彩色樱桃番茄果实挥发性风味物质分析

为了研究不同彩色樱桃番茄品种果实挥发性风味物质种类及相对含量差异,利用顶空固相微萃取-气相色谱-质谱联用技术测定了2个彩色樱桃番茄品种果实的挥发性物质成分和相对含量。结果表明,海棠黑彩和彩星分别含有72种和58种挥发性物质。海棠黑彩和彩星具有53种相同成分,其中醇类14种、酮类4种、酯类2种、醛类20种、烃类4种、其他类9种;包括18种主要风味成分,分别为3-甲基-1-丁醇、2-甲基-1-丁醇、1-戊醇、6-甲基-5-庚烯-2-醇、苯乙醇、1-戊烯-3-酮、6-甲基-5-庚烯-2-酮、β-紫罗兰酮、E-2-戊烯醛、E-2-己烯醛、E-2-庚烯醛、苯甲醛、苯乙醛、正壬醛、Z-4-癸烯醛、1-硝基-3-甲基丁烷、2-异丁基噻唑、1-硝基-2-苯乙烷,这些共有的挥发性物质构成了彩色樱桃番茄的主体风味。另外,海棠黑彩和彩星挥发性风味物质种类和相对含量存在显著性差异。海棠黑彩含有19种特有成分,其中E,E-2,4-癸二烯醛、愈创木酚、苯乙腈为主要风味物质。彩星含有5种特有成分,其中乙酸己酯为主要风味物质,为彩色樱桃番茄品种的高效利用提供了科学依据。     

Lipoxygenase-associated apple volatiles and their relationship with aroma perception during ripening

Several important odor-active volatiles are produced via processes initiated by cellular disruption brought about by cutting or mastication. Of these, six-carbon (C6) volatiles, including the aldehydes, cis-3-hexenal, its isomer trans-2-hexenal, and hexanal, as well as their corresponding alcohols, are produced from action of the lipoxygenase (LOX) pathway on substrates released by tissue disruption. We investigated the production of these and other odor-active volatiles from ‘Jonagold’ apple fruit for whole and disrupted tissues as a function of maturity/ripeness. The impact of ripening was determined by comparing ‘normally-ripening’ fruit with ‘non-ripening’ (1-methylcyclopropene-treated) fruit. The study was conducted over 8 weeks and evaluations were twice-weekly for two successive seasons. C6 aldehyde synthesis by crushed fruit was, at first, extremely high for non- and normally-ripening fruit such that the concentration of the aldehydes was several hundred times higher than their human odor thresholds in the containers used to present samples to the sensory panelists. cis-3-Hexenal, which remained constant throughout the experiment for non-ripening fruit, declined markedly for normally-ripening fruit, coincident with the onset of ripening. Conversely, trans-2-hexenal and hexanal increased in normally-ripening fruit as ripening progressed. Hexanol and hexyl acetate and other esters were produced in a ripening-dependent manner for disrupted as well as intact fruit tissues. The exception was cis-3-hexenyl acetate, which had same declining pattern as its aldehyde precursor, cis-3-hexenal. PCA determined that all volatiles except cis-3-hexenal, cis-3-hexenol and cis-3-hexenyl acetate, were highly associated with ripening. Also, cis-3-hexenal and cis-3-hexenyl acetate correlated negatively with all other variables (volatiles, ethylene, CO₂ and sensory tests). Sensory tests revealed that panelists were able to distinguish between non-ripening and normally-ripening fruit approximately 2 weeks before the onset of autocatalytic ethylene, the respiratory climacteric, and ripening-dependent ester production of normally-ripening fruit. The data indicate a shift in LOX pathway activity occurs during ripening, but it is not clear if it is due to changing enzyme activities or changing substrate levels. The shift in pathway activity may be related to perceived changes in aroma for macerated fruit prior to autocatalytic ethylene production.     

