Examining the Novel Technique of Cold Plasma in Food Preservation

Food encompasses any consumable substance that supplies nutrients essential for human growth. The spoilage of food is the main problem that occurs due to the growth of microorganisms that enter from various sources like soil, handler, air, storage environment and so on. Food is anything that is edible and provides nutrients for human growth. The main problem with food spoilage is the introduction of microorganisms from the environment. Spoilage microflora reduces the shelf life of foods by causing defects whereas pathogenic microflora cause diseases. This has prompted the development of food preservation techniques to hinder the growth of microflora. Heat treatments normally reduce the nutritive value of foods thus reducing their quality. Nowadays consumers focus on non-thermal-based foods. One method gaining traction today is cold plasma technology. Cold plasma is an innovative, non-thermal food processing technique that employs energetic, reactive gases to eliminate contaminating microbes on vegetables, fruits, cheese, poultry, and meat. This approach utilizes electricity along with a carrier gas such as oxygen, nitrogen, or helium. A wide array of cold plasma systems that operate at atmospheric pressures are under development. Reduction of more than 5 logs can be obtained in case of pathogenic bacteria such as Salmonella spp., Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus in the foods. Effective treatment with a time range can range from 120 sec to as less as 3 sec, depending on the food treated. The primary modes of action of cold plasma on microflora of food are due to UV light and reactive chemical products of the cold plasma ionization process that denature microbial cell proteins and mutate nucleic acids. Cold plasma is being used in the food industry to speed up the advancement of various techniques. These techniques include breaking down toxins and pesticide residue in food, deactivating enzymes, modifying food components such as proteins to improve digestion and enhancing functional properties like solubility, emulsification and foaming. Additionally, cold plasma is also used for sterilizing food items and for packaging purposes. Relatively early state of technology development, the complexity of necessary equipment and largely unexplored impacts of cold plasma treatment on sensory and nutritional qualities of treated foods may be considered as limitations. A more comprehensive understanding of the processes of the plasma system is required for effective optimization as well as enhancing the levels of commercial treatment on various types of foods. Significant research continues to enhance the utility of this promising technological domain. Besides limitations, this area of technology is promising and subject to active research to enhance efficacy. An attempt has been made in this review article to cover all the aspects of plasma treatment in the food industry.