微辣型风味榨菜挥发性成分的研究

采用同时蒸馏萃取技术和气相色谱-质谱联用技术研究微辣型风味榨菜的挥发性风味成分,共鉴定出6类20种化合物.20种化舍物中含烃类9种,醚类3种,酸类1种,酯类3种,酚类1种,含硫化合物3种.研究表明:异硫氰酸烯丙酯是榨菜的特征性香气物质,榨菜本身的挥发性成分和香料的挥发性成分共同作用形成微辣型风味榨菜特有的香味.     

采用GC×GC-TOF-MS分析酱香型白酒缺陷酒挥发性风味物质

采用顶空固相微萃取结合全二维气相色谱-飞行时间-质谱（GC×GC-TOF-MS）技术解析酱香型白酒缺陷酒,并初步推断导致酒体缺陷的物质种类。对酱香型白酒盐菜味缺陷酒中共鉴定出的415种挥发性组分进行归类,并着重分析了16种含硫化合物、20种含氮化合物、17种呋喃类化合物以及33种萜烯类化合物对白酒风味的贡献。结果表明,萜烯类、呋喃类以及含氮化合物是酱香型白酒重要的风味物质及功能化合物,而鉴定出的含硫化合物多具有低阈值且给白酒带来不愉快气味的特征,很有可能是酱香型白酒产生缺陷的重要物质来源。酱香型白酒缺陷酒中挥发性物质的解析对缺陷酒中异嗅物质的准确定性和定量研究具有指导意义。     

传统四川泡菜中挥发性成分分析

采用顶空固相微萃取(headspace solid phase micro-extraction,HS-SPME)结合气相色谱-质谱联用(gas chromatograph-mass spectrometry,GC-MS)技术对不同原料的传统四川泡菜中挥发性成分进行检测、分析。结果表明:5种原料泡菜中共检出化合物80种。不同原料泡菜中检出的挥发性成分差异较大,泡萝卜、泡芥菜、泡甘蓝、泡黄瓜、泡芹菜中分别检出化合物38、23、24、22、24种。酯类、醛类、酮类、醇类、萜类、芳香族化合物、含硫化合物及杂环化合物对泡菜风味形成具有重要影响。其中酯类是泡萝卜、泡芥菜和泡甘蓝中的特征挥发性成分,醛类、萜类分别是泡黄瓜、泡芹菜的特征挥发性成分。泡芥菜和泡甘蓝中异硫氰酸烯丙酯含量最高,泡萝卜、泡黄瓜、泡芹菜中含量最高的风味物质分别是中1-异硫代氰酸丁、反式-2,6-壬二烯醛、右旋萜二烯。对四川泡菜独特风味形成具有重要作用的风味物质是异硫氰酸戊酯、异硫氰酸苯乙酯、苯甲醛、壬醛、癸醛、右旋萜二烯和萘。     

不同品种菜籽原料与浓香菜籽油风味品质的相关性

通过分析不同品种菜籽原料的成分,结合浓香菜籽油22种关键风味化合物和6种风味属性强度差异,建立菜籽原料差异与浓香菜籽油风味品质的相关性。研究发现,菜籽原料中硫代葡萄糖苷的含量与浓香菜籽油中硫代降解产物（主要为3-丁烯基异硫氰酸酯、3-苯基丙腈等）及含硫化合物（主要为二甲基三硫化物等）含量具有一定相关性,对浓香菜籽油“刺激味”、“腌菜味”风味属性有积极贡献。同样,菜籽原料中蛋白质和碳水化合物含量影响浓香菜籽油中杂环类化合物（主要为2,5-二甲基吡嗪、2,3,5-三甲基吡嗪、2-乙基-6-甲基吡嗪等）含量,对浓香菜籽油的“烤香味”、“焦糊味”风味属性有积极贡献。     

