2009/07/25 by B.S.M. Mahmoud, Barakat S.M. Mahmoud
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Enterobacteriaceae and Cronobacter Research #Listeria monocytogenes in Food Safety #Radiation Effects and Dosimetry
paper · doi:10.1111/j.1472-765x.2009.02706.x
openalex publication_date 2009/07/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
AIMS: To determine the inactivation effect of X-ray treatments on Cronobacter (E. sakazakii) in tryptic soy broth (TSB), skim milk (0% fat), low-fat milk (1% and 2%) and whole-fat milk (3.5%). METHODS AND RESULTS: X-rays were produced using the RS 2400 generator system (Rad Source Technologies Inc.). Cronobacter (in TSB), inoculated skim milk (0% fat), low-fat milk (1% and 2% fat) and whole-fat milk (3.5% fat) were treated with 0.0, 0.1, 0.5, 0.75, 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 kGy X-ray doses. Surviving bacteria in the TSB and inoculated milk, before and after treatment, were enumerated using plating method onto trypticase soy agar. Greater than 7.0-log CFU reduction in Cronobacter population was observed with 4.0, 5.0, 6.0, 6.0 and 6.0 kGy X-ray in the TSB, skim milk, 1% fat milk, 2% fat milk and 3.5% fat milk, respectively. CONCLUSIONS: Treatment with X-rays significantly (P < 0.05) reduced Cronobacter to less than detectable limits (<1 log CFU ml(-1)) in skim milk at 5.0 kGy and milk with 1% fat content and greater at 6.0 kGy dose levels. The D-value for Cronobacter in TSB was significantly (P < 0.05) lower than those in milk samples. SIGNIFICANCE AND IMPACT OF THE STUDY: Treatment with X-rays could be an effective and safe alternative technology to control pathogenic bacteria (Cronobacter) in the dairy industry.