为探究油炸对牦牛肉风味物质及品质的影响,对不同油炸温度和时间下的牦牛肉进行感官评分、水分含量、色差值、质构指标的测定;采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid phase microextraction combined with gas chro...为探究油炸对牦牛肉风味物质及品质的影响,对不同油炸温度和时间下的牦牛肉进行感官评分、水分含量、色差值、质构指标的测定;采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid phase microextraction combined with gas chromatography-mass spectrometry,HS-SPME-GC-MS)分析油炸前后牦牛肉风味物质的种类和含量变化。结果表明:E_2组(160℃、80 s)牦牛肉感官评分、色差值、质构品质指标均最优。HS-SPME-GC-MS共鉴定出41种挥发性风味物质,包括醛类20种、醇类5种、酯类2种、酮类1种、呋喃类1种、烃类7种、有机酸类1种、其它类4种化合物;A组(参照组)检测出27种化合物,E_2组检测出38种化合物,两组牦牛肉中挥发性成分种类及相对含量有较大差异。根据香气特征雷达图得出,E_2组的香气种类更丰富。利用相对气味活度值对牦牛肉关键风味成分分析得出,A组关键挥发性风味物质有10种,E_2组关键挥发性风味物质有17种,其中反式-2-癸烯醛、壬醛、1-辛烯-3-醇相对气味活度值最大,分别为47.35、35.14、17.63,赋予油炸牦牛肉烤肉味、果香味、蘑菇香味。通过韦恩图得出,A组特有的挥发性风味物质有3种,E_2组特有的挥发性风味物质有14种,A组特有关键香气成分2种,E_2组特有关键香气成分9种。综合风味指标、质构指标和感官评价指标得出,油炸工艺对牦牛肉的风味及品质有明显提升。展开更多
采用顶空固相微萃取-全二维气相色谱-飞行时间质谱(headspace solid phase microextraction in combination with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry,HS-SPME-GC×GC-...采用顶空固相微萃取-全二维气相色谱-飞行时间质谱(headspace solid phase microextraction in combination with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry,HS-SPME-GC×GC-TOFMS)技术对全脂牛乳(whole milk,WM)、低脂牛乳(low-fat milk,LFM)和脱脂牛乳(non-fat milk,NFM)3种牛乳样品进行挥发性化合物分析,结果表明:共检测到49种挥发性化合物,其中2-壬酮、2-十一酮等奇数碳链的甲基酮构成WM的主要风味化合物;偏最小二乘法判别分析表明,其模型可以很好地区分3种牛乳样品,并且有较好的方差和交叉验证预测能力;通过变量投影重要性>1、P≤0.05且含量≥1%筛选出9种化合物,被认定为关键香气差异化合物,这些化合物可能是导致3种牛乳风味不同的主要因素;聚类热图结果表明,NFM因异味化合物(如十六醛)的存在可能导致不良感官表现,而WM和LFM存在更多的香气化合物,令其在感官方面具有饱满丰富的香气。本研究建立了HS-SPME-GC×GC-TOFMS分析牛乳的研究方法,为乳制品风味改进和乳制香精调配提供了理论指导。展开更多
The negative secondary ion mass spectrometry,in combination with the stereoselective derivatizations with substituted boronic acid RB(OH)_2,was used in the analysis of fourteen oligosac- charides.The mass spectra of t...The negative secondary ion mass spectrometry,in combination with the stereoselective derivatizations with substituted boronic acid RB(OH)_2,was used in the analysis of fourteen oligosac- charides.The mass spectra of the derivatives provide information on their linkage Positions and iso- merism of the individual monoscaccharide units.The results indicated that among the derivatives of the oligosaccharides analyzed,those with 1—4 and 1—6 linkages all presented the ion peaks at m/z 287,sometimes one more peak at m/z 449.Furthermore,a relationship was found between the linkage positions and the intensity orders of the derivative ions.Finally,the derivatives of the disaccharides with a galactose presented an intense ion peak at m/z 347,and those of oligosaccharides with 1—6 linkage to a galactose at terminal presented the ion at m/z 317.In the case of oligosaccharides with a fructose residue,characteristic ion of m/z 155 was produced.The conditions of stereoselective derivatizations and mass spectrometry were studied,in order to obtain a better reproducibility of the mass spectra.展开更多
