Re-investigation on odour thresholds of key food aroma compounds and development of an aroma language based on odour qualities of defined aqueous odorant solutions

Literature data on odour thresholds of volatile food constituents, and, in particular on their odour quality, may differ significantly. In order to obtain more reliable sensory data, the odour thresholds of eighty-four compounds previously characterised as key food odorants were re-evaluated and compared to literature results. In addition, the odour thresholds of ten odorants are reported here for the first time. On the basis of a distinct protocol, also the aroma attributes of the odorants were evaluated in order to define an aroma language, which can be used for specific purposes, e.g., training of panellists for GC-Olfactometry.     

新选308与铁观音乌龙茶香气成分比较分析

选用新选308和铁观音为研究对象,采用顶空-固相微萃取（HS-SPME）法富集其香气物质和GC-MS进行香气成分分析。结果表明:新选308的酯类组分（13.35%）、酮类组分（7.98%）和烯烃类（35.97%）比铁观音乌龙茶香气高,其他组分包括醇类、醛类、烷烃类、杂氧化合物、含氮化合物等均比铁观音低。新选308的主要香气成分是橙花叔醇（19.25%）、α-法呢烯（16.17%）、吲哚（13.1%）、反-β-罗勒烯（6.42%）、2-甲基-6-亚甲基-1,7-辛二烯-3-酮（4.39%）、己酸叶醇酯（3.8%）、α-香柑油烯（3.3%）、顺-茉莉酮（2.03%）、壬醛（1.94%）、苯乙醛（1.28%）、苯乙腈（1.24%）、己酸己酯（1.22%）、水杨酸甲酯（0.92%）等;通过对其感官审评比较,发现两种茶的感官评分相近,但两品种（系）所制乌龙茶呈现各自的品种香型,新选308所制乌龙茶香气似茉莉花香,而铁观音音韵显。      

Comparison between an odour profile and a flavour profile of dry fermented sausages

Summary  Two preparations of dry fermented sausage inoculated with one of four different strains of Staphylococcus were prepared a week apart and tested twice by 10 trained assessors. Profiles of eight attributes (vinegar, dry sausage, fat, dry cured-ham, pâté, milk, butter and nutty) were monadically assessed twice and scored on non-structured scales. During the first two sessions subjects tasted twice the four dry sausages from both preparations, and during the last two sessions 7 days later they assessed the odour of the same samples in duplicate by sparging with air. Principal component analysis showed that the eight samples (four strains X two preparations) of dry sausage were described similarly by tasting and sniffing except for the fat attribute. The principal component analysis showed that the eight samples of dry sausage were better discriminated by smell than by taste. The smelling procedure resulted in a better recognition of dry sausages inoculated with the same strain of Staphylococcus than that by tasting. Variance analysis showed that product effect was significant on common odour and flavour attributes: 'vinegar', 'fat' and 'butter'; and it was never significant on 'nutty' and 'pâté'. The F-values for 'vinegar', 'fat', 'dry-ham', 'milk' and 'butter' were higher by smell than by taste. Only 'dry-sausage' was better distinguished by taste.     

Flavour index and aroma profiles of fresh and processed honeys

This paper discusses the importance of flavour profiling in detecting indicative parameters for quality control of fresh and heated honey. Flavour compounds of six unifloral honeys (Lavandula stoechas, Castanea sativa, Dorycnium pentaphyllum, Rosmarinus officinalis, Eucalyptus sp and Robinia pseudoacacia) were investigated. The aroma extracts were obtained by a two‐step procedure involving (i) preliminary steam distillation under reduced pressure to evaluate the methylpyrazines generated in heated honeys by spectrophotometry (flavour index) and (ii) Likens–Nickerson's simultaneous steam distillation and solvent extraction (SDE) method with added NaCl. A combined total of 64 compounds were detected by gas chromatography/mass spectrometry (GC/MS), 58 of which were identified. Some compounds appeared to be characteristic of the floral source, particularly in Spanish lavender (methylated aliphatic acids and aromatic esters), eucalyptus (2,3‐pentanedione, acetoin, 1‐hexyl alcohol, 2‐acetyl‐5‐methylfuran, furfuryl propionate, 2‐phenylacetaldehyde and nerolidol), chestnut (acetophenone and 2‐aminoacetophenone), rosemary and D pentaphyllum (aromatic acids and esters, 2‐phenylacetaldehyde, farnesol and thymol) honeys. Robinia honey samples were characterised by very low levels of aromatic compounds. Twenty‐six flavour compounds were statistically closely related to the floral origin of the honeys (P ≤ 0.05). The flavour index was evaluated progressively in heated honeys, whereas in fresh honeys it showed a minimal value. © 2003 Society of Chemical Industry     

