The analysis of raw spirits – a review of methodology

Agricultural distillates (raw spirits) are alcoholic liquids obtained through distillation (preceded by alcoholic fermentation) of specific agricultural products that do not have the properties of ethyl alcohol or a spirit, but still retain the aroma and taste of the raw ingredients used. This review is a brief overview of agricultural distillates and of some methods commonly used (GC‐MS, GC‐FID, GC‐O, electronic nose) for performing quality assessments and for determining the composition and botanical origins of the raw spirits. Copyright © 2016 The Institute of Brewing & Distilling     

Response surface optimization of SPME extraction conditions for the analysis of volatile compounds in Brazilian sugar cane spirits by HS‐SPME‐GC–MS

The extraction of volatile compounds from distilled sugarcane spirits was investigated using central composite design associated with response surface methodology. The parameters evaluated were the extraction temperature, extraction time and desorption time. All of the parameters analysed, as well as their interactions, were significant for the process at a 95% confidence level. Although the extraction time and extraction temperature exhibited positive effects, the desorption time showed a negative effect. The second‐order polynomial model was adjusted appropriately for the response surface analysis. The optimized conditions were extraction temperature equal to 45°C, extraction time of 50 min and the desorption time corresponding to 100 s. Copyright © 2017 The Institute of Brewing & Distilling     

Volatile compounds of Panax ginseng C.A. Meyer cultured with different cultivation methods

The volatile compounds of Panax ginseng C.A. Meyer analyzed to interpret whether cultivation methods affect volatile compounds. The volatile compounds in Panax ginseng C.A. Meyer cultured with 3 different cultivation methods such as good agricultural practice, organic cultivation method, and general cultivation method were isolated by solid-phase microextraction fiber (polydimethylsiloxane 65 μm) and identified by gas chromatography mass spectrometry. Then, the scattering patterns of volatile compounds compared by principal component analysis. As the results, the 14 volatile compounds were identified from 30 ginseng samples and consisted mainly of sesquiterpene hydrocarbons. The differences among the different cultivation methods of the samples were obvious from the PC1 and PC2 scatter point plot. As the conclusion, the cultivation methods can affect to produce the volatile component of ginseng root. The organic and good agriculture practice cultivation can increase the ginseng characteristic volatile compounds.     

Volatile components of several virgin and refined oils differing in their botanical origin

BACKGROUND: The volatile components of virgin and refined oils whose compositions were very different in terms of oleic, linoleic and linolenic acyl groups were studied by solid phase microextraction (SPME) followed by gas chromatography/mass spectrometry (GC/MS), and their composition of acyl groups was determined by proton nuclear magnetic resonance ¹H NMR. The virgin oils studied were olive, linseed and walnut oils, while the refined oils were sunflower and rapeseed oils. RESULTS: Large differences were found among the headspace compositions of the virgin oils. These were due in part to compounds that could be considered as markers of different vegetable origins and manufacturing processes, but also to compounds resulting from degradative oxidation of the main acyl group components. By virtue of their being refined, fewer components were present in the refined oils, although differences in their headspaces were found owing to the presence of compounds resulting from oxidation of the determined acyl groups. CONCLUSION: The studied oils show specific characteristics regarding not only their main components, which are well known, but also their volatile components. The latter provide information on some of the processes to which oils have been submitted, on their oxidation level, on their botanical origin and on the compounds responsible for their odour. Copyright © 2011 Society of Chemical Industry     

Influence of the fermentation yeast strain on the composition of wine spirits

Fifteen indigenous strains of Saccharomyces cerevisiae, differentiated by their genetic polymorphism, were compared in standard conditions for their respective ability to produce volatile compounds during the alcoholic fermentation of grape must. The results were processed using analysis of variance and of principal components. They exhibited significant differences between strains, in particular for the higher alcohols, fatty acid esters, acetates or acetaldehyde. On the basis of their analytical profile, five strains were selected and compared on the pilot scale. Overall, the pilot results confirmed laboratory findings. As the strain effect appears to be determinant on the aromatic composition of wine spirits, a programme of selection based on both intraspecific molecular characterisation and chromatographic analysis is carried out to obtain specific yeast strains for high-quality spirits.     

