Bactericidal and bacteriostatic effects of sodium polyphosphate emulsifying salts on selected targets in processed cheese

Processed cheeses (PC) are products with extended shelf-lives, they have in their composition such additives as emulsifying salts and preservatives. Emulsifying salts are used due their desirable emulsification properties, however, little is known about their inhibitory activity against microorganisms that can survive and multiply in these products; jeopardizing cheese quality or even posing as hazards to consumers. The aim is to determine how mixtures of emulsifying salts (ESSP: emulsifying salt composed of short polyP; BSLP: bacteriostatic salt composed of long polyP; and trisodium citrate) can influence the microbial populations in PC during 90 days of storage. A total of 14 treatments (T1 - T14) were evaluated against eight target strains (Bacillus cereus INV 10(3); Bacillus subtilis ATCC 19659; Bacillus thuringiensis CFBP 3476; Clostridium perfringens ATCC 13124; Enterococcus faecalis FAIR-E 179; Listeria monocytogenes Scott A; Pseudomonas fluorescens 07A; and Staphylococcus aureus ATCC 6538) inoculated into PC. A treatment composed of emulsifying salts without antimicrobial effect (ESSP 1.5%) was considered as the positive growth control, and another treatment composed of antimicrobial additives (nisin and potassium sorbate) was considered as the negative growth control. Bacterial growth was analyzed using ANOVA and Tukey (p