The characterisation of some mushroom volatiles

A steam-volatile extract, possessing a strong mushroom-like odour, has been isolated from Agaricus bisporus, the cultivated white mushroom of the mushroom grower. The major volatile components present, viz., 3-methylbutanal, 3-octanone, oct-1-en-3-one, 3-octanol, oct-1-en-3-ol, furfural, benzaldehyde, phenylacetaldehyde and benzyl alcohol, were identified by combined gas chromatography-mass spectrometry, and several other components were either positively or tentatively identified. The properties of the mushroom-like odour of oct-1-en-3-one and of the corresponding alcohol in dilute aqueous solution were examined.     

Evolution of volatile odorous compounds during the storage of European seabass (Dicentrarchus labrax)

The aim of this work was to reliably identify odorous compounds of European seabass (Dicentrarchus labrax) after 1, 4 and 15 days of storage in order to find markers of freshness or spoilage. For this purpose, a dynamic headspace gas chromatography olfactometry device (DH-GC-MS/8O) was used with a panel of eight sniffers for comprehensive detection of odorants. One- and two-dimensional gas chromatography (GC-GC-MS/O) coupled with olfactometry and mass spectrometry gave reliable identification. More than 144 volatile compounds were detected in seabass flesh, of which only 13 proved to be odorant (their biochemical origins are discussed): methane-thiobis, thiophene, toluene + butanoic acid ethyl ester, hexanal, 1-hexanol, 1-octen-3-one, 1-octen-3-ol, dimethyl-trisulfide, octanal, 1-nonen-3-ol, (E)-2-nonenal and 2 unknown compounds. Amongst these compounds, only thiophene, hexanal, 1-octen-3-one, dimethyl-trisulfide, and 1-nonen-3-ol are proposed as markers of seabass quality.     

Influence of Dryer Infeed Matrices on the Retention of Volatile Flavor Compounds During Spray Drying

The retention of volatile flavor compounds (octane, 2-octanone, octanal, methyl-2-octenoate, oct-1-en-3-ol, octanol, thiophene, 2-ethylthiophene, thiazole, 2,5dimethylpyrazine, benzaldehyde, 5-methylfurfural) in model food systems during spray drying was studied. The flavor compounds were added to different model food systems (including malto dextrins DE 10 to 36.5, soy, casein and whey protein based systems and protein/fat systems) at 1 ppm and then spray dried using a Niro Utility Dryer employing centrifugal atomization. Flavor retention was found to be inversely related to DE of the maltrin carrier. Inclusion of protein in the infeed material resulted in better flavor retention than pure maltrin infeeds. Soy protein based model systems were most effective in retaining flavors followed by casein and whey protein based systems. Relative volatility of flavor compounds in different model systems was found to be an important factor pertaining to flavor retention during drying in different infeed materials.     

Selection of a representative extraction method for the analysis of odourant volatile composition of French cider by GC-MS-O and GC × GC-TOF-MS

The experimental conditions of a representative odour extraction method were determined after testing eight SPME, dynamic headspace and purge-and-trap procedures. Headspace SPME with a Car/PDMS fibre was evidenced to be the most suitable method to obtain representative extract of cider odour. This method was applied to extract the volatile compounds of two French ciders and gas chromatography-mass spectrometry-olfactometry (GC-MS-O) was used to analyse the odourant profile and the aroma-active compounds of these ciders. Thirty-six odourant zones were perceived in one cider and 24 in the other. Comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry was used to identify odour-active compounds which were undetermined after the first chromatographic separation. Ethyl 2-methylbutanoate, 2-phenylethanol, ethyl butanoate, ethyl 2-methylpropanoate, ethyl hexanoate, oct-1-en-3-one, 2-phenylethyl acetate, ethyl dodecanoate, 3-methyl-1-butanol and 2-methylbutanoic acid were among the most potent odourants in both ciders, as well as oct-1-en-3-one, which could be identified only by comprehensive GC. Thanks to the association of the two methods, 80% of the aroma-active compounds were identified, some of them being present at trace levels in ciders.     