油菜籽品种对浓香菜籽油风味及综合品质的影响

分别以双低油菜籽及传统油菜籽为原料,在相同条件下制取浓香菜籽油,采用溶剂辅助蒸发装置结合气相色谱-质谱联用仪对两种菜籽油中挥发性成分的种类和含量进行测定,并利用偏最小二乘判别分析（partial least squares discriminant analysis,PLS-DA）、气味活度值（odor activity value,OAV）对挥发性成分进行数据分析,确定导致两种菜籽油感官风味差异的关键挥发性风味成分,同时结合感官评价、脂肪酸组成、氨基酸组成、营养成分等指标分析比较两种菜籽油综合品质的差异。结果显示,双低菜籽油及传统菜籽油中分别检出12 类82 种和11 类90 种挥发性成分,总量分别为22 377.88、157 512.98 μg/kg,其中硫苷降解产物总量分别为3 311.07、146 492.82 μg/kg,酚类物质总量分别为12 125.47、4 613.03 μg/kg。利用PLS-DA结合OAV最终确定了13 种最重要的特征风味物质,分别为6-甲基硫基己腈、5-甲硫基戊腈、苯代丙腈、3-丁烯基异硫氰酸酯、苯乙腈、反-2-癸烯醛、正己醇、芳樟醇、乙基苯、苯乙醇、椰子醛、4-乙烯基-2,6-二甲氧基苯酚、3-甲基巴豆腈,其中6-甲基硫基己腈、苯乙腈、芳樟醇、5-甲硫基戊腈、苯代丙腈、3-丁烯基异硫氰酸酯6 种成分均对菜籽油独特的辛辣味具有贡献,且苯乙腈、芳樟醇仅在传统菜籽油中检出;正己醇、苯乙醇、椰子醛则在双低菜籽油中含量更高,对菜籽油的甜味具有重要影响;感官评价表明双低菜籽油的甜味优于传统菜籽油,而传统菜籽油辛辣味更强。双低菜籽油中未检出芥酸,而传统菜籽油中芥酸含量高达30.25%;双低菜籽油中VE和甾醇总含量均高于传统菜籽油。研究结果为不同香型浓香菜籽油的生产提供了原料选择和气味标识的支持。     

6类常见食品中含硫化合物风味特征及形成机理研究进展

挥发性含硫化合物广泛存在于多种食品中,具有阈值极低的特点,是对食品感官品质有重要贡献的特征风味组分,在形成食品独特风味特征中也起着至关重要的作用。不同种类的含硫化合物表现出的食品风味特征不尽相同,不同含量的含硫化合物对食品感官品质的影响也差异显著,因此,对感官风味受含硫化合物影响较大的6类常见食品中含硫化合物风味特征及其形成机理进行了研究。牛奶中主要含硫化合物是甲硫醇和二甲基三硫醚,通常表现为蒸煮味;2-甲基-3-呋喃硫醇是牛肉的关键含硫化合物,呈现为焙烤香和肉香;糠硫醇的焙烤香、3-巯基己烷-1-醇的果香是酒类中的关键风味组分;1,2,3,5,6-五硫杂环庚烷是呈现香菇独特气味的关键化合物;二丙基二硫醚、二甲基三硫醚和大蒜素分别为大葱、洋葱和大蒜风味形成的关键含硫化合物;二甲基硫醚和二甲基三硫醚是菜籽油呈现辛辣刺激风味的主要原因。含硫化合物主要是由含硫前体物质在微生物或酶的降解作用下形成,同时有些含硫化合物也产生于美拉德反应。通过对6类常见食品中含硫化合物的种类、对食品感官品质的影响及其形成机制进行全面介绍,总结常见食品中含硫化合物的风味及其对食品感官品质影响的一般规律,旨在为食品中含硫化合物形成机理及风味特征的进一步研究提供参考。     

方便榨菜挥发性成分分析

采用同时蒸馏萃取技术和气相色谱-质谱联用技术研究方便榨菜原料及成品的挥发性成分。结果表明：共鉴定出9类37种化合物,37种化合物中含烃类4种、醇类7种、醚类2种、醛类5种、酸类4种、酯类8种、酚类1种、含硫化合物5种、杂环化合物1种;两种样品共同检出的化合物有4种,分别为异硫氰酸烯丙酯、异硫氰酸苄酯、异硫氰酸环丙酯、二甲基三硫;方便榨菜原料检出挥发性成分中相对含量较高的为异硫氰酸烯丙酯(60.77%)、异硫氰酸环丙酯(6.10%);方便榨菜检出挥发性成分中相对含量较高的为对丙烯基茴香醚(47.54%)、异硫氰酸烯丙酯(11.41%)。     

