Bacteriophage inactivation and starter-inhibiting properties of a peracetic acid disinfectant
1996
Langeveld, L.P.M. | Montfort-Quasig, R.M.G.E. van
For disinfection of dairy equipment, chemical and heat treatments are generally applied. In recent years, interest in peracetic acid (PAA) as a chemical disinfectant has grown. As well as killing microorganisms, inactivation of bacteriophages of starter bacteria is important, and there are few reports available about this aspect. Lembke & Teuber (1981), Foissy & Fessler (1982) and Maris (1990) conducted investigations, but used high organic matter concentrations or long exposure times of 10 min or more. For normal dairy practice the effective concentrations in clean conditions are of greater interest, because under good manufacturing practice disinfection is often carried out on cleaned-in-place (CIP) surfaces. An example is the disinfection after hot CIP cleaning and cold rinsing of fermentation tanks for yogurt, fermented milk and quarg with, among other aims, the intention to inactivate bacteriophages that might have been sucked into the tank with the air during cold rinsing (Stadhouders et al. 1988). The aim of the present work was to increase knowledge of the phagocidal properties of disinfectants containing PAA using the disinfectant Limox SU 388. Bacteriophages for a mixed strain cheese starter and a two strain yogurt starter were chosen as typical of the kind of phages that contaminate dairy factories. We determined the concentration of disinfectant necessary to effect five decimal reductions of bacteriophages in suspension in 5 min at room temperature, under conditions of very low organic contamination. Since residues of disinfectants may remain in the equipment, the minimal inhibitory concentrations of the disinfectant on the starter organisms were also investigated.
显示更多 [+] 显示较少 [-]