大葱挥发油含量与化学成分的分析

采用水蒸气蒸馏法提取莱芜鸡腿葱中的挥发油 ,测知其含量为 0 0 1 % ;并用毛细管气相色谱 /质谱法定性鉴别了挥发油中的 2 5种化学成分。其中含硫有机硫化合物为 2 0种 ;主要成分有 :丙基甲基硫代硫磺酸酯 ,甲基烯丙基硫代硫磺酸酯 ,甲基丙烯基三硫醚 ,烯丙基硫醇 ,甲丙基二硫醚 ,反式甲基烯丙基二硫醚 ,二甲基三硫醚 ,二丙基二硫醚 ,反式烯丙基丙基二硫醚 ,二甲基四硫醚 ,二丙基三硫醚 ,反式烯丙基丙基三硫醚 ,顺式烯丙基丙基三硫醚 ,甲硫醇 ,丙硫醇 ,二巯基甲烷 ,2 ,5 二甲基噻吩等含硫化合物 ,还鉴定出不饱和脂肪醛 1种 (3 ,7 二甲基 2 ,6 二辛烯醛 ) ,脂肪酮 1种 (十一酮 2 ) ,萜烯类化合物 2种 (2 甲基 庚稀 2和顺式 2 ,6 二甲基 2 ,6 辛二烯 ) ,挥发性无机化合物 1种 (SO2 )。     

顶空固相微萃取气质联用分析大蒜挥发性风味成分

采用顶空固相微萃取——气相色谱-质谱联用法分别测定生、熟大蒜的挥发性风味物质,检出生大蒜挥发性风味物质共17个化合物,主要成分有二烯丙基二硫醚(61.68%)、二-2-丙烯基四硫醚(13.61%)、甲基2-丙烯基二硫醚(12.46%)、二-2-丙烯基三硫醚(3.20%)、烯丙硫醇(2.10%)、二乙基-1,3-二噻烷(1.74%)、二烯丙基硫醚(1.30%)、甲基1-丙烯基二硫醚(1.10%)共8种物质,占总含量的97.19%。检出熟大蒜挥发性风味物质共30个化合物,主要成分有二烯丙基二硫醚(32.87%)、甲基2-丙烯基二硫醚(16.47%)、二烯丙基硫醚(10.88%)、二-2-丙烯基四硫醚(5.60%)、甲基烯丙基硫醚(4.19%)、甲基2-丙烯基三硫醚(3.45%)、二-2-丙烯基三硫醚(3.06%)、二甲硫醚(3.05%)、甲基环硫乙烷(2.22%)、二乙基-1,3-二噻烷(2.18%)、甲基1-丙烯基二硫醚(1.85%)、1,3,5-三噻烷(1.83%)、苯甲醛(1.35%)、二甲基二硫醚(1.31%)、二甲基三硫醚(1.17%)共15种物质,占总含量的91.79%。     

同时蒸馏萃取- 气质联机分析腌渍野韭菜花香成分

以乙醚为溶剂,采用同时蒸馏萃取法提取腌渍野韭菜花精油,提取率0.29%。用气相色谱- 质谱法结合气相色谱保留指数定性方法,从腌渍野韭菜花精油中鉴定出37 种挥发性成分,占精油总成分的95.75%。主要成分为二甲基三硫醚(28.18%)、二甲基二硫醚(18.13%)、甲基丙烯基二硫醚(14.24%)、甲基烯丙基三硫醚(4.89%)、甲基烯丙基二硫醚(3.19%)、甲基甲硫基甲基二硫醚(3.10%)、4- 乙烯基愈创木酚(2.93%)、二烯丙基二硫醚(2.71%)、二甲基四硫醚(2.67%)、3- 羟基-2- 丁酮(2.42%)、2- 乙烯基-2- 丁烯醛(1.54%)、2,5- 二甲基-1,3,4- 五硫三环(1.45%)、苯甲醇(1.31%)和甲硫基甲磺酰基甲烷(1.28%)等。其中硫醚和多硫醚类成分11 种,相对含量79.99%,是腌渍野韭菜花的特征香气成分。     

三种水果韭花酱香气成分分析

采用顶空固相微萃取(HS-SPME)与气相色谱-质谱联用(GC-MS)法分析对照韭花酱及加入3种不同水果(苹果、梨、菠萝)韭花酱的香气成分。在温度20℃、萃取时间30min 的条件下,对3 种水果韭花酱香气成分测定。结果：从苹果韭花酱、梨韭花酱、菠萝韭花酱中分别鉴定出7、7、11 种香气成分;4 种韭花酱的共有成分为甲硫醇、二甲基二硫醚、一硫二丙烯、二甲基三硫醚,其中苹果韭花酱中特有成分为1- 甲硫基-1- 丙烯-(E),菠萝韭花酱中特有成分为丁酸甲基酯、2-甲基-丁酸-甲基酯、甲基酯己酸、甲基丙基二硫醚、二噻烷。     

