Odour‐active compounds in pineapple (Ananas comosus [L.] Merril cv. Red Spanish)

Application of solid‐phase microextraction, simultaneous distillation–extraction and liquid–liquid extraction combined with GC‐FID, GC‐MS, aroma extract dilution analysis, and odour activity value was used to analyse volatile compounds from pineapple (Ananas comosus [L.] Merril cv. Red Spanish) and to estimate the most odour‐active compounds. The analyses led to the identification of ninety‐four compounds, seventy‐two of them were positively identified. Twenty odorants were considered as odour‐active compounds, from which ethyl 2‐methylbutanoate, 2,5‐dimethyl‐4‐hydroxy‐3(2H)‐furanone, 1‐(E,Z,Z)‐3,5,8‐undecatetraene, ethyl 3‐(methylthio)propanoate, 1‐(E,Z)‐3,5‐undecatriene, ethyl hexanoate and methyl hexanoate were the most odour contributors and contribute to the typical pineapple aroma, while the others are responsible for fruity and sweet odour notes.     

Changes in volatile aroma compounds of pineapple (Ananas comosus) during freezing and thawing

Changes in the volatile aroma compounds of pineapple (Ananas comosus) during freezing and thawing were compared against fresh samples to determine the effect of freezing on pineapple flavour. An HS‐SPME–GC–MS analysis showed that the Smooth Cayenne pineapple variety had nineteen volatile compounds, in four classes of compounds including fourteen esters, two hydrocarbons, two sulphur‐containing compounds and one lactone. The main characteristic volatile compounds of the fresh pineapple were methyl hexanoate, ethyl hexanoate, ethyl 3‐methylthiopropanoate and 1‐(E,Z)‐3,5‐undecatriene. Freeze–thaw cycles were associated with the loss of some volatile aroma compounds, particularly the esters which were found to be the main characteristic of fresh pineapples. The freezing and thawing process was found to cause damage to the pineapple tissues due to ice recrystallisation and dehydration which lead to the reduction of volatile aroma compounds.     

不同品种草莓的特征香气成分

以"宝交""大将军"和"红宝石"3个品种的草莓为试材,采用顶空固相微萃取-气相色谱质谱联用技术(GC-MS)和嗅闻技术(GC-O)、感官评价以及快速气相电子鼻对果实的香气成分进行分析。3个品种共检测到71种挥发性成分,"宝交""大将军"和"红宝石"分别有60,70和66种。酯类物质种类最多(21~26种),而醛类物质含量最多(51.37%~63.63%)。其中,丁酸甲酯、丁酸乙酯、乙醛、己酸甲酯、(E)-2-己烯醛、己酸乙酯、乙酸己酯、芳樟醇在3个样品中具有较高的含量及香气强度,为草莓的主要特征香气物质。经感官评价,"宝交"较强甜香气的来源可能是由于2-戊酮的存在;"大将军"青香和花香更强,青香可能由于它具有更高的己醛和反式-2-己烯醛含量,而花香可能来源于芳樟醇、橙花叔醇和β-紫罗兰酮。由快速气相电子鼻可以显示出3个品种草莓很好的区分度。     

Changes in flavour and texture during the ripening of strawberries

The amount of total volatile compounds, total acidity, total sugar content (degrees Brix) and fruit firmness were used to characterize the degree of ripeness of three strawberry varieties (Carezza, Darselect and Marmolada). A novel concept using solid phase microextraction (SPME) and measurement of total volatile compounds to distinguish between various stages of strawberry ripeness was applied. The carboxene/polydimethylsiloxane SPME fibre was found to be best suited to differentiate between the stages of ripeness. The amount of total volatile compounds rapidly increased near to maturity (between the three-quarters red stage and the dark-red stage). Most of the volatile compounds identified were esters, followed by aldehydes, and alcohols. The most abundant volatile compounds were propyl butanoate, 3-phenyl-1-propanol, butyl butanoate, isobutyl butanoate, 3-methyl butyl butanoate and isopropyl hexanoate. The concentration of green aroma components such as hexanal, trans-2-hexenol and cis-3-hexenyl acetate progressively decreased during the maturation process until they became minor components in mature strawberries.     

