Study on the volatile profile characteristics of oyster Crassostrea gigas during storage by a combination sampling method coupled with GC/MS

In this work, a combination sampling method, including headspace solid-phase microextraction (HSSPME) and steam distillation (SD), was used to study the oyster volatiles during storage followed by GC–MS detection. Twenty and twenty seven volatile compounds of fresh and deteriorated oysters were identified respectively by HSSPME, and 16 oyster volatiles were isolated by SD. HSSPME and SD were suitable for low-boiling-point and high-boiling-point volatiles, respectively. Therefore, the combination of HSSPME and SD could obtain more species of oyster volatiles during storage than any single method. Different volatile profile characteristics during oyster storage obtained by HSSPME were specified by principal component analysis. The top ten volatiles contributing most to the difference of oyster volatile profile characteristics during storage were distilled by common model analysis. The results tentatively suggested that the difference of entire volatile profile characteristics during oyster storage would provide more precise alarming information for oyster deterioration during storage than individual volatiles.     

Study of the volatile composition of tomato during storage by a combination sampling method coupled with gas chromatography/mass spectrometry

BACKGROUND: The volatile compositions of common tomato (Lycopersicon esculentum var. commune) and cherry tomato (Lycopersicon esculentum var. cerasiforme) during storage were studied by a combination sampling method, including headspace solid phase microextraction (HSSPME), simultaneous distillation extraction (SDE) and steam distillation (SD), coupled with gas chromatography/mass spectrometry (GC/MS) detection. RESULTS: Twenty‐one and 14 volatile compounds of fresh and stale common tomatoes and 27 and 17 volatile compounds of fresh and stale cherry tomatoes were identified with various degrees of certainty. The main identified volatile compounds of common and cherry tomatoes were C6 alcohols and aldehydes. During storage, saturated hexanal increased gradually whereas unsaturated (E)‐2‐hexenal decreased. Different volatile compositional characteristics at the fresh and stale storage phases obtained by HSSPME were specified by principal component analysis (PCA). Different metabolic pathways and enzyme catalyses resulted in the various volatile compositional characteristics during tomato storage. Five typical volatile compounds contributing greatly to the difference in volatile compositional characteristics of common and cherry tomatoes at the fresh and stale storage phases were distilled by a common model strategy. These compounds are potential biomarkers for tomato degradation, but further study is needed. CONCLUSION: The preliminary results suggest that the combination of HSSPME and conventional sampling methods would yield more representative information on changes in tomato volatile composition during storage. Copyright © 2007 Society of Chemical Industry     

SPME/GC/MS法检测蒜薹中的挥发性成分

采用两种萃取头（50/30μm DVB/CAR/PDMS和100μm PDMS）,利用顶空固相微萃取（SPME）-气质联用（GC/MS）分析四个大蒜主产地蒜薹中的挥发性成分。研究结果表明,100μm PDMS萃取头适合分析蒜薹中的挥发性成分,永年、惠民、商河、广饶四个产地的蒜薹共有的含硫化合物为二烯丙基二硫醚、甲基烯丙基三硫醚、二烯丙基三硫醚、二烯丙基硫醚、3-乙烯基-1,2-二硫杂-4-环己烯、1,3-二硫酸-2-硫酮、3,4-二甲基噻吩、1,3-二噻烷,其中二烯丙基二硫醚的含量最高。进一步分析表明,蒜薹不同部位的含硫化合物含量有一定差异,蒜薹含硫化合物含量:根部>茎中部>茎上部。本研究对于促进蒜薹加工利用,拓宽蒜薹产业链具有重要意义。      

基于GC/MS的储藏粳稻谷挥发物质变化研究

应用顶空固相微萃取-气质联用分析技术,对不同储藏条件下的稻谷样品挥发物质进行测定,用主成分分析法(PCA)研究不同稻谷样品间挥发物质的差异,进而找出能够反应稻谷储藏品质的特征性挥发物。测定结果表明,共检测到不同储藏条件下的稻谷样品挥发物质117种,从中筛选出贡献较大的83种成分进行分析,其中烃类29种,醛类17种,酮类10种,醇类8种,酸酯类10种,杂环类9种。主成分分析(PCA)结果表明,储藏期间稻谷的酸酯类、醇类、醛类、酮类、烷烃类、烯烃类挥发物质下降明显,且温度越高下降程度越大;苯类挥发物质随储藏时间的延长有上升趋势,温度越高上升的越明显;杂环类挥发物质受储藏时间以及温度的影响较小。各类挥发物质受储藏条件影响大小顺序为酸酯类 > 醇类 > 酮类 > 醛类 > 烃类 > 杂环类,同时得到评判稻谷品质的特征性挥发物质。     