基于GC-MS和GC-O的浓香菜籽油特征风味物质分析

采用固相微萃取和气相色谱质谱联用技术(SPME/GC-MS)分析浓香菜籽油挥发性成分,采用气相色谱嗅闻分析(GC-O)方法中的时间-强度法(OSME)确定菜籽油特征风味物质,采用定量描述性分析法(QDA)评价菜籽油的感官特性强度,分析感官属性与GC-O分析特征风味成分的关系,推断其对整体风味的贡献程度。结果表明,GC-MS的分析检测到挥发性风味物质共有68种,包括吡嗪类8种,醇类4种,硫甙降解产物15种,醛类20种,酸类6种,酮类4种,烯类3种,杂环类化合物6种和酯类2种。GC-O分析OSME法鉴定出的菜籽油样品中有16种特征风味物质。感官评价结果表明坚果味、腌菜味以及焦糊味是菜籽油的主体风味,与GC-O特征风味物质分析结果一致。表明GC-MS、GC-O法结合感官评价可以有效综合评价菜籽油的特征风味物质。研究结果对浓香菜籽油解析香气特征、优化产品品质、分析呈香机理、建立质量评价体系具有重要意义。     

单菌与多菌接种发酵对多轮发酵四川泡菜风味的影响

以植物乳杆菌(Lactobacillus plantarum)、肠膜明串珠菌(Leuconostoc mesenteroides)以及食窦魏斯氏菌(Weissella cibaria)为出发菌株,pH、总酸、挥发性风味成分和感官评价为指标,研究3种单菌及多菌对多轮发酵四川泡菜风味品质的影响。结果表明,与自然发酵相比,接种发酵均能快速启动发酵,稳定泡菜品质;3种单菌产酸速度为肠膜明串珠菌>食窦魏斯氏菌>植物乳杆菌。采用顶空固相微萃取-气相色谱-质谱联用(headspace-solid phase microextraction-gas chromatography-mass spectrometry, HS-SPME-GC-MS)技术共检出挥发性风味成分85种,其中包括醇类27种、醛酮类17种、酯类16种、酸类2种、烃类13种、含硫化合物2种、苯环类5种、其他化合物3种;共分析出16种重要挥发性成分,包括二甲基三硫、二甲基二硫醚、桉叶油醇、芳樟醇、α-松油醇、壬醛、正辛醛、正葵醛、乙偶姻、异硫氰酸烯丙酯、3-丁烯基异硫氰酸酯、3-(甲硫基)丙基异硫氰酸酯、三芥子酸甘油酯、乙酸...     

葡萄酒中的二甲基硫(DMS)

葡萄酒中已发现有近百种含硫挥发性化合物,但仅有不到10种与葡萄酒的不良气味有关。据有关报道,含硫挥发性化合物常常在兆分之几的范围内就会对葡萄酒的风味产生显著的影响。当葡萄酒中的这类化合物的含量高于阈值时,会产生不愉快的、令人讨厌的气味,这些气味常常被描述成:芦笋味、玉米味、洋葱味、甘蓝味、糖蜜味或橡胶味。与之相反,低含量的硫醇,特别是二甲基硫(DMS)对葡萄酒的风味则有良好的影响,可以提高葡萄酒的果香。有关资料显示,二甲基硫以很低的含量添加到平静葡萄酒中,其感官鉴定结果显示,添加26.4ug/L的葡萄酒比没有添加或加二…     

Distribution of glucosinolate and pungent odors in rapeseed oils from raw and microwaved seeds

The current study was aimed to investigate the effect of glucosinolate degradation on the flavor precursors and pungent odors in raw and microwaved rapeseeds. Five isothiocyanates and six sulfur compounds were identified using comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry (GC× GC-TOF/MS). Comprehensive analysis with headspace solid-phase microextraction (HS-SPME) and aroma extract dilution analysis (AEDA) with altering split ratio showed that 1-isothiocyanato butane, allyl isothiocyanate and 4-isothiocyanato-1-butene were responsible for the sulfur, pungent and green odors in rapeseed oils, due to their high flavor dilution factor. Dimethyl sulfide, dimethyl trisulfide and dimethyl sulfoxide, might be derived from methionine or isothiocyanate rearrangement reactions imparted onion-like, cabbage-like, garlic-like, and sulfurous-pungent odors. Rapeseed samples were heated in a microwave for seven minutes, and the total glucosinolate content decreased from 28.2 ± 0.8 μmol/g to 14.5 ± 0.6 μmol/g in Brassica napus, from 101.2±3.0 μmol/g to 42.2 ± 5.4 μmol/g in Brassica campestris, and from 132.02 ± 9.31 μmol/g to 52.50 ± 6.50 μmol/g in Brassica juncea, compared to untreated ones. Differences in the concentrations of six main odorants and the glucosinolate precursors from genetic types were responsible for the intensity of the pungent odors in raw and microwaved rapeseeds. The result can assist to determine the flavor of the commercial rapeseed oils.     

