GC-O-MS对白酒中的糠味物质的研究

Research on Rice Husk-like Odor in Baijiu by GC-O-MS

以萃取率为评价指标,采用单因素实验对SPME萃取白酒中香气化合物的萃取条件进行了优化,最佳条件为:顶空模式,萃取温度60℃,萃取时间40min,加盐量2.5g,搅拌转速500rpm,解析时间6min,通过GC-O分析,确定了2-糠酸乙酯、4-乙烯基苯酚、4-乙烯基愈创木酚、1,4二甲氧基苯、1,2二甲氧基苯、笏、土嗅素、[3.3.1]壬二烯-3,7-二酮等八种物质是白酒中的糠味物质;建立了外标法快速定量七种主要的糠味物质的方法,该方法检测范围内线性关系良好(R2>0.99),并且有较好的重复性和回收率;通过对白酒酿造原辅料稻壳,高粱,高粱壳及大曲中糠味物质的调查,初步确认了典型的糠味物质产生的来源,生糠味物质[3.3.1]壬二烯-3,7-二酮主要是在稻壳受热时产生的,土糠味的土嗅素和湿糠味的1,2二甲氧基苯主要来自于大曲,是由微生物的污染产生的,2-糠酸乙酯是发酵过程产生的,呈现咸糠味。

In this study,regarded the extraction rate as evaluation index,the single factor test was used to optimize solid-phase micro extraction(SPME)condition for extracting aroma compounds in Baijiu,After optimization,the best extraction condition is Headspace mode,extraction temperature 60℃,extraction time 40min,salt content 2.5g,stirring speed 500rpm,desorption time 6min.Through GC-O,determine that 2-Furancarboxylicacid,ethylester,4-vinylphenol(4-VP),4-vinylguaiacol(4-VG),1,4-dimethoxybenzene,1,2-dimethoxybenzene,Fluorene,Geosmin(GSM),[3.3.1]-3-7decadiene-2,9-dione in Baijiu are rice bran odor(RBO)substances,Established a method for quickly and easily quantifying the six main RBO substances with the external standard method.The linearity of the method is good(R2>0.99),and it has good repeatability and recovery.The typical RBO is confirmed by the analysis of rice husk,sorghum,sorghum husk,Daqu,,the source of the RBO,[3.3.1]-3,7 decadiene-2,9-dione is mainly produced when the rice husk is steamed.The wet RBO 1,2-dimethoxybenzene and GSM is derived from the contamination by microorganisms,and the 2-Furancarboxylicacid,ethyl ester is produced by the fermentation process and shows a salty RBO.