GC-MS法分析南湾鳙鱼鱼肉挥发性成分的组成

以南湾鳙鱼为原料,采用SDE提取装置提取有效成分并结合气相色谱-质谱(GC-MS)技术对南湾鳙鱼的挥发性风味物质进行分析检测.结果表明,南湾鳙鱼含有丰富的风味物质,在检出的41种风味物质中,醛类15个(49.15％)、醇类5个(5.03％)、酮类3个(2.54％)、碳氢类化合物8个(10.3％)、酸类化合物2个(3.42％)、酯类化合物3个(9.63％)、杂环类化合物5个(9.34％).对其风味有贡献的主要挥发性物质为2,4-癸二烯醛、乙酸乙酯、1-辛烯-3-醇、2-乙基呋喃、己醛、十二醛.     

GC-MS分析同时蒸馏-萃取(SDE)黑胡椒挥发性成分

采用同时蒸馏-萃取(SDE)黑胡椒挥发性成分,用色谱/质谱法分析鉴定,并用总离子流色谱峰的峰面积进行归一法定量分析其成分.根据总离子图,分析鉴定出3-蒈稀(27.2%),反式-石竹烯(22.08%),柠檬烯(19.34%),β-蒎烯(9.16%),α-蒎烯(5.15%),l-水芹烯(3.86%),可巴烯(2.32%),δ-檀香烯(2.19%),m-伞花烯(1.88%),β-香叶烯(1.6%)等30种化合物.     

固相微萃取气质联用测定酸奶发酵过程中挥发性风味成分

将酸奶发酵过程视作一个仅与外界有能量交换的动态系统,采用顶空固相微萃取法(HS-SPME)制备样品,利用气相色谱-质谱法(GC-MS)分离分析酸奶中的挥发性风味成分。比较不同顶空萃取时间、萃取方式、萃取温度,获得最佳样品提取条件,同时优化GC-MS色谱测定条件,确定吸附温度45℃、磁力搅拌30 min、加入氯化钠量为3 g/12 g时吸附30 min为测定酸奶中挥发性成分的办法。最终测定19种风味成分,分析得出特征性成分如双乙酰、乙酸、棕榈酸等随时间变化的趋势,并通过主成分分析,采用5个向量表示酸奶发酵过程及在发酵不同阶段的特征性风味。     

SDE/SPME-GC-MS分析苦荞的挥发性香气成分

为了分析不同方法萃取苦荞样品中挥发性物质的差异,采用同时蒸馏萃取法（SDE）和固相微萃取法（SPME）提取苦荞样品中的挥发性成分,用气相色谱-质谱联用（GC-MS）技术定性鉴定,并用总离子流色谱峰的峰面积进行归一化定量分析。同时蒸馏萃取-气谱-质谱法（SDE-GC-MS）分析出23种挥发性成分,固相微萃取-气相色谱-质谱法（SPME-GC-MS）分析出35种挥发性成分,2种方法均提取出酯类、烃类、酮类、醛类和醇类,其中酯类和醛类的含量较多,说明酯类和醛类对苦荞的风味贡献较大。同时蒸馏萃取法适合对高沸点、低挥发性物质进行分离,固相微萃取法具有快速简便、不使用溶剂和样品检测非破坏性等优点,适合易挥发性化合物的检测。将两种提取方法相结合对苦荞挥发性物质提取能得到比较全面的结果。     

Vacuum-packed ripened sausages: evolution of volatile compounds during storage

BACKGROUND: Various studies have shown the ability of volatile compounds to influence the quality of charcuterie products because of their effect on sensorial properties. To the best of our knowledge, there are no data in the scientific literature concerning the evolution of volatile compounds of vacuum‐packed ripened sausages over time. The aim of this work was to evaluate the evolution of volatile compounds in vacuum‐packed ripened sausages over time, considering that this kind of packaging is the most commonly used to prolong the shelf‐life of these products. RESULTS: Sixty‐nine volatile compounds were identified. Those derived from spices represented the prevailing compounds at the beginning of storage and significantly decreased (P < 0.001) during 5 months of storage, as a result of the well‐known antioxidant activity. Conversely, compounds derived from the autoxidation of lipids, which are among those chiefly responsible of sensorial properties of meat products, significantly increased (P < 0.001). CONCLUSION: The research demonstrated that vacuum packaging influenced the evolution of volatile compounds during storage of ripened sausages. In particular, the increase of volatile compounds derived from autoxidation of the lipid fraction indicated that oxidative processes involved the fatty fraction of ripened sausages also in the scarcity of oxygen. Copyright © 2011 Society of Chemical Industry     

