本文采用顶空固相微萃取法提取紫薯酸奶和普通酸奶中的挥发性风味成分，用气相色谱-质谱仪进行测定，结合NISTLibrary数据库自动检索技术对有机风味化合物进行鉴定。在相同的检测条件下，分别检出紫薯酸奶和普通酸奶中有75和46种挥发性成分。乙酸、乙醛、双乙酰、丁位壬内酯等特征性风味物质在两种酸奶中均检测出来。普通酸奶含芳香杂环化合物和萜烯类各3种和1种，分别占1.42%和0.77%。而紫薯酸奶中含芳香杂环化合物和萜烯类达6种和5种，各占2.33%和5.96%。橙花醇、愈创木酚、香草醛等只在紫薯酸奶发现, 尤其是橙花醇占4.77%。这些特色风味成分的生成可能是发酵过程中紫薯本身成分参与了酸奶的发酵过程，生成了多种风味物质，导致紫薯酸奶中的挥发性成分较多，而且有效的风味物质也增加，赋予了紫薯酸奶柠檬样的果香。

In this study, volatile flavor components of purple sweet potato yogurt and regular yogurt were extracted by headspace solid-phase micro-extraction, detected by gas chromatography-mass spectrometry, and identified using the NIST Library automated retrieval system. There were 75 and 46 volatile compounds detected and identified from purple sweet potato yogurt and regular yogurt, respectively. Characteristic flavor compounds such as acetic acid, acetaldehyde, diacetyl, and delta-nonalactone were detected in both products. Three aromatic heterocycles and one terpene were detected in regular yogurt, accounting for 1.42% and 0.77%, respectively, whereas six aromatic heterocycles and five terpenes were detected in purple sweet potato yogurt, accounting for 2.33% and 5.96%, respectively. Neroli, guaiacol, vanillin, etc. were identified from purple sweet potato yogurt only, whereas neroli was accounted for 4.77%. These characteristic flavor compounds might be present due the purple sweet potato component, which may be responsible for the formation of several volatile and flavor-producing compounds during fermentation, thus giving a lemon-like fruit flavor to the purple sweet potato yogurt.

国家自然科学基金（31300789）；山东省自然科学基金（ZR2011CM026）；山东省研究生教育创新计划项目（SDYY11193）