Current approaches on cold plasma applied to dairy industry: Advantages and drawbacks

Abstract

Milk is rich in essential nutrients for human diet due to its composition of proteins, fat, and minerals, such as calcium. However, its shelf life is short due to the high microbial load, high water content and pH of 6.4. To extend the fluid milk shelf life, generally, thermal treatment such as heat pasteurization and sterilization (ultra-high temperature UHT) can be used. These methods are highly effective for inactivation of pathogenic microorganisms or spores, however, heat affects the nutritional, physicochemical and sensory properties of milk. Thus, several non-thermal technologies have been considered as an alternative to replace thermal treatments, such as cold plasma. Cold plasma is an efficient and innovative technology to inactivate microorganism such as Escherichia coli cells by up to 57 %, pathogens such as Listeria monocytogenes, and Salmonella typhimurium. Despite this potential (advantages when compared to thermal processing of milk), the regulatory legislations hamper the consumption of plasma processed foods. Furthermore, there is little data on the effect of cold plasma in the milk, in particular chemical composition and technological properties as rheological. Therefore, the aim of this works was to critically discuss the feasibility of cold plasma applied in milk, including a prospecting on dairy products.