EVALUATION OF BACTERICIDAL ACTIVITY OF A NEW PREPARATION P3 TSUNAMI USED FOR DISINFECTION OF FROZEN FRUIT AND VEGETABLES

摘要

The aim of the study was to determine, whether the new chemical preparation P3 Tsunami, product of Ecolab, shows bactericidal activity towards Hafnia alvei, Citrobacter freundii, Enterobacter cloacae. The P3 preparation has been suggested for reductio n of microbiological contamination in technological water used for washing fruit and vegetables prior to freezing. The tested bacterial suspension (1,5 x 10~8~8cfu/mL - 5,0 x 10~8cfu/mL) was added to prepared samples of tested preparation in four differe nt concentrations. After specified contact time (1 min or 5 min ± 10 sec) bactericidal activity of the preparation was neutralised by a validated method. After 5 min ±10 sec, 1 mL of neutralised mixture was transferred to Petri plates and 12-15 mL molt en TSA medium was added. After 48 h of incubation at 37°C±1°C, the number of bacteria colonies was determined and the decrease of viable count was calculated. Preparation which in the test conditions defined by EN 1040 norm: 1997 caused 10~3 or higher decrease of bacteria count was described as bactericidal. P3 Tsunami used in the concentration of 0,05% and 0.025% after 5 min contact time showed bactericidal activity towards all 30 bacterial strains used in the study; when used in the concentration o f 0.05% after 1 min contact time it caused 10~5 higher decrease of bacteria count in 27 strains. Bactericidal activity of P3 preparation after such a short contact time (1 min) suggests that it would fulfil the task of disinfecting technological water i n the process of freezing fruit and vegetables.