Quantification of aroma compounds in Parmigiano Reggiano cheese by a dynamic headspace gas chromatography-mass spectrometry technique and calculation of odor activity value

Potentially important aroma compounds in Parmigiano Reggiano cheese were quantified. Free fatty acids were isolated with ion-exchange chromatography and quantified by gas chromatography. Neutral aroma compounds were quantified with a purge-trap/gas chromatography-mass spectrometry with selective mass ion technique. Odor activity values were calculated based on sensory thresholds reported in literature. The calculated odor activity values suggest that 3-methylbutanal, 2-methylpropanal, 2-methylbutanal, dimethyl trisulfide, diacetyl, methional, phenylacetaldehyde, ethyl butanoate, ethyl hexanoate, ethyl octanoate, acetic, butanoic, hexanoic, and octanoic acids are the most important aroma contributors to Parmigiano Reggiano cheese.     

The key aroma compounds and sensory characteristics of commercial Cheddar cheeses

To study the key aroma components and flavor profile differences of Cheddar cheese with different maturity and from different countries, the flavor components of 25 imported commercial Cheddar cheese samples in the China market were determined by gas chromatography-mass spectrometry. The quality and quantity of 40 flavor compounds were analyzed by gas chromatography-olfactometry among 71 aroma compounds determined by gas chromatography-mass spectrometry. Combined with odor activity value calculation, principal component analysis (PCA) was conducted to analyze the relationship among 26 flavor compounds with odor activity values >1 and the maturity of Cheddar cheese. The PCA results showed significant differences between the group of mild Cheddar cheese and the groups of medium Cheddar cheese and mature Cheddar cheese, and no significant differences were observed between medium Cheddar cheese and mature Cheddar cheese. According to the results of PCA and consumers' preference test, representative Cheddar cheese samples with different ripening times were selected for the flavor profile analysis. Partial least squares regression analysis was conducted to obtain the relationship between sensory properties and flavor compounds of different Cheddar cheeses. Based on partial least squares regression analysis, 1-octen-3-one, hexanal, acetic acid, 3-methylindole, and acetoin were positively correlated with milky, sour, and yogurt of mild Cheddar cheese. Dimethyl trisulfide, phenylacetaldehyde, ethyl caproate, octanoic acid, and furaneol and other compounds were positively correlated with fruity, caramel, rancid, and nutty notes of the medium and mature Cheddar cheeses.     

Identification of aroma-active compounds in Cheddar cheese imparted by wood smoke

Cheddar cheese is the most popular cheese in the United States, and the demand for specialty categories of cheese, such as smoked cheese, are rising. The objective of this study was to characterize the flavor differences among Cheddar cheeses smoked with hickory, cherry, or apple woods, and to identify important aroma-active compounds contributing to these differences. First, the aroma-active compound profiles of hickory, cherry, and apple wood smokes were analyzed by solid-phase microextraction (SPME) gas chromatography-olfactometry (GCO) and gas chromatography-mass spectrometry (GC-MS). Subsequently, commercial Cheddar cheeses smoked with hickory, cherry, or apple woods, as well as an unsmoked control, were evaluated by a trained sensory panel and by SPME GCO and GC-MS to identify aroma-active compounds. Selected compounds were quantified with external standard curves. Seventy-eight aroma-active compounds were identified in wood smokes. Compounds included phenolics, carbonyls, and furans. The trained panel identified distinct sensory attributes and intensities among the 3 cheeses exposed to different wood smokes (P < 0.05). Hickory smoked cheeses had the highest intensities of flavors associated with characteristic “smokiness” including smoke aroma, overall smoke flavor intensity, and meaty, smoky flavor. Cherry wood smoked cheeses were distinguished by the presence of a fruity flavor. Apple wood smoked cheeses were characterized by the presence of a waxy, green flavor. Ninety-nine aroma-active compounds were identified in smoked cheeses. Phenol, guaiacol, 4-methylguaiacol, and syringol were identified as the most important compounds contributing to characteristic “smokiness.” Benzyl alcohol contributed to the fruity flavor in cherry wood smoked cheeses, and 2-methyl-2-butenal and 2-ethylfuran were responsible for the waxy, green flavor identified in apple wood smoked cheeses. These smoke flavor compounds, in addition to diacetyl and acetoin, were deemed important to the flavor of cheeses in this study. Results from this study identified volatile aroma-active compounds contributing to differences in sensory perception among Cheddar cheeses smoked with different wood sources.     

