Abstract:To further enrich the types of compound fruit vinegar and enhance the aroma of fruit vinegar，pineapple and jackfruit were used as raw materials for multi-strain mixed fermentation.With total acidity and the sensory score of vinegar as indicators，single-factor and orthogonal experiments were used to optimize the fermentation conditions，and headspace solid-phase microextraction（HS-SPME）combined with gas chromatography-mass spectrometry（GC-MS）was used to analyze the volatile substances of compound vinegar of pineapple and jackfruit.The results showed that the optimal process conditions were as follows：the volume ratio of pineapple to jackfruit of 6∶4，the initial pH of 4.5，the volume fraction of ethanol of 6%，the inoculum of acetic acid bacteria of 11%，and the fermentation temperature of 28 ℃in the acetic acid fermentation stage.After 8 days of fermentation under these conditions，the total acidity（in acetic acid）of the final pineapple-jackfruit compound vinegar was 31.92 g/L.The volatile substances were further identified and a total of 54 volatile substances were detected，including acetic acid，ethyl 3-hydroxybutyrate，isopentyl acetate，isoamyl alcohol，phenethyl alcohol，and benzaldehyde.The fermentation process and volatile substances of compound vinegar of pineapple and jackfruit were investigated to provide a reference for the development of the compound fruit vinegar.