Physical Methods for Cleaning and Disinfection of Surfaces

Abstract

Cleaning and disinfection are important operations in food processing because of the significant contributions to product hygiene and food safety. The transfer of residues from surfaces into a product and the contamination with adhering microorganisms must therefore be avoided with sufficient certainty. Traditional methods for the removal of adherents and inactivation of microorganisms are based on thermal, mechanical, or chemical principles and are known to be time-and energy-consuming. This has resulted in a search for alternative methods that show prospective potential for their use in food-processing plants. This review gives an overview on such methods, which are based on physical principles. In dry-ice cleaning, for example, carbon dioxide snow pellets are blasted onto a surface to remove adherents through a combined action of thermal and mechanical effects, followed by dissolution of these adherents. Ice-pigging is a procedure where an ice/ water mixture is forced through pipes, heat exchangers, or other equipment to carry off adhered substances. Another method for physical cleaning, mainly described in context with membrane filtration, is to use vibration in the ultrasonic frequency domain to reduce fouling and to stabilize permeate flux. Radiation from various sources (UV lamps, radionuclides, X-ray tubes) differs in its applicability and disinfection efficiency because of differences in energy and penetration depth. Cold plasma treatment is another promising technology that is currently under investigation for cleaning and disinfection of surfaces of inorganic and organic materials.

Streaming flow by oscillating bubbles: quantitative diagnostics via particle tracking velocimetry

“…Removing contamination from surfaces or cleaning inaccessible cavities can be achieved with ultrasound-driven microbubbles (Otto et al 2011;van Wijngaarden 2016). For example, the decontamination of medical instruments in hospitals and dental clinics is often preceded by a thorough ultrasonic cleaning.…”

Disinfection of selected vegetables under nonthermal treatments: Chlorine, acid citric, ultraviolet light and ozone

“…Some of the pathogenic microorganisms found in fresh produce and associated with these foodborne outbreaks are Escherichia coli, Salmonella, Shigella spp. and Listeria monocytogenes (Park, Alexander, Taylor, Costa, & Kang, 2008). Several recalls in the United States have been issued in 2011 involving the presence of E. coli O157:H7 in romaine lettuce and Salmonella in grape tomatoes and carrots, sold as separate units or as a part of pre-packaged salads, involving the entire country (FDA, 2012).…”

“…E. coli has shown the ability to attach very strongly to leafy structures, which makes it difficult to remove the cells from fresh produce (López-Gálvez, ). Some chemicals have been evaluated for use as disinfectant agents in produce, such as chlorinated water and chlorine dioxide (Park et al, 2008). However, the use of chlorine has been associated with the formation of carcinogenic compounds in the last few years, and some pathogens have been shown to be more resistant to the lethal action of these compounds (Allende, Selma, López-Gálvez, Villaescusa, & Gil, 2008).…”

“…However, the use of chlorine has been associated with the formation of carcinogenic compounds in the last few years, and some pathogens have been shown to be more resistant to the lethal action of these compounds (Allende, Selma, López-Gálvez, Villaescusa, & Gil, 2008). There is a current need to provide fresh and microbiologically safe fresh-cut produce for consumers (Allende, Tomás-Barberán, & Gil, 2006;Park et al, 2008). Also, there has been an important increase in the sale of fresh produce in the last several years because of consumers' trend to eat healthy food (Thilmany et al, 2007).…”

Influence of geometrical parameters of convergent sleeve on the value of limit stress

“…Both maintaining low temperature and sublimation in standard conditions make the material widely used in the food industry, e.g. in the process of water carbonation, cleaning and disinfecting surfaces or as an input to refrigerated containers [4][5][6][8][9][10][11][12][13][14]. Agglomeration of crystallized carbon dioxide is performed in order to reduce its volume and extend the time of sublimation.…”