顶空-固相微萃取-气质联用分析泡蒜中的挥发性成分

采用顶空-固相微萃取对泡蒜中挥发性成分进行了提取,并用气相色谱-质谱联用仪对提取出的挥发性成分进行了定性和定量分析。结果表明:从泡蒜中共鉴定出46个挥发性化合物,其中以含硫化合物为主体,共29种。泡蒜中的主要挥发性化合物有二烯丙基二硫醚(19.16%)、二烯丙基三硫醚(13.60%)、3-乙酰基-2-羟基-6-甲基-吡喃-4-酮(11.45%)、3-乙烯基-3,4-二氢-1,2-二噻烯(8.10%)、二烯丙基硫醚(4.07%)、2,4-二甲基噻唑(4.00%)、二烯丙基四硫醚(3.34%)、3-甲基-5-氨基-1,2,4-噻二唑(3.10%)。     

顶空固相微萃取与气质联用法分析大葱的挥发性风味成分

本文以经过切碎和打浆两种方法处理后的新鲜大葱为研究对象，采用顶空固相微萃取和气质联用的方法测定其挥发性成分，分别分离得到了多种风殊物质。其中，经过两种处理方法后共同检测出的物质为：正丙醛，二硫化碳，二甲基二硫醚，2．甲基1-2．戊醛，甲丙基瑚啾，二-塞烷，二甲基三硫醚，十一烷，二丙基鞠隧，2-十一酮，二丙鲞三硫醚，3，5二乙基-1，2，4-三硫窥杂环戊烷，2-十三酮，N-环己基吡咯烷酮。     

同时蒸馏-萃取法(SDE)提取葱油及工艺优化

以新鲜大葱为研究对象,采用同时蒸馏-萃取法(SDE)提取葱油,利用毛细管气相色谱/质谱法(GC/MS)鉴定出25种化合物,其中含硫化合物13种,主要成分有:烯丙基甲硫醚、甲基甲基硫代亚磺酸酯、丙基甲基硫代硫磺酸酯、反式烯丙基丙基三硫醚等;醛类3种,2-甲基-2-戊烯醛、2-丁炔二乙基乙缩醛、3-丁炔二乙基乙缩醛;酯类6种,主要成分有:2-丁烯酸甲酯、3-戊烯酸,4-甲基-2-丙烯酸酯、2-丁烯酸乙烯酯等;酸2种,乙烯丁酸和2-甲基庚酸;醇类1种,2,4-二甲基-3-戊醇。在单因素实验基础上,选取蒸馏温度、料液比、同时蒸馏-萃取时间以及水浴温度进行正交实验,确定同时蒸馏-萃取法提取葱油最佳工艺参数为:蒸馏温度95℃、料液比1∶2(g∶m L)、同时蒸馏-萃取时间3.5h、水浴温度55℃,此条件下测得含硫化合物含量可达25.15mg/g。     

SPME提取多星韭不同部位挥发油的化学成分研究

用固相微萃取技术分别提取新鲜多星韭的花、茎、叶部位的挥发性成分,同时采用气相色谱-质谱联用技术对不同部位挥发油化学成分进行分离和鉴定,并用峰面积归一化法确定各组分的相对含量。结果表明,分别从多星韭花、茎、叶挥发油分离、鉴定了30、18、19个化合物,花、茎、叶中分别有22、17、16个硫化物,硫化物占花、茎、叶挥发油总离子峰相对含量的76.20%、82.73%、78.15%。多星韭各个部位挥发油含量较高的化合物基本一致,主要是烯丙基丙基二硫醚、二烯丙基二硫醚、二丙基二硫醚、二烯丙基三硫醚、反式丙烯基丙基二硫醚、甲基烯丙基二硫醚等,但是相对百分含量有一定差异。     

金枕榴莲果实挥发性成分的热脱附-气相色谱/质潜分析

为了解榴莲异味的来源及果肉、果皮气味的差异,采用热脱附-气相色谱/质谱(TCT-GC/MS)联用技术,对动态顶空密闭循环吸附捕集的果肉、果皮样品挥发物进行分析检测.结果表明,榴莲挥发性成分中富含酯类化合物,尤其在果皮挥发物中占大多数,丙酸乙酯(47.37%)接近果皮挥发物总含量的半数;果肉挥发物中还有部分烷、烯、醇、醚、酮、酰胺等化合物.果肉挥发物中的含硫化合物,主要为二乙基二硫醚(8.03%)、乙基正丙基二硫醚(0.06%)、二乙基三硫醚(2.24%)和3-乙基2,4-二硫代-5-己酮(1.19%),而在果皮挥发物中则未检出.研究中检测到3-乙基2,4-二硫代-5-己酮,但未检测到3-羟基-2-丁酮以及大量烷烃,显示样品采集技术的不同将导致结论完全各异.     

