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1.
为考察细支与常规卷烟主流烟气中生物碱的逐口释放量变化,建立了同时测定卷烟逐口主流烟气中5种主要生物碱(烟碱、降烟碱、麦斯明、假木贼碱、新烟草碱)的气相色谱-串联质谱(GC-MS/MS)分析方法,并对8个不同卷烟样品进行了对比分析。结果表明:(1)各生物碱工作曲线的R~2在0.999 0~0.999 6之间,日内和日间相对标准偏差(RSD)为2.46%~9.70%,不同水平下的加标回收率为80.41%~107.09%。(2)整体上,细支卷烟逐口主流烟气中TPM及烟碱、降烟碱、麦斯明、假木贼碱、新烟草碱等主要生物碱的释放量均低于常规卷烟;非参数检验结果表明细支与常规卷烟之间的TPM、烟碱、降烟碱、假木贼碱及新烟草碱等成分的逐口释放量呈现显著差异,但麦斯明差异不显著。该方法重复性和准确度较好,适合用于逐口烟气中生物碱的检测分析。  相似文献   

2.
为测定卷烟烟气总粒相物中5种生物碱(烟碱、降烟碱、麦斯明、假木贼碱和新烟草碱),采用经改造的吸烟机对卷烟进行抽吸,用剑桥滤片捕集20支卷烟的每口烟气总粒相物,滤片经超声波萃取、离心后,取上层清液用GC/MS进行测定分析.结果显示:①利用该方法在所测定的5种生物碱中,测定结果的相对标准偏差为1.33%~7.58%,各生物碱的加标回收率为94%~106%;②逐口TPM量、逐口烟碱量以及逐口麦斯明量逐渐升高,逐口TPM量和逐口烟碱量在每口间传递的规律性最强;③降烟碱量都比较低,没有发现降烟碱逐口量随口数的明显变化趋势,每口之间都比较平稳,混合型卷烟F的降烟碱总量最大;④卷烟D、F和G等低焦油或混合型卷烟的主流烟气TPM中5种生物碱单口传递量较之于其它卷烟偏低.该方法适用于卷烟主流烟气总粒相物中生物碱含量的测定.  相似文献   

3.
分别以活性炭滤嘴卷烟和普通滤嘴卷烟为研究对象,对比分析滤嘴活性炭截留烟气生物碱的行为。通过单因素及正交实验建立滤嘴活性炭中生物碱的最优提取条件,并检测烟蒂及主流烟气生物碱释放量,分析活性炭滤嘴对主流烟气生物碱截留规律的影响。结果表明:(1)滤嘴活性炭中生物碱的最优提取条件为萃取剂三乙胺-氯仿溶液,萃取剂体积35 m L,超声萃取时间35 min,Na OH溶液添加量6 m L。(2)活性炭复合滤嘴对8种生物碱的截留能力低于普通滤嘴,这使活性炭滤嘴卷烟烟气劲头稍高。(3)滤嘴活性炭对生物碱的截留能力低于普通醋纤丝束;活性炭对8种生物碱截留能力由大到小依次为二烯烟碱、假木贼碱、烟碱、可替宁、麦斯明、2,3’-联吡啶、新烟草碱、降烟碱。(4)向滤嘴中添加活性炭会导致滤嘴中丝束部分对降烟碱、新烟草碱和2,3’-联吡啶的截留能力降低,对其他5种生物碱的截留能力增强。  相似文献   

4.
为阐明烟草生物碱对电子烟抽吸特性的影响,考察了8种烟草生物碱具有的嗅觉、味觉和化学感觉特征;并以次生烟碱替代电子烟中的烟碱,评价了8种生物碱在电子烟中的感官响应。依据GB/T22366—2008使用三点选配法(3-AFC)测定烟草生物碱的觉察阈值。结果表明:1烟草生物碱除了具有碱性气息外,还具有烘烤香和花香香气;在FDA限定浓度范围内,烟碱只具有辣感而次生烟碱可能同时具有苦味和辣感,烟碱的觉察阈值最低,为7×10~(-6)mg/m L;2麦斯明、二烯烟碱对电子烟香气有显著的影响;次生烟碱替代电子烟中烟碱后,电子烟喉部劲头和刺激性明显降低,并伴随口腔中甜腻感的降低。因此,不同种类的烟草生物碱会通过本身具有的嗅觉、味觉和化学感觉特征影响电子烟的抽吸特性。  相似文献   

