Abstract:Four lactic acid bacteria with high acid-producing capacity were screened from 60 strains and identified based on colony morphology， Gram staining， and 16S rDNA analysis. The metabolic products of the selected strains were analyzed using non-targeted metabolomics， and the antioxidant activity of both viable bacteria and postbiotics was evaluated. The results showed that four strains with high acid-producing capacity were identified as Lɑctiplɑntibɑcillus plɑntɑrum JLSC2-6， L. plɑntɑrum CXG-9， L. plɑntɑrum SXSCCH-1， and L.plɑntɑrum HNLJJ-2， all of which exhibited good acid and bile salt resistance as well as nitrite degradation ability. Metabolomics analysis revealed that the metabolic products of L. plɑntɑrum SXSCCH-1 differed from those of the other strains， with the main differential compounds being carboxylic acids and their derivatives， fatty acyl compounds， and glycerophospholipids. The antioxidant evaluation showed significant differences in antioxidant capacity between the different strains and within different components of the same strain. Strain JLSC2-6 exhibited strong ferric reducing ability and DPPH free radical scavenging activity in both viable bacteria and postbiotics. The dead bacterial fragments of strain SXSCCH-1 demonstrated strong ABTS+ radical scavenging activity and inhibition of linoleic acid peroxidation， while the viable bacteria of strain HNLJJ-2 showed good ABTS+ radical scavenging activity.