3个杏品种果实香气顶空固相微萃取气质联用分析

对三个杏品种“金太阳”、“鲁杏1号”、“鲁杏2号”成熟期果实顶空微萃取果肉中的挥发性物质进行气相色谱—质谱分析鉴定。金太阳杏检测出33种香气成分,占总峰面积的82.37%,主要香气物质为乙酸己酯、乙酸－4－己烯－1－酯、二羟乙酸、6－甲基－5－烯基－2－庚酮;“鲁杏1号”检测出10种香气成分,占总峰面积的51.18%,主要香气物质为二羟乙酸、苯乙醇、二乙基邻苯二甲酸酯、2-苯并噻吩;“鲁杏2号”检出10种香气成分,占总峰面积的48.06%。主要香气物质为乙醇、乙酸己酯、顺-3-己烯基-乙酸酯。三个品种间香气成分和含量均存在差异,杏香气成分是杏选育评价标准的重要指标之一。     

复烤烟叶挥发性香味成分同时蒸馏萃取的优化研究

为明确打叶复烤后烟叶挥发性香味成分含量,对其挥发性香味成分同时蒸馏萃取条件进行了优化研究,考查了同时蒸馏萃取溶剂不同厂家CH2Cl2、料液比、蒸馏时间、NaCl用量、CH2Cl2体积、水浴温度等因素对结果的影响,通过均匀试验设计分析法优化试验条件。结果表明,选用Dikma CH2Cl2的总离子流色谱图在40 min左右有少量的杂质峰,对挥发性成分无较大影响,去离子水体积为350 mL,蒸馏时间为3.0 h,NaCl用量为30 g,CH2Cl2体积为60 m L,水浴温度为60℃,该方法为复烤后烟叶挥发性香味成分含量提供支撑。     

不同成熟度烟叶中香味成分分析

为探索烟叶成熟度对香味成分的影响,研究了烟叶成熟度与香气质量关系。利用同时蒸馏萃取装置提取不同成熟度烟叶样品的挥发性香味成分,经毛细管气相色谱法对烟叶中主要香味成分变化进行了定性定量分析。结果表明：(1)烟叶中主要香气成分的总量、醇类和酮类香味成分随烟叶成熟度的提高而增加(2)糠醇、5-甲基糠醛、6-甲基-5-庚烯-2-酮、苯甲醇、芳樟醇、β-苯乙醇、异佛尔酮、茄酮、大马酮、二氢猕猴桃内酯、金合欢基丙酮等香味成分等香气成分含量则随着成熟度的提高而持续增加,最大值出现在完熟阶段;(3)糠醛、苯乙酮、二氢大马酮、巨豆三烯酮、香叶基丙酮等香味成分在烟叶成熟时含量最高,之后其含量缓慢下降。     

三种脱毒方法降低亚麻籽中氰化氢含量的效果比较

亚麻籽（flaxseed）富含α-亚麻酸、木脂素和其它营养成分。然而,由于生氰糖苷的存在限制了其在饲料和食品工业中的应用。本研究通过滴定测定加工过程中氢氰酸 (HCN生氰糖苷的转化产物）的去除量来确定溶剂提取、微波烘烤和水煮三种方法去除亚麻籽中生氰糖苷的效力。结果显示为：原料亚麻籽中HCN的测定值为157.68mg/kg,微波烘烤法对HCN的去除量为95.57%;溶剂提取法提取一次去除HCN量为52%,两次去除量为80%,三次去除量为89%;水煮法的去除量为88.12％。在这些方法中微波法对HCN的去除率最高;溶剂法相对于微波加工法更易实现规模化生产;蒸煮法和水煮法在特殊情况下才可考虑使用。     

