Submitted to: Institute of Food Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 3/21/2007
Publication Date: 7/28/2007
Citation: Sharma, M., Eastridge, J.S., Mudd, C.L. 2007. Effective disinfection methods of kitchen sponges [abstract]. Institute of Food Technologists. Control No. 3310.
Technical Abstract: Pathogenic foodborne bacteria can be disseminated in households through the use of contaminated sponges. Several household disinfecting treatments to kill bacteria, yeasts and molds on sponges were evaluated. Sponges were incubated in a suspension of ground beef and tryptic soy broth to develop bacterial and fungal populations of 7.3 and 7.1 log CFU/sponge, respectively. Sponges were soaked in 10 percent bleach for 3 min, lemon juice (pH 2.9) or deionized water for 1 min; heated in a microwave oven for 1 min; or placed in a dishwasher operating with a drying cycle. After treatments, sponges were neutralized, agitated, and enumerated for total bacterial counts and yeasts and molds. Microwaved sponges had significantly (P<0.05) lower total bacterial counts (< 0.4 log CFU/sponge) than those that were dishwashed (1.6 CFU/sponge). Sponges that were placed in a dishwasher or microwave oven had significantly lower total bacterial counts than those that were soaked in 10 percent bleach (6.4 log CFU/ sponge), lemon juice (6.9 log CFU/sponge), water (7.1 log CFU/sponge), or control (untreated) (7.3 log CFU/sponge). Sponges soaked in bleach had significantly lower bacterial counts than those that were untreated (control). Populations of yeasts and molds recovered from sponges placed in a microwave oven (< 0.4 log CFU/sponge) or dishwasher (0.4 log CFU/sponge) were significantly lower than those recovered from sponges soaked in lemon juice (5.9 log CFU/sponge) or 10 percent bleach (6.0 log CFU/sponge). Populations of yeasts and molds on sponges that were soaked in water (6.9 log CFU/sponge) or treated with control (7.1 log CFU/sponge) were significantly higher than those on sponges exposed to all other treatments. Microwave heating and dishwashing with drying were the most effective methods in inactivating bacteria, yeasts, and molds on sponges. These treatments may kill foodborne pathogens in a household kitchen environment.