Effectiveness of cleaning methodologies used for removal of physical, chemical and microbiological residues from produce

Abstract

An increasing number of disease outbreaks have been associated with produce, while pesticide levels continue to be a safety concern. With increased health awareness, fresh produce consumption has increased. As there is a need for microbial and pesticide removal intervention measures of proven efficacy to maintain confidence in food service produce preparation, a series of experiments were undertaken. Produce cleaning methods were tested by measuring removal of gross dirt, wax and environmental contaminants present on produce surface. Tests were performed on apples, cucumbers and lemons using water wash, produce brush, produce cleaner, produce cleaner with paper towel wipe, and water wash and paper towel wipe. Water rinse and paper towel dry was found superior to all other methods tested. Apples contaminated with a cocktail of pesticides were tested in waxed and unwaxed state. Following cleaning by various methods, including produce wash and produce brush, pesticides on skins were extracted and analyzed to determine concentrations of organophosphorous and organochlorine pesticides. In these experiments, it was shown that any treatment that included wiping with paper towels showed increased effectiveness over similar treatments or controls. Microbial efficacy experiments were performed involving 21 different types of laboratory inoculated produce. Two types of inoculum were employed, Tryptone Soya broth (TSB) and ground beef. After inoculation, produce was cleaned by dry wiping with paper towel, using water wash air dry, water wash paper towel dry or dipped in 200 p.p.m. chlorine dip for either 5 s or 1 min and compared to baseline values. One‐minute dip in 200 p.p.m. chlorine solution was more effective than rinsing and drying with a paper towel when TSB inoculum was used (P < 0.05). The effectiveness of the 200 p.p.m. chlorine dip diminished if ground beef was used as a test inoculum, with water rinse and paper towel providing significantly (P < 0.05) improved results. The efficacy shown by paper towels usage in this diverse set of experiments is based on frictional removal of offending soils.

Effect of ultrasound and commercial sanitizers in removing natural contaminants and Salmonella enterica Typhimurium on cherry tomatoes

“…Ultrasound is also considered a clean technology, as are other recently suggested sanitizer alternatives, such as electrolyzed water (Rahman, Ding, & Oh, 2010). Considering that the US Environmental Protection Agency (EPA) Scientific Advisory panel has stated that any treatment which can reduce microbial contamination by 2 logs would be significant and that any new sanitizer or test method presented should be compared to 200 mg/L chlorine as a standard for efficacy (Michaels, Gangar, Schattenberg, Blevins, & Ayers, 2003), we can conclude that the combination of peracetic acid and ultrasound has great potential to replace chlorine in the sanitization step of fresh fruits and vegetables. However, peracetic acid should always be handled in a dry and ventilated and avoided the incidence of direct sunlight.…”

“…Ultrasound was adopted by the electronics industry to decontaminate surfaces and its use has recently been recommended as an alternative sanitization step in the food industry (Adekunte, Tiwari, Scannell, Cullen, & O 0 Donnell, 2010;Cao et al, 2010;Knorr, Zenker, Heinz, & Lee, 2004;Lee, Heinz, & Knorr, 2003;Nascimento et al, 2008;Sagong et al, 2011). When applied to liquids, ultrasonic waves promote the occurrence of the cavitation phenomenon, which consists of the formation, growth and collapse of air bubbles.…”

Effect of handling and processing on pesticide residues in food- a review

“…The packing process before shipment to retail outlets was generally effective in removing pesticides that may be present on peel at the time of harvest. Tests on waxed and unwaxed apples contaminated with a cocktail of pesticides showed that treatments including wiping with paper towels were more effective than other procedures for pesticide removal (Michaels et al 2003). b) Storage: Lemons, oranges and grapefruits were dipped in a solution of diphenyl, o-phenyl phenol, 2,4-dichlorophenoxyacetic acid (2,4-D), imazalil, thiabendazole, benomyl and sec-butylamine or fumigated with methyl bromide and stored at 14°C.…”

Reviews of Environmental Contamination and Toxicology

“…Various methods were tested for removing pathogens, pesticides and other contaminants from the surfaces of fresh fruits and vegetables (Michaels et al 2003 ). A range of fresh produce was subjected to different combinations of cleaning processes, such as water rinsing steps, use of produce-cleaning brushes, disinfectants, air drying and paper towels.…”