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 )。     

小根蒜挥发性风味成分分析

为了研究小根蒜的特征香气成分,以独头蒜为对比,采用固相微萃取和液液萃取的方法提取小根蒜和独头蒜中的挥发性风味成分,通过连接HP-5柱子的气相色谱-质谱联用仪对其进行分离鉴定。结果显示：采用液液萃取法在小根蒜、独头蒜样品中共鉴定出23 种化合物;采用固相微萃取法在小根蒜、独头蒜样品中共鉴定出28 种化合物;2 种方法均检测到的化合物有9 种。小根蒜与独头蒜中相对质量分数最高的均为醚类化合物和含硫化合物,但二烯丙基硫醚和3-乙烯基-1,2-二硫环己-5-烯在独头蒜中含量较高,而甲基丙烯基二硫醚、二甲基三硫醚、二甲基四硫醚和3,5-二乙基-1,2,4-三硫杂环戊烷等仅在小根蒜中分析鉴定出。因此,这些化合物对小根蒜的特殊香气组成可能具有重要的作用。     

Evaluation of enzyme-assisted extraction on quality of garlic volatile oil

Application of enzymes to garlic prior to steam distillation/hydrodistillation resulted in a two fold increase in the yield of oil. The oil yield in case of cellulase, pectinase, protease and viscozyme pretreatment was in the range of 0.39–0.51%, as against 0.28% in a control sample by steam distillation, and in the range of 0.45–0.57% by hydrodistillation as against 0.31% in a control sample. Profiling of the garlic oil thus obtained was carried out by GC–MS. Di-2-propenyl trisulfide (52%) along with the corresponding di- and tetra-sulphides (11% and 5%) constituted the major portion of the oil. The other major flavour compounds identified were methyl 2-propenyl trisulfide (11.8%), vinyl dithiins (9.9%) and dithianes (4.1%). The studies demonstrate that enzymes facilitate the extraction of garlic oil, resulting in an increase in the yield of oil, with little change either in flavour profile or physicochemical properties of the oil.     

顶空固相微萃取气质联用分析香葱挥发性风味成分

采用顶空固相微萃取气质联用分析检测了香葱的挥发性风味成分,共检测到30种化合物,占总峰面积的98.18%。主要成分是二丙基二硫醚(31.94%)、二丙基三硫醚(16.4%)、1-丙硫醇(11.27%)、二甲基硫醚(10.36%)、甲基-2-丙烯基二硫(6.11%)、1-丙烯-1-甲基硫醇(3.49%),占总成分的79.57%。     

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。     

Effects of pH Adjustment and Subsequent Heat Treatment on the Formation of Volatile Compounds of Garlic

Effects of pH adjustment during the blending of garlic cloves and subsequence heat treatment on the formation of volatile compounds of garlic were studied by means of gas chromatography (GC). The formation of the two isomeric cyclic compounds 3-vinyl-[4H]-l,2-dithiin and 2-vinyl-[4H]-l,3-dithiin, which were artifacts from allicin, was favored around pH 5.5. Formation of diallyl trisulfide, methyl allyl trisulfide, cis-1-propenyl allyl disulfide, isobutyl isothiocyanate, 2,4-dimethylfuran, 1,3-dithiane, aniline, methyl allyl sulfide, dimethyl disulfide and 3-methyl-2-cyclopentene-l-thione were favored in neutral or weak acidic conditions, whereas formation of diallyl disulfide, diallyl sulfide, methyl allyl disulfide, propenylthiol, propyl allyl disulfide and 1,2-epithiopropane were favored around pH 9.0.     

Investigation of the volatile aroma components of garlic leaves essential oil. Possibility of utilization to enrich garlic bulb oil

The volatile aroma components of Egyptian green garlic leaves essential oil was investigated for the first time. After the utilization of garlic bulbs to prepare garlic oil or after drying the bulbs to produce garlic powder, garlic leaves are considered to be waste material, which is disposed of without any benefit. In this investigation, green garlic leaves were distilled and the essential oil was subjected to GC and GC-MS identification. The yield of the oil was 0.06% (based on wet weight of the leaves). The most prominent compounds of the essential oil were diallyl trisulfide (32.32%), followed by diallyl disulfide (31.35%) and methyl allyl trisulfide (11.40%); these compounds are the same as those found in garlic bulb oil. This means that garlic leaf oil is a rich, renewable and priceless source of garlic aroma compounds which could be utilized in fortification and enriching of garlic bulb essential oil to increase its quantity without changing the quality. Utilization of green garlic leaves for production of essential oil will also save, to some extent, the costs of disposing of large amounts of leaves in garlic possessing factories, transforming them into profits.     

Volatile Flavor Components of Nira (Allium tuberosum Rottl.)

