麦芽与黑啤中15种麦芽香特征物质的分析

Analysis of 15 kinds of malt aroma characteristic substances in malt and stout

采用顶空固相微萃取-气相色谱质谱联用法分别建立了麦芽和啤酒中15种特种麦芽香物质的检测方法。利用所建方法检测了5种国内外黑啤,发现含量存在显著差异,其中整体含量较高的是菠萝酮（OAV值高达4.99）和2-乙酰吡咯。感官品质最好的啤酒麦芽香含量处于中等水平。针对淡色、焦香和黑麦芽分析,发现3种麦芽中都能检测出麦芽酚、2-乙酰吡咯和2,3,5,6-四甲基吡嗪,其中焦香麦芽含量最高,黑麦芽其次。利用3种麦芽酿造黑啤（黑麦芽：2.5%,焦香麦芽：0%-35%）,发现麦芽酚、2-乙酰吡咯和菠萝酮是麦汁和黑啤中含量相对较高的物质,且随着焦香麦芽比例的增加而上升,后两者是黑啤中的重要麦芽香物质。其次是噻唑、吡嗪类等6种物质,含量随焦香麦芽比例的增加先升高后降低,含量在焦香麦芽比例为15%或25%时处于最高点。结合感官品评,发现当焦香麦芽比例为15%时啤酒麦芽香、酒花香及醇酯香总体最为协调,评分最高,其次是焦香麦芽比例为25%的啤酒。

The headspace solid phase micro extraction-gas chromatography mass spectrometry detection methods were established to detect 15 kinds of special malt aroma components in malt and beer separately. Five kinds of stout from home and abroad were detected using this method. And significant difference in the content was found. Pineap- ple-ketone （ OAV value up to 4.99） and 2-acetylpyrrole had higher overall contents. However the content of malt aro- ma components in beer with best sensation is at a medium level. Meanwhile analysis on pale malt, caramel malt and black malt showed that mahol, 2-acetylpyrrole and 2, 3, 5,6-tetramethylpyrazine could be detected and caramel malt had the highest content, black malt followed. Stout was brewed using these three kinds of malt （black malt： 2.5% , caramel malt： 0% -35% ）. We found that maltol, 2-acetylpyrrole and pineapple-ketone had relatively high content in stout and wort. Moreover, their content rose with the increase of caramel malt proportion. And the latter two sub- stances were important malt aroma in stout. Secondly, the content of six substances of thiazole and pyrazine increased at first then reduced. Basically the highest point was reached at the caramel malt ratio of 15% or 25%. On the basis of sensory evaluation, we found that the stout with best coordinated taste rated highest when the proportion of caramel malt was 15% , followed by caramel malt ratio of 25%.