分子蒸馏和同时蒸馏萃取法分析树苔浸膏的化学成分

采用分子蒸馏法和同时蒸馏萃取法与气相色谱-质谱仪联用对树苔浸膏的化学成分进行分析。结果表明:采用同时蒸馏萃取法共鉴定出85种化学成分,分子蒸馏法鉴定出61种成分,两种不同前处理方式所得萜类物质差异较大,同时蒸馏萃取法所得萜类成分种类多于分子蒸馏法,但两种不同方式提取的主要成分相同,均鉴定出苔黑酚单甲醚、分歧扁枝衣素单甲醚、扁枝衣酸乙酯、柔扁枝衣酸甲酯、β-苔黑酚羧酸甲酯、赤星衣酸乙酯、苔黑酚羧酸乙酯、柔扁枝衣酸乙酯、棕榈酸乙酯、油酸乙酯、亚麻酸乙酯和亚油酸乙酯等成分,而且所占比例较大(相对含量76%以上),为构成树苔浸膏典型苔清香的关键成分,同时,这些成分在分子蒸馏的重组分中得到较好的富集。     

酒花浸膏关键性香气成分分析

采用固相微萃取(solid-phase microextraction,SPME)与溶剂辅助蒸发萃取(solvent-assisted evaporative extraction,SAFE)法结合气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)联用技术分析酒花浸膏中的香气成分,同时采用气相色谱-嗅闻仪(gas chromatography-olfactory,GC-O)结合香气提取稀释分析(aroma extraction dilution analysis,AEDA)方法和香气活性值(odor activity value,OAV),最终确定酒花浸膏的关键性香气成分。结果显示,采用2种萃取方法结合GC-MS在酒花浸膏中共鉴定出111种香气成分;经GC-O分析共鉴定出27种香气活性化合物,其中异丁酸乙酯、丁二酸二乙酯、2-甲基丁酸含量最高,结合风味稀释因子和OAV分析共同确认酒花浸膏的关键香气成分为异丁酸乙酯、2-甲基丁酸、异己酸乙酯、辛酸乙酯、癸酸乙酯等化合物。     

桂花浸膏中长链酯的测定及对香气成分释放的影响

为探究长链酯对桂花浸膏香气成分释放的影响,采用GC-MS对桂花浸膏中的长链酯进行了定量分析;采用APCI-MS分析比较了含有长链酯和不含长链酯的桂花香精香气成分释放量的差异;利用SHS-GC-MS进一步分析了长链酯含量与香气成分释放量的关系。结果表明:(1)定量分析方法的精密度较好(RSD≤6.71%),检出限低(LOD0.46μg·m L-1),各目标物线性良好(R2≥0.998)。(2)金桂和银桂桂花浸膏中含量最高的长链酯均为亚麻酸乙酯,其次是棕榈酸乙酯、亚油酸乙酯和亚麻酸甲酯,金桂桂花浸膏中长链酯总含量(15.1～24.4 mg·g-1)显著高于银桂桂花浸膏(2.6～7.5 mg·g-1)。(3)长链酯的存在会改变桂花浸膏香气成分的顶空浓度,且能显著改善桂花香精的香气;随着亚麻酸乙酯含量的增加,各香气成分的释放量均降低,随着混合长链酯含量的增加,反式-氧化芳樟醇(吡喃型)、顺式-氧化芳樟醇(吡喃型)、γ-癸内酯和芳樟醇的释放量先分别增加了33.2%、21.8%、9.0%和2.5%,然后降低。(4)长链酯含量对桂花浸膏香气成分的释放量有显著影响,且对不同香气成分的影响存在较大差异。     

超临界流体萃取树苔净油研究

系统研究了超临界CO2 萃取树苔净油的工艺。探讨了萃取压力、温度、时间、夹带剂的用量等因素对树苔净油的品质和净油得率的影响 ,确定的最佳萃取工艺条件为 :萃取压力 1 5～ 1 8MPa ,萃取温度 4 0℃ ,夹带剂流量 2 0～ 3 0mL/h ,二氧化碳流量 2～ 3L/h ,萃取时间 3h。在此条件下萃取 ,树苔净油的得率为 2 .0 3 %。并用所得树苔净油进行了卷烟加香试验。评吸结果表明 :该树苔净油能增加烟香 ,掩盖杂气 ,降低刺激 ,明显提高卷烟的吸味品质。实验得出 3点结论 :①必须加入夹带剂 ,超临界CO2 才能有效地萃取树苔净油 ;②必须在适宜的工艺条件下才能萃取出适宜的烟用树苔净油 ;③树苔净油是一种理想的优质烟用香料。     