Comparison on aroma compounds in Chinese soy sauce and strong aroma type liquors by gas chromatography–olfactometry,chemical quantitative and odor activity values analysis

In order to elucidate the differences on aroma compounds in Chinese liquors with different aroma styles and the reasons, aroma compounds of Xijiu in soy sauce aroma and strong aroma type were investigated in the research. By gas chromatography–olfactometry (GC–O), aroma compounds in Chinese liquor were chosen for quantitative and odor activity value (OAV) analysis. Ethyl hexanoate, butanoic acid, 3-methylbutanoic acid, hexanoic acid and dimethyl trisulfide were considered to be the most powerful odorants in both liquor samples (aroma intensity ≥3.5) by GC–O. As important aroma compounds (OAV ≥10) in the liquors, ethyl propanoate, ethyl 2-methylpropanoate and 1-propanol were considered with much higher OAVs in soy sauce aroma type liquor, while OAVs of ethyl pentanoate, ethyl hexanoate, ethyl heptanoate, ethyl octanoate, ethyl lactate, hexyl acetate, butyl hexanoate, hexyl hexanoate and hexanoic acid were far lower in strong aroma type liquor. The OAV of ethyl hexanoate in strong aroma type liquor exceeded 50,000, which explained the reason why strong aroma liquor was considered with prominent fruity aroma. The odor differences between the liquors were mainly caused by the manufacturing practices.     

Methyl jasmonate in conjunction with ethanol treatment increases antioxidant capacity,volatile compounds and postharvest life of strawberry fruit

The antioxidant capacity, total anthocyanins, total phenolics, volatile compounds, and postharvest quality of strawberry fruit were evaluated after treatment with natural antimicrobial compounds and during storage at 7.5 °C. Strawberries treated with methyl jasmonate (MJ) in conjunction with ethanol (MJ-ETOH) showed higher antioxidant capacity, total phenolics, and anthocyanins than those treated with ethanol or control (non-treated). MJ-ETOH and ethanol treatments also increased volatile compounds during storage period. However, individual volatile compounds were affected differently. Methyl acetate, isoamyl acetate, ethyl hexanoate, butyl acetate, and hexyl acetate increased, while ethyl butanoate, 3-hexenyl acetate, and methyl hexanoate decreased during storage. The postharvest life was longer for those berries treated with MJ-ETOH and MJ than for those treated with ethanol or control fruit. In conclusion, strawberries treated with MJ-ETOH maintained an acceptable overall quality for the longest storage duration and retained higher levels of volatile compounds; also, berries treated with MJ showed the highest antioxidant capacity compared with other treatments during the postharvest period.     

白酒窖池中不同部位窖泥挥发性化合物的差异性分析

采用顶空固相微萃取(HS-SPME)与气相色谱-质谱(GC-MS)联用的方法,对泸州老窖50年窖龄窖池中窖壁与窖底窖泥中的挥发性物质进行检测和分析。结果表明,窖泥中共检测到以酯类、醇类、酸类、醛酮类及酚类化合物为主的65种挥发性化合物。窖壁窖泥与窖底窖泥中的醇类、醛酮类以及酚类化合物差异不大,而酸类与酯类化合物无论在种类还是数量上均存在显著差异,其中己酸、己酸丁酯、己酸己酯是窖壁窖泥中的主要特征成分,而窖底窖泥中则含有丰富的己酸甲酯。     

