Inhibition of Salmonella enterica serovar Typhimurium by combined carvacrol and potassium sorbate in vitro and in tomato paste

Abstract The efficiency of carvacrol and potassium sorbate (P.S.) alone and in combination was assessed against Salmonella enterica serotype Typhimurium in acidic pH in vitro and in tomato paste. Their effects on physicochemical and sensory characteristics of tomato paste were also evaluated. Carvacrol and P.S. showed Minimal Inhibitory Concentration at 312 μg/mL and 1250 μg/mL, and Minimal Bactericidal Concentration at 312 μg/mL and 10000 μg/mL, respectively. Carvacrol and P.S. combination presented additive interaction in checkerboard assay. In time-kill curve, no viable cells were recovered with carvacrol (78 μg/mL) + P.S. (39 μg/mL) after 48 h. In tomato paste, carvacrol + P.S. at the same concentrations completely inhibited bacterial growth on the third day of storage. Physicochemical properties did not change and sensory evaluation presented an acceptance index of 67% for overall acceptance. The combined use of these compounds improved their antimicrobial activity and eliminated Salmonella spp. from tomato paste.