Contamination of knives and graters by bacterial foodborne pathogens during slicing and grating of produce

• Published in: Food microbiology 2015-12, Vol.52, p.138-145
• Main Authors: Erickson, Marilyn C., Liao, Jean, Cannon, Jennifer L., Ortega, Ynes R.
• Format: Article
• Language: English
• Subjects: Cantaloupes; Carrot; Consumer Product Safety; Cooking and Eating Utensils; Cross-contamination; Cucumber; Cucumis melo; Daucus; E. coli O157:H7; Equipment Contamination; Escherichia coli; Escherichia coli O157 - growth & development; Escherichia coli O157 - isolation & purification; Food Contamination - analysis; Food Handling - instrumentation; Food Handling - methods; Foodborne Diseases - microbiology; Fragaria; Fruit - microbiology; Graters; Humans; Knives; Lycopersicon esculentum; Produce; Salmonella; Salmonella enterica; Salmonella enterica - growth & development; Salmonella enterica - isolation & purification; Strawberry; Tomato; Vegetables - microbiology
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/j.fm.2015.07.008

Poor hygiene and improper food preparation practices in consumers' homes have previously been demonstrated as contributing to foodborne diseases. To address potential cross-contamination by kitchen utensils in the home, a series of studies was conducted to determine the extent to which the use of a knife or grater on fresh produce would lead to the utensil's contamination with Escherichia coli O157:H7 or Salmonella enterica. When shredding inoculated carrots (ca. 5.3 log CFU/carrot), all graters became contaminated and the number of E. coli O157:H7 present on the utensil was significantly greater than Salmonella (p  0.05); however, subsequent contamination of 7 produce items processed with the contaminated utensils did occur. These results highlight the necessity of proper sanitization of these utensils when used in preparation of raw produce. •Incidence in contamination of knives varied with the type of produce being sliced.•Graters were very susceptible to being contaminated when shredding carrots.•Residue on knife or grater didn't affect pathogen transfer from contaminated produce.•Contaminated knives and graters led to contamination of multiple produce items.•Transfer of E. coli O157:H7 to graters was greater than Salmonella.