Influence of the Thermal Stabilization Process on the Volatile Profile of Canned Tomato‐Based Food

The literature contains several papers dealing with the volatile constituents contributing to the aroma of fresh and processed tomatoes. Along with the traditional tomato‐based products, tomato‐based pâtés, characterized by complex ingredient formulations, are commonly consumed as a seasoning for pasta, and as a dressing for meats, salads, and sandwiches. To the best of our knowledge, no investigations have been published on the influence of thermal stabilization treatments on the composition of volatile compounds in tomato‐based pâtés. To this aim, thermally stabilized and not stabilized tomato‐based pâtés were subjected to the analysis of volatile compounds. The results obtained highlighted the influence of the thermal stabilization process on the evolution of volatile composition tomato‐based pâtés. In particular, the terpenic compounds showed significant decreases after the thermal stabilization process treatment, due to their degradation and oxidation favored by high temperatures. The thermal stabilization caused, moreover, an increase in volatile compounds deriving from lipid oxidation and Maillard reaction, characterized by low‐sensory thresholds, and from the thermal degradation of carotenoids and fresh tomato‐derived compounds.     

Solid Phase Microextraction of Volatile Soybean Oil and Corn Oil Compounds

ABSTRACT: The qualitative and quantitative determination of volatile compounds in soybean and corn oils were analyzed by solid phase microextraction. Coefficients of variation and sensitivity of polydimethylsiloxane, carboxen/polydimethylsiloxane, polyacrylate, and carbowax/divinylbenzene for hexanal analysis in soybean oil were 3.2, 4.2, 7.2, and 10.7%, and 15, 30,20, and 10 ppb, respectively. Volatile compounds of soybean oil with peroxide value (PV) of 1 or 5 were extracted by polydimethylsiloxane at 60 °C for 60 min. The amount of volatile compounds of PV 5 soybean oil was 92% higher than the PV 1. Volatile compounds including 2,4-decadienal, 2-decenal, hexanal, and pentane were identified in soybean and corn oils by SPME-GC-MS and GC retention time. SPME was a simple, reproducible and sensitive method for the analysis of volatile compounds of vegetable oils. Keywords: solid phase microextraction, headspace volatile compounds, soybean oil, corn oil     

Volatile compounds in light, medium, and dark black walnut and their influence on the sensory aromatic profile

Light, medium, and dark colored kernels from 3 different cultivars (Emma K, Kwik Krop, and Sparks 127) and one wild species of black walnut were studied for their aroma volatiles. Solid-phase microextraction-gas chromatography-mass spectrometry was used to determine the aromatic compounds present in the headspace of these samples. Partial least square regression was used to correlate the instrumental aromatic data with the sensory responses, obtained in a previous study, for the same samples. Thirty-four aromatic compounds were found in the black walnut cultivars, highlighting among them the presence of 14 esters. Although more than 50% of the total concentration of volatile compounds, esters were not important compounds in determining the differences in the sensory aromatic profiles of the 3 colors of the nuts. As a general trend, the concentration of total volatile compounds was always significantly higher in light black walnuts than in the medium colored samples; medium colored samples had higher volatile content than the dark black walnuts. The presence of hexanal was related to rancid and acrid aromas and was determined to differentiate the dark black walnuts from the medium and light colored samples. PRACTICAL APPLICATION: The data presented in this article will help understand the aromatic differences between light, medium, and dark colored kernels of domestic and wild black walnut. The aromatic profile of these nuts, not studied until this moment, can be used as a model to develop flavorings and new products by the food industries.     

Volatile components of raw and smoked black bream (Brama raii) and rainbow trout (Oncorhynchus mykiss) studied by means of solid phase microextraction and gas chromatography/mass spectrometry

Solid phase microextraction followed by gas chromatography/mass spectrometry of raw and smoked black bream and rainbow trout was carried out. The volatile components of the raw fish belong to a limited number of groups of compounds. Raw black bream has a higher presence of acids than raw trout, while the latter contains more alcohols, hydrocarbons, esters and phenol derivatives; both contain similar concentrations of saturated aldehydes. The volatiles of the smoked fish basically comprise the compounds also detected in the raw fish together with others produced during the processing. Smoke components detected in both smoked fish species were mainly phenol, guaiacol and syringol derivatives, ketones, acetic acid and some polycyclic aromatic hydrocarbons. Smoked black bream contained a higher number and higher concentrations of smoke components than smoked rainbow trout. Large variations in concentrations of smoke components in the smoked fish samples indicated that the smoking process had not been totally homogeneous. The presence of autoxidatively derived compounds, such as unsaturated aldehydes, was mainly detected in some smoked bream samples, showing that this degradation process is not occurring homogeneously. The usefulness of the applied techniques for the study of volatile components of raw and smoked fish is shown. © 2002 Society of Chemical Industry     

Identification of Volatile Compounds in Raw Spirits of Different Organoleptic Quality