基于厌氧环境的低盐雪菜挥发性风味物质分析

为研究厌氧环境对低盐雪菜挥发性风味物质的影响,运用顶空固相微萃取-气-质联用(SPME-GC-MS)分别对低盐、高盐和CO₂、N₂低盐厌氧环境处理的雪菜中挥发性物质进行了分析。结果表明,4组不同的腌制雪菜中共分析出46、40、46和44种挥发性化合物,相对含量分别为91.12%、79.29%、84.17%和88.09%,主要包括酯类、醛醇类、酸类、烷烃及其杂环类物质,一起共同构成了雪菜的整体风味。异硫氰酸酯类化合物为低盐、高盐和低盐CO₂厌氧处理3组雪菜中最主要的挥发性物质,分别占雪菜中酯类物质的72.75%、81.50%和43.29%。低盐量N₂处理组中并未检出异硫氰酸酯类化合物,且醛醇类化合物比其他3组的含量高。雪菜挥发性化合物种类主成分分析(PCA)表明,雪菜挥发性物质中,酯类、醇类、酸类和醛类化合物与不同盐量与保存方式相关。     

热榨和冷榨胡麻油挥发性物质与关键风味物质组成的分析

采用顶空固相微萃取-气相色谱-质谱联用技术,对比了冷榨和热榨胡麻油中挥发性物质的组成,并结合相对气味活度值法,分析了胡麻油中关键风味物质。结果表明:胡麻油中挥发性物质有醛类、醇类、杂环类、酮类、烷烃类、酸类和酯类,含量最高的是醛类物质,主要是己醛和反式-2,4-庚二烯醛;冷榨和热榨胡麻油醛类物质分别占挥发性物质总含量的40.79%和68.53%,两种胡麻油共有的关键风味物质有壬醛、己醛、反-2-辛烯醛和反式-2,4-庚二烯醛;冷榨和热榨胡麻油挥发性物质中对总体风味贡献最大的分别是壬醛和反式-2,4-癸二烯醛;热榨胡麻油的关键风味物质中还有2,5-二甲基吡嗪和2-戊基呋喃,这两种物质是热榨胡麻油特有的烤香味的来源。     

焙炒处理对不同植物油品质特性的影响北大核心CSCD

为了研究焙炒对植物油品质的影响,以油菜籽、亚麻籽、花生、葵花籽和芝麻为原料,经焙炒处理后采用液压压榨法制油(热榨油),分析植物油的理化指标(酸值、过氧化值、水分及挥发物、色泽)、主体组分(脂肪酸组成及含量、甘三酯组成及含量、挥发性组分)和总酚含量,并与未焙炒处理直接压榨制取的油(冷榨油)作对比。结果表明:热榨油酸值和过氧化值显著高于冷榨油(p<0.05),其中,热榨亚麻籽油酸值(KOH)最高(0.96 mg/g),热榨菜籽油过氧化值最高(1.02 mmol/kg);冷榨油水分及挥发物含量显著高于热榨油(p<0.05),其中冷榨花生油水分及挥发物含量最高(0.16%);热榨油的色泽较冷榨油深,其中热榨菜籽油的色泽最深(R1.1,Y31);焙炒对植物油脂肪酸和甘三酯组成及含量无显著影响(p>0.05);热榨油中醇类、醛类和酸类等挥发性组分较少,但杂环类物质较多;热榨菜籽油、亚麻籽油、花生油、葵花籽油和芝麻油总酚含量分别是其冷榨油的1.38、1.57、1.51、1.80倍和1.27倍。因此,焙炒对植物油品质影响较大,应根据生产需要选择合适的预处理方式。     

Synergetic Use of Principal Component Analysis Applied to Normed Physicochemical Measurements and GC × GC‐MS to Reveal the Stabilization Effect of Selected Essential Oils on Heated Rapeseed Oil

Lipid oxidation leads to the formation of volatile compounds and very often to off‐flavors. In the case of the heating of rapeseed oil, unpleasant odors, characterized as a fishy odor, are emitted. In this study, 2 different essential oils (coriander and nutmeg essential oils) were added to refined rapeseed oil as odor masking agents. The aim of this work was to determine a potential antioxidant effect of these essential oils on the thermal stability of rapeseed oil subject to heating cycles between room temperature and 180 °C. For this purpose, normed determinations of different parameters (peroxide value, anisidine value, and the content of total polar compounds, free fatty acids and tocopherols) were carried out to examine the differences between pure and degraded oil. No significant difference was observed between pure rapeseed oil and rapeseed oil with essential oils for each parameter separately. However, a stabilizing effect of the essential oils, with a higher effect for the nutmeg essential oil was highlighted by principal component analysis applied on physicochemical dataset. Moreover, the analysis of the volatile compounds performed by GC × GC showed a substantial loss of the volatile compounds of the essential oils from the first heating cycle.     

