with Different Volatile ProfilesJOURNAL OF FOOD SCIENCE, Issue 6 2008M. Riu-Aumatell ABSTRACT:, The aim of this study was the sensory characterization of dry gins in relation to their chemical volatile composition. The development of a specific vocabulary was necessary as a basis for quality control and to ensure the brand flavor integrity. The lexicon was obtained according to ISO 11035 (1994), on the basis of discussions between the panelists and the panel leader, reference materials, and an aroma wheel. Ten notes of the preliminary vocabulary were reduced by calculating the geometric mean (M) and applying ANOVA and principal component analysis. Finally, juniper, citric, aniseed, spice, and licorice were applied to describe 4 London Dry Gins (G1 to G4) and 2 gins with geographic indications (G5 and G6) by generic descriptive analysis (GDA). The latter were characterized by citric and juniper notes, respectively, while G1 was characterized by spice and aniseed attributes. Licorice was uniform in all of the samples. Chemical volatile composition of samples obtained by headspace-solid phase microextraction (HS-SPME) coupled with gas chromatography/mass spectrometry (GC/MS) was in agreement with the sensory results. [source] Insoluble Grape Material Present in Must Affects the Overall Fermentation Aroma of Dry White Wines Made from Three Grape Cultivars Cultivated in GreeceJOURNAL OF FOOD SCIENCE, Issue 1 2002S. Karagiannis ABSTRACT: Musts from 3 grape varieties were used to elucidate the effect of the presence of grape solids in must on the volatile composition of the resultant white wines. Volatile compounds were analyzed by GC/MS and GC/FPD except H2S, which was measured spectrophotometrically. Increasing quantities of grape insoluble material decreased the substances that enhanced aroma of Savatiano and Batiki wines. Simultaneously, the levels of compounds that degrade wine aroma, when formed in large amounts, were increased. However, in Muscat of Hamburg wines, the levels of some volatiles were not influenced by must turbidity in the same way as in wines of the other cultivars. [source] Changes in volatile composition during fruit development and ripening of ,Alphonso' mangoJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2009Sagar S Pandit Abstract BACKGROUND: Volatile blends of five developing and five ripening stages of mango (Mangifera indica L. cv. Alphonso) were investigated along with those of flowers and leaves. Raw and ripe fruits of cv. Sabja were also used for comparison. RESULTS: A total of 55 volatiles belonging to various chemical classes such as aldehydes, alcohols, mono- and sesquiterpene hydrocarbons, lactones and furanones were identified. In all Alphonso tissues monoterpenes quantitatively dominated, with 57,99% contribution; in particular, (Z)-ocimene was found in the highest amount. Ripeness was characterized by the de novo appearance of lactones and furanones in the blend of monoterpenes. Sabja was distinguished by the abundance of monoterpene hydrocarbons in the raw fruit, and that of sesquiterpene hydrocarbons and their derivatives in the ripe stage. CONCLUSION: Various stages of the Alphonso fruit during transition from flower to ripe fruit are characterized by unique volatile signatures that are distinguished from each other by the qualitative and quantitative appearance of different volatile compounds. Thus volatiles can be highly informative markers while studying the development and ripening of mango. Copyright © 2009 Society of Chemical Industry [source] Comparative study of the volatile composition in wines obtained from traditional vinification and from the Ganimede methodJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2008Teresa Garde-Cerdán Abstract BACKGROUND: This study compares the volatile composition between wines obtained from vinification carried out by the traditional method or using a new method of vinification (so-called Ganimede). For this, Shiraz, Merlot and Cabernet Sauvignon musts were fermented by both vinification methods. RESULTS: The volatile compounds that were above their threshold of perception in the wines were practically the same, irrespective of the vinification method used. Most of the compounds studied did not present significant differences in their concentrations between the wines obtained from the traditional and the new vinification methods. When there were significant differences, the concentration of alcohols and acids was higher in the wines vinificated by the traditional method rather than in the wines vinificated by the Ganimede method, whereas for esters, the concentration in the wines depended on the grape variety. CONCLUSION: The Ganimede method favoured polyphenol extraction without greatly affecting the studied volatile composition of the wines. Copyright © 2008 Society of Chemical Industry [source] Electronic Nose Technology in Quality Assessment: Predicting Volatile Composition of Danish Blue Cheese During RipeningJOURNAL OF FOOD SCIENCE, Issue 6 2005Jeorgos Trihaas ABSTRACT This work describes for the 1st time the use of an electronic nose (e-nose) for the determination of changes of blue cheeses flavor during maturation. Headspace analysis of Danish blue cheeses was made for 2 dairy units of the same producer. An e-nose registered changes in cheeses flavor 5, 8, 12, and 20 wk after brining. Volatiles were collected from the headspace and analyzed by gas chromatography-mass spectrometry (GC-MS). Features from the chemical sensors of the e-nose were used to model the volatile changes by multivariate methods. Differences registered during ripening of the cheeses as well as between producing units are described and discussed for both methods. Cheeses from different units showed significant differences in their e-nose flavor profiles at early ripening stages but with ripening became more and more alike. Prediction of the concentration of 25 identified aroma compounds by e-nose features was possible by partial least square regression (PLS-R). It was not possible to create a reliable predictive model for both units because cheeses from 1 unit were contaminated by Geotrichum candidum, leading to unstable ripening patterns. Correction of the e-nose features by multiple scatter correction (MSC) and mean normalization (MN) of the integrated GC areas made correlation of the volatile concentration to the e-nose signal features possible. Prediction models were created, evaluated, and used to reconstruct the headspace of unknown cheese samples by e-nose measurements. Classification of predicted volatile compositions of unknown samples by their ripening stage was successful at a 78% and 54% overall correct classification for dairy units 1 and 2, respectively. Compared with GC-MS, the application of the rapid and less demanding e-nose seems an attractive alternative for this type of investigation. [source] Influence of ripening stage on volatiles composition, physicochemical indexes and sensory evaluation in two varieties of muskmelon (Cucumis melo L var reticulatus Naud)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2005Emilio Senesi Abstract The quality parameters of muskmelon (Cucumis melo L var reticulatus Naud) are often related to sugar content and aroma composition. A study of aroma composition using two different extraction techniques (GC-HS and GC-MS extraction concentration) was performed in order to find correlations with sensory descriptors, other quality indices and ripening stage. Two muskmelon varieties (Calypso and Pamir) were assayed at three different ripening stages (unripe, ripe, overripe). Chemical, physical and sensory analyses were performed on the muskmelon samples just after harvest and after 7 days of cold storage. Solid soluble content (SSC) changed from about 10°Bx in unripe samples to about 15°Bx in ripe and overripe samples. Different aroma composition and sensory evaluation were found depending on the ripening stages. The main flavour components detected were esters which increased 10,15-fold from unripe to ripe and overripe stages. The acceptance judgements by panellists were strongly correlated with the sensory descriptor flavour. High statistical correlations were also found between sensory descriptor flavour and some classes of aroma compounds, mainly with total esters (about 0.66,0.69), formates (0.70) and acetates (0.64 and 0.72). The paper demonstrates that some classes of esters are very important to assess the sensory flavour and overall eating quality of muskmelons. Copyright © 2005 Society of Chemical Industry [source] | ||||||||||