5.
建立了超声萃取-气相色谱-串联质谱法(GC-MS/MS)同时测定卷烟主流烟气中8种生物碱(烟碱、降烟碱、麦斯明、二烯烟碱、假木贼碱、新烟草碱、2’3-联吡啶和可替宁)的分析方法。捕集了卷烟主流烟气总粒相物的剑桥滤片经8%的Na OH溶液浸泡后,用乙酸乙酯超声萃取,在多反应监测(MRM)模式下进行GC-MS/MS分析,内标法定量。结果表明:8种生物碱线性良好,r~2为0.9991~0.9999,方法的检出限(LOD)和定量限(LOQ)分别为0.02~2.47μg/支和0.06~8.22μg/支,加标回收率为97.0%~125.5%,相对标准偏差为0.5%~6.8%。该方法操作简便、灵敏,适合用于卷烟主流烟气中8种生物碱释放量的测定。  相似文献   

6.
为分析贵州中部山区烤烟生物碱含量积累特点以及与生态因子的关系,以贵州中部山区25份土壤样品和对应的C3F初烤烟叶样品为材料,采用气相色谱法测定烟叶中烟碱、降烟碱、麦斯明、假木贼碱、新烟草碱5种生物碱含量,分析生态因子与烟叶生物碱含量间的相关关系。结果表明,贵州中部山区烟叶烟碱含量为2.83%,各生物碱含量依次为烟碱新烟草碱降烟碱假木贼碱麦斯明;降水量、空气湿度、气温及昼夜温差对烟叶生物碱含量的影响较大,而地温、日照时数对其的影响不明显;从生物碱含量来看,假木贼碱、新烟草碱含量受降水量和昼夜温差的影响程度较大;各生物碱组分含量均随着土壤碱解氮含量的升高而增高,烟碱和假木贼碱含量与土壤p H呈正效应,麦斯明含量与有效钾呈负效应。贵州中部山区烤烟生物碱含量受降水量、空气湿度、气温、昼夜温差以及土壤碱解氮含量的影响较大。  相似文献   

7.
为了分析卷烟主流烟气总粒相物(TPM)中的酸味成分,利用凝胶色谱分离TPM,通过流份感官评价定位了酸味特征组分,利用GC/MS法分析出含15种化合物的酸味成分组群;测定了15种酸味成分的味觉阈值,考察了这些成分在12个牌号卷烟TPM中的分布特征和味觉活性值(TAV),明确了不同酸味成分的贡献度差异;通过卷烟注射加香评吸方式,明确了上述酸味成分在卷烟中的感官作用。结果表明:①该15种酸味成分均对卷烟味觉具有贡献,乙酸和乳酸对酸味的贡献最大;不同品牌卷烟间乳酸TAV的差异较大,人为调控因素较高。②部分酸味成分具有甜味及涩感表现。③施加酸味成分组群能够降低卷烟刺激性、改善余味,明显提高卷烟的酸味口感、甜香香韵及甜味口感。  相似文献   

