为了确定传统豆酱香气品质最佳的发酵时期,以东北自然发酵豆酱为研究对象,采用顶空固相微萃取(HP-SPME)结合气质联用(GC-MS)技术,以对甲氧基苯甲醛为内标,对不同发酵时期的豆酱样品中的香气成分进行定性和半定量分析,并运用因子分析构建传统豆酱香气品质评价模型,以综合得分作为评价指标,结果表明:在16个不同发酵时期的豆酱样品中共检测出56种香气成分,其中酯类9种,醇类6种,醛类5种,酮类4种,酸类9种,酚类9种,杂环类7种,烃类5种,以及其他类2种。豆酱样品中香气成分含量变化明显,发酵45 d豆酱样品中香气成分含量最多,为8 176.422 ng/g,随着发酵过程的进行香气成分含量整体上呈下降趋势,发酵70 d和发酵75 d香气成分含量分别为4 052.849和2 265.616 ng/g。因子分析得到3个公因子分别命名为调和型香气因子、贡献型香气因子和增香型香气因子,比较不同发酵时期豆酱样品的香气品质综合得分可知,发酵45 d豆酱样品综合得分最高,其次是发酵65 d和发酵55 d的样品,发酵70 d和发酵75 d的豆酱样品综合得分较低,因此豆酱的最佳发酵时间为45~65 d。

In order to determine the fermentation period during which the traditional soybean paste possesses the best aroma quality,aroma components in different fermentation periods of traditional fermented soybean paste in Northeast region were extracted by headspace solid phase micro-extraction( HS-SPME),and analyzed by gas chromatography-mass spectroscopy( GC-MS) when p-methoxybenzaldehyde was used as internal standards in semi-quantitative analysis. Factor analysis was used to construct the model of aroma quality evaluation of soybean paste and comprehensive scores were used as evaluation indexes. Results showed that totally 56 volatile compounds in different fermentation periods were identified,including 9 esters,6 alcohols,5 aldehydes,4 ketones,9 acids,9 phenols,7 heterocyclics,5 phenols,and two other compounds. Contents of aroma components in soybean paste changed obviously,on Day 45,content of 8176. 422 ng /g was the highest,along with the fermentation processing,the content of aroma components was on the decline as a whole,on Day 70 and Day 75,the contents of aroma components were 4052. 849 and 2265. 616 ng /g respectively. Three common factors were obtained by factor analysis and named mixed factor,contribution factor and increased aroma factor respectively. Comparison of comprehensive scores of aroma in soybean paste in different fermentation periods showed that score was the highest on Day 45 followed by Day 65 and Day 55,score was lower on Day 70 and 75,so the best fermentation periods was from Day 45 to Day 65.