磷酸氢二铵/尿素复配体系对造纸法再造烟叶热解行为及羰基化合物的影响

为深入了解磷酸氢二铵(DAP)/尿素(UR)这种常用再造烟叶复配添加剂的作用机制,从热降解的角度研究了DAP/UR改性造纸法再造烟叶(DURTS)和未添加DAP/UR的造纸法再造烟叶(RTS)在热降解过程及热解生成羰基化合物上的差异。结果表明：（1）与RTS相比,DURTS降低了第2(142~275℃)和第5阶段(539~710℃)的热降解;同时也使得第4热降解阶段(372~539℃)的最大热降解速率由8.9 %/min下降至6.9 %/min,对应的峰值温度(T_p4)也升高了11.2℃。（2）DAP/UR使热释放的终止温度显著升高（由532℃上升至564℃）,提升了再造烟叶在高温区的热稳定性。（3）DAP/UR复配体系对羰基化合物的生成均有明显的抑制作用,羰基化合物的生成总量降低了21.6%。（4）DAP/UR复配体系在改善RTS余味、刺激性、香气质、浓度和杂气方面作用明显。     

梨花和油菜花挥发性气味物质的鉴定及差异分析

为了解花朵中挥发性气味物质对吸引传粉昆虫采集所起到的作用,采用固相微萃取(SPME)和气相色谱-质谱联用(GC-MS)技术,检测梨花和油菜花全花、花药、花蜜中挥发性气味物质成分,并进行主成分及与昆虫采集相关性分析。鉴定梨花中挥发性气味物质成分有9种,氧烷类为主要挥发性气味物质,占44.44%,通过主成分分析,气味贡献物主要来自于二甲基硫醚、十四甲基环七硅氧烷、苯丙腈、苯甲醛等化合物。油菜花中挥发性气味物质成分有23种,酯类和氧烷类为主要气味挥发性物质,分别占8.7%和16.09%,气味贡献物主要来自于反-2-己烯醛、异硫氰酸-2-苯乙酯、4-异硫氰酸根合-1-丁烯、二甲基三硫醚、二甲基二硫醚等化合物;花药的挥发性气味物质种类比花蜜中更丰富。传粉昆虫调查发现,试验地共有传粉昆虫4目10科11种,梨和油菜传粉昆虫数量上有显著差异(P<0.05),但各成分与采集昆虫数量均没有显著相关性(P>0.05)。研究发现梨花和油菜花挥发性气味物质成分有显著差异,将为研究气味物质主要贡献物在吸引传粉昆虫中发挥的作用提供参考。     

存放时间对光皮木瓜芳香物质的影响

以成熟光皮木瓜为试材,在采后2d和采后1月两次采用顶空固相微萃取与气质联用方法分析检测木瓜果实中的芳香成分,共鉴定出64种芳香物质,主要为醛类、醇类、酮类、呋喃类、萜类、烯烃类和酯类化合物。含量较高的芳香成分有2-己烯醛、反式-2-甲基-环戊醇、4-(2,6,6-三甲基-环己--1-烯基)-2-丁醇、正已醛、(E,E)-2,4-己二烯醛、(E)-3-己烯-1-醇等。存放1月后检测,光皮木瓜的芳香物质含量不但没有降低,而且有很大的提高。其中醛类、醇类、酮类、酸类和酯类化合物的含量有不同程度的增加,而呋喃类和烯烃类化合物含量有所降低。试验中看出C6化合物是构成光皮木瓜果实清香味的主要成分     