基于SPME-GC-MS法比较新疆哈萨克族不同居住区奶酪风味差异

采用顶空固相微萃取-气相色谱-质谱联用技术,对采集自新疆哈萨克族不同居住地区20?种奶酪样品中挥发性风味组分进行研究。结果表明：20?种奶酪样品中共检测出52?种主要挥发性化合物,其中主要特征风味包括酸类（乙酸、丁酸、庚酸、辛酸）、醇类（乙醇、苯乙醇、3-甲基丁醇）、酯类（乙酸乙酯、己酸乙酯、辛酸乙酯、丁二酸二甲酯）、酮类（2-壬酮、2-庚酮、乙偶姻）、醛类（正己醛、庚醛、壬醛）等。主成分分析显示不同地区奶酪的挥发性风味组分差别较大,和地区相吻合,其中伊犁地区和哈密地区奶酪风味物质差异显著,得到明显区分。阿勒泰和塔城地区奶酪风味成分相似度较高,归为一类。伊犁地区样品主要风味物质乙酸、乙酸乙酯、3-甲基-1-丁醇乙酸酯、己酸乙酯、2-甲基丁酸乙酯、3-羟基-2-丁酮、2-丁醇、2-羟基丙酸乙酯和2-甲基丙醇含量较高,区别于其他地区样品。哈密地区样品中,巴里坤（H1）风味物质良好,明显区别于同地区其他样品,其中醛类（己醛、2-庚醛、壬醛、苯甲醛）、酯类物质（丙酸乙酯、乙酸丁酯、丙酸丁酯、2-丙烯酸丁酯、丁酸丁酯）和2-壬酮含量较高。     

GC-IMS分析典型浓香型白酒挥发性成分差异

以五粮液、泸州老窖、剑南春、洋河、中华杜康、古井贡酒等8种典型浓香型白酒为试样,采用气相色谱-离子迁移谱（GC-IMS）技术分析白酒中挥发性物质成分,同时采用指纹图谱、动态主成分分析（DPCA）和欧氏距离对样品进行鉴别。结果表明,样品中共检测出挥发性成分34种,其中酯类17种,醛类7种,醇类6种,酮类2种,酸类1种和吡嗪类1种;指纹图谱结果表明,不同样品中均检出己酸乙酯、戊酸乙酯、丙酸乙酯、丁酸乙酯、乙酸丁酯等物质,其中己酸乙酯为浓香型白酒的标志性挥发性成分,不同样品其他挥发性物质成分存在特征差异,五粮液酒样中挥发性物质成分在种类和含量上最突出;DPCA和欧氏距离结果表明,该方法能区分不同类型浓香型白酒特征挥发性成分。     

Characterization of volatile compounds in Cowart muscadine grape (<Emphasis Type="Italic">Vitis rotundifolia</Emphasis>) during ripening stages using GC-MS combined with principal component analysis

Muscadine grape (Vitis rotundifolia) is a popular fruit in the Southeastern United States because of its unique aroma and strong antioxidant capacity. Volatile compounds of a locally cultivated muscadine cultivar Cowart were characterized by solid-phase microextraction coupled with GC-MS. Twenty-eight volatile compounds, including fruity short-chain esters, alcohols, terpenes, and carbonyl compounds, were detected based on mass spectra and Kovats indices. Based on principal component analysis and hierarchical clustering, the grapes in stages I and II had relatively similar flavor patterns, which were different from that in stage III. Butyl-2-butenoate, hexyl acetate, propyl acetate, ethyl trans-2-butenoate, hexyl-2-butenoate, ethyl acetate, butyl acetate, 1-octanol, ethyl hexanoate, and β- citral were present as distinct volatile chemicals in stage III, while nonanal, decanal, and β-citronellol were distinct in stage II, and myrcenol, β-ocimene, and l-limonene were biomarkers in stage I. Understanding volatile compounds at each stage can assist farmers in choosing the optimal time to harvest muscadine grapes.     