云烟净油有机膜分离成分中关键香气成分与感官属性的关联系分析

  目的  研究云烟净油成分与卷烟感官指标的关联性。  方法  采用GC-MS分析云烟净油有机膜分离组分中的香气成分组成,计算ROAV值确定关键香气成分,用偏最小二乘回归分析法（PLSR）建立云烟净油有机膜分离组分的关键香味成分与感官指标的PLS模型。  结果  （1）在100 kDa有机膜截留液中,有25种不同的挥发性香味物质,油酸乙酯,癸醛,壬醛,肉豆蔻醛,3, 5-二叔丁基-4-羟基苄醇,苯并噻唑为该组分中的关键香气成分,干草香与云烟净油100 kDa有机膜截留液中的油酸乙酯相关性较强;（2）在100 kDa有机膜透过液中,有30种不同的挥发性香味物质,硬脂酸乙酯,癸醛,甲酸辛酯,正辛醛,壬醛,巨豆三烯酮为该组的关键香气成分,清甜香与云烟净油100 kDa有机膜透留液中的壬醛相关性较强。      

苔清致香成分柔扁枝衣酸乙酯的合成

为研究苔清香型香料橡苔和树苔提取物中的关键组分——2-羟基-4-甲氧基-6-丙基苯甲酸乙酯(柔扁枝衣酸乙酯,化合物4)的合成方法,以3-庚烯-2-酮和丙二酸二乙酯为起始原料,经过加成缩合、芳构化、催化加氢和甲基化4步反应得到化合物4。结果表明:(1)该反应路线原料易得,条件温和,中间体和目标化合物的产率高、易分离,反应的总产率为53%。(2)在化合物4的制备中,为了防止副反应的发生,选择逐滴加入碘甲烷,碘甲烷与2,4-二羟基-6-丙基苯甲酸乙酯(化合物3)的最佳比例为1∶1。     

气相色谱-质谱联用分析晚香玉净油的成分

本文对云南产的单瓣晚香玉和重瓣晚香玉提取净油,并运用气相色谱-质谱法（GC-MS）分析成分及含量。结合评香结果,研究单瓣晚香玉和重瓣晚香玉净油成分的差异性。结果表明：两个品种的晚香玉主成分是：alpha凇油醇、邻氨基苯甲酸甲酯,异丁香酚甲醚、金合欢醇、苯甲酸苄酯、水杨酸苄酯等。单瓣晚香玉净油的主香成分含量较高,如：单瓣晚香玉净油的alpha．松油醇、邻氨基苯甲酸甲酯、金合欢醇、苯甲酸苄酯的含量分别为3．679％、11．564％、13．263％、39．785％;重瓣晚香玉净油的alpha凇油醇、邻氨基苯甲酸甲酯、金合欢醇、苯甲酸苄酯的含量分别为2．706%、6．038％、6．394％、26．005％。重瓣晚香玉浸膏、净油得率较高。     

基于HS-SPME-GC-MS和电子鼻技术对干枣及其不同提取物挥发性成分分析

为探究干枣及其不同提取物的香气品质差异,利用顶空固相微萃取-气相色谱-质谱（headspace solid phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS）联用结合电子鼻技术对干枣及其加热回流和微波辅助热回流提取获得的浸膏和净油的挥发性成分进行研究。结果表明：干枣及其提取物共检测出96 种挥发性成分,主要香气成分为酸类、酯类、醛类和酮类;加热回流提取方式下,酸类挥发性成分的相对含量最高,浸膏和净油中分别为44.433%和39.304%,并且酮类挥发性成分含量显著高于其余几个样品（P＜0.05）;微波辅助热回流提取方式下,酯类挥发性成分的相对含量最高,浸膏和净油中分别为52.196%和45.863%。GC-MS和电子鼻分析结果显示,由浸膏提取得到的2 种净油具有相似的香气特征,载荷分析表明,W1S、W1W、W2S和W2W为干枣及其不同提取物香气成分的主要识别传感器。总而言之,HS-SPME-GC-MS结合电子鼻技术可以较好地用于分析干枣及其不同提取物的香气品质。     

超临界提取黄芩挥发油及在卷烟中的应用

利用超临界提取黄芩挥发油,经气相色谱-质谱联用仪对挥发油的香味成分进行分析,鉴定了64种成分,并用面积归一化法测定了各种成分的质量分数,占总质量分数的96.81%,其主要成分为棕榈酸、棕榈酸甲酯、亚油酸甲酯、薄荷酮、2-甲基丁酸等.通过卷烟加香试验发现,黄芩挥发油能有效地掩盖卷烟杂气,使烟气柔和、香气细腻,对改进烟气质量作用明显.     

