气相色谱-质谱法分析比较超高温灭菌乳和巴氏杀菌乳中的10种内酯类风味物质

Analysis and comparison of 10 kinds of lactone flavor substances in ultra-high temperature milk and pasteurized milk by gas chromatography-mass spectrometry

中文关键词:  超高温灭菌乳  巴氏杀菌乳  内酯类风味物质  气相色谱-质谱法  溶剂萃取

英文关键词:ultra-high temperature milk  pasteurized milk  lactone flavor substances  gas chromatography-mass spectrometry  solvent extraction

中文摘要:

      目的 建立气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)分析比较超高温灭菌乳(ultra-high temperature milk, UHT)和巴氏杀菌乳中10种内酯类风味物质的分析方法。方法 液体乳样品用乙腈提取、无水硫酸镁干燥、正己烷除脂后, 经Stabile-WAX色谱柱分离, 在单离子监测(single ion monitoring, SIM)模式下进行测定, 采用基质匹配外标法进行定量。结果 10种风味物质在1~20 μg/L浓度范围内线性关系良好, 相关系数均大于0.99, 方法的检出限为0.2~4.0 μg/kg, 定量限为0.7~13.0 μg/kg。各目标化合物在3个基质加标浓度(1、5、10 μg/L)下的平均回收率为85.94%~116.44%, 相对标准偏差为1.06%~6.36% (n=6)。超高温灭菌乳样品中检出δ-癸内酯、γ-十二内酯、δ-十二内酯, 巴氏杀菌乳样品中检出δ-癸内酯和δ-十二内酯, 前者内酯类风味物质的种类和含量略高于后者。结论 建立的方法操作简单, 适用于液体乳中内酯类风味物质的检测。

英文摘要:

      Objective To establish a method for the determination of 10 kinds of lactone flavor substances in ultra-high temperature milk (UHT) and pasteurized milk by gas chromatography-mass spectrometry (GC-MS). Methods The liquid milk samples were extracted with acetonitrile, dried with anhydrous magnesium sulfate and the fat was removed with n-hexane. The liquid was performed on a Stabile-WAX column, determined under single ion monitoring (SIM) mode with mass spectrometry and quantified by matrix matching external standard solution. Results Ten kinds of lactone flavor substances showed good linear relationships in the concentration range of 1? 20 μg/L with linear regression coefficients greater than 0.99, the limits of detection were 0.2?4.0 μg/kg and limits of quantification were 0.7?13.0 μg/kg. The average recoveries of the target compounds were 85.94%?116.44% with the relative standard deviations of 1.06%?6.36% (n=6) at 3 standard concentrations (1, 5, 10 μg/L). δ-decalactone, γ-dodecolactone and δ-dodecolactone were detected in UHT milk, δ-decalactone and δ-dodecolactone were detected in pasteurized milk samples. The types and content of lactones in the former were slightly higher than those in the latter. Conclusion This method is simple to operate and suitable for the determination of lactone flavor substances in liquid milk.