安吉白茶挥发性成分及关键呈香成分分析

采用搅拌棒吸附萃取结合气相色谱-质谱联用技术研究安吉白茶的挥发性成分组成特点,并利用气相色谱-嗅闻-质谱技术结合相对气味活性值分析了安吉白茶的关键呈香成分。结果表明,在20 个安吉白茶样品中共检测到109 种挥发性成分,其中含量最高的成分有香叶醇、邻苯二甲酸二异丁酯、植醇、水杨酸甲酯、顺式茉莉酮、亚麻酸、芳樟醇等;不同等级安吉白茶的挥发性成分含量存在较大差异;此外,基于34 个共有特征峰,建立安吉白茶挥发性成分指纹图谱;16 种化合物被鉴定为安吉白茶的关键呈香成分,包括反式-β-紫罗兰酮、香叶醇、芳樟醇、己醛、庚醛、(E)-2-庚烯醛、α-紫罗兰酮和(Z)-己酸-3-己烯酯等。     

离子迁移谱法检测蒸馏酒中4种风味成分

目的建立一种蒸馏酒中风味成分分析的气相色谱-离子迁移谱检测方法。方法以韩国真露烧酒为研究对象,利用全自动顶空进样,气相色谱-离子迁移谱法(GC-IMS)对样品中的正庚酸、正辛酸、己酸丁酯、月桂酸乙酯等4种风味化合物进行外标法分析检测,得到0~20 mg/L浓度范围内4种化合物的离子迁移谱回归曲线。结果本方法在25 min内完成样品的平衡、进样和分析。样品中4种风味化合物的含量分别为:正庚酸3.6 mg/L,正辛酸2.1 mg/L,己酸丁酯1.7 mg/L,月桂酸乙酯4.2 mg/L。结论与传统的分析手段相比,离子迁移谱法操作简单,检测速度快,灵敏度高,在食品风味物质分析等领域具有广阔的应用前景。     

Volatile composition of wines from cvs. Blanco lexítimo,Agudelo and Serradelo (Vitis vinifera) grown in Betanzos (NW Spain)

Wine aroma is formed by volatile compounds of different chemical natures and origins. Betanzos is the most northern viticole geographic area from Galicia (NW Spain). The aromatic profiles of wines produced from two white varieties (Blanco lexítimo and Agudelo) and one red variety (Serradelo) from Betanzos, harvested in 2006 and 2007, have been established by gas chromatography (GC/FID). A total of 35 varietal and fermentative aroma compounds were identified and quantified in free volatile form, which include terpenols, C₁₃‐norisoprenoids, alcohols, esters, volatile fatty acids and volatile phenols. To ascertain the compounds with major impact odours, the Odour Activity Value (OAV) was calculated. Twelve compounds showed concentrations above their perception threshold (OAV>1). The results obtained suggest that ethyl octanoate (apple), isoamyl acetate (banana), ethyl hexanoate (fruity) and β‐damascenone (floral) were the most powerful odorants for the white wines Blanco lexítimo and Agudelo from Betanzos. Ethyl octanoate and β‐damascenone (fruity and floral aroma respectively) were the most odorant for the red wine Serradelo.     

Quantitative composition of volatile constituents in cultivated strawberries,Fragaria ananassa cv. senga sengana,senga litessa and senga gourmella

The volatile components of cultivated strawberries Fragaria ananassa cv. Senga Sengana, Senga Litessa and Senga Gourmella were studied by gas chromatography-mass spectrometry. Employing standard-controlled aroma separation by combined vacuum distillation-liquid-liquid extraction, as well as prefractionation on silica gel, the aroma substances of freshly harvested and deep-frozen strawberries from two growing seasons were quantitatively determined by gas chromatography. Methyl and ethyl butanoate, methyl and ethyl hexanoate, trans-2-hexenyl acetate, trans-2-hexenal, trans-2-hexen-1-ol as well as 2,5-dimethyl-4-methoxy-3(2H)-furanone were identified as main volatile components. In comparison to Senga Litessa and Senga Gourmella, Senga Sengana showed higher amounts of aroma compounds. In general, deep-freezing resulted in decreases of the concentrations of most of the aroma substances, but higher amounts of 2,5-dimethyl-4-methoxy-3(2H)-furanone were found in deep-frozen berries than in the freshly harvested ones.     

