吡嗪类化合物在白云边酒中的变化

Changes of Pyrazines in Baiyunbian Liquor

吡嗪类化合物是白酒中重要的含氮化合物,对白酒的风味有重要的影响。为分析吡嗪类化合物在白云边酒中的变化,建立了间接固相微萃取与气相色谱–质谱(GC-MS)联用技术,采用外标法快速定量检测白云边酒中2-甲基吡嗪、2,5-二甲基吡嗪、2,3,5-三甲基吡嗪、2,3,5,6-四甲基吡嗪的含量。间接固相微萃取:先对酒样预处理,将酒样用H2SO4调节pH值为1,用旋转蒸发仪蒸发浓缩,收集浓缩液用NaOH调节pH值为12。再顶空固相微萃取,取1 ml浓缩液于顶空瓶中,加入NaCl直到浓缩液饱和。40℃保持15 min,并且在相同的温度下萃取20 min。气相色谱–质谱分析结果显示:吡嗪类化合物含量与年份有着密切关系。白云边年份酒中尤其12年~15年是各类吡嗪含量变化的转折点,四种吡嗪总含量随年份增长而递增。

Pyrazines are one of the most important flavors in liquor. To analyze the changes of pyrazines in Baiyunbian liquor, a technique of indirect solid phase microextraction and GC-MS was established. The contents of 2-methylpyrazine, 2,5-dimethylpyrazine, 2,3,5-trimethylpyrazine, 2,3,5,6-tetrame- thylpyrazine in Baiyunbian liquor were detected by external standard method. Indirect solid phase microextraction: First wine was pretreated, the samples were adjusted to pH1 with H2SO4, evaporate and concentrate with a rotary evaporator, then adjusted to pH12 with NaOH. Headspace solid phase microextraction: take 1 ml of concentrate in a headspace bottle and add NaCl until the concentrate is saturated. The temperature is kept at 45?C for 15 min, and the concentrate was extracted at the same temperature for 20 min. The results show that the content of pyrazines is closely related to the year. 12 - 15 years is the turning point of the change in pyrazine content, the total content of four pyrazines increased with the year.