Effect of atmospheric cold plasma (ACP) with its extended storage on the inactivation of Escherichia coli inoculated on tomato

The study investigated the efficacy of atmospheric cold plasma (ACP) treatment on inactivation of E. colt load during extended storage period of 48 h at both the temperatures of refrigeration (4 degrees C) as well as room (25 degrees C). The tomato samples were spot inoculated with E. coil and exposed to ACP at 15 and 60 kV for 5, 10, 15, and 30 min followed by their storage at 4 degrees C and 25 degrees C. The highest log reduction of 6 log CFU mL(-1) was achieved in population of E. con after 15 min of ACP treatment at 60 kV, which was sustained up to storage duration of 48 h at both the temperatures. Furthermore, significant reduction in E. coil was found at plasma treatment of 60 kV in comparison to 15 kV. The inactivation of E. coil was significantly (p < 0.01) affected by combination of treatment higher voltage at extended treatment time, however, treatment time with prolonged storage of sealed ACP treated tomato was observed as a key factor in reduction of E. colt In addition, investigation of E. coli exposed tomato surface was done using scanning electron microscopy that clearly showed the breakdown of cell cover of E. coli as a consequence of ACP. The study predicts the promising potential of the technique in sanitization of vegetables that are eaten raw like tomato.