基于ATD-GC-MS技术检测铁观音做青过程环境挥发性成分的动态变化

采用全自动热脱-气相色谱-质谱法捕集和检测铁观音做青关键工艺节点的环境挥发性成分，应用短时间序列表达挖掘器（short time-series expression miner,STEM）和偏最小二乘法判别分析（partial least squaresdiscriminantanalysis,PLS-DA）对铁观音做青过程中挥发性成分进行分析。结果显示，铁观音做青环境中共鉴定出122种挥发性成分，包括醇类、酯类、烯烃类、烷烃类、醛类、芳香烃类、酮类和其他化合物8大类，其中酯类是做青环境中的主要挥发物；STEM结果表明，检测出的挥发性成分可划分成19种变化趋势，且在2种趋势模型中有显著性富集，其中仲丁醇、乙酸乙酯、异戊醛、异戊醇、正己醇、2-庚醇、己酸甲酯、甲基庚烯酮、异丁酸辛酯等挥发性成分带有特殊香气并随着做青次数的增加而显著增加；PLS-DA结果表明，摇青和晾青两部分可有效区分开，并鉴定出7种共同特征挥发性成分（变异权重参数值>1）:(Z)-乙酸-4-己烯-1-酯、反-3-己烯基丁酯、叶醇、3-己烯醛、异戊腈、(3E)-4,8-二甲基壬-1,3,7-三烯、罗勒烯异构体混合物。...     

Changes in volatile compounds of Habanero chile pepper (Capsicum chinense Jack. cv. Habanero) at two ripening stages

The steam volatile components of Yucatan Habanero chile pepper (Capsicum chinense Jack. cv. Habanero) at two ripening stages (green and orange) were analyzed using GC and GC/MS. Both samples had several compounds in common. One hundred and two compounds were identified, from which (E)-2-hexenal, hexyl 3-methylbutanoate, (Z)-3-hexenyl 3-methylbutanoate, hexyl pentanoate, 3,3-dimethylcyclohexanol, and hexadecanoic acid were found to be the major constituents. During Habanero chile pepper maturation, the majority of volatile compounds decreased or even disappeared, some of them with green odour notes while esters, which have fruity odour notes, increased at the same time.     

基于相对气味活度值法的新疆大盘鸡中主要挥发性风味物质分析

采用固相微萃取和气相色谱-质谱联用技术对新疆大盘鸡中的挥发性风味物质进行萃取和分离鉴定,采用相对气味活度值法确定对新疆大盘鸡香气具有主要贡献作用和修饰作用的香气物质。结果表明：共检测出64 种挥发性风味物质,醇类和醛类物质含量所占比例较高,分别为26.9%、36.4%;柠檬醛、1-辛烯-3-醇、壬醛、己醛、β-紫罗兰酮、桉树醇、苯甲醛、D-柠檬烯、芳樟醇、β-月桂烯、辛醛、1-庚醇、庚醛及2-戊基呋喃14 种物质对新疆大盘鸡香气贡献较大;苯乙醇、苯乙醛、正己酸乙烯酯、苯甲醇、(E)-2-辛烯醛、戊醛、乙酸芳樟酯、α-蒎烯、茴香烯、β-罗勒烯、二烯丙基二硫、6-甲基-5-庚烯-2-酮、乙酸庚酯、正辛醇、3-辛酮、正己醇、1-壬醇、松油醇及苯乙烯对新疆大盘鸡的香气起修饰作用。     

Comparative study of extra virgin olive oil flavor profile of Koroneiki variety (Olea europaea var. Microcarpa alba) cultivated in Greece and Tunisia during one period of harvesting

