Comparison and analysis of the volatile compounds in solid-state and liquid-state fermented vinegars

Globally, vinegar is a widely used acidic condiment with unique flavors and rich nutritional value. Aroma can be used as an important factor to measure the quality of vinegar and affect consumers’ choices and preferences. Volatile components provide different aroma characteristics of vinegar and have an important impact on its sensory quality. In this study, the volatile components in solid-state fermented vinegar and liquid-state fermented vinegar were investigated by headspace solid-phase microextraction followed by gas chromatography—mass spectrometry. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) for evaluating and distinguishing between solid-state fermented vinegar and liquid-state fermented vinegar based on their composition of volatile components were carried out. The results showed that a total of 38 different volatile compounds were identified, including 5 alcohols, 17 ethers, 3 acids, 4 heterocyclic compounds, 4 aldehydes, and 5 other volatiles. PCA and HCA have proven to be effective methods for identifying volatile compounds as well as evaluating and comparing of solid-state fermented vinegars and liquid-state fermented vinegars. Multivariate statistical analysis revealed substantial variation between solid-state and liquid-state fermented vinegars.