采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)技术研究8个产区香椿挥发性成分差异。共鉴定出56种化合物,醇类和醛类的相对含量较高。基于化学计量学主成分分析和偏最小二乘判别分析(partial least sq...采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)技术研究8个产区香椿挥发性成分差异。共鉴定出56种化合物,醇类和醛类的相对含量较高。基于化学计量学主成分分析和偏最小二乘判别分析(partial least squares-discriminant analysis,PLS-DA)可以很好区分8个产区香椿样品。基于PLS-DA模型的变量投影重要性(variable importance in projection,VIP)得分对8个产区香椿挥发性有机化合物进行判别分析,筛选出12种(VIP>1)标志挥发性化合物,其中(E)-2-己烯醛-D、乙酸乙酯-D、苯酚、糠醛、苯乙醇是主要的差异代谢物。不同产区香椿挥发性化合物存在较大差异。GC-IMS可以实现对不同产区香椿挥发性化合物的差异化快速分析,为香椿挥发性香气差异研究提供有益依据。展开更多
为探明创新型联合杀青方式对绿茶栗香形成的影响,以滚筒杀青为对照,设定滚筒-微波、滚筒-远红外、滚筒-微波-远红外、滚筒-远红外-微波联合杀青,共5种方式,结合感官审评,通过气相色谱-质谱检测成品茶样香气成分68种,采用偏最小二乘-判...为探明创新型联合杀青方式对绿茶栗香形成的影响,以滚筒杀青为对照,设定滚筒-微波、滚筒-远红外、滚筒-微波-远红外、滚筒-远红外-微波联合杀青,共5种方式,结合感官审评,通过气相色谱-质谱检测成品茶样香气成分68种,采用偏最小二乘-判别分析(partial least squares-discriminant analysis,PLS-DA)、层次聚类分析、香气活度值法、差异显著性分析等探明绿茶栗香形成的最佳杀青方式,寻找栗香关键组分。结果表明,滚筒联合远红外有利于栗香品质的提升,其中以滚筒-远红外-微波联合杀青可获得高扬持久的栗香,且滋味鲜爽,整体品质最优;滚筒联合远红外杀青处理利于高沸点醇类、酮类、芳香烃类如芳樟醇、反式-β-紫罗酮等的转化与形成,以滚筒-远红外-微波处理含量显著最高;PLS-DA及层次聚类分析可根据栗香强度将不同类杀青方式准确区分及聚类,结合香气活度值,明确反式-β-紫罗酮、芳樟醇、顺-3-己酸己烯酯、壬醛、香叶醇、苯乙醛6种物质为栗香关键组分。本研究可为定向化、标准化生产优质栗香绿茶提供理论基础和技术指导。展开更多
采用气相色谱-离子迁移谱技术分析了牦牛乳干酪成熟过程中挥发性风味物质的变化。该研究共鉴定了46个信号峰中的22种挥发性风味物质。不同成熟时间牦牛乳干酪中挥发性风味物质的含量存在明显差异,成熟前期(1 d)乙偶姻和乙醇含量最高;成...采用气相色谱-离子迁移谱技术分析了牦牛乳干酪成熟过程中挥发性风味物质的变化。该研究共鉴定了46个信号峰中的22种挥发性风味物质。不同成熟时间牦牛乳干酪中挥发性风味物质的含量存在明显差异,成熟前期(1 d)乙偶姻和乙醇含量最高;成熟中期(30~90 d)2,4,6-三甲基吡啶、乙酸异戊酯和丁酸乙酯含量随着成熟时间的延长明显增加;成熟后期(120~180 d)丁酸乙酯、己酸乙酯二聚体、乙酸异戊酯和乙酸乙酯二聚体等含量达到最高。偏最小二乘-判别分析筛选出了12种特征挥发性标志物[变量重要性(variable important for the projection,VIP)>1],包括3-甲基-3-丁烯-1-醇、乙酸乙酯二聚体、乙偶姻、乙酸异戊酯、乙醇、丁酸乙酯、2-丁酮、正丁醇、己酸乙酯二聚体、烯丙基腈、2-戊酮和苯甲醛。主成分分析结果能够较好地区分牦牛乳干酪的成熟阶段。该研究结果可为今后牦牛乳干酪的产品开发和品质控制提供参考依据。展开更多
Objective： To investigate the antipyretic mechanism of Herba Ephedrae （Eph）-Ramulus Cinnamomi （RC） herb pair on yeast-induced pyrexia in rats. Methods： Totally 30 qualified male SD rats were randomly assigned to...Objective： To investigate the antipyretic mechanism of Herba Ephedrae （Eph）-Ramulus Cinnamomi （RC） herb pair on yeast-induced pyrexia in rats. Methods： Totally 30 qualified male SD rats were randomly assigned to the normal control （NC） group, the pyrexia model （model） group, the Eph, RC and Eph-RC treatment groups by a random digital table, 6 rats in each group. Each rat received a 20% aqueous suspension of yeast （10 mL/kg） except the NC group. The 3 treatment groups were administered 8.1, 5.4 and 13.5 g/kg Eph, RC and