Flavour formation in callus cultures of guava (Pridium guajava) fruit

Explants from guava Pridium guajava L fruit, when cultured on Murashige and Skoog media containing different combinations of IAA, NAA, 2,4-D and kinetin, yielded unorganised callus cultures. Light (>2000 lux) and kinetin (>5 mg litre^?1) promoted chlorophyllous callus. However, none of the tested variations yielded organised cultures. Increase in kinetin from 0.2 to 0.8 mg litre^?1 resulted in a slight increase in the growth of the callus. There was perceptible guava fruit flavour in all three passages of callus cultures, all of which exhibited a slow growth rate. GC-MS analysis of the volatile flavour fraction of the callus tissue revealed (Z)hex-3-en-1-ol, 3-phenylpropyl acetate, (E)hex-3-en-1-ol, hexan-1-ol, (Z)hex-3-ynyl acetate, (E)hex-2-enal and cinnamyl acetate as prominent peaks. Incorporation of ¹⁴C glucose, ¹⁴C phenylalanine and ¹⁴C acetate from the growth medium into the volatile fraction of the callus cultures was 0.07, 0.09 and 0.14% respectively during a 4-day incubation.     

Contribution of Penicillium sp. to the Flavors of Brie and Camembert Cheese

Volatile flavor compounds produced by Penicillium caseicolum in domestic and French Brie cheese were identified by gas chromatography-mass spectrometry; they included carbon-5, carbon-7, Carbon-9, carbon-11 methyl ketones, and corresponding secondary alcohols, 2-octanone, 3-octanone, 1-octen-3-ol, 1,5-octadien-3-ol, 1,5-octadien-3-one, and 2-methylisoborneol. Lipoxygenase formation of the eight carbon compounds responsible for the mushroom, plant-like flavors of mold surface-ripened cheeses was enhanced either by the disruption of mold mycelia or the addition of specific ω-3 and ω-6 fatty acid precursors. The occurrence of 8-nonen-2-one in mold-ripened cheeses was associated with the β-oxidative conversion of a specific unsaturated fatty acid resulting from initial lipoxygenase attack on either linoleic or linolenic acids.     

四种食用菊花主要成分分析

采用滴定法、紫外分光光度法、高效液相色谱法对4种食用菊花SYJ1、SYJ2、SYJ3和SYJ4主要化学成分(氨基酸、可溶性糖、可溶性蛋白、总黄酮、抗坏血酸、绿原酸、槲皮素和黄芩苷)进行含量测定。采用水蒸气蒸馏法提取食用菊花中的挥发油,用气相色谱-质谱法对其挥发油化学成分进行鉴定,并用峰面积归一化法测其相对含量。结果表明:食用菊SYJ3中主要化学成分含量较高,其氨基酸、可溶性糖、可溶性蛋白、总黄酮、抗坏血酸、绿原酸、槲皮素和黄芩苷含量分别为15.69、65.03、39.72、156.97、69.95、1.96、3.13和17.62 mg·g-1。4种食用菊花挥发油成分数量分别为37个、33个、25个和38个,最主要成分为α-蒎烯、1,8-桉叶油素、双环(2.2.2)癸烷-2-烯-5-酮、2,6,6-三甲基-双环(3.1.1)-庚-2-烯-4-醇-乙酯、β-榄香烯、(-)-β-石竹烯和α-荜澄茄烯。不同品种食用菊花主要化学成分含量及挥发油种类和含量差异显著(p<0.05)。     

Changes in lipid profiles and volatile compounds of shrimp (Penaeus vannamei) submitted to different cooking methods

Herein, the effect of three common cooking methods (boiling, baking and microwaving) on lipids and volatile compounds in shrimp (Penaeus vannamei) was assessed. The results revealed that contents of phospholipid, triglyceride, cholesterol and free fatty acids in the cooked shrimp significantly declined when compared to the raw shrimp. And these decreases occurred especially in the boiling and microwaving treatment. Among free fatty acids, the contents of palmitic acid (C_16:0), oleic acid (C_18:1n9c) and linoleic acid (C_18:2n6c) also decreased greatly in the boiled and microwaved shrimp, while EPA and DHA enhanced in each cooked group (P < 0.05). Furthermore, microwaved samples exhibited higher levels of oxidation parameters, such as acid value (AV) and thiobarbituric acid-reactive substances (TBARS). For volatile compounds, a total of 31 volatile compounds were detected by GC-IMS, and these contents increased after cooking. Aliphatic volatile compounds, including 1-octen-3-one, pentane-1-ol, 1-propanol, octanal, heptanal, pentanal and hexanal, were main flavour contributors in cooked shrimp, with higher contents observed in microwaved shrimp. In addition, the correlation analysis showed that linoleic acid was a substrate for 15 volatile compounds of cooked shrimp meat. These results indicate that microwave cooking exerts more influences on lipid profiles in shrimp and consequently caused more volatile compounds.     

