顶空固相微萃取-气相色谱-质谱法测定小米黄酒风味成分

Determination of flavor compounds in foxtail millet wine by gas chromatography-mass spectrometry coupled with headspace solid phase microextraction

为全面了解小米黄酒风味成分的构成和气味特征,优化了85μm聚丙烯酸酯(PA)、100μm聚二甲基硅氧烷(PDMS)、75μm碳分子筛(CAR)/PDMS、50/30μm二乙烯基苯(DVB)/CAR/PDMS萃取头提取小米黄酒风味成分的条件,采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)-气相色谱-质谱法(GC-MS)对风味成分进行定性、定量分析,并计算气味活性值(odor active value,OAV),同时利用OAV分析风味成分的气味特征和气味强度。结果显示:不同萃取头的最优萃取条件为样品量8 mL、萃取时间40 min、萃取温度60℃、NaCl添加量1.5 g。小米黄酒风味成分由醇、酯、含苯化合物、烃、酸、醛、酮、烯、酚和杂环类化合物构成,醇为主要风味成分。通过OAV确定了苯乙醇、苯乙烯、2-甲基萘、1-甲基萘、苯甲醛、苯乙醛、2-甲氧基-苯酚为小米黄酒气味特征成分,苯基乙醇、苯乙醛对气味贡献最大。PA和PDMS萃取头分别对极性和非极性化合物具有较好的吸附效果,CAR/PDMS和DVB/CAR/PDMS萃取头对中等极性化合物具有较好的吸附效果。该研究全面了解了小米黄酒风味成分的构成,为其产品开发及品质控制提供理论了依据。

To comprehensively understand flavor compounds and aroma characteristics of fox-tail millet wine,extraction conditions were optimized with 85 pm polyacrylate （PA）,100 pm polydimethylsiloxane （PDMS）,75 pm carboxen （CAR）/PDMS and 50/30 pm divinylbenzene （DVB ）/CAR/PDMS fibers. The flavor compounds in foxtail millet wine were investigated by gas chromatography-mass spectrometry （GC-MS） coupled with headspace solid phase microex-traction （HS-SPME）,and the odor characteristics and intensity were analyzed by odor active values （OAVs）. The samples of 8 mL were placed in headspace vials with 1.5 g NaCl,then the headspace vials were heated at 60 ^ for 40 min. Using HS-SPME with different fibers,a total of 55 flavor compounds were identified from the samples, including alcohols, esters, benzene derivatives, hydrocarbons, acids, aldehydes, ketones, terpenes,phenols and heterocycle com-pounds. The main flavor compounds were alcohols compounds. According to their OAVs,phenylethyl alcohol,styrene, 1-methyl-naphthalene, 2-methyl-naphthalene, benzaldehyde,benzeneacetaldehyde and 2-methoxy-phenol were established to be odor-active compounds. Phenylethyl alcohol and benzeneacetaldehyde were the most prominent odor-active compounds. PA and PDMS fibers had good extraction effect for polar and nonpolar compounds, respectively. CAR/PDMS and DVB/CAR/PDMS provided a similar compounds profile for moderate polar compounds. This research comprehensively determined flavor compounds of foxtail millet wine, and provided theoretical basis for product development and quality control.