基于GC-MS联用技术分析传统鱼露发酵过程中挥发性风味成分和脂肪酸组分变化

为探明鱼露在不同发酵时间点挥发性物质的差异以及脂肪酸对传统鱼露的香气物质形成的影响,实验采用气相色谱—质谱联用(GC-MS)技术分析鱼露发酵过程中的挥发性风味成分和脂肪酸组成。结果显示,在5个不同发酵时间点的鱼露样品中共检测出7大类56种挥发性化合物,并用内标法对各挥发性化合物进行定量。以OVA值为依据,从56种挥发性化合物中筛选出12种对鱼露风味轮廓贡献显著的主体呈香化合物如3-甲硫基丙醛等。鱼露的主体特征风味可描述为蘑菇香味、土豆香味、麦芽香味、香草味、水果香味和鱼腥味。鱼露中的脂肪酸主要分布范围为C15~C26,不饱和脂肪酸(UFA)相对含量高达67.23%。在鱼露发酵过程中,风味相关的亚油酸和亚麻酸变化较为显著,与主体挥发性风味化合物的变化呈现一定的相关性,证明不饱和脂肪酸是鱼露发酵过程中产生特征风味的重要前体物质。

Analysis of volatile flavor components and fatty acids in fish sauces during fermentation by GC-MS

In order to explore the differences of volatile components at different time points of fish sauce fermentation and the influence of fatty acids on the formation of flavor components, GC-MS techniques were applied to identify volatile flavor components and fatty acids in fish sauces during fermentation process. As a result of GC-MS analysis, 56 volatiles components that can be divided into 7 types were identified in fish sauce samples during different fermented time and further quantified based on internal standard analysis. And 12 kinds of key flavor compounds were selected as main aroma compounds, such as 3-Methylthiopropional. Therefore, the main characteristics flavors of fish sauces can be described as mushroom, potatoes, malt, vanilla, fruity and fishy flavors. The main distribution of fatty acids in fish sauce ranged for C15-C26, and the content of unsaturated fatty acid was high up to 67.23%. Moreover, the contents of linoleic acid and linolenic acid related to flavor changed significantly which were correlated with the changes of volatile compounds during fermentation. Accordingly, fatty acids were important precursor substances for characteristic flavor during fish sauces fermentation.