Characterisation of bound flavour components in kiwifruit

Glycosidically bound volatiles in kiwifruit have been studied. The compounds were isolated from kiwifruit juice by absorption onto a column of Amberlite XAD-2 followed by washing with pentane and elution with methanol. Volatiles were released by enzymic hydrolysis with β-glucosidase. Major components found and identified by GC-MS were E-hex-2-enal and benzaldehyde. Compounds not previously identified in kiwifruit include octan-3-ol, camphor, 4-methylbenzaldehyde, 2-hydroxybenzaldehyde, neral, geranial, methyl 2-hydroxybenzoate, nerol, geraniol and 2-phenylethanol.     

黄牛肝菌中挥发性成分的GC-MS分析

利用顶空GC-MS技术对黄牛肝菌干品和蒸馏萃取得到的黄牛肝菌馏分中的挥发性成分进行了分析。从黄牛肝菌干品中鉴定出59种挥发性成分,占色谱流出峰总面积的相对质量分数为61.42%,主要为杂环类、酸类、酮类和酯类,主要成分有:戊酸、2,6-二甲基吡嗪、1-乙基-2-甲酰基吡咯、苯乙酮、苯甲醛、2,5-二甲基吡嗪、丙位戊内酯、2-乙基-(5或6)-甲基吡嗪和乙醇。从黄牛肝菌馏分中鉴定出46种挥发性成分,占色谱流出峰总面积的相对质量分数为55.25%,主要为酮类、醛类、酯类和醇类,主要成分有:苯乙酸甲酯、苯甲醛、1-辛烯-3-酮、1-辛烯-3-醇、苯乙酮、环辛醇和2-辛烯醛。微量芳香含硫化合物在黄牛肝菌馏分中有检出。样品在两种处理方式下鉴定得到16种相同组分,主要成分相对质量分数有显著差异。研究发现,干品分析得到的挥发性组分种类较馏分组分丰富,但蒸馏萃取对挥发性组分含量有富集作用。     

Baker's yeast-mediated synthesis of endo-2-cineolylol, a starting compound for potential cosmetic odourants

Synopsis
Baker's yeast-mediated reduction of (+)-1,3,3-trimethyl-2-oxabicyclo[2,2,2]octan-6-one yields the corresponding 1,3,3-trimethyl-2-oxabicyclo[2,2,2]octan-6-ol as endo configuration in optically pure form. To study the reaction behaviour we have developed a RP-HPLC method. The synthesis and the olfactive character of some esters obtained from the endo -2-cineolylol are reported. A comparative odour evaluation between these esters and the corresponding compounds synthesized from the endo-exo alcohol mixture was performed.
Résumé
La réduction de (+)-1,3,3-triméthyl-2-oxabicyclo[2,2,2]octan-6-one par la lévure conduit au 1,3,3-triméthyl [2,2,2]octan-6-ol correspondant, de configuration endo avec une forme optique pure. On a développé une méthode RP-HPLC pour enregistrer le comportement de la réaction. La synthèse et le caractère olfactif des esters obtenus de cet alcool sont rapportés.. On a comparé l'évaluation de l'odeur de ces composés avec celle des composés correspondants, dérivés du mélange endo-eso des alcools.     

Sorption of volatile compounds into electron beam irradiated EVA film in the vapour phase

In order to investigate the sorption of volatile compounds by electron beam irradiated ethylene/vinyl acetate copolymer (EVA) films, permeation measurements in the vapour phase were carried out. The diffusion coefficients of octane, ethyl hexanoate, octanal, octan-1-ol and d-limonene increased with an increase in the irradiation dose. The sorption of all volatile compounds in this study was depressed in electron beam irradiated film: the decreases in solubility coefficients for 20 Mrad EVA film were 15% for octane and ethyl hexanoate, 45% for octan-1-ol and octanal, and 50% for d-limonene. The enthalpy change in sorption (ΔH) of ethyl hexanoate was ?13·4 kJ mol^?1 for 50 g kg^?1 EVA film at a dose of 20 Mrad compared with ?27·6 kJ mol^?1 for the unirradiated one. In a homologous series of aliphatic alcohols, sorption was significantly depressed with increasing carbon chain length. Judging from both heat-seal strength and sorption behaviours, the most appropriate irradiation dose for the practical usage of irradiated EVA film was less than 15, 10 and 5 Mrad for 50, 95 and 150 g kg^?1 EVA film, respectively.     