芝麻香型白酒中含硫风味组分的分析

采用液-液萃取、固相微萃取的前处理方法提取扳倒井芝麻香型白酒中的香味物质成分,结合气相色谱(GC)、气相色谱-嗅闻仪联用(GC-O)及气相色谱-质谱联用(GC-MS)方法分析该香型白酒中含硫特征风味物质,结果表明,除了之前报道的4种含硫化合物外,还检测到二甲基二硫醚、二甲基四硫醚、3-甲硫基丙醛、糠硫醇、二异丙基二硫、二糠基二硫醚和甲基甲烷硫代磺酸酯。其中二甲基四硫醚、糠硫醇、二异丙基二硫、二糠基二硫醚和二甲基硫代亚磺酸酯是首次在芝麻香型白酒中发现。     

固相微萃取与GC-MS法分析发酵型臭豆腐中挥发性成分

采用固相微萃取技术结合气质联用分析了北京产发酵型臭豆腐中挥发性香成分,共鉴定出31种成分,其中酯类9种、含硫类化合物6种、醛酮类5种、醇类4种、酸类2种、含氮化合物1种、酚类1种、其他3种,检测到的含量较高的化合物有二甲基三硫、吲哚、二甲基二硫、苯酚、乙酸丁酯、正丁醇、丁酸乙酯、二甲基四硫、丁酸、正己醛、丁酸丙酯。      

Off-odor Study with γ-Irradiated Orange Juice Using Sensory and Volatile Compound Analyses

ABSTRACT: As irradiation dosage increased from 0 to 0.5, 1.0, 2.0, and 3.0 kGy, total volatile compounds increased by 12%, 15%, 24%, and 54%, respectively. Sensory evaluation showed that irradiated orange juice was significantly different from the nonirradiated control orange juice ( P < 0.05). Dimethyl sulfide, dimethyl disulfide, and 2-butanone were found in irradiated orange juice but not in nonirradiated samples. As irradiation dosage increased, dimethyl sulfide and dimethyl disulfide increased, and off-odor increased. Chemical mechanisms for the formation of dimethyl sulfide and dimethyl disulfide by irradiation are proposed. Dimethyl disulfide, dimethyl sulfide, and possibly other sulfur-containing compounds seem to be partly responsible for the off-odor in irradiated orange juice.     

A New Essential Oil Chemotype of Allium Roseum Analyzed by an Apolar Column

This study deals with the chemical characterization of a medicinal and an aromatic plant of the Tunisian flora: Allium roseum var. odoratissimum, and aimed to identify new bioactive natural compounds in its flower essential oil. These compounds were extracted by hydrodistillation and were analyzed by GC and GC/MS, using an apolar column. The most important compounds characterized were organo-sulphurous (46%), including methyl 2-propenyl trisulfide, di-2-propenyl trisulfide, di-1-propenyl disulfide, di-2-propenyl disulfide, dimethyl trisulfide, methyl 2-propenyl disulfide, and di-1-propenyl trisulfide, found as 10.75, 9.07, 5.81, 4.98, 3.90, 3.30, and 2.53%, respectively. Moreover, heneicosane and pentacosane were identified for the first time at relatively high rates (8.18 and 4.49%, respectively) in the Allium roseum essential oil. This essential oil composition exhibited newly identified sulphurous compounds at relatively high rates (46.53%) when compared with what was found while using polar column.     

CHEMICAL AND SENSORY CHARACTERIZATION OF COMMERCIAL SAUERKRAUT1

Canned sauerkraut from eight U.S. companies was analyzed for salt, titra-table acidity (TA), fermentation substrates and end products, volatile sulfur compounds and sensory characteristics. The TA ranged from 0.9–1.5%, while salt content ranged from 1.4–2.0%, which was lower than in previous surveys. High performance liquid chromatography (HPLC) was used to monitor lactic, acetic, malic, succinic, propionic and butyric acids; mannitol, ethanol, propanol, glycerol, glucose, fructose and sucrose. Low concentrations of propionic acid, propanol and glycerol were found. These three compounds are not characteristic of lactic acid fermentations. No butyric acid was detected. GC analysis revealed seven main sulfur compounds (hydrogen sulfide, methanethiol, dimethyl sulfide, carbon disulfide, dimethyl disulfide, allyl isothiocyanate (AITC) and dimethyl trisulfide) and six other organic compounds (methanol, ethanol, n-propanol, 2propanol, acetaldehyde and ethyl acetate) in the headspace of sauerkraut juice. A profile panel characterized aroma, flavor and after-taste of sauerkraut with ten distinct notes. The sour, sulfur and salt notes had the greatest impact on sauerkraut flavor.     

