Volatile organic compounds in the aril juices and seeds from selected five pomegranate (Punica granatum L.) cultivars

A study was conducted to investigate the distribution of volatile organic compounds in the juice and seed of the most popular five pomegranate cultivars (“Ek?i,” “Devedi?i,” “Hicaz,” “Kat?rba??,” and “Keben”) in Turkey. The volatile organic compounds were analyzed using solid phase micro-extraction and gas chromatography–mass spectrometry. A total of 60 volatile organic compounds, belonging to six chemical groups including aldehydes, alcohols, esters, terpenes, ketones, acids, and phenol were identified. There were 11 volatile organic compounds (1-hexanol, [Z]-3-hexen-1-ol, 1-octanol, α-terpineol, β-myrcene, limonene, [E]-α-bergamotene, β-caryophyllene, hexanal, [E]-2-hexenal, and guaiacol) common to all five pomegranate juices and seeds. Hexalin, phenylacetaldehyde, 3-methyl butanal, and methyl-(1-methylethenyl) benzene were found in seeds only. According to discriminant analysis based on Eigenvalues, volatile organic compounds recovered in the juices could be used to discriminate and classify the pomegranate cultivars. “Devedi?i” and “Hicaz” were the most promising cultivars with respect to the largest volatile organic compounds, high total soluble solid and deep red color.     

Characterization of aroma-impact compounds in dry jujubes (Ziziphus jujube Mill.) by aroma extract dilution analysis (AEDA) and gas chromatography-mass spectrometer (GC-MS)

Aroma-impact compounds of dry jujubes obtained from Z. jujuba Mill. cv. “tangzao” (Y1), Z. jujuba Mill. cv. “muzao” (Y2), Z. jujuba Mill. cv. “lizao” (Y3), and Z. jujuba Mill. cv. “qingrunhongzao” (Y4) were analyzed by gas chromatography-olfactometry (GC-O). The result revealed 35, 29, 34, and 33 aroma-impact volatiles in the Y1, Y2, Y3, and Y4 samples, respectively. The compounds bearing the highest FD factor in each sample were (E)-2-hexenal, (E)-2-heptenal (FD = 256) for Y1, 2,3-butanedione, (E)-2-hexenal, 2,5-dimethylpyrazine, (E)-2-heptenal and β-damascenone (FD = 64) for Y2, 2,3-butanedione and β-damascenone (FD = 256) for Y3, and 2,5-dimethylpyrazine (FD = 256) for Y4.     

Biotransformation of Linalool by Botrytis cinerea

Biotransformation of linalool was studied using grape must and three strains of Botrytis cinerea (5901/2; 5909/1; 5899/4). Capillary gas chromatography and combined capillary gas chromatography-mass spectrometry revealed predominant conversion (>90%) of linalool to (E)-2,6-dimethyl-2,7-octadiene-1,6-diol. in minor concentrations (<10%), the corresponding (Z)-isomer, 2-vinyl-2-methyl-tetrahydro- furan-5-one, the four (E)-and (Z)-linalool oxides in their furanoid and pyranoid forms, the (E)- and (Z)-acetates of pyranoid linalool oxides as well as 3,9-epoxy-p-menth- 1 -ene identified.     

基于OAV和GC-O-MS法鉴定香椿中的关键香气成分

采用固相微萃取（Solid-Phase Microextraction,SPME）与溶剂辅助风味蒸发（Solvent-Assisted Flavor Evaporative,SAFE）法结合香气活性值（Odor Activity Value,OAV）和气相色谱-嗅闻-质谱联用技术（Gas Chromatography-Olfactory-Mass Spectrometry,GC-O-MS）分析鉴定新鲜香椿中关键香气成分。结果显示,采用两种萃取方法共鉴定出90种挥发性化合物,主要包括含硫类12种,醛类11种,萜烯类34种,酮类2种,醇类4种,酯类4种,酚类1种,酸类1种,烷烃类15种,环烷烃类4种,其他类2种。经OAV值计算,共确定出(E,E)/(E,Z)/(Z,Z)-二丙烯基二硫醚、反-2-巯基-3,4-二甲基-2,3-二氢噻吩、2-甲基环硫乙烷、己醛、3-甲基-正丁醛、反-2-己烯醛、反-2-辛烯醛等9种香气成分;经GC-O-MS分析,共鉴定出(E,E)/(E,Z)/(Z,Z)-二丙烯基二硫醚、2-甲基环硫乙烷、反-2-巯基-3,4-二甲基-2,3-二氢噻吩、己醛、反-2-己烯醛等7种香气活性物质。综合OAV和GC-O-MS分析,最终确认(E,E)/(E,Z)/(Z,Z)-二丙烯基二硫醚、反-2-巯基-3,4-二甲基-2,3-二氢噻吩、2-甲基环硫乙烷、己醛、反-2-己烯醛为新鲜香椿的关键香气成分。     

