EFFICACY OF NEUTRALISED ELECTROLYSED WATER AND MILD HEAT AGAINST FOODBORNE PATHOGENS ISOLATED FROM FICUS CARICA

Abstract

Problems with microorganism toxins in dried fig exports are becoming very important. Chlorine-based sanitizers are effective way of controlling microorganisms, but on the other hand their reaction with natural organic and inorganic matter may potentially form carcinogenic products. Therefore, different sanitizers for the disinfection of food and food contact surfaces are required as an alternative to chlorine-based sanitizers. Some earlier studies revealed that neutralised electrolysed water (NEW) may be a potential substitute for cleaning and sanitizing agents in packaged products. In order to make a contribution to solve toxins problems, the antibacterial and antifungal effect of neutralised electrolysed water (NEW) on the foodborne pathogens were evaluated in this study. Spores of Aspergillus flavus and Penicillium expansum were isolated from the surface of fig fruits. Escherichia coli and Bacillus cereus known to occur on the surface of figs were also evaluated. Vegetative cells and spores of bacterium and fungi were exposed to five different concentrations of NEW (100, 75, 25, 5 and 1%) at three different temperatures (22, 50 and 70 degrees C) for 1, 3 and 5 min. According to the results, at 22 degrees C, 1% neutralised electrolysed water exposure for 1 min effectively decreased the number of vegetative cells of E. coli and B. cereus by approximately 8.5 log cfu/ml and 6.3 log cfu/ml, respectively. At 50 degrees C, 5% neutralised electrolysed water exposure for 1 min significantly reduced the A. flavus and P. expansum spore numbers by 5.54 log cfu/ml and 7 log cfu/ml, respectively. With the effect of mild temperature (22-50 degrees C), low chlorine neutralised electrolysed water (9.22 mg/l - 33.85 mg/l available chlorine concentrations) showed a strong antibacterial and antifungal activity against foodborne pathogens. As a conclusion, neutralised electrolysed water can be used widely as a sanitizer in fig enterprises, instead of high cost chlorine based disinfectants.