Climacteric or non-climacteric behavior in melon fruit: 1. Aroma volatiles

A near-isogenic line (NIL) SC3-5 and a further nine NILs of melon contained introgressions of an exotic non-climacteric accession of Cucumis melo ‘Shongwan Charmi’ [SC (PI 161375), Conomon Group)] into the non-climacteric Spanish Inodorus type of melon cultivar ‘Piel de Sapo’ (PS). The NILs exhibited different climacteric behavior and aroma. Fruit from SC3-5 and seven NILs showed a climacteric pattern, while fruit from one NIL, both parentals and the cultivar ‘Nicolás’, were non-climacteric. The NILs were compared with the reference aromatic cultivars ‘Fado’ and ‘Védrantais’, which show climacteric behavior with high levels of respiration and ethylene production. The twenty-eight aromatic compounds common to the cultivars and NILs studied defined the aroma profile, which was composed of fifteen esters, six aldehydes, two alcohols, three derived sulfur compounds (methyldisulfanylmethane; methanethiolate; methyl 2-sulfanylacetate) and other three compounds (1,7,7-trimethylnorbornan-2-one; acetone; 2-ethylfuran). On the basis of the total ion count peak area, three compounds (isobutyl acetate; benzyl acetate; pentanal) allowed the climacteric to be distinguished from the non-climacteric NILs according to univariate analysis. Multivariate analysis of the aroma data on the basis of total ion count peak area separated the aromatic attributes of the climacteric ‘Védrantais’ and ‘Fado’ melons from the NILs that were closer to their inbred parentals when analyzed by partial least squares regression plus discriminant analysis. In the climacteric reference cultivars or NILs, esters were the predominant volatiles while aldehydes predominated in non-climacteric ones. These results support the hypothesis that at least one QTL in linkage group III boosts a series of maturation signals that are characteristic of climacteric fruit, including a different aroma profile.     

The effect of cutting direction on aroma compounds and respiration rate of fresh-cut iceberg lettuce (Lactuca sativa L.)

The purpose of this research was to investigate whether cutting direction and storage temperature could influence aroma formation and respiration rates in minimally processed lettuce. Lettuce was cut both longitudinally and transverse to the mid-rib and stored at 6 and 10 °C for 4 and 5 days. The experiment was performed in January and March 2008. Changes in respiration rate were analyzed during storage, and aroma analysis was carried out after 4 and 5 days of storage in January and March, respectively. Respiration rates increased with increasing storage temperatures. Transverse cuts to the rib were strongly related with volatiles of the lipoxygenase (LOX) pathway i.e. cis-3-hexenal, cis-3-hexenol and trans-2-hexenol, while longitudinal cutting enhanced formation of volatiles from other metabolic routes. Aroma formation was also influenced by storage temperature, where higher storage temperatures resulted in increases in α-longipinene, 2-methylbutanal and 3-methylbutanal. Our results demonstrate that cutting the lettuce transverse to the mid-rib caused more severe damage to the tissue than longitudinal cutting, based on aroma production of LOX volatiles.     

不同生态环境对烤烟内在质量的影响

(云南省烟草科学研究所,云南玉溪 653100)     

贵州四种名优茶叶的电子鼻鉴别与香气成分分析

为实现贵州4种名优茶叶（湄潭翠芽茶、石阡苔茶、凤冈锌硒茶、都匀毛尖）的鉴别，本文通过线性判别分析（LDA）和载荷分析（Loadings），研究电子鼻技术对贵州4种名优茶叶的鉴别能力，并采用顶空固相微萃取-气相色谱-质谱联用技术对香气成分进行分析。结果表明：电子鼻中LDA方法能够将4种名优茶叶有效鉴别，而Loadings分析表明2号（氮氧化合物）和7号（萜烯类、硫化物）传感器在整体气味鉴别中起到主要作用。对4种名优茶叶的具体香气成分分析表明，4种茶叶中共检出香气成分77种，共有成分14种。其中，醇类和烷烃类在4种茶叶香气成分中的相对含量均较高，4种茶叶均未检测出独立的醛类化合物。芳樟醇、2-丁基-1-辛醇、5-庚基苯-1,3-二醇、癸烷分别是湄潭翠芽、石阡苔茶、凤冈锌硒茶和都匀毛尖茶中检测出独有的且相对含量最高的香气成分，说明不同种类的茶叶均有独自的香气成分。因此，不同种类的茶叶由于挥发性成分种类及相对含量有差异导致其香气不同，并且电子鼻技术可以对贵州这4种茶叶进行有效鉴别。     

