Antimicrobial effects of Zataria multiflora essential oil and Lactobacillus acidophilus on Escherichia coli O157 stability in the Iranian probiotic white‐brined cheese

Abstract The effects of Zataria multiflora essential oil (ZEO) alone and in combination with probiotic bacterium Lactobacillus acidophilus PTCC 1643 on the growth and stability of Escherichia coli O157 in cheese were investigated during storage time. The effect of different concentrations of ZEO (0, 50, 75, and 150 ppm) and L. acidophilus, on E. coli O157 count, pH and sensory characteristics in a manufactured cheese were determined. Various concentrations of the ZEO alone and in combination with L. acidophilus significantly decreased the E. coli O157 enumerations, compared to the control group (p < .01). Also pH decline, the number of E. coli O157 also decreased in cheese samples. The synergistic effects on the stability of E. coli O157 was not observed in different treatments of ZEO and L. acidophilus. The addition of ZEO and probiotics in samples showed a synergistic trend on the reduction of E. coli and significantly improved sensorial properties. Practical applications Lactobacillus spp. are widely used as probiotic species in fermented foods. Zataria multiflora essential oil (ZEO) is applied in food industries to prolong shelf life of the products with desired sensorial characteristic. The association of Escherichia coli O157 in the Iranian probiotic white‐brined cheese and the antimicrobial effect of ZEO are particular concern to the dairy plants. The aim of current work was to study the effects of ZEO alone and in combination with probiotic Lactobacillus acidophilus PTCC 1643 on the growth and stability of E. coli O157 in cheese during the storage period. The significant (p < .05) synergistic inhibitory effect of the ZEO and probiotic on E. coli O157 shown in this study which emphasizes ZEO function in the food industry.