title: Inactivation of Escherichia coli O157:H7 and Salmonella typhimurium DT 104 on alfalfa seeds by levulinic acid and sodium dodecyl sulfate.
abstract: Studies were conducted to determine the best concentration and exposure time for treatment of alfalfa seeds with levulinic acid plus sodium dodecyl sulfate (SDS) to inactivate Escherichia coli O157:H7 and Salmonella without adversely affecting seed germination. Alfalfa seeds inoculated with a five-strain mixture of E. coli O157:H7 or Salmonella Typhimurium were dried in a laminar flow hood at 21°C for up to 72 h. Inoculated alfalfa seeds dried for 4 h then treated for 5 min at 21°C with 0.5% levulinic acid and 0.05% SDS reduced the population of E. coli O157:H7 and Salmonella Typhimurium by 5.6 and 6.4 log CFU/g, respectively. On seeds dried for 72 h, treatment with 0.5% levulinic acid and 0.05% SDS for 20 min at 21°C reduced E. coli O157:H7 and Salmonella Typhimurium populations by 4 log CFU/g. Germination rates of alfalfa seeds treated with 0.5% levulinic acid plus 0.05% SDS for up to 1 h at 21°C were compared with a treatment of 20,000 ppm of calcium hypochlorite or tap water only. Treatment of alfalfa seeds with 0.5% levulinic acid plus 0.05% SDS for 5 min at 21°C resulted in a >3.0-log inactivation of E. coli O157:H7 and Salmonella.
authors.affiliation: Center for Food Safety, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223, USA.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhao
authors.forename: Ping
authors.initials: P
authors.lastname: Zhao
authors.forename: Michael P
authors.initials: MP
authors.lastname: Doyle
mesh_terms: D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004202:Disinfectants / Q000494:pharmacology*; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000254:growth & development; D005516:Food Microbiology; D018525:Germination / Q000187:drug effects; D006801:Humans; D007982:Levulinic Acids / Q000494:pharmacology*; D000455:Medicago sativa / Q000254:growth & development / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000254:growth & development; D012639:Seeds / Q000382:microbiology; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology*; D013696:Temperature; D013997:Time Factors
chemical_list: D004202:Disinfectants; D007982:Levulinic Acids; D012967:Sodium Dodecyl Sulfate; C032246:levulinic acid