8.
随机采集了全国9个省(自治区)烤烟烟叶样品141份和进口烟叶样品40份,采用气相色谱法分析了5种主要生物碱含量,并进行了感官评价。结果表明,国产烟叶生物碱含量变幅大于进口烟叶,烟叶生物碱含量由高到低依次是烟碱、新烟草碱、去甲基烟碱、假木贼碱、麦斯明。各种生物碱的相关关系都达到了极显著正水平。不同地区烤烟总生物碱含量:广西〉福建〉湖南〉山东〉贵州〉辽宁〉云南〉河南〉四川;烟叶烟碱转化率:下部〉上部〉中部,烟碱转化率:四川〉河南〉辽宁〉云南〉贵州〉湖南〉山东〉福建〉广西。四川省烤烟的烟碱和生物碱含量都最低,但其烟碱转化率却最高;广西和福建两省烤烟的烟碱和生物碱都最高,但烟碱转化率却最低。烟叶吸食质量与生物碱有显著的相关关系,其中烟碱对吸食质量影响最大,与香气质、余味、杂气、刺激性4项指标得分显著负相关。5种生物碱与烟支综合评价都表现为极显著负相关,但烟碱转化率及烟碱率与感官质量却没有显著的相关关系,烟碱转化率与综合评价也没有显著相关关系。  相似文献   

9.
目的:研究大豆蛋白水解物的苦味程度,寻找苦味评价方法。方法:采用感官评价和电子舌分析大豆蛋白水解物的苦味程度;采用高效液相色谱法分析游离氨基酸含量和肽分子质量分布;采用偏最小二乘回归分析(partial least squares regression,PLSR)研究游离氨基酸含量、感官苦味强度以及电子舌苦味响应值评价的相关性,同时建立苦味值预测模型。结果:电子舌评价蛋白水解物苦味响应值结果优于感官评价结果,可以很好分辨样品间苦味值差异。F1样品苦味最强,其呈苦味游离氨基酸、分子质量小于1 000 Da肽的含量高于其他样品。不同质量浓度样品的感官评价苦味强度与电子舌苦味响应值具有良好线性关系,利用PLSR建立了电子舌响应值与感官评价苦味强度预测分析模型,得回归方程:Y=0.484X1+0.537X2+0.509X3+0.522X4(Y为感官苦味强度预测值;X1、X2、X3、X4分别为电子舌传感器苦味、鲜味、丰富度、咸味响应值),所建立模型校正数据集和验证数据集的决定系数R2分别为0.93和0.97,校正均方根误差分别为0.18和0.10,说明模型的拟合效果较好,可靠性很高。结论:感官评价与电子舌模型具有很高的可靠性,电子舌评价可以代替感官评价对植物蛋白水解物进行苦味值评价,可为后续植物蛋白水解物苦味值研究提供一种新的评价方法。  相似文献   

10.
烟丝pH值的变化对卷烟烟气烟碱和感官质量的影响   总被引:2,自引:0,他引:2  
为了解烟丝pH值对卷烟烟气烟碱和感官质量的影响,用0.2 mol/L盐酸和0.5 mol/L NaOH水溶液分别处理两个牌号卷烟的烟丝,而后测定烟丝的pH值、烟丝烟碱、烟气烟碱和烟气游离烟碱量,并进行了感官评吸.结果表明:①烟丝pH值对其总烟碱和烟气烟碱量没有明显影响;②同一牌号卷烟,烟气游离烟碱量与烟丝pH值极显著正相关;③烟气劲头随着烟丝pH值的增大而增大,而其它感官评吸指标则变化不大.因此,通过调节烟丝pH值可在一定范围内改变其烟气的游离烟碱量和劲头.  相似文献   

11.
This study investigated the effect of simultaneously manipulating the spatial distribution of a sweet masking agent and bitter tastant within gelatine–agar gels on bitterness suppression, using sucralose and quinine. Sixty subjects participated in a series of paired comparison tests comparing different gel designs containing both sucralose and quinine, against a homogeneous control gel of identical overall sucralose (0.3 mM) and quinine content (0.3 mM). Twenty subjects also determined the bitterness reduction achieved in the homogeneous control gel by the addition of 0.3 mM sucralose to 0.3 mM quinine. Separating quinine and sucralose into different portions of the gel had no influence on bitterness suppression. Inhomogeneously distributing the quinine and sucralose into the same parts of the gel reduced the effectiveness of bitterness suppression. Inhomogeneously distributing the sucralose, while maintaining a homogeneous distribution of quinine, had no influence on bitterness suppression. Although an inhomogeneous distribution of sucralose increased sweetness perception and the addition of sucralose (0.3 mM) was found to substantially reduce bitterness in the homogeneous control, bitterness suppression was not enhanced when distributing the masking agent (sucralose) inhomogeneously.  相似文献   