Antioxidant efficacy of extracts produced from pickled and dried mustard in rapeseed and peanut oils

Antioxidant efficacy of 70% ethanol extract (EE), 70% methanol extract (ME), and water extract (WE) produced from pickled and dried mustard (Brassica juncea Coss. var. foliosa Bailey) was evaluated in rapeseed and peanut oils by using the Schaal oven method. The protective effects of aforesaid 3 extracts in stabilizing vegetable oils were tested by measuring their peroxide values, conjugated diene values, and p-anisidine values during storage of 15 d at 60 °C. Results showed that the different solvent extracts produced from pickled and dried mustard, at concentrations of 0.5% and 1.0% (w/w) in vegetable oils, could significantly (P < 0.05) lower the peroxide value, conjugated diene value, and p-anisidine value of oils during storage at 60 °C. However, the extracts at various concentrations showed a less antioxidant effect than butylated hydroxytoluene (BHT) at 200 ppm. The ultraviolet spectra of different extracts exhibited a single maximum absorbance at 268 nm. The qualitative analysis of antioxidants present in the extracts was carried out by reverse phase high performance liquid chromatography (HPLC) using a C18 column. Two phenolic compounds, gallic and protocatechuric acids, were identified. The antioxidant activity of the extracts might be attributed to the presence of these phenolics. These results indicated that the pickled and dried mustard could be used as a potential source of natural antioxidants. PRACTICAL APPLICATION: The antioxidant activity of extracts produced from pickled and dried mustard toward rapeseed and peanut oils oxidation and the characterization of active phenolic compounds may be useful in developing natural antioxidants for vegetable oils. Moreover, the extracts could safely be used as potential antioxidant to suppress lipid oxidation in lipid-containing food products.     

LOCALIZATION OF MYROSINASE (THIOGLUCOSIDE GLUCOHYDROLASE, EC 3.2.3.1) IN COTYLEDON CELLS OF RAPESEED

Myrosinase (thioglucoside glucohydrolase, EC 3.2.3.1) activity in dehulled seeds of Brassica napus cultivar Tower, B. campestris cultivar Candle and B. juncea (oriental mustard) was localized by cyto-chemical and biochemical procedures. It was found to be associated with the plasmalemma (plasma membrane) in the majority of embryonic cells which is contrary to the general belief that myrosinase is found only in a few specialized idioblasts called ‘myrosin cells’. The presence of lead and sulfur in electron-opaque deposits resulting from in situ myrosinase activity was confirmed by energy dispersive X-ray analyses. Association of myrosinase activity with the plasmalemma was also verified by fractionation and biochemical procedures. Although there were indications of some myrosinase activity in aleurone grains (protein bodies), the evidence was inconclusive.     

Volatile Flavor Sulfur and Nitrogen Constituents of Brassica rapa L.

The volatile flavor constituents of Brassica rapa L. var laciniitolia Kitamura and Brassica rapa L. subvar Hiroshimana Kitamura have been investigated by a combination of chromatographic and spectioscopic methods. These volatile oils possess a characteristic pungent odor and taste. A total of 14 sulfur and nitrogen compounds were identified positively, including 4 isothiocyanates, 3 nitriles, 2 methylthio isothiocyanates, 4 methylthio nitriles and 1 sulfide.     

不同储藏温度下油菜种子生活力的基因型差异

以发芽率为指标,研究了40份甘蓝型、白菜型和芥菜型油菜在-20℃、4℃、25℃、37℃、60℃温度储藏3个月、6个月、12个月后种子生活力的变化。结果显示：-20℃和4℃储藏下,不同基因型间种子发芽率变异较小,而25℃、37℃和60℃储藏下,基因型间种子生活力存在明显差异,选择60℃高温储藏不同时间的种子进行生活力鉴定,从甘蓝型、白菜型和芥菜型油菜中均筛选得到耐储藏的基因型。