Volatile compounds, odor, and aroma of La Serena cheese high-pressure treated at two different stages of ripening

La Serena cheeses made from raw Merino ewe's milk were high-pressure (HP) treated at 300 or 400 MPa for 10 min on d 2 or 50 after manufacture. Ripening of HP-treated and control cheeses proceeded until d 60 at 8°C. Volatile compounds were determined throughout ripening, and analysis of related sensory characteristics was carried out on ripe cheeses. High-pressure treatments on d 2 enhanced the formation of branched-chain aldehydes and of 2-alcohols except 2-butanol, but retarded that of n-aldehydes, 2-methyl ketones, dihydroxy-ketones, n-alcohols, unsaturated alcohols, ethyl esters, propyl esters, and branched-chain esters. Differences between HP-treated and control cheeses in the levels of some volatile compounds tended to disappear during ripening. The odor of ripe cheeses was scarcely affected by HP treatments on d 2, but aroma quality and intensity scores were lowered in comparison with control cheese of the same age. On the other hand, HP treatments on d 50 did not influence either the volatile compound profile or the sensory characteristics of 60-d-old cheese.     

主成分分析法评价树莓中挥发性香气成分气味活度值

目的以气味活度值为依据,采用主成分分析法评价树莓中典型性挥发性香气成分。方法应用顶空固相微萃取技术与气相色谱-质谱联用技术分离鉴定不同树莓的挥发性香气成分,结合气味阈值评价16个不同品种树莓的气味活度值,并采用气味轮图法确定树莓的香气类型,运用主成分分析评价树莓中不同香气成分对整体香气的贡献。结果 Macblack和Bristol主要香气成分是芳樟醇、香叶醇,总气味活度值均低于10,以玫瑰香、花香和香脂香为代表香型;其余14种树莓中Reveille总气味活度值最高,β-紫罗兰酮、α-紫罗兰酮、芳樟醇、1-壬醛为关键性风味化合物,香气类型以紫罗兰香为主,以柑橘香和玫瑰花香为辅;主成分分析表明主成分1贡献率为53.98%,主成分2贡献率为46.01%,Bristol和Macblack与主成分2呈显著负相关(P<0.05),其余14个品种与主成分1呈显著正相关(P<0.05)。结论芳樟醇、β-紫罗兰酮、α-紫罗兰酮、1-壬醛对树莓香气的贡献最大,是树莓的典型性挥发性香气成分。     

GC-O-AEDA法在食品风味分析中的应用

芳香萃取物稀释分析法是气相色谱-嗅觉测量法中一种有效地利用稀释因子(FD)具体说明气味活性物质贡献大小的方法。文章介绍它的原理、主要的样品稀释方法及其所对应采用的前处理方法,并综述该技术在食品风味分析中的应用。     

Effects of pectic fat mimetics and transglutaminase on the regularity of protein and fat degradation and flavour compounds in Cheddar cheese during ripening

The effect of simultaneous transglutaminase (TGase) treatment with pectic fat mimetics (PFM) addition on regularity of protein and fat degradation and flavour compound variations in Cheddar cheese during ripening was investigated. In the early stages of fermentation, the cheese with 20% PFM and 15 U/L TGase had a higher amino acid content. In the middle stage of fermentation, cheese with high concentration of TGase hydrolysed more proteins. Cheese supplemented with PFM and TGase showed increased content of long-chain polyunsaturated fatty acids, especially linoleic acid (C18:2). In addition, PFM and TGase compensated the flavour deficiencies of low-fat cheeses and had positive effects on volatile compounds such as alcohols, acids and methyl ketones. Overall, the characteristics and flavours of Cheddar cheese with the addition of PFM and TGase were superior to the control group, which could provide a theoretical basis for the application of PFM and TGase in cheese production.     

