The effect of Cold Plasma (Combined Argon-Helium Gases) on Microbial Contamination and Physicochemical Properties of Minced Sheep Meat

Introduction: The demand for consuming healthy food has increased due to the developed techniques for assessing food safety and detection of microbial contamination. Among the non-thermal processing methods, using cold plasma along with atmospheric pressure, has received much attention. The present study aims to investigate the effect of cold plasma, the combination of argon and helium gases, on the reduction of microbial load and physicochemical changes in minced sheep meat. Methods: In this study, minced sheep meat was subjected to 36 cold atmospheric plasma treatments with different time intervals (3, 6, and 9 min) and argon/helium gas ratios (1:8 and 2:7). Microbial counts and physiochemical properties (moisture, color, free fatty acids, and pH) were measured according to the Iranian national standards. Results: Both ratios of argon/helium (1:8 and 2:7) were effective in reducing the microbial load of minced sheep meat via cold atmospheric plasma in all exposure intervals (3, 9 and 12 min). However, the argon/helium ratio of 2:7 and an exposure time of 12 min, was the most effective combination in decreasing microbial contamination. Conclusion: Our findings elucidated that the cold plasma processing method was effective in reducing the microbial load of minced sheep meat. Furthermore, we concluded that both parameters of time and gas composition affect microbial load reduction by cold plasma.