Eph-RC respectively at 5 and 12 h after yeast injection, the NC group and the model groups were administered equal volume of distilled water. Rectal temperatures were measured at 0, 6, 8, 10, 12, 15, 18, 24 and 30 h and urine was collected prior to yeast injection and at 6, 10, 18, 24, 30, and 36 h after yeast injection. Then urine metabolomic profiling by gas chromatography tandem mass spectrometry, coupled with multivariate statistical analysis and pattern recognition techniques were used to explore the antipyretic effects of Eph-RC. Partial least squares discriminate analysis was used to analyze the metabolomics dataset including classification and regression in metabolomics plot profiling. Results： Compared with the NC group, rectal temperatures were significantly higher in the model group （P〈0.01）, while 3 treatment groups decreased significantly compared with the model group （P〈0.05 or P〈0.01）. Rectal temperatures of Eph-RC-treated rats started to go down at 6 h, and markedly decreased at 8, 12, 15, 18 and 24 h （P〈0.05 or P〈0.01）, while those of the Eph and RC groups had decreased firstly at 8 h and were markedly lower at 12 h （P〈0.05 or P〈0.01）. Seventeen potential biomarkers related to pyrexia were confirmed and identified, including pyruvic acid, L-phenylalanine, L-tyrosine, phenylacetic acid, hippuric acid, succinic acid, citrate and so on. Eight potential alterations of metabolic pathways including phenylalanine metabolism, citrate 展开更多
文摘采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)技术研究8个产区香椿挥发性成分差异。共鉴定出56种化合物,醇类和醛类的相对含量较高。基于化学计量学主成分分析和偏最小二乘判别分析(partial least squares-discriminant analysis,PLS-DA)可以很好区分8个产区香椿样品。基于PLS-DA模型的变量投影重要性(variable importance in projection,VIP)得分对8个产区香椿挥发性有机化合物进行判别分析,筛选出12种(VIP>1)标志挥发性化合物,其中(E)-2-己烯醛-D、乙酸乙酯-D、苯酚、糠醛、苯乙醇是主要的差异代谢物。不同产区香椿挥发性化合物存在较大差异。GC-IMS可以实现对不同产区香椿挥发性化合物的差异化快速分析,为香椿挥发性香气差异研究提供有益依据。
文摘为探明创新型联合杀青方式对绿茶栗香形成的影响,以滚筒杀青为对照,设定滚筒-微波、滚筒-远红外、滚筒-微波-远红外、滚筒-远红外-微波联合杀青,共5种方式,结合感官审评,通过气相色谱-质谱检测成品茶样香气成分68种,采用偏最小二乘-判别分析(partial least squares-discriminant analysis,PLS-DA)、层次聚类分析、香气活度值法、差异显著性分析等探明绿茶栗香形成的最佳杀青方式,寻找栗香关键组分。结果表明,滚筒联合远红外有利于栗香品质的提升,其中以滚筒-远红外-微波联合杀青可获得高扬持久的栗香,且滋味鲜爽,整体品质最优;滚筒联合远红外杀青处理利于高沸点醇类、酮类、芳香烃类如芳樟醇、反式-β-紫罗酮等的转化与形成,以滚筒-远红外-微波处理含量显著最高;PLS-DA及层次聚类分析可根据栗香强度将不同类杀青方式准确区分及聚类,结合香气活度值,明确反式-β-紫罗酮、芳樟醇、顺-3-己酸己烯酯、壬醛、香叶醇、苯乙醛6种物质为栗香关键组分。本研究可为定向化、标准化生产优质栗香绿茶提供理论基础和技术指导。
