Effect of cold plasma on different polyphenol compounds: A review

Thermal processing has been predominantly used in the food industry to improve food safety and shelf life. However, heat treatment induces detrimental effects like cooked flavor, texture change, and alteration in sensory attributes. These disadvantages encouraged the food industry to adopt non-thermal food processing technologies. Cold plasma is a promising non-thermal food processing method that uses charged, highly reactive gaseous molecules and species to inactivate contaminating microorganisms present in foods. Thus, it has attracted the attention of scientists globally. This review gives the reader an overview of cold plasma technology fundamentals and the detailed mechanism of interaction of reactive plasma species with the polyphenol compounds (simple phenolic acid, individual phenolic compounds, flavonoids, and anthocyanin) present in food. The impact of cold plasma on polyphenol compounds mainly depends on the food matrix and plasma process parameters, viz. voltage, feed gas, and treatment time. Among various polyphenols, flavonoids are degraded faster because of their high ability to scavenge plasma-generated free radicals. The reactive species cause oxidative degradation, double bond cleavage of polyphenol compounds, and aid in the extraction of phenolic compounds. The cold plasma technology has both positive and negative impacts on polyphenol concentration.