荞麦籽油脂肪酸的气相色谱/质谱法分析

采用石油醚抽提荞麦籽,然后将油样进行皂化、甲酯化,以毛细管色谱-质谱联用法测定荞麦籽油中的组分,从分离出的50个峰中确认了23种组分,所鉴定的组分占总峰面积的96.95%。其中脂肪酸中主要成分含量:C18:2≥32.91%,C18:1≥24.73%,C16:0≥20.04%。奇数碳原子脂肪酸、鲨烯、23s-甲基胆甾醇、5-烯-3β-豆甾醇、5,24-二烯,3-豆甾醇、12-烯-3-醇-齐墩果、12-烯-3-醇-熊果等未见报道。     

14 种侧耳属食用菌干品挥发性香味成分分析

挥发性香味成分是影响食用菌品质的重要指标。为探究不同侧耳属食用菌挥发性香味物质的组成和相对含量,采用顶空固相微萃取结合气相色谱-质谱联用方法对14 种侧耳属食用菌干品中的挥发性香味物质进行分析,并通过相对气味活度值（relative odor activity value,ROAV）和共有成分分析研究不同组分对整体风味的贡献。结果显示：14?种侧耳属食用菌干品中共鉴定出41?种挥发性化合物,主要包括醛类、醇类、酮类、酯类、羧酸类和呋喃类等;其中共有成分8?种,分别为正己醛、2-丁基-2-辛烯醛、1-己醇、1-辛烯-3-醇、正辛醇、2-辛烯-1-醇、3-辛酮和1-辛烯-3-酮;此外,醇类化合物在14?种侧耳属食用菌中相对含量远高于其他类化合物。除佛罗里达侧耳PF6中主体挥发性香气成分为1-辛烯-3-酮、1-辛烯-3-醇和正辛醛外,其他13?种侧耳属食用菌中主体挥发性香气成分均为1-辛烯-3-酮和1-辛烯-3-醇。共有香气物质主成分分析显示前3?个主成分方差累计贡献率达到83.627%,主要代表性成分为1-己醇、正己醛、2-丁基-2-辛烯醛、正辛醇、2-辛烯-1-醇、1-辛烯-3-酮和3-辛酮等,它们是影响食用菌风味的关键性香味成分。     

莱菔子化学成分的分离与鉴定

目的：研究莱菔子化学成分,探索生品莱菔子的物质基础。方法：采用大孔吸附树脂HP-20、聚苯乙烯型大孔吸附树脂（MCI gel）、ODS、硅胶及LiChroprep RP-18等色谱技术进行分离纯化,运用光谱学方法对得到的化合物进行结构鉴定。结果：从莱菔子甲醇提取物中分离鉴定了16?个化合物：顺-13-二十二碳烯酸（1）、豆甾-4-烯-3-酮（2）、（22E,24R）-麦角甾-5,22-二烯-3β-醇（3）、豆甾-5-烯-3β-醇（4）、反-阿魏酸甲酯（5）、反-芥子酸甲酯（6）、β-豆甾醇-3-O-β-D-葡萄糖苷（7）、α-D-吡喃半乳糖基-（1-6）-α-D-吡喃葡萄糖基-（1-2）-β-D-呋喃果糖苷（8）、β-D-呋喃果糖基-α-D-（6-芥子酰基）葡萄糖苷（9）、β-D-（3-芥子酰基）呋喃果糖基-α-D-葡萄糖苷（10）、β-D-（3-芥子酰基）呋喃果糖基-α-D-（6-芥子酰基）葡萄糖苷（11）、β-D-（3,4-二芥子酰基）呋喃果糖基-α-D-（6-芥子酰基）葡萄糖苷（12）、异鼠李素-3-O-β-D-葡萄糖苷（13）、异鼠李素-3,4’-O-β-D-二葡萄糖苷（14）、异鼠李素-3-O-β-D-葡萄糖-7-O-α-L-鼠李糖苷（15）、3’-O-甲基-（－）-表儿茶素-7-O-β-D-葡萄糖苷（16）。结论：化合物2、3、7～10、13～16为首次在该植物中得到。     

