红枣醋不同发酵阶段香气成分的变化

采用顶空固相微萃取结合气质联用法,研究了液态发酵枣醋在不同发酵阶段产物(初始枣汁、枣酒醪和枣醋)的香气成分。从三种产物中分别分离鉴定出56、56、54种香气成分,各占总香气成分的94.57%、97.37%、98.86%,主要是烃类、酸类、酯类、醇类、醛酮类以及少量其他化合物。三种产物香气成分的种类总数差别不大,但种类构成比例和相对含量差异较大。在酒精发酵阶段,烃类、酮类物质明显增加,酸类、醛类物质有所增加,酯类、醇类物质基本不变;在醋酸发酵阶段,烃类、醇类、酮类物质降低,酸类、酯类物质显著升高。枣醋的香气成分主要来源于酸类和酯类物质,少量的烃类、醇类、酮醛类等物质也是枣醋香气成分不可或缺的一部分,这些香气成分共同赋予枣醋特殊的风味和品质。

Changes of Aroma Compounds of Jujube Vinegar at Different Fermentation Stages

Solid phase micro-extraction coupled with gas chromatography mass spectrometry (SPME/GC-MS) technique was applied in isolation and identification of aroma compounds of the products in different liquid fermentation stages including the initial jujube juice, the jujube wine mash and the jujube vinegar. The results showed that 56, 56 and 54 kinds of aroma components were identified in the three stages, accounting for 94.57%, 97.37% and 98.86% of the total aroma, respectively. The main aroma components were hydrocarbons, acids, esters, alcohols, aldehydes, ketones, and a small amount of other compounds. The number of aroma components in three products showed little difference, but the component ratio and relative content were significantly different. In the alcohol fermentation process, hydrocarbons content increased significantly, the acids content increased slightly, and the ester and alcohol contents decreased. In the acetic fermentation process, the alcohols and aldehydes contents decreased while the contents of acids and esters increased significantly. These acids and esters were the main components of aroma compounds, and a small amount of hydrocarbons, alcohols, aldehydes, ketones were also an indispensable part of the aroma. These aroma compounds endowed jujube vinegar the unique flavor and quality.