The main purpose of the research was to determine the composition of the volatile fraction of raw spirits, as well as isolation of the aroma profiles for spirits differing in their sensory properties. Profiles were created using a headspace solid‐phase microextraction (HS‐SPME) and capillary gas chromatography‐mass spectrometry technique (GC‐MS). The results indicated the presence of over 200 compounds, of which significant numbers were identified. The most significant groups included esters, higher alcohols, aldehydes, acetals, as well as furans, sulphur compounds, terpenoids and benzene derivatives. Among the above‐mentioned compounds, over 50 were identified whose presence or high content could decrease the quality of the distillates. In particular, this pertains to higher quantities of compounds such as acetals and certain esters, as well as the two compounds, dimethyl trisulphide and geosmin. Aside from the dependence between volatile composition and the sensory quality, differences between distillates originating from different distilleries were observed.     

5种不同品种苦荞的易挥发性成分比较分析

采用顶空固相微萃取(Headspace Solid Phase Micro Extraction,HS-SPME)-气相色谱-质谱(Gas Chromatography-Mass Spectrometry,GC-MS)联用技术,对5种不同品种的苦荞易挥发性成分进行了系统研究与比较。结果表明:通过GC-MS分析,5种不同品种的苦荞共检测到烷烃类、烯烃类、酯类、醛类、醇类、含N物质及其他7类挥发性化合物。5种苦荞共有14种共同组分,包括9种烷烃化合物(2,2,4,6,6-五甲基庚烷、十一烷、十二烷、十三烷、2,9-二甲基十一烷、3-亚甲基十三烷、十四烷、壬基环戊烷、正十五烷)以及5种烯烃类化合物(乙基苯、萘、1-十二烯、1-十三烯、2E-十四烯);不同品种的挥发性成分的差异主要体现在醇类、醛类以及酯类化合物,醇类及酯类化合物一般具有花香和果香,醛类化合物有脂肪香味,这些物质相互作用产生综合气味,从而使不同品种的苦荞呈现不同的特点。     

鲟鱼不同部位挥发性成分分析

采用固相微萃取结合气相色谱-质谱联用技术分析鲟鱼不同部位挥发性成分,初步探究鲟鱼特征气味及主要腥味物质。从鲟鱼腹肉、背肉、尾肉、皮、鳃、肝中共检出6 0余种挥发性物质,这些物质包括醛类、酮类、醇类、烃类和酸类等,其中醛类、醇类、烃类含量较高。不同部位挥发性成分种类和含量不同,醛、烃在鲟鱼各部位挥发性物质中所占比重较大,醇类在肝(32.08%)、皮(44.96%)、鳃(5.51%)含量较高;背肉挥发性物质检出总量最低。鲟鱼的主要特征气味为青草味、鱼腥味及脂类气味;己醛、1-辛烯-3-醇等是构成鲟鱼鱼腥味的主要成分。     

不同萃取头固相微萃取分析小米清酒挥发性成分的研究

采用PA、PDMS、PDMS/DVB、CAR/PDMS和DVB/CAR/PDMS 5种萃取头,并通过固相微萃取（SPME）与气质联用（GC-MS）对小米清酒中挥发性成分进行提取、鉴定,运用聚类热图分析不同SPME萃取头提取小米清酒挥发性成分差异。结果表明：5种萃取头SPME检测到小米清酒挥发性成分含有醇、酯、醛、碳氢化合物、含苯衍生物和其他化合物,使用不同萃取头进行固相微萃取能得到较为相似的主挥发性成分：1-戊醇、苯乙醇、正己酸乙酯、丁二酸二乙酯、辛酸乙酯、十六烷,DVB/CAR/PDMS萃取头检测效果最好。聚类热图显示,不同萃取头SPME提取到的挥发性成分效果差异较大,按萃取效果可分为PA萃取头、PDMS萃取头和复合萃取头（PDMS/DVB、CAR/PDMS和DVB/CAR/PDMS）三类,使用不同种萃取头SPME可较为全面地了解小米清酒挥发性成分构成。     

不同香型芝麻油中挥发性风味成分的研究

采用固相微萃取-气质联用技术,对52个不同香型芝麻油样品中的挥发性风味成分进行检测,建立了芝麻油风味成分的指纹图谱,并探讨了不同香型芝麻油挥发性风味成分相对含量的差异.结果表明:芝麻油的风味是由多种物质共同作用的结果,风味成分由25种物质构成,分为吡嗪类、噻唑类、呋喃类、酮类、醛类、酚类、酸类、醇类、含硫化合物、吡啶类和异噻唑类共11类;浓香型芝麻油风味最优,主要挥发性风味成分中乙酸、甲基吡嗪、2-甲氧基苯酚和5H-5-甲醇-6,7-二氢环戊并吡嗪的相对含量高于其他两种香型芝麻油,这4种挥发性风味成分对芝麻油香味影响最大,可以作为芝麻油香味品质的重要客观评价依据.     