用大孔树脂层析法和水提法分离金银花中的致香组分

结合水提法和大孔树脂层析法对金银花进行提取分离,通过单因素试验,确定了最佳水提工艺,即料液比1∶9,提取温度90℃,提取次数2次;并采用气相色谱/质谱仪联用对此金银致香组分进行分析,共鉴定出38种成分,主要含有芳樟醇、棕榈酸甲酯、棕榈酸乙酯、十八酸乙酯、8,11-十八碳二烯酸甲酯、亚油酸乙酯、亚麻酸甲酯、亚麻酸乙酯、棕榈酸、油酸、亚油酸、(Z,Z,Z)-9,12,15-十八碳三烯-1-醇等.将此致香组分0.05%添加于卷烟中,具有丰富烟香、增加清香香韵、掩盖卷烟杂气、柔和烟气等作用.     

Preparation of an oakmoss absolute with reduced allergenic potential

Oakmoss absolute, an extract of the lichen Evernia prunastri , is known to cause allergenic skin reactions due to the presence of certain aromatic aldehydes such as atranorin, chloratranorin, ethyl hematommate and ethyl chlorohematommate.
In this paper it is shown that treatment of Oakmoss absolute with amino acids such as lysine and/or leucine, lowers considerably the content of these allergenic constituents including atranol and chloratranol. The resulting Oakmoss absolute, which exhibits an excellent olfactive quality, was tested extensively in comparative studies on guinea pigs and on man. The results of the Guinea Pig Maximization Test (GPMT) and Human Repeated Insult Patch Test (HRIPT) indicate that, in comparison with the commercial test sample, the allergenicity of this new quality of Oakmoss absolute was considerably reduced, and consequently better skin tolerance of this fragrance for man was achieved.     

A Study of the Fate of Volatile Hop Constituents in Beer

SUMMARY— The volatile material from a pilot plant brewed beer (hopped) has been analyzed by the direct combination of capillary gas chromatography and mass spectrometry. None of the major volatile terpenoid hydrocarbons of hops (myrcene, caryophyllene, humulene) could be detected in the beer volatiles. The only volatile constituents in the beer which could be assigned to hops with some certainty were ethyl dec-4-enoate and ethyl deca-4,9-dienoate, which exist in the hop oil as the methyl esters.
A capillary gas chromatography analysis of a beer which was brewed without hops but with methyl dec-4-enoate (0.02 g/L) showed that this ester was converted to the ethyl ester by the fermentation.
A study was also carried out using model systems to parallel the "kettle boiling" step of brewing. This involved boiling hops with water for a set period and filtering the water extract from the hops. It was found that the pattern of volatile hop constituents in the filtrate (hopped water) was quite different from hop oil and consisted principally of free organic acids, humulene epoxide, humulenol, and other hop oil oxygenated components. With fine filteration through Celite, very little myrcene, humulene, or caryophyllene were transferred into the water, even though they form the major part of hop volatiles. If, however, only coarse filtration was used, a greater amount of these hydrocarbons were found in the filtrate.
It is concluded that the amount of volatile hop oil constituents reaching the final beer probably depends upon the exact conditions of the brewing process used. No evidence could be found in the present work to support the view that the tiny amounts that do survive in beer prepared by the typical American process could contribute more than a very minor amount to the characteristic beer aroma.     

乳清酒发酵过程中细菌群落演替与风味物质变化的相关性分析

采用气相色谱-质谱联用分析乳清酒中重要香气成分的变化规律，运用高通量测序技术分析乳清酒的细菌群落变化，并进行相关性分析。结果表明：乳清酒发酵过程中风味物质的数量整体增加，共检测出102种挥发性风味物质，其中酯类含量最高。通过计算香气活力值可以得出苯甲酸乙酯、乙酸苯乙酯、丁酸乙酯等15种香气物质构成了乳清酒的重要香气成分。发酵前期乳杆菌属（Lactobacillus）为绝对优势菌属，随着发酵的进行，Lactobacillus和乳球菌属（Lactococcus）成为绝对优势菌属。细菌功能预测表明，乳清酒代谢活动主要以氨基酸代谢和碳水化合物代谢为主。进一步展开关联分析，发现大多数的风味物质与Lactococcus和拉乌尔菌属（Raoultella）呈正相关，其中Lactococcus和Raoultella与乙酸苯乙酯、癸酸乙酯、己酸乙酯、乙酸乙酯呈显著正相关。Lactobacillus与柠檬醛、辛酸、癸酸、4-乙基苯酚、庚酸乙酯、癸酸甲酯、油酸乙酯等呈正相关。本研究可为乳清酒发酵剂的筛选及风味调控提供理论依据。     

