GC-O-MS法鉴定黑巧克力中关键香气物质

Use of GC-O-MS to Identify Key Aroma Compounds in Dark Chocolate

采用同时蒸馏萃取法(SDE)和吹扫捕集法(P&T)对醇浓黑巧克力中挥发性物质进行提取。利用气相色谱-嗅闻-质谱联用的方法对其中的挥发性性物质定性分析,共鉴定出52种物质,包括醛类、烯醛类、吡嗪类、醇类、酯类、酮类、呋喃类、酸类等物质,其中吡嗪类物质的种类最多,其次为醛类物质。通过香气提取物稀释分析(AEDA)和动态顶空稀释分析(DHDA),确定关键的香气物质(log3FD≥4/FD值≥125)共有10种,分别为醛4种(2-甲基丙醛、3-甲基丁醛、2-甲基丁醛、苯乙醛),吡嗪4种(乙基吡嗪、2,3-二甲基吡嗪、三甲基吡嗪、四甲基吡嗪),酯1种(苯甲酸异戊酯),吡咯1种(2-乙酰基-1-吡咯啉)。其中巧克力香气特征主要表现为黑巧克力香、爆米花味、烤香、水果香、咖啡香、坚果香等。

The volatile compounds in dark chocolate was extracted using the methods of simultaneous distillation extraction （SDE） and purge ＆trap （P＆T）. Gas chromatography-olfactometry-mass spectrometry （GC-O-MS） was used to identify the aroma compounds, fifty-five compounds were identified Including aldehydes, olefmic aldehydes, pyrazines, alcohols, esters, ketones, furans, acids, ect., among which pyrazines has the maximum content, followed by aldehydes. Ten key aroma compounds were identified use of aroma extract dilution analysis （AEDA） and dynamic beadspace dilution Analysis （DHDA）, which were 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, phenylacetaldehyde, ethyl-pyrazine, 2,3-dimethyl-pymzine, trimethylpyrazine, tetramethylpyrazie, isopentyl benzoate, and 2-acetyl-l-pyrroline. The odor characteristics of chocolate was deep chocolate smell, popcorn flavor, roast flavor, coffee flavor, nutty and so on.