基于GC-MS的贵人香葡萄酒与蒸馏酒香气成分分析

采用搅拌棒吸附萃取-气相色谱-质谱联用法研究了贵人香葡萄酒和蒸馏酒的香气成分。结果表明,贵人香蒸馏酒中检测到55种香气成分,比贵人香葡萄酒中多出14种,主要是酯类、萘酚类、醛酮类、酸类、醇类和萜烯类化合物等。贵人香蒸馏酒中酯类含量为779.91 mg/L,是贵人香葡萄酒中的2.6倍。醇类中含量最多的为异戊醇,其在蒸馏酒中的含量为330.06 mg/L,是贵人香葡萄酒中的14倍,主要带给蒸馏酒指甲油味和威士忌味。蒸馏酒中的含量大于其嗅觉阈值的香气成分有10种,这些物质主要赋予蒸馏酒紫罗兰、菠萝、梨等花果香和脂肪味,蒸馏酒中含量较多的萘酚类物质在增加其香气复杂性方面有一定作用。     

百香果全果与果汁发酵酒滋味成分及香气成分对比

目的：提升百香果酒品质。方法：以百香果全果和果汁为原料酿制百香果酒,分别测定其有机酸、氨基酸和挥发性化合物含量,并结合电子舌试验结果评价百香果酒风味成分。结果：2种百香果发酵酒中主要有机酸为酒石酸、柠檬酸、乳酸和苹果酸,但全果酒的前3种有机酸含量均显著高于果汁酒中的（P<0.05）,全果酒和果汁酒中含量最多的有机酸分别为酒石酸（27.20 mg/mL）和柠檬酸（12.49 mg/mL）;除半胱氨酸未检出外,全果酒和果汁酒中16种游离氨基酸总含量分别为88.16,68.88 mg/100 g,且全果酒中4类呈味氨基酸含量高于果汁酒;电子舌测试发现,2种百香果发酵酒中咸味信号强度差异性最大,且全果酒中的鲜味、咸味最强,酸味、涩味和甜味最弱;HS-SPME-GC-MS共检出179种香气成分,全果酒中挥发性风味化合物种类比果汁酒多4种,但其萜烯类物质含量和种类分别比果汁酒的多1,3倍。结论：相比于果汁酒,新型百香果全果酒整体风味（鲜味、咸味、萜烯类物质等）较突出,提升了百香果资源的综合利用度。     

凤凰单丛茶老枞茶树和新枞茶树茶叶的香气和生化成分比较

通过比较老枞和新枞凤凰单丛茶树茶叶挥发性香气物质和化学成分的异同,为凤凰单丛茶古茶树资源的评价和利用提供理论依据。以老枞蜜兰香、老枞八仙、新枞蜜兰香和新枞八仙4个样品茶叶为研究对象,采用感官审评、同时蒸馏萃取(simultaneous distillation extraction, SDE)制备、气相色谱质谱(gas chromatography-mass spectrometer, GC-MS)分析和茶叶品质生化成分分析方法,对4个样品茶叶外形、汤色、香气、滋味、叶底、香气物质成分和品质生化成分进行审评、测定和比较。结果显示,老枞八仙在感官评审中得分最高,新枞蜜兰香得分最低。GC-MS分析显示,4个样品共检测得到醇类、杂环类、烯烃类、酯类、烷烃类和酮类等化合物61种香气成分,其中老枞蜜兰香与新枞蜜兰香相同的香气物质有30种,老枞八仙与新枞八仙相同的香气物质有38种。4个茶叶样品相同的香气物质有21种,占全部香气物质种类的34.4%。茶叶品质生化成分测定结果显示,茶多酚和儿茶素含量最高的是新枞蜜兰香,氨基酸和水浸出物含量最高的是老枞八仙,咖啡碱含量最高的是老枞蜜兰香。综合实验结果,老枞茶树茶叶的感官品质和化学品质与新枞茶树茶叶有一定差异,这种差异与茶树的茶龄有关。     

猕猴桃白酒陈酿期间香气成分变化分析

以猕猴桃为原料,经过发酵、两次蒸馏制得猕猴桃白酒,利用顶空固相微萃取法与气相质谱联用技术（HS-SPME-GC-MS）,对陈酿期间各个时期（一、二、四、七、十一个月）的猕猴桃白酒的香气成分进行分析。结果表明:猕猴桃白酒陈酿期间,共检出有香气物质为129种,酯类、缩醛类总体呈下降趋势,醇类、酸类、醛酮类及萜烯类呈上升趋势。猕猴桃白酒经陈酿后,香气成分经历了平衡、稳定及成熟的微妙动态变化,使酒体变得更加细腻、柔和、醇厚、丰满、典型性突出。      