The flavor components of Nira (Allium tuberosum Rottl.) have been studied by a combination of gas chromatography and mass-spectrometry. Twenty-nine compounds were identified in the oil obtained from extraction of the steam distillate of Nira. The identified compounds include 7 sulfides, 2 ketones, 18 alcohols and 2 esters. The main volatile components were dimethyl disulfide and dimethyl trisulfide.     

固相微萃取-气相色谱/质谱联用技术分析茉莉精油化学成分

采用固相微萃取、气相色谱 -质谱联用技术分析了茉莉精油的化学成分 ,共分离、鉴定了 4 1种化学物质 ,占其挥发性成分的 99.4 3%。结果表明 ,茉莉精油中的主要成分为 :芳樟醇、苯甲基乙酸酯、N ,N -二丙基苯甲酰氨及α -金合欢烯等。     

韭菜籽挥发油组分的分析鉴定

韭菜籽挥发油中分析鉴定出的27 种成分分别占三种韭菜籽挥发油总量的92.79%、93.00% 和92.01%,其中包括7 种二硫化合物、1 种四硫化合物、3 种醛类化合物、2 种酮类化合物、3 种醇类化合物。己醛(17.74%)、十九烯-2- 酮(10.39%)和2- 戊基呋喃(6.50%)是“791”韭菜籽挥发油的主要成分。韭菜籽挥发油中含有大量的己醛,韭菜籽挥发油中含32.43% 的二硫化合物。     

Investigation on the volatile oil of Makó onions

The authors have developed a method for determining the volatile oil content of onions. Using this method they found in the Hungarian Makó onions 0.019—0.031 % volatile oil, depending on storage. The composition of onion oil was studied by GC; GC-MS and TLC methods. GC-MS revealed 20 volatile sulphur compounds identified as 10 trisulphides, 6 disulphides, 3 tetrasulphides, and 1 thiophene derivative as well as one unsaturated aldehyde. Three of these: ethyl cis-1-propenyl trisulphide, ethyl trans-1-propenyl trisulphide, and butyl methyl trisulphide were described for the first time in onions. Carbonyl compounds were studied in the form of derivatives obtained with 2,4-dinitrophenyl hydrazine. On the basis of Rf-values and by addition, propanal, butanal, pentanal and hexanal were identified in the aldehyde fraction, while in the dicarbonyl fraction — beside an unknown compound — glyoxal and methyl glyoxal were identified. The presence of these two compounds in onion oil has been reported for the first time.     

Effects of Onion (Allium cepa L.) and Garlic (Allium sativum L.) Essential Oils on the Aspergillus versicolor Growth and Sterigmatocystin Production

Abstract: In the present study the effects of individual and combined essential oils (EOs) extracted from onion (Allium
cepa L.) bulb and garlic (Allium sativum L.) clove on the growth of Aspergillus versicolor and sterigmatocystin (STC) production were investigated. The EOs obtained by hydrodistillation were analyzed by GC/MS. Twenty one compounds were identified in onion EO. The major components were: dimethyl‐trisulfide (16.64%), methyl‐propyl‐trisulfide (14.21%), dietil‐1,2,4‐tritiolan (3R,5S‐, 3S,5S‐ and 3R,5R‐ isomers) (13.71%), methyl‐(1‐propenyl)‐disulfide (13.14%), and methyl‐(1‐propenyl)‐trisulfide (13.02%). The major components of garlic EO were diallyl‐trisulfide (33.55%), and diallyl‐disulfide (28.05%). The mycelial growth and the STC production were recorded after 7, 14, and 21 d of the A. versicolor growth in Yeast extract sucrose (YES) broth containing different EOs concentrations. Compared to the garlic EO, the onion EO showed a stronger inhibitory effect on the A. versicolor mycelial growth and STC production. After a 21‐d incubation of fungi 0.05 and 0.11 μg/mL of onion EO and 0.11 μg/mL of garlic EO completely inhibited the A. versicolor mycelial growth and mycotoxins biosynthesis. The combination of EOs of onion (75%) and garlic (25%) had a synergistic effect on growth inhibition of A. versicolor and STC production. Practical Application: A substitution of synthetic preservatives with natural antimicrobial compounds in food safety to control fungal contamination and mycotoxin production.     

