Bactericidal activities against pathogenic bacteria by selected constituents of plant extracts in carrot broth

► Isolation and identification of plant extract constituents. ► Determination of MIC50 for Escherichia coli and Staphylococcus aureus. ► Bactericidal activities in a model food system, Tyndallised carrot broth (TCB). ► 15 mg/L naphthazarin or 47 mg/L shikonin caused 6 log reductions in E. coli counts. ► Rhein and carnosic acid displayed moderate bactericidal effects on S. aureus.