猕猴桃白酒陈酿期间香气成分变化分析

以猕猴桃为原料,经过发酵、两次蒸馏制得猕猴桃白酒,利用顶空固相微萃取法与气相质谱联用技术(HS-SPME-GC-MS),对陈酿期间各个时期(一、二、四、七、十一个月)的猕猴桃白酒的香气成分进行分析。结果表明:猕猴桃白酒陈酿期间,共检出有香气物质为129种,酯类、缩醛类总体呈下降趋势,醇类、酸类、醛酮类及萜烯类呈上升趋势。猕猴桃白酒经陈酿后,香气成分经历了平衡、稳定及成熟的微妙动态变化,使酒体变得更加细腻、柔和、醇厚、丰满、典型性突出。     

浓香型烤烟中性致香成分及多酚含量与香气质量 的关系研究 , 浓香型烤烟中性致香成分及多酚含量与香气质量 的关系研究

以国内浓香型主产烟区的284份烤烟C3F为材料,采用偏相关分析、通径分析及逐步回归的分析方法,研究了浓香型烤烟中性致香成分及多酚含量与香气质量的关系。结果表明:中性致香物质和多酚类物质各指标对香气量、香气质的直接影响均不同;（1）香气质受6-甲基-5-庚烯-2-酮和绿原酸的直接正面影响最大,而受茄酮的直接负面影响最大,同时莨菪亭对其也有负面影响;（2）香气量受2-乙酰基吡咯和绿原酸的直接正面影响最大,而受苯乙醇的直接负面影响最大;（3）苯乙醛、糠醛、新植二烯、二氢猕猴桃内酯、巨豆三烯酮1、绿原酸、芸香苷对香气质和香气量均有直接正面影响;茄酮和藏花醛对香气质和香气量均有直接负面影响。因此,可通过调节调制条件提高中性致香物质和多酚物质中对香气质量有益成分,控制和降低对其不利的成分,改善其烟叶内在质量。, 以国内浓香型主产烟区的284份烤烟C3F为材料,采用偏相关分析、通径分析及逐步回归的分析方法,研究了浓香型烤烟中性致香成分及多酚含量与香气质量的关系。结果表明:中性致香物质和多酚类物质各指标对香气量、香气质的直接影响均不同;（1）香气质受6-甲基-5-庚烯-2-酮和绿原酸的直接正面影响最大,而受茄酮的直接负面影响最大,同时莨菪亭对其也有负面影响;（2）香气量受2-乙酰基吡咯和绿原酸的直接正面影响最大,而受苯乙醇的直接负面影响最大;（3）苯乙醛、糠醛、新植二烯、二氢猕猴桃内酯、巨豆三烯酮1、绿原酸、芸香苷对香气质和香气量均有直接正面影响;茄酮和藏花醛对香气质和香气量均有直接负面影响。因此,可通过调节调制条件提高中性致香物质和多酚物质中对香气质量有益成分,控制和降低对其不利的成分,改善其烟叶内在质量。      

The impact of maturation on concentrations of key odour active compounds which determine the aroma of tequila

Samples of non‐mature and añejo (matured) tequila of the same brand/provenance were analysed using GC–MS and gas chromatography olfactometry (GC‐O)/aroma extract dilution analysis (AEDA) to provide quantitative data on the most odour active compounds that contribute to the aroma of these spirits. Extracts of non‐mature tequila were characterized by 26 odour‐active regions, which included ethyl hexanoate, ethyl octanoate, 2‐phenylethyl acetate, β‐damascenone, isoamyl alcohol and octanoic acid as the most odour‐active compounds (flavour dilution, FD, factor ≥ 6561). In contrast, extracts of the mature spirit showed 36 odour‐active zones, where the compounds with the highest FD factors (6561) were ethyl hexanoate, ethyl octanoate, 2‐phenylethyl acetate, isoamyl alcohol, phenethyl alcohol, guaiacol, 4‐ethyl guaiacol, vanillin, cis/trans whisky lactones, β‐damascenone and octanoic acid. The aromagram of mature tequila was thus differentiated from that of the non‐mature spirit owing to the presence of cask‐extractive compounds and the increased FD factors of certain terpenes, higher alcohols and acetals. This study provides a comprehensive and quantitative understanding of changes in key odourants of tequila as a result of the maturation process and also reveals a further characterization of the likely impact of each compound on overall spirit flavour, in terms of odour activity values. Copyright © 2016 The Institute of Brewing & Distilling     