HS-GC-O-MS分析细叶韭花易挥发性风味成分

采用顶空-气相色谱-质谱联用技术对细叶韭花中易挥发性成分的萃取条件及气相色谱-质谱分离检测条件进行系统研究,并结合嗅闻仪确定挥发性风味成分。在选定HP-5MS色谱柱的分离条件下,最优顶空条件为样品用量1.0 g/20.0 mL顶空瓶,平衡温度100℃,平衡时间40 min。结果表明:经气相色谱-嗅闻-质谱联用分析,共分离得到52种化合物,确定结构46种,占总易挥发性成分的99.15%。其中,含硫类17种、醛类10种、烃类4种、酮类4种、呋喃类3种、醇类4种、酸类2种、芳香族类1种、萜类1种。根据嗅闻结果结合相对气味活度值可得,细叶韭花挥发性风味成分主要是二甲基硫醚、二甲基二硫醚、二甲基三硫醚、3-甲基丁醛、2-甲基丁醛、1,3-二噻烷。     

Dose-dependent changes of chemical attributes in irradiated sausages

To determine the effects of irradiation on the chemical attributes of sausages, TBARS values, volatile compounds, gaseous compounds, and hydrocarbons of vacuum-packaged sausages were analyzed during 60 d of refrigerated storage. A sulfur-containing volatile (dimethyl disulfide), a gas (methane), and radiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane) were mainly detected in irradiated sausages and the concentrations of these compounds were irradiation dose-dependent with R(2) = 0.9585, 0.9431, and 0.9091-0.9977, respectively. Especially methane and a few hydrocarbons were detected only in irradiated sausages and their amounts were dose-dependent. On the other hand, TBARS values, other off-odor volatiles (carbon disulfide, hexanal), and gases (carbon monoxide, carbon dioxide) were found both in irradiated and nonirradiated sausages. Therefore, it is suggested that radiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane), dimethyl disulfide, and methane can be used as markers for irradiated sausages.     

GC-IMS评价双螺杆挤压处理对香菇柄挥发性成分的影响

本文以香菇柄为研究对象,采用气相离子色谱技术分析在不同加水量(20%、50%)条件下经双螺杆挤压膨化处理香菇柄的挥发性成分的变化。结果表明,实验共检测并定性了醇、酯、醛、酮、呋喃类、含硫化合物6大类共35种挥发性物质。香菇柄在120℃加20%水的条件下经双螺杆挤压处理后,主要特征风味成分含硫化合物二甲基二硫醚相对百分含量从2.67%增加至3.62%。增加含水量至50%进行双螺挤压,二甲基二硫醚含量进一步增至6.66%;但对于1-辛烯-3-醇影响不显著。利用ROAV及主成分得分分析确定了1-辛烯-3-醇、芳樟醇、正己酸乙酯、丙酸乙酯、正辛醛、3-甲基丁醛、庚醛-M、异丁醛、丁醛、2-正戊基呋喃、二甲基二硫共11种物质为主要香味贡献成分,且感官评价与主成分得分分析显示在120℃加水20%条件下进行双螺杆挤压得分更高,可以增加挥发性风味成分的释放,改善风味。     

Involvement of Volatile Sulfur Compounds in Ionizing Radiation-induced Off-odor of Fresh Orange Juice

ABSTRACT: The influences of ionizing radiation on volatile sulfur compounds in fresh Valencia orange juice were analyzed using gas chromatography (GC)-pulsed flame photometric detection and sensory evaluation. Methyl sulfide (MS) and methanethiol (MT) were induced most, followed by dimethyl disulfide and dimethyl trisulfide. Carbon disulfide was reduced by irradiation, while hydrogen sulfide was not consistently affected. Sensory evaluation indicated that the odor of irradiated juice differed from the nonirradiated samples at 0.5, 1, 2, or 3 kGy. Addition of the 2 major irradiation-induced sulfur compounds (MS and MT) into fresh juice changed the juice odor, indicating that those 2 compounds were probably involved in the development of irradiation-induced off-odor.