GC-MS/O结合香气活性值表征烧麦中关键香气成分及其贮存过程中的变化情况

为确定烧麦中的关键香气成分及其贮存过程中的变化情况,采用溶剂萃取结合溶剂辅助风味成分蒸发提取烧麦中的挥发性成分,所得提取物经气相色谱-嗅闻联用仪与气相色谱-质谱联用仪分析,共鉴定出50个香气活性成分。通过香气提取物稀释分析,测定香气活性成分的香气稀释因子,其中1-辛烯-3-醇、茴香脑、愈创木酚、2-戊基呋喃等具有最高的香气稀释因子（6 561）。采用内标标准曲线法对37个香气稀释因子不低于81的成分进行定量分析;根据定量结果和阈值,计算物质的香气活性值,其中21个香气活性成分的香气活性值不低于1,被确定为烧麦的关键香气成分。通过分析室温贮存0～13个月后烧麦中37个成分含量并计算其香气活性值,发现烧麦贮存过程中关键香气成分的数量不变,除酱油酮、己醛和4-乙烯基愈创木酚的含量下降外,烧麦中多数重要香气活性成分含量变化较小。     

清香型志都五谷酒关键香气成分分析

通过液液萃取和顶空固相微萃取技术,结合气相色谱-质谱-嗅闻联用仪分析一种清香型志都五谷酒香气活性成分.通过香气提取稀释分析法共得到40种香气物质,且香气稀释(flavor dilution,FD)因子最大的为异丁酸、月桂酸乙酯、愈创木酚和2-苯乙醇(FD＞4 096),通过质谱、保留指数、香气特征和标准品比对共定性出3...     

2种芝麻香型白酒中香气活性成分分析

应用液液萃取法结合气相色谱-质谱-嗅闻联用仪分析2 种芝麻香型白酒（BTQ、YH）中香气活性成分。经保留指数、香气特征并结合标准品比对,BTQ和YH分别定性出挥发性化合物75 种和68 种;结合气相色谱-质谱-嗅闻联用通过芳香萃取物稀释分析分别嗅闻出香气活性化合物48 种和46 种,BTQ中香气稀释（flavor dilution,FD）因子值最大的是3-甲硫基丙醛（FD=6 561）;YH中FD最大的是苯乙醇、3-甲基-1-丁醇、丁酸乙酯、戊酸乙酯（FD=2 187）。通过多种方法联用,对嗅闻到的51 种香气活性成分和28 种非嗅闻活性成分进行定量分析,并结合相关阈值进行香气活性值（odor activity value,OAV）分析,比较它们对整体香气的贡献程度,发现BTQ中有40 种化合物OAV不小于1,YH中有36 种化合物OAV不小于1,2 种酒中香气贡献度最高的是己酸乙酯、3-甲基丁醛、丁酸乙酯、3-甲基丁酸乙酯。结合FD因子及OAV,对这2 种芝麻香型白酒香气有重要贡献的化合物有己酸乙酯、丁酸乙酯和3-甲基丁醛。     

Evaluation of potent odorants in heated egg yolk by aroma extract dilution analysis

Egg yolk was extracted using the method of Likens-Nickerson (simultaneous distillation/extraction). The resulting aroma extract, which smelled characteristic of heated egg yolk was analysed by aroma extract dilution analysis and gas chromatography–mass spectrometry. Of 41 odorants that were detected, 19 could be identified. Compounds with high flavour dilution factors were methional, phenyl acetaldehyde, 2-acetyl-1-pyrroline, heptanal, 1-octen-3-one and (E,E)-2,4-decadienal. Strecker degradation of methionine, phenylalanine and proline, as well as autoxidation of phospholipid-bound linoleic and arachidonic acids are proposed as the major factors for egg yolk flavour formation.     

MMSE-GC-O结合OAV法鉴定蒸制崇明地区 中华绒螯蟹中关键气味物质

目的 分析蒸制雄性崇明地区中华绒螯蟹不同可食部位的挥发性成分,筛选关键气味物质,为解析其优良风味提供理论依据。方法 采用7个MonoTrap RCC18 吸附子在100 ℃下对5 g样品顶空萃取50 min,运用GC-MS对各挥发物进行分离鉴定,以内标法对其进行半定量,联用GC-O法和OAV法进一步筛选得到关键气味物质。结果 雄性中华绒螯蟹中共鉴定得到71种挥发性成分,体肉、钳肉、足肉和性腺中分别得到50种、48种、52种和62种成分。从所有71种物质中进一步筛选得到19种“关键气味物质”,其中6种为“主要关键气味物质(MKOCs)”(气味强度值≥3且气味活性值≥10)。三甲胺(鱼腥味)为4个部位所共有的MKOC,除三甲胺外,苯甲醛(杏仁味)和(Z)-4-庚烯醛(鱼腥味)分别为体肉和足肉中的MKOC,己醛(青草味)、1-辛烯-3-醇(蘑菇味)和壬醛(青草味)是性腺中的MKOCs。结论 6种MKOCs被OAV法和GC-O法同时证实具有较高的气味活性,可表征雄性崇明中华绒螯蟹不同部位的关键香气特征,其形成机制值得进一步研究。     

