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Butanoic Acid (butanoic + acid)
Selected AbstractsOdour-active compounds of Jinhua hamFLAVOUR AND FRAGRANCE JOURNAL, Issue 1 2008Huanlu Song Abstract Using DHS, SAFE, GC,O and GC,MS, the odour-active compounds of Jinhua ham were identified and ranked according their odour potencies. For DHS, the ham powder was purged with a nitrogen stream at a flow rate of 50 ml/min for 25 min, 5 min and 1 min, respectively. The effluent of sample headspace was trapped by a Tenax tube, which was placed onto the vessel for GC,O. The most important odorants (FD factor = 125) in Jinhua ham headspace were ethyl 2-methylbutanoate/ethyl 3-methylbutanoate, hexanal, 1-hexen-3-one, 1-octen-3-one, 2-acetyl-1-pyrroline and 2-methoxyphenol, followed by the following odorants (FD factor = 25): 3-methyl butanal, dimethyl trisulphide, 1-nonen-3-one, butanoic acid, phenylacetaldehyde, 3-methylbutanoic acid, 2-methyl(3-methyldithio)furan, , -nonalctone and 4-methylphenol (p -cresol). For SAFE, the ham powder was extracted with diethyl ether, distilled by SAFE and then separated into neutral/basic and acidic fractions. Both fractions were subjected to AEDA. The relatively high-odour impact compounds (Log3FD Factor ,5) of the N/B fraction of SAFE extract of Jinhua ham were 1-octen-one, ethyl 3-methylbutanoate, methional, phenylacetaldehyde, 2-phenylethanol, (E)-4,5-epoxy-(E)-decenal, p -cresol (4-methylphenol); 3-methylbutanal, hexanal, 2-acetyl-1-pyrroline, decanal, (E,Z)-2,6-nonadienal and (E,E)-decadienal. The important odorants of the Ac fraction of SAFE extract of Jinhua ham were butanoic acid, 3-methylbutanoic acid, hexanoic acid, phenylacetic acid and an unknown. It was shown that the aroma of Jinhua ham consisted of a variety of compounds having different odour properties; a single compound could not characterize the aroma of Jinhua ham. Copyright © 2008 John Wiley & Sons, Ltd. [source] Determination of the aroma impact compounds in heated sweet cream butterFLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2003D. G. Peterson Abstract This study was conducted to determine which volatile compounds are primarily responsible for the aroma of heated sweet cream butter. Static headspace analysis was used for aroma isolation and gas chromatography,olfactometry (GC,O) for the selection of odour-active components. Quanti,cation of selected odourants was done via purge and trap-GC/mass spectrometry (MS). Nineteen odour-active compounds were detected in the headspace (static) of heated butter (hydrogen sulphide, methanethiol, acetaldehyde, 2,3-butanedione, 1-hexen-3-one, butanoic acid, 3-methylbutanoic acid, 2-heptanone, methional, dimethyl trisulphide, 1-octen-3-one, hexanoic acid, furaneol, , -hexanolactone, nonanal, (E)-2-nonenal, , -octanolactone, skatole and , -decanolactone). Aroma recombination studies followed by sensory analysis indicated that the aroma of our heated butter model was rated the same (similarity) as a heated commercial butter (obtained from local market) in comparison to a heated freshly manufactured butter. The aroma of a heated commercial unsalted butter and a heated butter aroma model of Budin 1 also were signi,cantly less similar than the aroma of our heated butter model in comparison to a heated freshly manufactured butter. Copyright © 2003 John Wiley & Sons, Ltd. [source] Aroma Components of American Country HamJOURNAL OF FOOD SCIENCE, Issue 1 2008H. Song ABSTRACT:, The aroma-active compounds of American country ham were investigated by using direct solvent extraction-solvent assisted flavor evaporation (DSE-SAFE), dynamic headspace dilution analysis (DHDA), gas chromatography-olfactometry (GCO), aroma extract dilution analysis (AEDA), and gas chromatography-mass spectrometry (GC-MS). The results indicated the involvement of numerous volatile constituents in the aroma of country ham. For DHDA, 38 compounds were identified as major odorants, among them, 1-octen-3-one, 2-acetyl-1-pyrroline, 1-nonen-3-one, decanal, and (E)-2-nonenal were the most predominant, having FD-factors , 125 in all 3 hams examined, followed by 3-methylbutanal, 1-hexen-3-one, octanal, acetic acid, phenylacetaldehyde, and FuraneolÔ. For the DSE-SAFE method, the neutral/basic fraction was dominated by 1-octen-3-one, methional, guaiacol, (E)-4,5-epoxy-(E)-decenal, p-cresol as well as 3-methylbutanal, hexanal, 2-acetyl-1-pyrroline, phenylacetaldehyde, and ,-nonalactone. The acidic fraction contained mainly short-chain volatile acids (3-methylbutanoic acid, butanoic acid, hexanoic acid, and acetic acid) and Maillard reaction products (for example, 4-hydroxy-2,5-dimethyl-3(2H)-furanone). The above compounds identified were derived from lipid oxidation, amino acid degradation, and Maillard/Strecker and associated reactions. Both methods revealed the same nature of the aroma components of American country ham. [source] Amide and lactam hydrolysis of N -(2-hydroxyacetyl)-2-pyrrolidone: effective catalysis,JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 11 2006Lisaedy García Borboa Abstract When N -(2-hydroxyacetyl)-2-pyrrolidone (open form) is dissolved in water at pH,>,8, irreversible cleavage of the exocyclic and endocyclic amide CN bond occurs. The latter rupture corresponds to the lactam opening yielding N -(4-hydroxyacetyl)butanoic acid (NBA). NBA is produced from the ester hydrolysis of the ester-amide macrocycle that is in equilibrium with the cyclol form of the open form. We have previously reported this latter equilibrium for N -(2-aminoacetyl)-2-lactams. 