Controlling Growth of Listeria monocytogenes and Pseudomonas fluorescens in Thermally Processed Ground Beef by Sodium Lactate, Encapsulated or Unencapsulated Polyphosphates Incorporation

Abstract This work was undertaken to evaluate the effectiveness of using sodium lactate (SL), encapsulated (e) and unencapsulated (u) polyphosphates (PP; sodium tripolyphosphate, STP; sodium acid pyrophosphate, SPP), and various combinations of these additives on growth of Listeria monocytogenes and Pseudomonas fluorescens in cooked ground beef during 30 d refrigerated storage. The study consisted of two independent work packages as L. monocytogenes and P. fluorescens in the same experimental settings. During storage, analysis of oxidation-reduction potential (ORP), water activity (aw), pH, and counts of L. monocytogenes and P. fluorescens were carried out. Results indicated that there was no difference among the groups in terms of L. monocytogenes or P. fluorescens counts on processing day. Although only PP incorporated groups had higher (P This study showed that encapsulation is not a factor affecting antimicrobial efficiency of PP and using PP-SL combinations have synergistic effect on reducing the viability of L. monocytogenes and P. fluorescens and their subsequent growth ability in cooked ground beef. Therefore, cross-contamination of L. monocytogenes or P. fluorescens cells on RTE meat products may be controlled more effectively with combinations of SL with ePP or uPP or uePP.