特香型白酒酿造用不同种类大米营养成分和挥发性香气成分的差异性分析

大米是影响特香型白酒酿造的重要因素之一,该研究对4种酿酒原料大米（早籼米、粳米、籼糯米、粳糯米）的主要营养成分和挥发性香气成分进行测定。结果表明,所选4种大米的淀粉、蛋白质和脂肪含量存在显著差异（P＜0.05）,早籼米、粳米、粳糯米和籼糯米的淀粉含量分别为71.41%、74.79%、73.12%和70.55%;蛋白质含量分别为6.76%、7.11%、6.13%和5.66%;脂肪含量分别为0.21%、0.28%、0.58%和0.42%。在早籼米、粳米、粳糯米和籼糯米中分别鉴定出了26种、22种、29种和17种挥发性香气物质。4种大米的主要挥发性香气成分种类基本相似,主要为醇类、醛类、酮类、酯类和酸类,其中棕榈酸、亚油酸、油酸、壬醛等在4种大米含量均较高。早籼米中特有的苯乙醇、2,4-二叔丁基酚等对白酒风味有积极作用的挥发性香气物质含量分别为0.49%和2.31%。     

现代工艺和传统工艺酿造小曲清香型白酒感官表征及风味成分分析

运用感官分析、气相色谱-嗅闻-质谱技术、项空固相微萃取-气相色谱-质谱联用技术,研究现代工艺和传统工艺酿造而成的小曲清香型白酒的主要香气轮廓及风味成分.采用保留指数结合标准品比对法分别从现代工艺和传统工艺小曲清香型白酒中鉴定出116种和121种挥发性成分;并进一步通过芳香萃取物稀释分析法从现代工艺和传统工艺小曲清香型白...     

基于顶空固相微萃取法-气相色谱-质谱法和相对气味活度值分析13种凤凰单丛茶香气成分

目的 探究13种凤凰单丛茶香气成分及各香气成分对总体风味的贡献。方法 采用顶空固相微萃取法(headspace solid phase microextraction, HS-SPME)和气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)对13种单丛茶进行香气成分分析, 并结合相对气味活度值(relative odor activity value, ROAV)筛选各单丛茶关键香气成分。结果 在13种单丛茶样品中检出香气成分179种, 新检出成分88种, 共有香气成分53种。同时, 根据挥发性成分的ROAV值, 共检出17种关键香气成分, 对总体香气的贡献率由大到小依次为1-辛烯-3-醇、癸醛、β-环柠檬醛、异丁醛、β-紫罗兰酮、法尼醇、香叶醇、α-法尼烯、异戊醇、顺-1,5-辛二烯-3-醇、顺-3-己烯醇、庚醛、脱氢芳樟醇、反-3-戊烯-2-酮、2-癸酮、2-庚烯醛、6-甲基-5-庚基-2-酮; 另外, 检出16种重要修饰成分, 共有关键香气5种, 分别为1-辛烯-3-醇、法尼醇、β-环柠檬醛、癸醛和β-紫罗兰酮。结论 各关键香气成分在不同单丛茶中含量及贡献度存在明显差异。     

基于气相色谱-嗅闻-质谱法和风味活度值分析安丘大姜中关键风味活性物质

目的：利用香气活性值和气相色谱-嗅闻-质谱联用法鉴定安丘大姜关键香气活性成分,为安丘大姜的种植、质量控制及风味评价提供指导。方法：运用气相色谱-质谱法（gas chromatography-mass spectrometry,GC-MS）对各挥发物进行分离鉴定,以内标法对其进行半定量,用气相色谱-嗅闻-质谱法（gas chromatography-olfactometry-mass spectrometry,GC-O-MS）和风味活度值（odor activity value,OAV）进一步筛选得到关键气味物质。结果：通过GC-MS鉴定出59种挥发性化合物,OAV法和GC-O-MS法分别确定了31种和13种风味活性物质。综合两种方法发现安丘大姜关键性风味物质为莰烯、月桂烯、β-蒎烯、芳樟醇、α-松油醇、橙花叔醇、香茅醇、香茅醛、乙酸香茅酯、冰片。结论：确定了安丘大姜关键风味活性物质,为安丘大姜产业发展提供指导,为生姜风味物质鉴定提供理论支持。     