基于AEDA和OAV值确定西瓜汁香气活性化合物的比较

本研究采用溶剂辅助风味蒸发提取西瓜汁的香气成分,利用气相色谱-质谱联用结合嗅闻仪定性定量分析其香气活性化合物,共鉴定出49种化合物,主要是小分子的酮、醛、硫醚等物质,酯类物质中只检测到一种物质,即乙酸乙酯,且浓度较低。本研究首次检测到醚类物质。OAV计算和AEDA两种方法共同鉴定出11中物质,顺,顺-3,6-壬二烯醛、顺-3-壬烯-1-醇、反,顺-3,6-壬烯-1-醇、反-2-壬烯醛、壬醛、1-壬醇、2-戊基呋喃、己醛、辛醛、顺-6-壬烯醛、反-2-辛烯醛。其中有五种香气活性物质,即顺,顺-3,6-壬二烯醛、顺-3-壬烯-1-醇、顺-6-壬烯醛、顺-2-壬烯醛、反,顺-3,6-壬烯-1-醇都能被实验员嗅闻到,且具有较高的OAV值。这表明,AEDA和OAV计算在西瓜汁香气活性化合物分析上具有一定的相似性。     

基于顶空固相微萃取/气质联用的红茶特征香型呈香活性成分研究

香气是茶叶（Camellia sinensis（L.）O.Kuntze）感官品质的一项关键因子,本研究拟对红茶\     

静态顶空与固相微萃取法分析婴幼儿辅食营养包中哈喇味的主要成分

为研究婴幼儿辅食营养包中哈喇味的主要成分,采用静态顶空与顶空固相微萃取技术提取婴幼儿辅食营养包中的气味成分,通过气相色谱-质谱联用技术进行定性分析,对两种方法所得的气味成分进行比较分析。结果表明:加速氧化实验后,样品中醛类含量变化最明显,两种检测方法中严重组和中度组挥发性成分都以醛类化合物为主。推测己醛、2-戊基呋喃、（E,E）-2,4-壬二烯醛、（Z）-14-甲基-8-十六碳烯-1-缩醛可能是婴幼儿辅食营养包中产生哈喇味的主要因素,而哈喇味可能是由其中几种物质相互作用而产生的。      

Characterization of aroma-active volatiles in three Chinese bayberry (Myrica rubra) cultivars using GC–MS–olfactometry and an electronic nose combined with principal component analysis

Chinese bayberry (Myrica rubra Sieb. et Zucc.) is one of the most popular and valuable fruits in China because of its unique and exquisite flavor. In this study, headspace solid-phase micro-extraction (HS-SPME) coupled with gas chromatography–mass spectrometry and olfactometry (GC–MS–O) analyses were used to characterize the aroma-active profiles of the fruits from three different bayberry cultivars. The aim was to differentiate the bayberry cultivars by their aroma. Fifty-five volatile components, composed of aldehydes (10), alcohols (9), esters (8), terpenes (17), and others (11), were identified by optimized HS-SPME/GC–MS. Meanwhile, 36 aroma-active compounds were detected by olfactometry using detection frequency analysis (DFA). Hexanal (grass-like), (E)-2-hexenal (green), nonanal (fruit, flower), 1-hexanol (flower), and isocaryophillene (wood) were identified in all three cultivars. Further principal component analysis (PCA) of the active aromas revealed their contributions to the odor differences among the bayberry cultivar groups. The BQ bayberry was characterized by having a stronger “herb” odor, which is mainly caused by benzoic acid and methyl ester. DK bayberry had a stronger “grass” odor, which is mainly caused by 2,6-dimethyl-2,4,6-octatriene, while FHZ bayberry had a stronger “pine” odor, which is caused mainly by α-pinene. The GC–MS–O and electronic nose techniques, when combined with PCA, could be used to successfully distinguish between different bayberry cultivars.     

Stereo-isomeric flavour compounds

2-Alkyl-substituted 4-methyl(4,5-dimethyl)-1,3-dioxolanes are synthesized by the cyclization of propan-1,2-diol and butan-2,3-diol with “Strecker aldehydes” as the carbonyl compounds. The stereo-isomeric 1,3-dioxolanes are separated by micro-preparative multidimensional gas chromatography and their structures assigned using¹H-NMR spectroscopy (300 MHz). These references with definite stereochemistry are required for reliable interpretation of their chromatographic behaviour with Ni(II)-bis-[3-heptafluorobutanoyl-(1R,2S)-pinanoate] and Ni(II)-bis-[heptafluorobutanoyl]-(1R)-camphorate] respectively, as the chiral stationary phases.     