The effects of geographical region, irrigation and ripening degree of olives on the profile of volatile compounds isolated by monovarietal virgin olive oils from Crete and Tunisia of Koroneiki variety (Olea europaea var. Microcarpa alba) using the SPME GC/MS technique were investigated. Fruits obtained from Greece (island of Crete) and Tunisia (Sfax region) were picked at three and two different growth stages respectively and then immediately processed. The most important compounds identified were esters, alcohols, carbonyl compounds and hydrocarbons. The main volatile compounds present in the oil samples were C6 derivatives, such as [E]-2-hexenal, [E]-2-hex-1-enol, [Z]-3-hexen-1-ol and 1-hexanol. In addition to C6 compounds, the aroma of the studied samples contained reasonable amounts of various classes of C5 components. The tested oil samples showed different volatile profiles. Specifically, the concentration of total esters, carbonyl, C6 and C5 compounds increased significantly with the ripening degree in Cretan, but not in Tunisian olive oils. Principal component analysis of the results indicated that primary maturity and geographical region rather than irrigation affected significantly the volatile’s profile of olive oil.     

同时蒸馏萃取结合GC-MS分析酿酒五粮原料蒸煮香气成分

采用同时蒸馏萃取结合气相色谱-质谱分别对浓香型白酒生产使用的五粮（高粱、小麦、玉米、糯米、大米）以及按生产比例制备的混合粮食样品的蒸煮香气中挥发性成分进行分析。结果表明,5种单粮中共鉴定出153种化合物;高粱、小麦、玉米、糯米、大米中分别鉴定出108、93、93、66、66种化合物,其中鉴定出较多数量的醛类、醇类、酮类、芳香类、酯类等化合物。采用双柱定性,在混合粮食样品中共鉴定出140种化合物。采用气相色谱-嗅闻-质谱联用法在混合粮食样品中共鉴定出29种香气活性化合物,结合香气提取稀释分析和香气活性值评价不同化合物对粮食蒸煮整体风味的影响。经计算,苄硫醇、(E,E)-2,4-癸二烯醛、(E)-2-壬烯醛、壬醛、己醛、辛醛、(E)-2-辛烯醛、(E,Z)-2,6-壬二烯醛、正庚醇、(E)-2-癸烯醛、(E,E)-2,4-壬二烯醛、苯乙醛、4-乙基愈创木酚、己酸乙酯、香叶基丙酮、辛酸乙酯、香草醛17种化合物的香气活性值不低于1,被认为是对粮香有贡献的重要风味化合物,其中苄硫醇和(E,Z)-2,6-壬二烯醛首次在蒸煮粮食香气中被鉴定。     

刺梨与无籽刺梨果实中药化学成分及抗氧化物质的比较分析

为全面剖析无籽刺梨中挥发性成分的组成及其呈香贡献,采用顶空固相微萃取（Head-Space Solid Phase Microextraction,HS-SPME）和液液萃取联合溶剂辅助风味蒸发（Liquid-Liquid Extraction-Solvent-Assisted Flavor Evaporation,LLE-SAFE）,并结合气相质谱联用（Gas Chromatography-Mass Spectrometry,GC-MS）分析无籽刺梨（Rosa sterilis）的挥发性成分,使用香气活性值（Odor Active Value,OAV）分析香气的贡献。结果表明,两种方法共鉴定出115种挥发性成分,HS-SPME检测到59种,LLE-SAFE检测到75种,其中,酯类为25种、醇类27种、醛类11种、酮类14种、酸类18种、萜烯类14种和其他类6种。两种提取方法对挥发性成分的提取效率有较大差异,HS-SPME对酯类（32.23%）和醛类（30.44%）的提取效率较高,LLE-SAFE对酸类（57.35%）和醇类（34.49%）的提取效率较高。香气活性值（OAV）分析表明,有30种挥发性成分对无籽刺梨的香气贡献较强,包括异戊醇、2-己烯醛、己酸乙酯、乙酸乙酯、丁酸乙酯、己醛和己酸等。本研究能够为揭示无籽刺梨香气轮廓其香气化学本质提供理论支持。