红腐乳中挥发性风味物质的分析

采用同时蒸馏萃取法结合气相色谱-质谱联用提取分析自制红腐乳及两种不同品牌红腐乳中的挥发性风味物质；同时以甲醛滴定法测定坯体与汤料中的氨基酸态氮含量。结果显示：坯体比汤料中的风味物质种类多，自制、王致和、鼎丰腐乳坯体中酯类分别为18、24、27种，醛类13、11、15种，醇5、7、6种，酮3、4、4种，均含呋喃类1种。其中以长链脂肪酸酯含量最高，占风味物质总量的90%以上。那同时存在于坯体和汤料的风味物质中，甲基吡嗪、亚油酸乙酯等酯类双亲分子较其他风味物质更倾向于存在于汤料中。汤料中的氨基酸态氮含量比坯体中高，且3种腐乳中氨基酸态氮含量存在显著差异。

Analysis of Volatile Flavor Components in Red Fermented Soybean Curds

Volatile flavor components in three different red fermented soybean curds were extracted by a simultaneous steam distillation extraction method and analyzed by gas chromatography-mass spectrometry.The content of amino nitrogen in pehtze and soup were determined by formaldehyde titration.Results showed that more flavor components in pehtze were detected than in soup,which included 18,24 and 27 kinds of esters,13,11 and 15 kinds of aldehydes,5,7 and 6 kinds of alcohols,3,4 and 4 kinds of ketones and one furan were detected in pehtze from three kinds of sufu,respectively.Among these flavor components,esters were the major components,and long chain fatty acid esters were accounted for more than 90%.Methyl pyrazine,linoleic acid ethyl ester and other amphiphilic esters were more abundant in sufu juice.Amino nitrogen in sufu juice was more than in sufu pehtze,and amino nitrogen contents in three kinds of sufu revealed a significant difference.