Volatile acids in tropical fruits: cherimoya (Annona cherimolia, Mill.), guava (psidium guajava, L.), mango (Mangifera indica, L., var. Alphonso), papaya (Carica papaya, L.)

The volatile acids extracted by pentane/dichloromethane (2 + 1) from tropical fruit pulps were identified and determined by capillary gas chromatography (HRGC) and combined capillary gas chromatography-mass spectrometry using EI- and CI mode (HRGC-EI/CIMS). In cherimoya (A. cherimolia, Mill.) fruit pulp 47 acids were characterized; major compounds were hexanoic (3 mg/kg) and octanoic (1 mg/kg) acid. Fifty one acids were identified in guava (P. guajava, L.), 54 in mango (M, indica, L., var. Alphonso) and 56 in papaya (C. papaya, L.). (E)-cinnamoic acid (0.4 mg/kg) and (Z)-3-hexenoic acid (0.2 mg/kg) were determined as major constituents in guava; in mango 5-hydroxy-(Z)-7-decenoic acid (2 mg/kg) and 3-hydroxyoctanoic acid (1.1 mg/kg) and in papaya pulp butanoic acid (1.2 mg/kg) were established as major constituents.     

Reduction of cinnamaldehyde and unsaturated acids byBotrytis cinerea

Summary The bio-transformation of cinnamaldehyde (1), (E)-3-hexenoic acid (5) and (E)-3-octenoic acid (10) was studied with four strains ofBotrytis cinerea in two different media. In all cases, predominant microbial reduction of (1), (5) and (10) was observed leading to (E)-cinnamic alcohol (2) and dihydrocinnamic alcohol (4) as well as (E)-3-hexen-l-ol (6) and (E)-3-octen-l-ol (11) respectively. Moreover, minor amounts of the by-products (Z)-cinnamic alcohol (3), (E)-2-(7), (Z)-3- (8) and (Z)-2-hexen-l-ol (9) as well as (E)-2-(12) and (Z)-3-octen-l-ol (13) and 1-octen-3-ol (14) were found. The bio-conversion products were identified by capillary gas chromatography (HRGC) and coupled capillary gas chromatography-mass spectrometry (HRGC-MS) after extraction and sample preparation.

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Reduktion von Zimtaldehyd und ungesättigten Säuren durchBotrytis cinerea

Zusammenfassung Die Biotransformation von Zimtaldehyd (1), (E)-3-hexensäure (5) und (E)-3-octensäure (10) ist mit vierBotrytis cinerea-Stämmen in zwei unterschiedlichen Nährmedien untersucht worden. In allen Fällen wurden mit (E)-Zimtalkohol (2) und Dihydrozimtalkohol (4) sowie (E)-3-Hexen-1-ol (6) und (E)-3-Octen-1-ol (11) als jeweiligen Hauptkomponenten mikrobielle Reduktionsprodukte von (1), (5) und (10) nachgewiesen. Als Nebenprodukte sind (Z)-Zimtalkohol (3), (E)-2-(7), (Z)-3-(8) und (Z)-2-Hexen-1-ol (9) sowie (E)-2-(12) und (Z)-3-Octen-1-ol(13) und 1-Octen-3-ol (14) in geringeren Anteilen gefunden worden. Die Identifizierung der Metabolite erfolgte capillargaschromatographisch (HRGC) und mittels Capillargaschromatographie-Massenspektrometrie (HRGC-MS) nach extraktiver Probenaufarbeitung.

     

虎纹蛙肌肉挥发性成分和脂肪酸分析

对虎纹蛙肌肉中的挥发性成分和脂肪酸分别进行测定。采用顶空固相微萃取-气相色谱-质谱联用技术(HS-SPME-GC-MS)分析虎纹蛙肌肉中的挥发性成分。结果共鉴定出36种成分,其中醛类化合物有15种,且含量最高,占挥发性成分总量的68.76%;己醛、(Z)-4-庚烯醛、(E,Z)-2,4-癸二烯醛、(E,E)-2,4-癸二烯醛、1-辛烯-3-醇和2,3-戊二酮等可能对虎纹蛙肉的整体风味贡献较大;虎纹蛙肌肉脂肪酸主要由不饱和脂肪酸(UFA)组成,占脂肪酸总量的72.89%;在日常饮食中,虎纹蛙肉为n-3多不饱和脂肪酸(n-3 PUFA)较为丰富的食物资源;亚麻酸(C18:3 n-3,ALA)、二十碳五烯酸(C20:5 n-3,EPA)和二十二碳六烯酸(C22:6 n-3,DHA)为主要的n-3 PUFA。UFA为虎纹蛙肉的重要风味前体物质。     

