College of Food Science, Woosuk University , Samrea-Up, Wanju-Kun, Jeonbuk Province 565-701, Republic of Korea.
J Agric Food Chem. 2013 Sep 11;61(36):8514-23. doi: 10.1021/jf402487a. Epub 2013 Sep 5.
A new headspace (HS)-solid phase microextraction (SPME)-gas chromatography-tandem quadrupole mass spectrometry (GC-MS(2)) was established for the simultaneous characterization and quantitation of pyrazines in perilla seed oils. HS-SPME conditions such as fiber choice, extraction temperature, and adsorption times were tested. The established GC-MS(2) showed low detection limit (LOD) and high specificity, recovery, and precision for analysis of pyrazines in perilla seed oils. The LODs for the pyrazines were in the range of 0.07-22.22 ng/g oil. The relative standard deviations (RSDs) for the intra- and interday repeated analyses of pyrazines were less than 9.49 and 9.76%, respectively. The mean recoveries for spiked pyrazines in perilla seed oil were in the range of 94.6-107.92%. Perilla seed oils were obtained by mechanical pressing from perilla seeds roasted to different degrees of roasting (mild, medium, medium dark, and dark roasting). Fourteen pyrazine compounds in perilla seed oils were isolated, identified, and quantitated. Among them, 2-methyl-3-propylpyrazine, tetramethylpyrazine, and 2,3-diethyl-5-methylpyrazine were the first identified in perilla seed oils. Degree of roasting influenced greatly the composition and contents of pyrazines in perilla seed oils. In light-roasted perilla seed oil, 2,5-dimethylpyrazine was the most predominant pyrazine. However, in dark-roasted perilla seed oil, 2-methylpyrazine was the most abundant pyrazine in the oil, representing 38.3% of its total pyrazine content. Dark-roasted perilla seed oil contains 16.78 times higher quantity of pyrazines than light-roasted perilla seed oil. This represents the first report on the quantity of pyrazines in perilla seed oils.
一种新的顶空固相微萃取-气相色谱-串联四极杆质谱（HS-SPME-GC-MS(2)）方法被建立用于同时鉴定和定量鉴定芝麻油中的吡嗪类化合物。测试了顶空固相微萃取条件，如纤维选择、萃取温度和吸附时间。所建立的 GC-MS(2) 对芝麻油中吡嗪类化合物具有低检测限（LOD）和高特异性、回收率和精密度。吡嗪类化合物的 LOD 在 0.07-22.22 ng/g 油的范围内。吡嗪类化合物的日内和日间重复分析的相对标准偏差（RSD）分别小于 9.49%和 9.76%。在芝麻油中添加吡嗪类化合物的平均回收率在 94.6-107.92%的范围内。芝麻油是通过对不同程度烘烤的芝麻种子（轻度、中度、中度深烤和深烤）进行机械压榨而获得的。从芝麻油中分离、鉴定和定量了 14 种吡嗪类化合物。其中，2-甲基-3-丙基吡嗪、四甲基吡嗪和 2,3-二乙基-5-甲基吡嗪是首次在芝麻油中鉴定出的。烘烤程度对芝麻油中吡嗪类化合物的组成和含量有很大影响。在轻度烘烤的芝麻油中，2,5-二甲基吡嗪是最主要的吡嗪。然而，在深度烘烤的芝麻油中，2-甲基吡嗪是油中最丰富的吡嗪，占其总吡嗪含量的 38.3%。深度烘烤的芝麻油中吡嗪类化合物的含量比轻度烘烤的芝麻油高 16.78 倍。这是芝麻油中吡嗪类化合物含量的首次报道。
