摘要：现代生活中人们越来越重视饮食的香和风，对食物选择标准升高，由于酸奶是一种对人体有益的饮品，购买率和使用率大大增高，因此我们在酸奶风物质方面的研究具有很大意义。本次实验主要是利用气相色谱-质谱法（GC-MS），电子鼻检测，感官评价3个方面对酸奶的风物质进行检测分析。试验中通过GC-MS对萃取条件进行优化，以总峰面积和峰个数进行衡量，经实验得出最优的萃取头是50/30μm DVB/CAR/PDMS，萃取时间是40min，萃取温度是55℃。用GC-MS检测不同发酵时间酸奶有73种物质，不同储存期酸奶有80种物质。采用电子鼻监测能很好区分不同发酵阶段和储存期的香气物质。通过感官评价评定酸奶在储藏8-14d时风较好。48989

毕业论文关键词：酸奶；GC-MS；香气；感官评定；发酵过程监控

Study on changes of aroma during the fermentation of yogurt

Abstract：In modern life, people pay more and more attention to diet aroma and flavor of food, there selection are increased, because the yogurt is a kind of beneficial drink and buy rate and utilization rate are greatly increased, so the research of the yogurt flavor material is great significant. This experiment is mainly detected and analyzed yogurt flavor substances from  3 aspects：the GC-MS, electronic nose detection and sensory evaluation. The extraction conditions were optimized by GC-MS in the experiment. The optimum extraction head was 50/30μm DVB/CAR/PDMS, the extraction time was 40min, the extraction temperature was 55 degrees Celsius. GC-MS was used to detect different fermented time of yogurt, it has 73 kinds of substances, and detect different storage period of yogurt has 80 kinds of substances. The aroma compounds in different fermentation stages and storage periods can be distinguished by electronic nose monitoring. The flavor of yogurt was better in the storage 8-14 days by sensory evaluation.

Keywords：Yogurt; GC-MS; Aroma; Sensory evaluation; Fermentation process monitoring 

目录

1 绪论 1

1.1 概述 1

1.1.1 酸奶概述 1

1.1.2 酸奶的营养价值 1

1.1.3 酸奶感官评价 2

1.2 本课题研究现状 2

1.3 本课题的研究的目的和意义 3

1.4本次课题的实验流程图 3

2 实验材料与方法 4

2.1 实验材料与试剂 4

2.2实验仪器与设备 4

2.3实验方法 4

2.3.1 酸奶的制备 4

2.3.2感官评定 4

2.3.3萃取条件的优化 5

2.3.4 GC-MS的测定 6

2.3.5 电子鼻测定 7

3.实验结果与讨论 8

3.1萃取条件的优化 8

3.1.1 萃取头的优化 8

3.1.2 萃取温度的优化 9

3.1.3 萃取时间的优化 10

3.2酸奶香气监控 10

3.2.1 酸奶发酵过程香气物质测定 10

3.2.2 酸奶储存期香气物质测定 15

3.3 酸奶发酵过程电子鼻测定