The aroma volatile repertoire in strawberry fruit: a review

Aroma significantly contributes to flavor, which directly affects the commercial quality of strawberries. The strawberry aroma is complex as many kinds of volatile compounds are found in strawberries. In this review, we describe the current knowledge of the constituents and of the biosynthesis of strawberry volatile compounds, and the effect of postharvest treatments on aroma profiles. The characteristic strawberry volatile compounds consist of furanones, such as 2,5‐dimethyl‐4‐hydroxy‐3(2H)‐furanone and 4‐methoxy‐2,5‐dimethyl‐3(2H)‐furanone; esters, including ethyl butanoate, ethyl hexanoate, methyl butanoate, and methyl hexanoate; sulfur compounds such as methanethiol, and terpenoids including linalool and nerolidol. As for postharvest treatment, the present review discusses the overview of aroma volatiles in response to temperature, atmosphere, and exogenous hormones, as well as other treatments including ozone, edible coating, and ultraviolet radiation. The future prospects for strawberry volatile biosynthesis and metabolism are also presented. © 2018 Society of Chemical Industry     

Volatile constituents of feijoa—headspace analysis of intact fruit

The volatile constituents emanating from intact feijoa fruit during storage were concentrated on to Tenax GC using a headspace trapping technique. Analysis by gas chromatography and gas chromatography-mass spectrometry led to the identification of 11 components of which myrcene, ethyl hexanoate, trans β-ocimene, 2-heptyl butanoate, cis hex-3-enyl butanoate and cis hex-3-enyl hexanoate are reported for the first time. Measurement of sequential changes in the aroma profile following natural abscission of the fruit suggests that ethyl benzoate may be an important compound in determining optimum ripeness of feijoa. Gas chromatographic sniffing trials on the headspace concentrate led to the conclusion that ethyl butanoate, methyl benzoate and ethyl benzoate are important in the aroma of intact feijoa fruit.     

用热脱附方法分析哈密瓜香气成分

为探究哈密瓜主要香气成分,该文采用热脱附方法对哈密瓜果肉、哈密瓜果汁的香气进行富集,经气相色谱质谱法(GC-MSD)联机进行检索分析.结果显示,哈密瓜果肉、哈密瓜果汁香气成分和含量存在一定的差异,并从中检测出56种香气成分,其中哈密瓜肉香气成分有31种,哈密瓜汁的香气成分有46种,共同香气物质为乙酸甲酯、乙酸乙酯、丙酸...     

新型嘉宝果起泡酒香气成分及特征香气分析

以热带水果嘉宝果为原料,采用新型发酵工艺酿造香气怡人的嘉宝果起泡酒。通过搅拌棒萃取法提取酒样香气成分,利用气相色谱-质谱联用结合内标法进行定性定量分析。共检测到104种香气成分,其中主要有酯类、醇类、有机酸类、醛酮类、萜烯类以及芳香族化合物。根据气味活性值,从中筛选出12种特征香气成分,其活性值由大到小依次为:肉桂酸乙酯、反-肉桂酸乙酯、己酸乙酯、辛酸乙酯、癸酸乙酯、丁酸乙酯、乙酸异戊酯、乙酸苯乙酯、苯甲酸甲酯、里那醇、异戊酸乙酯、月桂酸。这些特征香气成分的描述词均以果香和花香为主。由30名经过葡萄酒标准香气物质培训的品尝员进行感官量化分析,得到的实际特征香气与筛选鉴定出的香气成分的气味描述相符程度较高。验证采用新型工艺酿造的嘉宝果起泡酒具有以草莓等果香和花香为主体,并伴随着蜂蜜和其他复杂香气的香气特征。     

Composition of West Indian bay oils

Bay oil is obtained by the steam distillation of leaves of Pimenta racemosa (Mill.) J. W. Moore. In Dominica, now the only major producer of bay oil, two other varieties of bay exist which, although similar in appearance to P. racemosa, yield oils with aroma characteristics very different from those of bay oil. These trees are generally described as anise- or lemon-scented, according to the aroma of their oils. Any contamination of bay oil with these oils is considered to be highly undesirable. Using a variety of chromatographic and spectroscopic techniques, a detailed study has now been made of the constituents of the three types of oil. The results show that oils from P. racemosa and the anise-scented variety have similar overall compositions but differ in the functional state of the major phenolic constituents. Eugenol and chavicol are the phenolic constituents of the former but in the anise-scented variety these phenols are mainly present as their methyl ethers. The lemon-scented variety resembles bay oil only in the minor constituents and contains no phenols or phenolic ethers. Citral comprises more than 80% of this oil.