A microbial survey of food service can openers, food and beverage can tops and cleaning methodology effectiveness

Abstract

A can opener and food/beverage can top survey was undertaken to identify potential microbiological hazards. Results indicated the potential for high levels of bacterial and fungal contamination. Characterization of microorganisms from 10 can openers indicated the most common contaminants as Klebsiella pneumoniae and a variety of Staphylococcus and spore‐forming Bacillus species. In contrast to previous commercial food service surveys, no Escherichia coli or Salmonella species were found on the cans or can openers, however, low numbers of Bacillus cereus (22 of 25 cans) and Clostridium perfringens (15 of 25 cans) were identified. The effectiveness of various can‐cleaning methods was evaluated using marker bacteria (Serratia marcescens) suspended in soil consisting of tryptone soya broth, ground beef or vacuum cleaner dust. In addition to rinsing under running water, two paper towel types and a paper napkin product were used for wiping, moist wiping and wiping after rinsing. The most effective cleaning method was rinsing and wiping combined (P < 0.0003), while wiping alone was not as effective as moist wiping (P = 0.038) or rinsing with water (P = 0.061). Food cans were more easily cleaned than beverage cans because of the tab area. Soil type influenced the degree of effectiveness of the cleaning methods, with mean log10 reduction values for each type at 3.4 and 3.1 for food and beverage cans (tab area excluded), respectively. No significant difference was observed in the effectiveness of paper products (P = 0.433).

Assessment of Hygienic Quality of Beverage Cans Surfaces with and without Protective Cover

“…survive on hands, sponges/cloths and utensils for hours or days after initial contact with the microorganisms (Scott and Bloomfield, 1990;Jiang and Doyle, 1999;Kusumaningrum et al, 2002;Kusumaningrum et al, 2003). Food stored under the sink or in locations where water, drain or heating pipes may pass; run an increased risk of pest invasion (Daniels, 1991;Michaels et al, 2003). Insects and rodents are common to these spaces, as they are difficult to seal and often contain moisture that is attractive to pests (Michaels et al, 2003).…”

“…Food stored under the sink or in locations where water, drain or heating pipes may pass; run an increased risk of pest invasion (Daniels, 1991;Michaels et al, 2003). Insects and rodents are common to these spaces, as they are difficult to seal and often contain moisture that is attractive to pests (Michaels et al, 2003). Cockroaches are known to carry Salmonella spp.…”

“…Cockroaches are known to carry Salmonella spp. and it is believed that they may represent reservoirs capable of spreading this organism to food products (Devi and Murray, 1991;Michaels et al, 2003). Dust on canned goods could also represent a potential infection hazard, as Salmonella spp.…”

“…Dust on canned goods could also represent a potential infection hazard, as Salmonella spp. have been found viable in dust for up to 10 months (Michaels et al, 2003). Even though the cans are produced under hygienic conditions, they are exposed to some bacteria and germs during storage period, transportation and service.…”

“…Because of these reasons, The Food and Drug Administration recommends washing all dirty canned goods with soap and water before opening. Even though the risks of having dirty beverage cans are quite different from food cans, there is a general abhorrence to drinking out of a can with a visibly dirty top, many people use a perfunctory to wipe of cans with paper products rather than rinsing or washing with soap and water (CFP 2000;US Navy, 2003;Michaels et al, 2003).…”