移栽期对冬季烤烟上部烟叶致香成分和质量评价的影响

为揭示冬季烤烟烟叶生长后期致香成分的生成规律,改善冬季烤烟香气品质,以‘KRK26’上部烟叶(B₂F)为材料,采用SDE（同时蒸馏萃取）-GC/MSD气质联用法对同一产区4个不同移栽期的相同栽培及初考条件下的烟叶致香成分及相对含量进行检测。结果表明,致香成分总量与感官评吸结果吻合度较好,可能对冬烟烟叶整体香气质量起基础作用;次年1月15日移栽处理(K3)新植二烯含量显著高于其他3个处理,且烤后烟叶评吸质量较优,显示新植二烯含量可能对冬烟烟叶整体香气质量起主导作用;类胡萝卜素降解产物中的大马士酮、香叶基丙酮、3-羟基大马酮及芳樟醇;类西柏烷类致香物质中的茄酮;美拉德反应产物中的糠醛、2,3-二氢呋喃、5-甲基-2-糠醛、3-甲基-2-(5H)-呋喃酮和2,3-二氢苯并呋喃;苯丙氨酸类降解产物中的苯甲醛、苯甲醇、苯乙醛、苯乙醇和吲哚;其他类致香物质中的2-乙酰呋喃、杜烯、棕榈酸甲酯、香叶基香叶基焦磷酸、棕榈酸等,可能是影响冬烟烤后烟叶香气质量的重要成分。研究结果可为云南冬烟栽培技术优化,改善冬烟烟叶香气品质及提高上部烟叶可利用性提供科学依据。     

葡萄果实单萜生物合成与调控的研究进展

萜烯是一系列以异戊二烯为单元的烯烃类化合物,在葡萄果实中主要以单萜为主,它们具有愉悦的花、果香气味。因为萜烯类物质的阈值很低,所以尽管它们在葡萄果实中的含量不高,依然对葡萄果实与葡萄酒的香气品质有着重要贡献,提高果实单萜含量则成为了葡萄香气育种的主要目标。本研究主要综述了葡萄果实单萜合成途径关键基因-单萜合成酶基因和糖基转移酶基因的研究进展,分析了基因型和气候因素对单萜生物合成的影响,结果发现:不同品种的葡萄果实中,单萜合成路径的关键酶VvGT7以及VvDXS都在关键活性位点存在氨基酸种类的差异,且已经证实这种差异会导致萜烯含量的不同;光照、水分以及温度等环境因素的差异都是导致葡萄果实中萜烯含量不同的原因。最后对单萜在转录水平上的调控研究进行了展望。     

云南与津巴布韦烤烟致香物质含量差异研究

【研究目的】为明确云南与津巴布韦烤烟在致香物质方面的差距，指导云南部分替代进口烤烟的研究和生产，提高烟叶质量，特进行此项试验。【方法】采用比色法测定了烟叶多酚总量，索式提取法测定石油醚提取物，硫酸甲酯、三氯甲烷萃取法测定多元酸和高级脂肪酸，水蒸汽-二氯甲烷同时蒸馏萃取、GC/MS-内标定量检测挥发性香气物质；并分类分析比较了云南与津巴布韦烤烟的多酚总量、石油醚提取物、多元酸、高级脂肪酸及挥发性香气物质等烟草致香物质含量的差异。【结果】结果表明云南烤烟各部位烟叶的石油醚提取物、芳香氨基酸降解的香气物质超过津巴布韦烤烟，多酚、高级脂肪酸则低于津巴布韦烤烟；上部烟叶的西柏烷类香气物质高于津巴布韦烤烟，多元酸、类胡萝卜素降解的香气物质、梅拉德反应的香气物质则低于津巴布韦烤烟；中部和下部烟叶的多元酸、类胡萝卜素降解的香气物质、梅拉德反应的香气物质高于津巴布韦烤烟，而西柏烷类香气物质则低于津巴布韦烤烟。云南与津巴布韦烤烟在致香物质方面的差距，主要表现在上部烟叶的柠檬酸、油酸、巨豆三烯酮、金合欢基丙酮、β-二氢大马酮、二氢猕猴桃内酯、糠醇、糠醛等致香物质含量低于津巴布韦烟叶。【结论】云南与津巴布韦烤烟的致香物质差异比较明显，上部烟叶致香物质含量明显不如津巴布韦。     