顶空固相微萃取结合气相色谱-质谱联用法对3种洋葱挥发性风味成分的分析

为研究洋葱挥发性成分,利用顶空固相微萃取法提取洋葱的挥发性风味成分,通过气相色谱-质谱联用法分析测定,以总峰面积和化合物个数为指标考察萃取纤维头、萃取温度、萃取时间和解吸时间4个因素对萃取效果的影响,得出最优萃取条件为:萃取纤维头50/30 μm DVB/CAR/PDMS,萃取温度60 ℃,萃取时间60 min,解吸时间5 min。利用最优萃取条件对三种色泽洋葱挥发性风味成分进行分析鉴定。结果表明:三种色泽洋葱共鉴定得到挥发性风味物质61种,其中白皮、红皮、黄皮洋葱分别测到37、40、49种挥发性成分,相对含量分别占流出组分总量的70.29%、81.92%、79.03%。61种挥发性成分中含硫化合物27种、醛类13种、醇类13种、酮类4种,其他4种。三种色泽洋葱的共有挥发性成分有22种,其中含硫化合物占比较大,特别是二异丙基二硫醚和(E)-1-丙烯基-2-丙烯基二硫醚相对含量的总和在三种色泽洋葱的挥发性成分中占比率都超过了20%,对形成洋葱特征风味贡献较大。红皮和黄皮洋葱的含硫化合物的相对含量远高于白皮洋葱,红皮洋葱中2-甲基-2-戊烯醛相对含量高于白皮和黄皮洋葱。     

固相微萃取GC-MS法测定不同干燥方式下枣产品的芳香成分

采用顶空固相微萃取与气相色谱-质谱联用技术对枣鲜样及不同干燥方式枣产品的芳香成分进行分析.结果表明,河北滩枣鲜样主要芳香成分为:酸类物质占24.31%,烯类物质占14.2%,烷烃类物质占11.73%.热风干燥处理后产生较多酯类和酮类物质,使产品呈现蒸煮味道,损失较多烷烃类物质;微波干燥处理后除酯类和酮类物质增多外,其余...     

基于HS-SPME-GC-MS法分析3 种金橘的香气挥发性成分

采用顶空-固相微萃取-气相色谱-质谱法,并结合多元统计方法分析金橘香气成分。通过对萃取条件进行优化,得到最佳固相微萃取条件为DVB/CAR/PDMS萃取头、萃取温度40?℃、萃取时间70?min、样品质量3.0?g、解吸时间5?min。在此基础上对3?种金橘（阳朔脆皮金橘、浏阳金弹、融安油皮金橘）的挥发性有机化合物进行检测,初步鉴定出萜烯、醇、醛、酯、酮和烷烃6?类成分,共76?种挥发性成分,其中萜烯类化合物含量最丰富。此外,在浏阳金弹、阳朔脆皮金橘、融安油皮金橘中分别检测到62、58?种和48?种具有香气活性的化合物。香树烯、4-蒈烯、α-芹子烯、(－)-马兜铃烯、(E)-(＋)-异柠檬烯、香芹醇和(＋)-二氢香芹酮等是浏阳金弹中特有的香气物质。2-蒈烯、(E)-菖蒲萜烯、十二醛和十一烷等是阳朔脆皮金橘特有的香气物质。融安油皮金橘特有的香气物质有氧化柠檬烯、佛术烯、β-愈创木烯、β-萜品烯、β-罗勒烯和二氢香芹酮等。结合气味活度值分析,月桂烯、(d)-柠檬烯、芳樟醇、癸醛和紫苏醛等可能是构成金橘香气的重要成分。通过主成分分析和聚类分析,得到基于挥发性有机化合物区分金橘品种是有效的。该结果可为研究金橘风味、品质和产地鉴别提供一定理论依据。     

单花种蜂蜜植物源黄酮标记物的研究进展

利用蜂蜜中特征成分来鉴别和标识不同种类单花种蜂蜜的植物源及其产地是当前蜂蜜研究的热点。文中介绍了黄酮化合物作为单花种蜂蜜植物源标记物的研究进展,旨在为我国单花种蜂蜜的溯源及其质量控制提供参考。