Faculty of Veterinary Medicine, Urmia University Veterinary Research Forum 2008-8140 10 3 2019 09 01 Efficacy of lyophilized cell-free supernatant of Lactobacillus salivarius (Ls-BU2) on Escherichia coli and shelf life of ground beef 193 198 35915 10.30466/vrf.2019.101419.2417 EN Mehran Moradi Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran 0000-0002-6004-6874 Hossein Tajik Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Karim Mardani Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran 0000-0002-2327-0535 Parya Ezati Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Journal Article 2019 01 09 In the present study, the effect of different concentrations of cell-free supernatant (CFS; 10.00 and 35.00 mg g^-1) of <em>Lactobacillus salivarius</em> (Ls-BU2) on chemical, microbial and sensorial specifications of ground beef stored under the refrigerated condition was investigated. The antibacterial activity of CFS on <em>Escherichia coli</em> was also assessed. According to agar-disk diffusion method, CFS of Ls-BU2 revealed a promising antibacterial activity against <em>E. coli</em> in culture media compared to CFS of a well-known probiotic (<em>L. acidophilus</em> LA-5). In meat, CFS of Ls-BU2 showed a minimal effective concentration (MEC) of 35.00 mg g^-1on <em>E. coli</em>, while CFS of <em>L. acidophilus</em> represented a MEC of > 45.00 mg g^-1. The CFS of Ls-BU2 at 35.00 mg g^-1concentration retained psychrophilic counts of meat at a lower value than maximum accepted level (7 log₁₀ CFU g^-1). In a similar trend, CFS of Ls-BU2 at 35.00 mg g^-1concentration was also displayed high sensorial scores compared to other CFS-treated samples. In conclusion, we demonstrated that CFS of Ls-BU2 and to some extent CFS of <em>L. acidophilus</em> could act as a safe food additive for the control of bacterial pathogens and to extend the shelf life of ground beef. https://vrf.iranjournals.ir/article_35915_72ec488cc13c530187b1184f58c26a3f.pdf