Influence of methyl jasmonate in conjunction with ethanol on the formation of volatile compounds in berries belonging to the Rosaceae

The effect of methyl jasmonate in combination with ethanol on the formation of aroma constituents in berryfruit belonging to the Rosaceae was investigated. Postharvest treatments of raspberries, strawberries and blackberries were carried out. After evaluating the aromatic fractions of the berries, esters and terpenes were the most abundant compounds. There were different effects of the treatment according to the berry species. In contrast to raspberries, which exhibited a significant decline (p < 0.05) in the total amount of volatiles after treatment, a significant (p < 0.05) enhancement of total volatile compounds was observed in strawberries, while no significant effect was found in blackberries. Esters and terpene compounds responded similarly in strawberries and blackberries suggesting similarity in the biochemistry of their aroma synthesis. In contrast, raspberry volatile compounds showed a different pattern, reflecting different biosynthetic pathways for aroma formation in raspberry. The natural volatile compounds, methyl jasmonate and ethanol, seemed to have either promoting effects on the formation of the (−)-enantiomers of chiral terpenes and ionones or inhibitory effects on the synthesis of the corresponding (+)-enantiomers.     

老枞水仙品质特征分析

为揭示决定老枞水仙茶“枞味”的关键香气成分和关键性生化成分物质,应用气相-离子迁移谱技术(GC-IMS)、高效液相色谱法(HPLC)对不同香型老枞水仙的挥发性物质、主要理化成分进行特征分析。试验共鉴定出38种挥发性物质。木质味老枞水仙特征性香气成分是戊醛、己醛;青苔味老枞水仙特征性香气成分是3-己烯-1-醇单聚体和二聚体、芳樟醇单聚体;粽叶味老枞水仙特征性香气物质是2-戊基呋喃、苯甲醛。另外,生化成分中水浸出物、咖啡碱的增加对老枞水仙茶“枞味度”品质的提升有显著的积极作用,酯型儿茶素含量的增加将造成老枞水仙茶滋味品质的下降。特别值得注意的是,儿茶素品质指数的降低,对老枞水仙茶“枞味”的进一步提升有积极作用。本研究可实现老枞水仙的快速判别,为制定老枞水仙企业标准提供科学依据。     

日光温室不同栽培茬口番茄需水量初探

作物的需水量由植株蒸腾和棵间蒸发两部分构成。试验分别研究了日光温室冬春茬和秋冬茬的植株蒸腾量和棵间蒸发量,同时也研究了植株蒸腾量和棵间蒸发量与日光温室内的光、温、湿以及水面蒸发的相关性。结果表明：番茄植株蒸腾量在秋冬茬随生育进程呈逐渐减少的趋势,最大值在开花结果期为457.92ml H2O/(d·plant),到成熟采摘时最少,为78.95ml H2O/(d·plant);冬春茬则相反,随番茄的生长发育进程植株的蒸腾逐渐增加,在营养期最低为135.78ml H2O/(d·plant),在果实膨大期最大为524.24ml H2O/(d·plant)。棵间蒸发在两个栽培茬口的趋势与植株蒸腾相似。经计算得到秋冬茬番茄的需水量为2098.95m3/hm2,冬春茬番茄的需水量为2789.25 m3/hm2。冬春茬对植株蒸腾与棵间蒸发影响最大的分别是温度和湿度;而在秋冬茬对植株蒸腾与棵间蒸发影响最大均为光强。