老抽酱油储存期间关键气味物质分析及其风味特征的变化

为阐明老抽酱油在不同储存期的关键气味化合物及其风味特征的变化,采用液液萃取与气相色谱-嗅闻-质谱(GC-O-MS)相结合提取并鉴定不同储存期老抽酱油中的挥发性气味化合物,并利用香味提取物稀释分析(AEDA)鉴定关键气味化合物。结果表明:在老抽酱油样品中共检测到56种气味活性物质,其中FD因子>1024的化合物分别为2-甲基吡嗪、2,6-二甲基吡嗪、5-甲基-2(3H)-呋喃酮、2-乙酰基呋喃、2-乙酰基-5-甲基呋喃、1,4-丁内酯、5-甲基-2-呋喃甲醇、2-羟基-3-甲基-2-环戊烯酮、愈创木酚、麦芽酚和4-羟基-2,5-二甲基-3(2H)-呋喃酮 (HDMF),其中,2,6-二甲基吡嗪、5-甲基-2(3H)-呋喃酮、2-羟基-3-甲基-2-环戊烯酮、麦芽酚和HDMF的香气活性值>1,对老抽酱油整体香气起主要贡献作用。感官评价结果表明,老抽酱油随着储存时间的延长,烤香味和烟熏味的气味强度得分升高。该研究分析了老抽酱油的关键气味化合物以及在储存过程中气味特征变化,为老抽酱油相关风味研究提供了理论参考。     

基于顶空固相微萃取气质联用和rOAV值分析不同发酵时间玫瑰红茶香气的差异

目的 探究不同发酵时间处理对玫瑰花茶香气及感官品质的影响。方法 本实验在相同环境条件下,以玫瑰花瓣为材料,采取萎凋、揉捻、发酵、干燥四道制作工艺,分0 h发酵、2 h发酵、4 h发酵、6 h发酵4个处理,采取顶空固相微萃取-气质联用(HS-SPME-GC-MS)鉴定玫瑰花挥发性成分,筛选其关键呈香物质。结果 共检测出4种处理938种16类挥发性代谢物。发酵2、4、6 h与发酵0 h的挥发性代谢物存在显著差异物质554种,相对0 h发酵分别增加差异显著代谢物364种、388种、400种,同时对照4种处理呈玫瑰花香气的rOAV,结合感官评审结果,得出本实验发酵4小时为玫瑰花红茶的最好处理,且发现关键呈玫瑰花香气的物质为壬醇、异戊酸苯乙酯、苯乙醛、2-苯乙醇、香叶醇、大马士酮、苯甲醇、异丁酸香叶酯、(E)-6,10-二甲基-5,9-十一碳烯-2-酮、壬酸乙酯。结论 玫瑰花瓣能制作成质量优异的玫瑰红茶,常规发酵过程中4 h发酵的玫瑰红茶品质最佳。以上结果阐明了玫瑰发酵过程中香气成分变化,为实现玫瑰花产业资源化利用提供了参考依据。     

气相色谱-质谱联用与相对气味活度值法分析坛子肉风味物质的研究

目的 分析探讨坛子肉中的关键性风味物质。方法 应用固相微萃取-气相色谱-质谱法(solid phase microextraction-gas chromatography-mass spectrometry, SPME-GC-MS)对5种不同坛子肉的挥发性风味物质进行分离鉴定, 并应用相对气味活度值法(relative odor activity value, ROAV)对5种坛子肉共有的挥发性风味物质进行特征性分析。结果 5种不同坛子肉中分别检测出60、57、51、54、57种挥发性风味物质, 坛子肉主要风味物质有醛、醇、酯、酸、酮等物质, 其关键挥发性风味物质为己醛、乙酸乙酯、反式-2-壬烯醛、1-辛烯-3-醇、壬醛、3-甲基丁醛和2-己烯醛。结论 本研究方法可以得出坛子肉的主要及关键挥发性风味物质, 方法有一定的实用性。