2-pyrrolidone (lactam) and glycolic acid are produced from direct hydrolysis of the open form by means of the amide exocyclic cleavage. The [NBA]/[lactam] ratio increases at higher pH since the NBA production is second order with respect to [OH,] while the corresponding lactam formation is only first order. The obtained kobs is hence the sum of the rate constants that yield lactam and NBA, respectively. This kobs is uncatalyzed and specific base catalyzed with unusually high rate constants of 2.1,×,10,6,s,1 and 0.025,M,1,s,1, respectively. The stability of the corresponding tetrahedral intermediate formed and the intramolecular alkoxy nucleophilic attack on the lactam carbonyl group combined with an effective protonation of the lactam nitrogen that promotes the CN cleavage, contribute to increase the reaction rates and lactam opening. Rate constants for the two parallel reactions are obtained from kobs and [NBA]/[lactam] versus pH plots. Copyright © 2006 John Wiley & Sons, Ltd. [source] One-pot synthesis of ABC miktoarm star terpolymers by coupling ATRP, ROP, and click chemistry techniquesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 12 2009Yanfeng Zhang Abstract We report on the one-pot synthesis of well-defined ABC miktoarm star terpolymers consisting of poly(2-(dimethylamino)ethyl methacrylate), poly(,-caprolactone), and polystyrene or poly(ethylene oxide) arms, PS(- b -PCL)- b -PDMA and PEO (- b -PCL)- b -PDMA, taking advantage of the compatibility and mutual tolerability of reaction conditions (catalysts and monomers) employed for atom transfer radical polymerization (ATRP), ring-opening polymerization (ROP), and click reactions. At first, a novel trifunctional core molecule bearing alkynyl, hydroxyl group, and bromine moieties, alkynyl(OH)Br, was synthesized via the esterification reaction of 5-ethyl-5-hydroxymethyl-2,2-dimethyl-1,3-dioxane with 4-oxo-4-(prop-2-ynyloxy)butanoic acid, followed by deprotection and monoesterification of alkynyl(OH)2 with 2-bromoisobutyryl bromide. In the presence of trifunctional core molecule, alkynyl(OH)Br, and CuBr/PMDETA/Sn(Oct)2 catalytic mixtures, target ABC miktoarm star terpolymers, PS(- b -PCL)- b -PDMA and PEO(- b -PCL)- b -PDMA, were successfully synthesized in a one-pot manner by simultaneously conducting the ATRP of 2-(dimethylamino)ethyl methacrylate (DMA), ROP of ,-caprolactone (,-CL), and the click reaction with azido-terminated PS (PS- N3) or azido-terminated PEO (PEO- N3). Considering the excellent tolerability of ATRP to a variety of monomers and the fast expansion of click chemistry in the design and synthesis of polymeric and biorelated materials, it is quite anticipated that the one-pot concept can be applied to the preparation of well-defined polymeric materials with more complex chain architectures. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3066,3077, 2009 [source] Chemostimuli implicated in selection of oviposition substrates by the stable fly Stomoxys calcitransMEDICAL AND VETERINARY ENTOMOLOGY, Issue 3 2007P JEANBOURQUIN Abstract Horse and cow dung were tested as substrates for oviposition by the stable fly Stomoxys calcitrans (L) (Diptera: Muscidae) in laboratory cages. Odour alone from either horse or cow dung was sufficient to attract flies for oviposition. This was confirmed in wind tunnel experiments, where both horse and cow dung were shown to attract gravid stable flies. However, when S. calcitrans was offered a choice between these two oviposition substrates, flies always chose horse dung over cow dung, both when allowed to contact the substrates and when relying on dung odour alone. Analyses of volatile compounds emanating from horse and cow dung by gas chromatography linked antennogram recordings from S. calcitrans antennae revealed no differences in the chemostimuli released from the two substrates. The predominant chemostimulant compounds in both substrates were carboxylic acids (butanoic acid), alcohols (oct-1-en-3-ol), aldehydes (decanal), ketones (octan-3-one), phenols (p -cresol), indoles (skatole), terpenes (,-caryophyllene) and sulphides (dimethyl trisulphide). Higher levels (20,40 p.p.m.) of carbon dioxide were recorded over horse dung compared with cow dung, a factor that may contribute to the preference exhibited by S. calcitrans for this substrate for oviposition. [source] Sensory and behavioural responses of the stable fly Stomoxys calcitrans to rumen