Abstract:In this study,the volatile substances of fermented Porphyrɑ yezoensis sauce with Lɑctobɑcillus plɑntɑrum MMB-05,Lɑctobɑcillus cɑsei FJAT-7928,mixed strain（volume ratio 1∶1 of L.plɑntɑrum MMB-05 to L.cɑsei FJAT-7928）and control group for 24 h and 48 h were detected by headspace-solid phase microextractiongas chromatograph-mass spectrometry（HS-SPME-GC-MS）. The key flavor substances of each fermentation sample were analyzed using odour activity value（OAV）,principal component analysis（PCA）and heatmap,and a total of 57 volatile compounds were identified in fermented P. yezoensis sauce,among which the ketone content（29.03%）of the L. plɑntɑrum MMB-05 group was significantly higher than that of other types of compounds at 24 h of fermentation,and the hydrocarbon volatiles of the L. cɑsei FJAT-7928 and the mixed group（45.39% and 42.85%）had the highest percentage. The OAV and heatmap analyses showed that（Z）-2-heptenal,（E,Z）-2,6-nonadienal played a major contributing role to the sauce aroma of the four groups of samples at 24 h of fermentation,but by the later stages of fermentation,the L.plɑntɑrum MMB-05 group had more of the major aroma substances and added the key flavour component of L-lactic acid OAV>1.It was comprehensively determined that the P.yezoensis sauce fermented by L.plɑntɑrum MMB-05 had richer flavor components and a stronger overall flavor.