文摘采用气相色谱-离子迁移谱技术分析了牦牛乳干酪成熟过程中挥发性风味物质的变化。该研究共鉴定了46个信号峰中的22种挥发性风味物质。不同成熟时间牦牛乳干酪中挥发性风味物质的含量存在明显差异,成熟前期(1 d)乙偶姻和乙醇含量最高;成熟中期(30~90 d)2,4,6-三甲基吡啶、乙酸异戊酯和丁酸乙酯含量随着成熟时间的延长明显增加;成熟后期(120~180 d)丁酸乙酯、己酸乙酯二聚体、乙酸异戊酯和乙酸乙酯二聚体等含量达到最高。偏最小二乘-判别分析筛选出了12种特征挥发性标志物[变量重要性(variable important for the projection,VIP)>1],包括3-甲基-3-丁烯-1-醇、乙酸乙酯二聚体、乙偶姻、乙酸异戊酯、乙醇、丁酸乙酯、2-丁酮、正丁醇、己酸乙酯二聚体、烯丙基腈、2-戊酮和苯甲醛。主成分分析结果能够较好地区分牦牛乳干酪的成熟阶段。该研究结果可为今后牦牛乳干酪的产品开发和品质控制提供参考依据。
基金Supported by the National Natural Science Foundation of China(No.81030066)
文摘Objective： To investigate the antipyretic mechanism of Herba Ephedrae （Eph）-Ramulus Cinnamomi （RC） herb pair on yeast-induced pyrexia in rats. Methods： Totally 30 qualified male SD rats were randomly assigned to the normal control （NC） group, the pyrexia model （model） group, the Eph, RC and Eph-RC treatment groups by a random digital table, 6 rats in each group. Each rat received a 20% aqueous suspension of yeast （10 mL/kg） except the NC group. The 3 treatment groups were administered 8.1, 5.4 and 13.5 g/kg Eph, RC and Eph-RC respectively at 5 and 12 h after yeast injection, the NC group and the model groups were administered equal volume of distilled water. Rectal temperatures were measured at 0, 6, 8, 10, 12, 15, 18, 24 and 30 h and urine was collected prior to yeast injection and at 6, 10, 18, 24, 30, and 36 h after yeast injection. Then urine metabolomic profiling by gas chromatography tandem mass spectrometry, coupled with multivariate statistical analysis and pattern recognition techniques were used to explore the antipyretic effects of Eph-RC. Partial least squares discriminate analysis was used to analyze the metabolomics dataset including classification and regression in metabolomics plot profiling. Results： Compared with the NC group, rectal temperatures were significantly higher in the model group （P〈0.01）, while 3 treatment groups decreased significantly compared with the model group （P〈0.05 or P〈0.01）. Rectal temperatures of Eph-RC-treated rats started to go down at 6 h, and markedly decreased at 8, 12, 15, 18 and 24 h （P〈0.05 or P〈0.01）, while those of the Eph and RC groups had decreased firstly at 8 h and were markedly lower at 12 h （P〈0.05 or P〈0.01）. Seventeen potential biomarkers related to pyrexia were confirmed and identified, including pyruvic acid, L-phenylalanine, L-tyrosine, phenylacetic acid, hippuric acid, succinic acid, citrate and so on. Eight potential alterations of metabolic pathways including phenylalanine metabolism, citrate