volatilesMEDICAL AND VETERINARY ENTOMOLOGY, Issue 3 2007P. JEANBOURQUIN Abstract Analysis of volatiles from rumen digesta by gas chromatography linked antennogram recordings from Stomoxys calcitrans (L) (Diptera: Muscidae) antennal receptor cells revealed about 30 electrophysiologically active constituents, the most important of which is dimethyl trisulphide with a sensory threshold in the femtogram range. The behavioural responses of S. calcitrans to five chemostimulants (dimethyl trisulphide, butanoic acid, p -cresol, oct-1-en-3-ol and skatole) were tested in a wind tunnel where activation and attraction of hungry flies to rumen volatiles were recorded. Dimethyl trisulphide, butanoic acid and p -cresol were found to attract S. calcitrans. This sensitivity to rumen volatile constituents, that also occur in animal wastes used for oviposition by Stomoxys spp., as well as in flowers used by stable flies as sources of nectar is discussed in the context of the behavioural ecology of these flies. [source] Odorous compounds in paperboard as influenced by recycled material and storagePACKAGING TECHNOLOGY AND SCIENCE, Issue 4 2001Gottfried Ziegleder Abstract Many volatile compounds can be identified in unprinted paperboard by means of steam distillation in combination with capillary gas chromatography, mass spectrometry and olfactometry. Paperboards produced with recycled material exhibit additional volatiles which partly contribute to off-odours. Using sniffing techniques, benzaldehyde, acetophenone, 1-octen-3-ol, 1-octen-3-one, 2-nonenal, methylguajacol, butanoic and 3-methyl butanoic acid were identified as the most odorous volatiles. The aromatic substances mainly exude from inks and printing solvents in waste materials used for paperboard manufacturing. During storage under controlled conditions, the microbial load of paperboard decreased slightly, and no odorous metabolic products were generated. Copyright © 2001 John Wiley & Sons, Ltd. [source] Induction of resistance to downy mildew (Peronospora parasitica) in cauliflower by DL-,-amino- n -butanoic acid (BABA)PLANT PATHOLOGY, Issue 1 2002D. Silué Of the three isomers of aminobutyric acid, only the , isomer (BABA) was effective in inducing resistance against Peronospora parasitica, the causal agent of downy mildew, in cauliflower (Brassica oleracea var. botrytis). A single foliar spray applied to 7-day-old seedlings protected the plants against Peronospora parasitica for at least 15 days. Of the enantiomers (R and S), only the R was effective. Resistance was accompanied by a hypersensitive-like reaction (necrotic spots) which was evident before inoculation. BABA was systemically effective when applied to the roots, but failed to protect cotyledons adjacent to treated ones. Unlike other chemical inducers, BABA was effective when applied several hours postinoculation. It had no effect on P. parasitica spore germination. In cauliflower seedlings, BABA did not induce the accumulation of the pathogenesis-related protein PR-1, PR-2, PR-3, PR-5 and PR-9. Only treated and challenged seedlings accumulated PR-2. [source] A serum metabolomic investigation on hepatocellular carcinoma patients by chemical derivatization followed by gas chromatography/mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 19 2008Ruyi Xue The purpose of this study was to investigate the serum metabolic difference between hepatocellular carcinoma (HCC, n,=,20) male patients and normal male subjects (n,=,20). Serum metabolome was detected through chemical derivatization followed by gas chromatography/mass spectrometry (GC/MS). The acquired GC/MS data was analyzed by stepwise discriminant analysis (SDA) and support vector machine (SVM). The metabolites including butanoic acid, ethanimidic acid, glycerol, L-isoleucine, L-valine, aminomalonic acid, D-erythrose, hexadecanoic acid, octadecanoic acid, and 9,12-octadecadienoic acid in combination with each other gave the strongest segregation between the two groups. By applying these variables, our method provided a diagnostic model that could well discriminate between HCC patients and normal subjects. More importantly, the error count estimate for each group was 0%. The total classifying accuracy of the discriminant function tested by SVM 20-fold cross validation was 75%. This technique is different from traditional ones and appears to be a useful tool in the area of HCC diagnosis. Copyright © 2008 John Wiley & Sons, Ltd. [source] Parallel kinetic resolution of D -labelled 2-aryl-propionic and butanoic acids using quasi -enantiomeric combinations of oxazolidin-2-onesCHIRALITY, Issue 2 2010Elliot Coulbeck Abstract The parallel kinetic resolution of racemic 2-aryl-2-deuterio-propionic and butanoic acids using an equimolar combination of quasi -enantiomeric oxazolidin-2-ones is discussed. The levels of diastereoselectivity were high leading to enantiomerically pure D -labeled products in good yield. Chirality, 2010. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||