二种方法提取紫苏挥发油的气相色谱-质谱比较

采用超临界CO2流萃取紫苏挥发油，对在不同条件下萃取的紫苏挥发油，用色谱-质谱（GC-MS）联用方法进行了化学组分的测定和分析，并与水蒸气蒸馏法所得之挥发油化学组分相比较，发现超临界CO2流萃取的挥发油香气、品质和产率均优于蒸馏法所得。     

地毯有机挥发物的ETC-ATD-GC/MS联用测试法

采用环境测试舱(ETC)、自动热脱附仪(ATD)和气相色谱/质谱(GC/MS)联用技术,建立了地毯中13种挥发性有机物(VOCs)的分析方法。该方法对VOCs单体的最小检出限(LODs)范围为0.008～0.4μg/m~3,方法的加标回收率为90%～106%,相对标准偏差(RSD)小于11%。将该方法用于多种市售地毯的VOCs测试,发现地毯释放VOCs的种类,与地毯底层材料有较大关联,沥青底胶层的方块地毯释放出较多的2-乙基-1-己醇,黄麻背衬地毯和聚酯背衬地毯释放出较多的苯乙烯和4-苯基环己烯,而薄层聚丙烯背衬地毯则释放出较多的直链或支链烷烃。     

冷藏期间真空包装鲻鱼肉中特征性挥发物研究

为了探讨鲻鱼肉中特征性挥发物,利用顶空固相微萃取-气-质联用（HS-SPME-GC-MS）法检测真空包装0℃下贮藏期间鲻鱼肉挥发性风味。实验结果显示,共鉴定出七大类76种化合物,并分析贮藏期间鲻鱼肉中主要的挥发物相对含量变化、气味特征及其来源。研究发现,鲻鱼挥发性风味以烃类、杂环类、醇类和醛类为主,冷藏期间一直能够被检测到的8种主要特征性挥发物分别为:十二烷、十六烷、二十八烷、甲苯、萘、2,4-二叔丁基苯酚、二丁基羟基甲苯和亚硫酸。通过主成分分析冷藏期间鲻鱼特征性挥发物变化规律,提炼出4个主成分因子,为进一步研究鲻鱼挥发性风味成分奠定了基础。      

固相微萃取结合气-质分析东北大酱的挥发性成分

采用固相微萃取结合气-质联用分析东北大酱的挥发性成分,并考察了提取时间和提取温度对挥发性成分提取效果的影响。结果表明,提取时间为40 min、提取温度为60 ℃时对东北大酱的挥发性成分提取效果较好。从东北大酱中共鉴定出28种挥发性成分,相对含量占总流出物的89.02%,包括酮类3种（相对含量为53.57%）、酸类3种（相对含量13.36%）、醇类2种（相对含量13.20%）、酯类8种（相对含量3.57%）、酚类2种（相对含量2.44%）、醛类5种（相对含量1.55%）、其他类5种（相对含量1.33%）。其中苯乙醛、3-辛酮、2,3,5,6-四甲基吡嗪、愈创木酚、4-乙烯基-2-甲氧基苯酚等挥发性成分对东北大酱整体香气贡献较大。     

Determination of the volatile profile of stoned table olives from different varieties by using HS-SPME and GC/IT-MS

BACKGROUND: The volatile composition of alcaparras stoned table olives produced from five of the most representative olive cultivars (cv. Cobrançosa, Madural, Negrinha de Freixo, Santulhana and Verdeal Transmontana) from the Trás‐os‐Montes region (north‐east of Portugal) was analytically characterised using headspace–solid phase microextraction/gas chromatography–ion trap–mass spectrometry. RESULTS: Overall, 42 volatile compounds were identified, belonging to distinct chemical classes: 15 aldehydes, seven esters, five alcohols, five sesquiterpenes, four norisoprenoids derivates, three monoterpenes, o ne ketone and two alkenes. Aldehydes were the major chemical class identified in all olive cultivars studied (more than 74% of all the volatile compounds identified). Hexanal, phenylacetaldehyde and (E,E)‐2,4‐heptadienal were the major volatile compounds identified. CONCLUSIONS: It was possible to discriminate the results obtained from the volatile profile of the five olive cultivars by using principal component analysis. Both qualitative and quantitative fractions of alcaparras table olives were influenced by olive cultivar, which confers a single aroma. This fact certainly influences consumer preference and acceptability towards a specific olive cultivar. Copyright © 2011 Society of Chemical Industry     

Effect of the type of oil on the evolution of volatile compounds of taralli during storage

