Headspace solid-phase microextraction analysis of volatile compounds in hawthorn vinegars fermented by two strains of Acetobacter

Hawthorn (Crataegus oxyacantha), which is wildly distributed in northern China, has a long history as a medicinal substance, for the treatment of digestive ailments, dyspnea, kidney stones and cardiovascular disorders, etc. Today, it is currently used for the juice production and is used as the raw material for hawthorn wine and vinegar production. However, the flavor of fruit vinegars diversifies with the strain used for vinegar fermentations. In this work, the volatile components of hawthorn vinegars fermented by two acetic acid bacteria (Acetobacter pasteurianus AC2005 and Acetobacter rancens AS1.41), were analyzed quantitatively and identifiably by the method of headspace solid-phase microextraction combined with gas chromatography-mass spectrometry. As a result, 45 kinds of volatile compounds were found in hawthorn vinegar produced by AC2005, including 9 esters, 12 alcohols, 3 ketones, 12 acids, and 9 other compounds. And 39 kinds were found in that fermented by AS1.41, including 13 esters, 9 alcohols, 2 ketones, 10 acids, and 5 other compounds. Among them, 26 kinds of volatile compounds detected in two vinegars were the same. The characteristic of each strain of Acetobacter was responsible for the diversity of vinegars in flavor.