Chemical composition,antioxidant and antimicrobial activities of essential oil obtained from Ferula assa-foetida oleo-gum-resin: Effect of collection time

The properties of essential oils obtained from Ferula assa-foetida oleo-gum-resins (OGRs) collectioned in three collections times in 15 June (OGR1), 30 June (OGR2) and 15 July (OGR3) 2011 was investigated. Essential oil from OGR1 was constituted high levels of (E)-1-propenyl sec-butyl disulfide (23.9%) and 10-epi-γ-eudesmol (15.1%). Essential oil from OGR2 was constituted high levels of (Z)-1-propenyl sec-butyl disulfide (27.7%) and (E)-1-propenyl sec-butyl disulfide (20.3%). Essential oil from OGR3 was constituted high levels of β-pinene (47.1%) and α-pinene (21.3%). Inhibitory concentration (IC50) for radical scavenging were 0.012–0.035, 0.025–0.047 and 0.035–0.066 mg/ml of essential oil obtained from OGR1, OGR2 and OGR3, respectively. Minimal inhibitory concentration (MIC) for Gram-positive and Gram-negative bacteria and fungi grpwth were 0.028–0.111, 0.027–0.107 and 0.018–0.058 mg/ml of essential oil obtained from OGR1, OGR2 and OGR3, respectively. Essential oils obtained from different OGRs have different composition and biological activity thus have different applications in food and health industry.     

Volatile Flavor Components of Chive (Allium schoenoprasum L.)

Using well-established techniques, a sample was obtained of the steam volatile oil of chive (Allium schoenoprasum L.). A total of 30 components were identified and the neutral oil contained mainly sulfur compounds (16.8%). The most important constituents are dipropyl disulfide, methyl pentyl disulfide, pentyl hydrodisulfide and (cis and trans) 3,5-diethyl-1,2,4-trithiolane. Methyl pentyl disulfide and pentyl hydrodisulfide have not been described previously.     

Volatile constituents from Romanesco cauliflower

The volatile and semi-volatile constituents of Brassica oleracea L. var. Botrytis L., Romanesco group, Navona variety, were extracted by steam distillation from leaves and inflorescence, using a Likens–Nickerson-type apparatus. The extracts from fresh, ripening and frozen vegetables were investigated by gas chromatography and mass spectrometry. From the fresh leaves extract, a total of 61 compounds were identified, representing 96.8% of the oil. The major constituent was found to be hex-3(Z)-enol (61.1%). From fresh disrupted inflorescence tissues of Romanesco, 35 compounds were detected, representing 97.7% of the extract. Dimethyl disulfide, dimethyl trisulfide and hex-3(Z)-enol were identified as major constituents of the hydrodistillation products, representing, respectively, 30.2, 24.2 and 21.7% of the volatiles. From ripening and frozen inflorescence tissues, dimethyl disulfide and trisulfide were again detected as predominant components. In the latter, hex-3(Z)-enol had almost disappeared (0.8%) whereas dimethyl trisulfide represented 49.7% of the oil. This is the first report concerning the steam distillation compounds present in the leaves and inflorescence tissues of this species.     

热反应对鸡肉味香味料挥发性成分影响初探

用同时蒸馏提取技术对由半胱氨酸、硫胺素、味精、葡萄糖、I +C、甘氨酸、丙氨酸组成的经热反应产生的鸡肉味香味料的挥发性成分进行了分离和浓缩 ,所得到的浓缩物用GC MS技术定量分析 ,共鉴定出 40余种化合物 ,并计算出它们的含量。其中 ,重要的肉味化合物如 2 甲基 3 呋喃硫醇、二 (2 甲基 3 呋喃基 )二硫、(2 甲基 3 呋喃基 ) (2 甲基 4,5 二氢 3 呋喃基 )二硫、二 (2 甲基 4,5 二氢 3 呋喃基 )二硫、呋喃、噻吩等被鉴定出来 ,并对其感觉特性及形成途径进行了简略说明     

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。     

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。     

发酵对小根蒜挥发性物质、有机硫化合物及其抗氧化活性的影响

为了研究新鲜小根蒜经发酵后,其挥发性物质变化情况及有机硫化物抗氧化活性变化。采用GC-MS方法检测了新鲜小根蒜及其发酵产品中的挥发性物质,并对比了分离纯化后的主要挥发性物质—有机硫化物组分抗氧化活性。结果显示,共检测到了39种挥发性物质,主要由醛、醇、酯、酸及有机硫化物组成,其中新鲜小根蒜含有27种,发酵小根蒜中仅含有23种。小根蒜发酵后挥发性物质消失了16种,主要有1,3-二噻烷、丙醛、丙烯基甲基硫醚、戊醛、己醛、二甲基四硫醚、甲基丙烯基二硫醚等;新增12种,主要有乙酸、2-丁醇、1,2-丙二醛等;10种挥发性物质减少,主要有甲醇、二甲基三硫醚、二甲基二硫醚等硫醚类物质。将新鲜小根蒜及其发酵产品中的有机硫化物进行分离纯化并对纯化后的各组分进行了DPPH自由基清除能力、Fe2+螯合能力、·OH清除能力、总还原能力4个方面的抗氧化活性研究,发现新鲜小根蒜分离纯化液的第2个组分,其·OH清除能力及总还原能力较强。而发酵小根蒜分离纯化液的第1个组分,其DPPH自由基清除能力和总还原能力较强。     

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.