文摘为探究油炸对牦牛肉风味物质及品质的影响,对不同油炸温度和时间下的牦牛肉进行感官评分、水分含量、色差值、质构指标的测定;采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid phase microextraction combined with gas chromatography-mass spectrometry,HS-SPME-GC-MS)分析油炸前后牦牛肉风味物质的种类和含量变化。结果表明:E_2组(160℃、80 s)牦牛肉感官评分、色差值、质构品质指标均最优。HS-SPME-GC-MS共鉴定出41种挥发性风味物质,包括醛类20种、醇类5种、酯类2种、酮类1种、呋喃类1种、烃类7种、有机酸类1种、其它类4种化合物;A组(参照组)检测出27种化合物,E_2组检测出38种化合物,两组牦牛肉中挥发性成分种类及相对含量有较大差异。根据香气特征雷达图得出,E_2组的香气种类更丰富。利用相对气味活度值对牦牛肉关键风味成分分析得出,A组关键挥发性风味物质有10种,E_2组关键挥发性风味物质有17种,其中反式-2-癸烯醛、壬醛、1-辛烯-3-醇相对气味活度值最大,分别为47.35、35.14、17.63,赋予油炸牦牛肉烤肉味、果香味、蘑菇香味。通过韦恩图得出,A组特有的挥发性风味物质有3种,E_2组特有的挥发性风味物质有14种,A组特有关键香气成分2种,E_2组特有关键香气成分9种。综合风味指标、质构指标和感官评价指标得出,油炸工艺对牦牛肉的风味及品质有明显提升。
文摘采用顶空固相微萃取-全二维气相色谱-飞行时间质谱(headspace solid phase microextraction in combination with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry,HS-SPME-GC×GC-TOFMS)技术对全脂牛乳(whole milk,WM)、低脂牛乳(low-fat milk,LFM)和脱脂牛乳(non-fat milk,NFM)3种牛乳样品进行挥发性化合物分析,结果表明:共检测到49种挥发性化合物,其中2-壬酮、2-十一酮等奇数碳链的甲基酮构成WM的主要风味化合物;偏最小二乘法判别分析表明,其模型可以很好地区分3种牛乳样品,并且有较好的方差和交叉验证预测能力;通过变量投影重要性>1、P≤0.05且含量≥1%筛选出9种化合物,被认定为关键香气差异化合物,这些化合物可能是导致3种牛乳风味不同的主要因素;聚类热图结果表明,NFM因异味化合物(如十六醛)的存在可能导致不良感官表现,而WM和LFM存在更多的香气化合物,令其在感官方面具有饱满丰富的香气。本研究建立了HS-SPME-GC×GC-TOFMS分析牛乳的研究方法,为乳制品风味改进和乳制香精调配提供了理论指导。
基金Project supported by the National Natural Science Foundation of China
文摘The negative secondary ion mass spectrometry,in combination with the stereoselective derivatizations with substituted boronic acid RB(OH)_2,was used in the analysis of fourteen oligosac- charides.The mass spectra of the derivatives provide information on their linkage Positions and iso- merism of the individual monoscaccharide units.The results indicated that among the derivatives of the oligosaccharides analyzed,those with 1—4 and 1—6 linkages all presented the ion peaks at m/z 287,sometimes one more peak at m/z 449.Furthermore,a relationship was found between the linkage positions and the intensity orders of the derivative ions.Finally,the derivatives of the disaccharides with a galactose presented an intense ion peak at m/z 347,and those of oligosaccharides with 1—6 linkage to a galactose at terminal presented the ion at m/z 317.In the case of oligosaccharides with a fructose residue,characteristic ion of m/z 155 was produced.The conditions of stereoselective derivatizations and mass spectrometry were studied,in order to obtain a better reproducibility of the mass spectra.