12.
This study investigated the effect of inhomogeneous distributions of quinine on bitterness intensity of gelatine–agar composite gels. It also investigated the effect of inhomogeneous distributions of the gel’s hydrocolloid constituents (the gelatine and agar) on the bitterness intensity of the quinine. Fifty-two screened subjects participated in four paired comparison tests comparing inhomogeneous designs of quinine (with a homogeneous hydrocolloid distribution) and inhomogeneous designs of the hydrocolloids (with a homogeneous quinine distribution), against a homogeneous control of identical overall quinine and hydrocolloid composition. Using the same gel designs, a mastication trial was undertaken where ten subjects were asked to chew each gel system until the point of swallowing, and eleven subjects participated in a time-intensity trial where bitterness intensity was monitored during mastication and after expectoration. Paired comparison tests showed that the inhomogeneous distribution of quinine increased bitterness intensity, while inhomogeneous distributions of the hydrocolloids did not. Mastication was not influenced by changes in the distribution of quinine or the hydrocolloids. Time intensity curves showed the gels having an inhomogeneous distribution of quinine had greater bitterness intensity throughout mastication, however no differences in bitterness intensity were observed between any gel designs in the latter stages of aftertaste measurements. Time intensity curves also showed a slight delay in time to maximum bitterness intensity for the gels with inhomogeneous distributions of hydrocolloids. Results suggest a homogeneous distribution of bitter compounds is the most suitable structure for minimising bitterness perception.  相似文献   

13.
The established technique of time-resolved fluorescent spectroscopy has been applied to the rapid measurement of beer bitterness. This novel application utilises the unique long-lived fluorescence properties of the lanthanide, europium. Europium ions have the ability to selectively chelate β-tricarbonyl structures such as the iso-humulones. The resultant complex is measured by irradiating the sample at a specific wavelength and measuring the intensity of the long-lived emission. The bitterness method measures the total contribution of iso-alpha acids and related congeners. A linear relationship between standard iso-alpha acids solutions and emission intensity was found. However, in beer the effects of colour and other interfering compounds were significant. Decolourization of the beer did not improve the correlation with BU. This paper presents a preliminary investigation into the potential applications of this novel method.  相似文献   

14.
In order to screen for the bitter compounds generated from hop-derived precursors during the wort boiling process, an ethanolic hop extract was fractionated; the fractions obtained were thermally treated under model wort boiling conditions and, then, sensorially evaluated for their bitterness. Besides the isomerisation of the α-acids into the intensely bitter iso-α-acids, the bitterness of the fraction containing the β-acids was also found to be enhanced after wort boiling. To gain first insights into the β-acid-derived bitter compounds, the β-acid colupulone was isolated, thermally treated under wort boiling conditions and, then, investigated for bitter tasting degradation products by means of a taste dilution analysis (TDA). Besides the cohulupone, five previously unreported bitter-tasting colupulone degradation products, all of which exhibited a lingering, β-acid-like bitter taste with low recognition thresholds between 37.9 and 90.3 μmol/l, were isolated and their structures determined as two tricyclocolupone epimers, two dehydrotricyclocolupone epimers, and nortricyclocolupone, respectively, by means of LC–TOF–MS and 1D/2D-NMR spectroscopy.  相似文献   

15.
The impact of the degree of polymerization and of the concentration of procyanidins in a model solution of French cider was investigated. Four purified fractions of procyanidins at three concentrations were added in a solution containing water, ethanol, fructose and malic acid. The four studied sensory characteristics (bitterness, astringency, sweetness and sourness) were modified according to the concentration of procyanidins. The degree of polymerization (DP) of procyanidins influenced only bitterness and astringency but this impact was not the same for all concentrations. Despite the fact that pH, fructose and malic acid concentrations were the same in all samples, the perception of sweetness and sourness were modified according to the concentration of procyanidins.  相似文献   

