GC-MS/GC-O结合化学计量学方法研究不同产地阿胶的关键香气组分

采用同时蒸馏萃取（SDE）和气相色谱-质谱（GC-MS）联合气相色谱-嗅闻（GC-O）技术及化学计量法方法系统地分析了原产地东阿阿胶和其他地区阿胶香气成分的特征与差异，并对东阿阿胶的关键香气组分进行了分离鉴定。经GC-MS共鉴定出65种香气成分，主要为醛类，吡嗪类，其次为酮类，含硫化合物等。经GC-O技术共分离出23种活性香气成分，其中硫代乙酸甲酯、2,6-二甲基吡嗪和2-乙基-3,6-二甲基吡嗪等对阿胶风味贡献较大。化学计量法研究结果表明，不同产地阿胶样品分离明显，5种阿胶间最大相关系数仅为0.5285。GC-MS/GC-O技术联合化学计量学方法不仅能准确鉴定阿胶的关键香气组分，而且为鉴别和评价不同产地阿胶品质提供了一种可靠的技术手段。
Using GC-MS and a pulsed flame photometric detector (PFPD), 65 aroma compounds were identified and quantified in Colla Corii Asini (CCA) samples. The main volatile components of the CCAs were aldehydes, pyrazines, ketones, and sulfur compounds. Using GC-O and aroma extract dilution analysis (AEDA), 23 aroma-active compounds were detected. Based on the flavor dilution (FD) factor, the most powerful aroma-active compounds identified in the extracts were S-methyl thioacetate (sulfurous/burnt), 2,6-dimethylpyrazine (roasted nut), and 2-ethyl-3,6-dimethylpyrazine (roast). Principal components analysis (PCA) and correlation analysis were performed on the 23 aroma-active compounds. The principal components scores demonstrated significantly different patterns for five CCAs. Moreover, correlation coefficients (Pearson's r) among the five CCAs were very low and the largest correlation coefficient was 0.5285 obtained between Dong-E and Zhangjiachuan CCAs. It was concluded that GC-MS/GC-O can provide an effective and reliable tool for the analysis and characterization of the aroma components in CCA. Although it is rarely considered, aroma was demonstrated to be an important aspect of CCA quality. Chemometric analysis of the patterns of the 23 aroma-active compounds showed potential for quality evaluation and identification of CCAs from different habitats.