Efficacy of various plant hydrosols as natural food sanitizers in reducing Escherichia coli O157:H7 and Salmonella Typhimurium on fresh cut carrots and apples

• Published in: International journal of food microbiology 2011-07, Vol.148 (1), p.30-35
• Main Authors: Tornuk, Fatih, Cankurt, Hasan, Ozturk, Ismet, Sagdic, Osman, Bayram, Okan, Yetim, Hasan
• Format: Article
• Language: English
• Subjects: Colony Count, Microbial; Daucus; Daucus carota - drug effects; Disinfectants - pharmacology; E. coli O157:H7; Escherichia coli; Escherichia coli O157 - drug effects; Food Contamination - analysis; Lamiaceae - chemistry; Lauraceae - chemistry; Malus; Malus - microbiology; Natural sanitizer; Nigella - chemistry; Plant Extracts - pharmacology; Plant hydrosols; Rosmarinus; S. Typhimurium; Salmonella typhimurium; Salmonella typhimurium - drug effects; Shredded apples and carrots; Thymus; Turkey
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2011.04.022

In the present study, inhibitory effects of the hydrosols of thyme, black cumin, sage, rosemary and bay leaf were investigated against Salmonella Typhimurium and Escherichia coli O157:H7 inoculated to apple and carrots (at the ratio of 5.81 and 5.81 log cfu/g for S. Typhimurium, and 5.90 and 5.70 log cfu/g for E. coli O157:H7 on to apple and carrot, respectively). After the inoculation of S. Typhimurium or E. coli O157:H7, shredded apple and carrot samples were washed with the hydrosols and sterile tap water (as control) for 0, 20, 40 and 60 min. While the sterile tap water was ineffective in reducing ( P > 0.05) S. Typhimurium and E. coli O157:H7, 20 min hydrosol treatment caused a significant ( P < 0.05) reduction compared to the control group. On the other hand, thyme and rosemary hydrosol treatments for 20 min produced a reduction of 1.42 and 1.33 log cfu/g respectively in the E. coli O157:H7 population on apples. Additional reductions were not always observed with increasing treatment time. Moreover, thyme hydrosol showed the highest antibacterial effect on both S. Typhimurium and E. coli O157:H7 counts. Inhibitory effect of thyme hydrosol on S. Typhimurium was higher than that for E. coli O157:H7. Bay leaf hydrosol treatments for 60 min reduced significantly ( P < 0.05) E. coli O157:H7 population on apple and carrot samples. In conclusion, it was shown that plant hydrosols, especially thyme hydrosol, could be used as a convenient sanitizing agent during the washing of fresh-cut fruits and vegetables. ► Hydrosols are known as floral water, distillate water or aromatic water and obtained by distillation from plant materials. ► Thyme and rosemary hydrosol treatments for 20 min reduced E. coli O157:H7 number on the apples at the various levels. ► Thyme hydrosol showed the highest antibacterial effect. ► The thyme hydrosol could be used as natural sanitizing agents for the purpose of washing fresh fruit and vegetable cuts.