16.
米甜酒苦味形成机理的研究   总被引:7,自引:0,他引:7  
试验表明,米甜酒致苦的机理是由于酵母的厌气(酒精)发酵或产酸菌的活动所致,但对发酵液中游离氨基氮总量影响不明显,延长酵母的对数生长期,便可延迟米甜酒的变苦,定期移走发酵酒液或补充碳源,对延迟米甜酒的变苦有明显效果;补充碳源的效果与碳源的补给比例成正相关;同时与碳源的种类有关,蔗糖效果稍好于麦芽糖但两者明显好于糊化糯米粉;加碳源去米甜酒苦味的效果。蔗糖明显好于糊化糯米粉与麦芽糖。  相似文献   

17.
    
Soluble and isoelectric soluble soybean protein hydrolysates were prepared by Alcalase treatment to a degree of hydrolysis of 3–15%. The bitterness intensity of the hydrolysates obtained was assessed on a five-point scale. The average relative molecular masses of peptides in the soluble hydrolysates (2250-1400) and isoelectric soluble hydrolysates (1313-800) and their hydrophobic peptide fractions (575-400) were determined by the trinitrobenzenesulphonic acid method. The molecular mass distribution of peptides in soluble and isoelectric soluble soybean hydrolysates and their hydrophobic peptide fractions was determined by gel permeation HPLC using a Zorbax Bio Series GF-250 column. The results suggest that the main reason for the bitterness of soybean protein hydrolysates prepared by Alcalase treatment are hydrophobic bitter peptides of relative molecular mass less than 1000.  相似文献   

18.
蛋白酶水解物苦味的探讨   总被引:3,自引:0,他引:3  
蛋白质经酶法水解产生小分子产物,它们具有独特的营养和功能特性.但酶法水解过程中也产生了不同程度的苦味,限制了蛋白水解物在食品工业中的应用.本文对酶法水解蛋白产生苦味的机理、影响因素及去除方法进行了讨论.  相似文献   

19.
Two fluorescence spectroscopic methods with the aim to develop a fast quantitative determination of bitterness in beer were tested. The first method was based on autofluorescence of the diluted and degassed beer samples without any further processing. A total of 21 dark and light beer samples were analyzed and multivariate Partial Least Squares (PLS) regression models to bitterness in form of international bitter units (IBU) were performed. A prediction error in the form of Root Mean Square Error of Cross‐Validation (RMSECV) of 2.77 IBU was obtained using six PLS components. Focusing only on the light beer samples the RMSECV was reduced to 1.81 IBU. The second method developed was based on addition of europium to induce delayed fluorescence signals in the beer samples. PLS models yielded an RMSECV of 2.65 IBU for all beers, while a model on the light beer samples gave an RMSECV of 1.75 IBU. The obtained prediction errors were compared to the errors given in the literature for the traditional extraction method of determining IBU.  相似文献   

20.
Relationships between angiotensin-(I)-converting enzyme inhibition and the bitter taste of peptides were studied. In cases where ACE inhibition or bitter taste had not been experimentally determined, their activity was estimated using several different peptide quantitative structure–activity relationship (QSAR) models. Significant correlations between increased ACE inhibition and bitterness were found for dipeptides using both observed and QSAR-predicted values. The relationship between ACE inhibition and bitter taste was attributed to the importance of hydrophobicity for both properties. Limited structural variations for dipeptides could make it difficult to have features that limit the effect of C-terminal hydrophobicity, necessary for ACE inhibition, on bitter taste. A similar modelling approach was also done on data from observed bitter oligopeptides derived from milk proteins. The relationship between QSAR-predicted ACE inhibition and observed bitter taste was not as strong as that found for dipeptides. Larger structural variation possibilities for oligopeptides than for dipeptides may thus make it, more feasible to find a highly efficient ACE inhibitory oligopeptide with a negligible bitter taste than a dipeptide.  相似文献   

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