The enzymic oxidative breakdown of linoleic acid in mushrooms (Psalliota bispora)

Summary A homogenate of the mushroomPsalliota bispora was incubated with (U-¹⁴C)linoleic acid. After extraction with ethyl ether and separation by thin-layer chromatography, two labelled products were detected. These were identified as 1-octen-3-ol and 10-oxo-trans-8-decenoic acid by GC, MS, IR and, additionally by derivatisation. During incubation both compounds were formed in a molar ratio of about 1:1.13-L(S)-hydroperoxy-cis-9,trans-11-octadecadienoic acid which has been suggested in the literature as the precursor of 1-octen-3-ol was reduced by the mushroom homogenate only to the corresponding 13-hydroxy fatty acid.

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Enzymatisch-oxidativer Abbau von Linolsäure in Champignons (Psalliota bispora)

Zusammenfassung Ein Homogenat aus Champignons (Psalliota bispora) wurde mit (U-¹⁴C)-Linolsäure inkubiert. Zwei markierte Produkte wurden in einem Ether-Extrakt nach dünnschichtchromatographischer Trennung gefunden. Sie wurden mittels GC-, MS-, IR-Spektroskopie und nach Derivatisierung als 1-Octen-3-ol und 10-Oxo-trans-8-decensäure identifiziert. Beide Verbindungen wurden bei der Inkubation im molaren Verhältnis von annähernd 1:1 gebildet. 13-L(S)-Hydroperoxy-cis-9,trans-11-octadecadiensäure, die in der Literatur als Vorläufer von 1-Octen-3-ol vermutet wird, wurde vom Pilz-Homogenat nur zur entsprechenden 13-Hydroxyfettsäure reduziert.

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Synonym withAgaricus bisporus     

Determination of volatile compounds in New Zealand Greenshell™ mussels (Perna canaliculus) during chilled storage using solid phase microextraction gas chromatography–mass spectrometry

Greenshell™ mussels (Perna canaliculus) were dry-stored at 6.44 ± 0.54 °C for 8 days during which time volatile organic compounds (VOCs) were monitored using SPME GC–MS. Thirty-four VOCs were identified in homogenised mussel meat and 29 in the mussel liquor (i.e. the seawater enclosed in the mantle cavity). Of the 34 VOCs identified 20 were reliably identified throughout the storage treatment and 9 were found to change in relative concentration in homogenised mussel meat. Dimethyl sulphide, 1-penten-3-ol, 1-hexen-3-ol and 1-octen-3-ol increased during storage, whereas pentanal, hexanal, heptanal, octanal and 3-undecen-2-one decreased. In the mussel liquor, dimethyl sulphide was undetectable pre-storage, becoming detectable after 2 days, and a large increase was noted after 6 days. SPME GC–MS was a useful tool for monitoring VOC profiles of Greenshell™ mussels and could aid in the development of technologies that monitor and improve product quality and consistency.     

Volatile off-flavour compounds in desiccated coconut

Aliphatic methyl ketones and secondary alcohols have been isolated from desiccated coconut and shown to be responsible for the rancid off-flavour. Two series of compounds have been isolated. The series with an odd number of carbon atoms (C_5,7,9,11) comprising pentan-2-one, pentan-2-ol, heptan-2-one, heptan-2-ol, nonan-2-one, nonan-2-ol and undecan-2-one is derived from even chain fatty acids one carbon atom longer, present in the coconut oil by a modified β-oxidation due to growth of moulds. Heptan-2-one and nonan-2-one were present in the greatest concentration in the rancid coconut. These compounds gave an odour reminiscent of rancid almonds and turpentine respectively while heptan-2-ol and nonan-2-ol gave an odour similar to rancid coconut as well as a musty, stale odour. This type of off-flavour has been called ketonic rancidity and is an oxidative variation of the hydrolytic type of rancidity. The presence and origin of the even numbered series (C_6,8), hexan-2-one, hexan-2-ol and octan-2-one is discussed. The increase in C_5,6,7,8,9,11 oxidation products in the rancid samples occurred at the expense of C_8,10,12 short chain fatty acids.     

Aroma components of American country ham

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 Furaneol™. 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 γ-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.