Assessment of the aroma profiles of low-alcohol beers using HS-SPME–GC-MS

The volatile profile of low-alcohol and alcohol-free beers was compared with that of alcoholic ones. Qualitative and quantitative differences were analyzed by headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME–GC-MS). Fermentation compounds as esters (isoamyl acetate, ethyl hexanoate, ethyl octanoate), alcohols (1-octanol, decanol, isobutanol, isoamyl alcohol) and fatty acids (hexanoic and octanoic acid) were present in higher quantities in alcoholic beers. The low-alcohol beers were characterized by compounds derived from malt and the roasting process, including pyrazines and furanes, and volatile compounds such as linalool, β-humulene and α-terpineol derived from the essential oil of hops. Benzaldehyde, acetylpyrrole, furfural and 2-furanmethanol were characteristics of free-alcohol beers.     

不同产地白肋烟中性香气成分及生物碱组成和含量分析

采用气质联用仪、高效液相色谱仪和气相色谱仪对我国四川、湖北、重庆、云南白肋烟及美国白肋烟中性香气成分、类胡萝卜素及生物碱含量进行了分析测定,结果表明,巨豆三烯酮、香叶基丙酮等重要类胡萝卜素降解产物在美国白肋烟中的含量显著高于国内烟叶,β-大马酮、β-紫罗兰酮、β-二氢紫罗兰酮和氧化异佛尔酮等香气成分含量与国内主产区白肋烟差别不大。西柏三烯二醇主要降解产物茄酮含量国内烟叶一般高于美国烟叶。云南烟叶与其它产地烟叶相比,大多重要的类胡萝卜素降解产物含量较低,但叶黄素、β-胡萝卜素含量以及巨豆三烯酮形成过程的中间产物3-氧化-а-紫罗兰醇的含量显著高于其它产区烟叶。美国烟叶中苯乙醛、苯甲醛含量低于国内烟叶;云南烟叶中糠醛含量明显高于其它产区,其它成分含量各产区比较接近。我国湖北和云南白肋烟烟碱含量高于美国白肋烟,而四川和重庆白肋烟烟碱含量显著低于美国烟叶。我国白肋烟产区除云南外均存在烟碱向降烟碱转化问题,其中四川烟叶烟碱转化率高达62.4%,对其品种进行改良是当务之急。     

浅谈企业精神与企业文化的关系

当前,在企业精神与企业文化的研究中,有些同志或者将二者等同起来,或者虽稍加区分,但又缺乏明确的解释,致使人们对企业精神与企业文化之间究竟是什么关系,两者各自的内涵是什么,把握不准,由此带来实践中的偏颇。企业精神和企业文化既有联系又有区别,本文试就二者关系谈些粗浅看法。     

浓香型烤烟叶片单叶重与中性香气成分含量的关系研究

以豫中烟区主栽品种NC89为试验材料,研究了中上部叶片单叶重与中性香气成分含量的关系.结果表明:中部叶多数类胡萝卜素降解产物、棕色化反应产物及茄酮含量在单叶重12 g时达到最大值,随着单叶重的继续增加含量迅速降低并趋于平缓;大部分苯丙氨酸裂解产物在单叶重10 g时达到最大值,随单叶重的增加而逐渐降低.上部叶大部分中性香气成分含量在单叶重12～15 g时达到最大值,茄酮含量在单叶重为9 g时含量最高,随单叶重的增加逐渐降低.除新植二烯外的香气成分总量变化幅度表现为中部叶大于上部叶,且二者均在单叶重12 g时达到最大值.综合各香气成分的含量,中部叶与上部叶的最适单叶重范围分别为10～12 g和12～15 g.     

Comparison of aroma properties of infant formulas: Differences in key aroma compounds and their possible origins in processing

Aroma is an important attribute of infant formula (IF). In this study, 218 volatiles and 62 odor-active compounds were detected from IF by dynamic headspace sampling combined with comprehensive 2-dimensional gas chromatography-olfactometry-mass spectrometry. Aldehydes and ketones were determined as the most abundant odor-active compounds. Among them, the contents of pentanal and hexanal were the most abundant, while 1-octen-3-one had the highest flavor dilution factor and odor activity value in most of the IF. Sensory evaluation and electronic nose analysis showed that the skimming process, the fatty acid composition, and powdered or liquid milk base used for the production of IF may be important factors resulting in their differences in aroma profiles and compounds. These differences were assumed to be mainly ascribed to the Maillard reaction and lipid oxidation, which were largely influenced by the temperature and water activity.