丁香提取物的成分分析及对肉品中常见腐败菌和致病菌的抑菌效果

对丁香乙醇提取物的化学成分及其抗菌活性进行了研究。用气相色谱—质谱联用技术对其丁香乙醇提取物组分进行分离和鉴定,运用气相色谱面积归一化法确定各组分的相对含量,并利用正构烷烃系列物质对各组分进行定性确定。从丁香醇提取物中鉴定出29种化学成分,其主要组分有丁香酚（30.7%）、石竹烯（30.6%）、（Z,Z）-9,12-十八碳二烯酸甲酯（5.05%）、α-石竹烯（4.62%）。研究了丁香乙醇提取物对一些肉品中常见致病菌和腐败菌的抑菌效果,其提取物对肉中常见的腐败菌和致病菌包括大肠杆菌（ATCC25922）、荧光假单胞菌（AS1.1802）、单增李斯特菌（NICPBP54002）、清酒乳杆菌（AS1.80）均有显著的抑制和灭活作用,其中对单增李斯特菌的抑制效果最好,最小抑菌浓度（MIC）为0.63mg/mL,对另外三种菌的最小抑菌浓度均为1.25mg/mL。      

小网箱养殖大黄鱼挥发性风味物质检测与分析

应用气相色谱-质谱联用仪(GC-MS)固相微萃取(SPME)法对小网箱养殖大黄鱼的挥发性成分进行检测与分析,结合感觉阈值,利用相对气味活度值确定鱼类的主体风味成分,并分析主要挥发性风味组分的气味特征及其生成途径。结果表明,小网箱养殖大黄鱼的主要风味成分由壬醛、辛醛、三甲胺、(E)-2-辛烯醛、己醛、戊酸乙酯、庚醛、(Z)-4-庚烯醛、(E,E)-2,4-庚二烯醛、1-辛烯-3-醇、(E)-2-己烯醛、癸醛、戊醛、(Z)-3-己烯-1-醇、2-戊基呋喃等15种化合物构成。     

Characterization of the key odor-active compounds in steamed meat of Coilia ectenes from Yangtze River by GC–MS–O

In this study, the key odor-active compounds in the steamed meat of Coilia ectenes from Yangtze River were isolated by headspace monolithic material sorptive extraction and analyzed by gas chromatography–mass spectrometry–olfactometry (GC–MS–O). A total of 49 volatile compounds were identified and quantified in the extract. The results of gas chromatography–olfactometry analysis combined with odor activity value showed that trimethylamine (fishy, ammonia-like), 3-methylbutanal (dark chocolate), decanal (green, oily), hexanal (green), (Z)-4-heptenal (fishy, boiled potato) and benzaldehyde (bitter almond) were the key odor-active compounds contributing primarily to the overall aroma of steamed Coilia ectenes meat. Among them, trimethylamine and (Z)-4-heptenal were the most potent odor-active compounds on the basis of their detection frequency at high odor intensities.     

萎凋时间对“英红九号”白茶香气的影响

采用顶空固相微萃取和气相色谱-质谱联用法,分析不同萎凋时间"英红九号"白茶香气化合物的组成及含量。结果表明,"英红九号"白茶的香气总量随萎凋时间的延长呈现先增后降趋势,萎凋24 h含量最高,达到858.40 ng/g。白茶香气主要由醇类、酯类、醛类、酮类和烃类组成,其中醇类化合物所占比例最大。不同萎凋时间白茶的香气化合物组成比较相似。顺-3-己烯-1-醇、芳樟醇、乙酸-顺-3-己烯酯、丁酸-顺-3-己烯酯、水杨酸甲酯、己酸-顺-3-己烯酯、己醛、苯甲醛、反,反-2,4-庚二烯醛、壬醛、反,反-3,5-辛二烯-2-酮、3,5-辛二烯-2-酮、β-紫罗兰酮、β-香叶烯、柠檬烯、反-β-罗勒烯和β-罗勒烯,这17种香气化合物在多数样品中含量较高,其含量总和占各样品香气总量的67.3%~76.0%,对香气总量变化影响较大;其中芳樟醇、水杨酸甲酯等多数化合物含量随着萎凋进行先增后降;而苯甲醛和β-香叶烯含量在30 h的萎凋过程中总体持续上升。     

Gas Chromatographic Determination of Hydrolyzed Sugars in Commercial Gums

A modified GC method was utilized for the detection and quantitative determination of sugars derived from commercial gum, Agar, Carageenan, Xanthan, Gum Ghatti, Gum Arabic, Emulgum, Gum Tragacanth, and Gum Karaya. The polysaccharides were cleaved by acid hydrolysis, derivatized with “STOX” hydroxylamine to form oxime with “TMSI” or “HMDS+TFAA” for silylation. The separation and quantitation was performed by gas chromatography, using phenyl-BD-glucopyranoside as the internal standard for quantitative analysis. Sugar molar ratios (percent) for all commercial gums tested were similar to literature values.