Baking process leads to a huge quantity of newly formed volatile compounds, which play a major role in developing the flavor of the final product. The aim of this work was to investigate on the evolution of the volatile profile of taralli as a function of both the kind of oil used in the dough and the storage time. The volatile compounds from the taralli were extracted by headspace solid-phase microextraction and analyzed by gas-chromatography/mass spectrometry (GC/MS). Forty-four volatile compounds were identified in taralli, most of which produced by thermically induced reactions occurring during baking process, such as volatiles deriving from Maillard reaction and/or sugar degradation and lipid oxidation. The results obtained demonstrated the essential role played by the type of oil on the formation and on the release of volatile compounds. The volatile compounds significantly increased during storage and their individual levels were in most cases significantly lower in taralli made with extra virgin olive oil than in those made with refined oils. Finally, the taralli made with extra virgin olive oil, compared with those prepared with other vegetable oils, showed to be more resistant to oxidation, probably due to the presence of natural antioxidants.     

Changes in volatile aroma compounds of organic fragrant rice during storage under different conditions

BACKGROUND: Aroma of fragrant rice greatly affects palatability as well as consumer acceptability. Loss of desirable volatile compounds such as 2‐acetyl‐1‐pyrroline (2‐AP) and increase in volatile lipid oxidation products in aged rice have been reported. The aim of this study was to monitor the changes in key volatile compounds of organic red fragrant rice cv. Hom Daeng during storage. Effects of packaging material, storage temperature and time were evaluated using solid phase microextraction/gas chromatography/mass spectrometry. RESULTS: Thirteen key volatile compounds including ten lipid oxidation products were monitored. For samples vacuum packed in Nylon/LLDPE pouches at ambient temperature, significant increases in hexanal, 2‐pentylfuran, 1‐octanol and 4‐vinyl guaiacol and significant decreases in 2‐AP and geranyl acetone were found after the second month (P?0.05). Vacuum packing in OPP/Al/LLDPE pouches or storage at 15 °C better retarded the formation of volatile lipid oxidation products and greater retained desirable odorants, including 2‐AP. However, accumulation of lipid oxidation products and 4‐vinyl guaiacol was apparent after the sixth month under these storage conditions. CONCLUSION: A greater extent and higher rate of undesirable changes in volatile compounds were found in samples stored under Nylon/LLDPE/ambient temperature condition. Nevertheless, this condition is acceptable for the retail trade of organic rice in Thailand. Storage conditions using reduced temperature or better packaging materials may be more appropriate for exported rice or superior‐grade fragrant rice to better maintain the desirable rice aroma. Copyright © 2010 Society of Chemical Industry     

芥末油、青芥辣、冲菜的挥发性风味成分的SPME/GC/MS测定

利用固相微萃取／气相色谱／质谱(SPME／GC／MS)联用技术对芥末油、青芥辣、冲菜的挥发性风味成分进行了研究。本试验条件下，这三种样品分别鉴定出6、12、17种挥发性风味成分，主要风味物质均为具有辛辣风味的异硫氰酸烯丙酯(AITC)，相对丰度分别为73．45％、64．25％、32．74％，二硫化碳的相对丰度也较高，分别为14．37％、25．40%、51．67％。     

Freshness characterisation of whiting (Merlangius merlangus) using an SPME/GC/MS method and a statistical multivariate approach

BACKGROUND: The freshness of whiting was studied at five stages of ice storage by comparing the analysis of volatile compounds obtained through solid phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) with two sensory methods. RESULTS: Of the volatile compounds identified, 38 were analysed using a statistical multivariate approach and classified according to their role in the estimation of freshness during storage as markers of freshness or spoilage. Regarding the evolution of the presence or absence of individual compounds, three categories were defined. For example, the volatile compounds propanal, hexanal, 1‐penten‐3‐ol, pentanal, 2,3‐pentanedione, 1‐penten‐3‐one, heptanal, (E)‐2‐pentenal, 2,3‐octanedione, (Z)‐2‐penten‐1‐ol, 1‐pentanol, butanal, octanal, 3,5,5‐trimethyl‐2‐hexene, 1‐hexanol and 4,4‐dimethyl‐1,3‐dioxane appeared highly relevant, because they are found throughout storage and can be divided into several categories that are directly related to the quality of fish. CONCLUSION: SPME/GC/MS combined with a statistical multivariate approach may be a useful method to identify volatile compounds and characterise fish freshness during storage. Copyright © 2010 Society of Chemical Industry     

GC/MS法测定薯莨酒中的香气成分

利用固相微萃取法对薯莨酒中的挥发性成分进行提取,采用气相色谱-质谱(GC/MS)技术对其分析,鉴定出54种挥发性成分,利用TIC峰面积归一化法测定了香味成分的相对含量。