Effect of quantity of food residues on resistance to desiccation of food-related pathogens adhered to a stainless steel surface

• Published in: Food microbiology Vol. 46; pp. 234 - 238
• Main Authors: Kuda, Takashi, Shibata, Gensui, Takahashi, Hajime, Kimura, Bon
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2015
• Subjects: Bacteria; Bacterial Adhesion; Biofilms; Carrots; Daucus; Desiccants; Desiccation; Drying; Food Analysis; Food Handling; Food Microbiology; Food residue; Foods; Gram-Positive Bacteria - growth & development; Gram-Positive Bacteria - physiology; Listeria monocytogenes; Microbial Viability; Milk; Pathogens; Rendering; Residues; Salmonella Typhimurium; Stainless Steel - analysis; Staphylococcus aureus; Surface contamination; Listeria monocytogenes; Food residue; Surface contamination; Staphylococcus aureus; Salmonella Typhimurium
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/j.fm.2014.08.014

In order to study the effect of food residues on the survival of food-borne pathogens, Salmonella Typhimurium, Staphylococcus aureus, and Listeria monocytogenes were subjected to drying conditions in the presence of small amounts of food such as carrot juice, aqueous solution of nori, milk, and soy-milk. After drying for 2 h at room temperature in the absence of food residue, cell counts of S. Typhimurium, S. aureus, and L. monocytogenes decreased from 8 to 3, 6, and 5 log cfu/dish, respectively. Five milligrams of fresh carrot, 0.05 mg dried nori, and 100 nL milk or soy milk per 10 mm φ surface were sufficient to demonstrate a protective effect on the adhered pathogens, as confirmed by atomic force microscopy. Results from this study suggest that small sediments of food, not only protein rich but also carbohydrate rich, increase the resistance of surface-adherent bacteria to desiccation, rendering sanitization processes ineffective and encouraging cross contamination. •Drying decreased pathogens on stainless steel dishes.•Tolerant of Gram positives were observed by AFM.•Only small sediments of food increased the resistance of surface-adherent bacteria.•For examples, 100 nL milk or soy milk could protect a part of the adherent cells.