title: Activity of citrus essential oils against Escherichia coli O157:H7 and Salmonella spp. and effects on beef subprimal cuts under refrigeration.
abstract: Escherichia coli O157:H7 and Salmonella spp. are bacterial pathogens often associated with beef, and cause many cases of foodborne illness each year in the United States. During beef slaughter and processing, these bacteria may spread from the hide or intestines to the carcass. The objective of this research was to investigate the use of naturally occurring compounds citrus essential oils (CEOs) extracted from orange peel to reduce or eliminate these pathogens at the chilling stage of processing, or during fabrication. Brisket flats (used to simulate beef subprimals) were spot inoculated with approximately 6 log of surrogate generic E. coli cocktail (previously shown to be identical in growth and survival parameters to E. coli O157:H7 and Salmonella spp.). Following drying, CEOs were applied by spraying at concentrations of 3% and 6% to the surface of different pieces of meat. Treatments were applied using a custom built spray cabinet at 2.07 bar and applied at a rate of 3.79 L/min to replicate commercial practices. The CEOs significantly reduced (P < 0.05) the concentration of E. coli on the brisket flats in comparison to inoculated no spray or water sprayed controls over a period of 90 d, while causing an initial reduction of approximately 1.4 log units. Total aerobic bacteria and psychrotrophic counts were also reduced on uninoculated briskets following treatment. These results indicate that 3% cold-pressed terpeneless Valencia orange oil could be used as an additional intervention against E. coli O157:H7 and Salmonella spp. at the refrigerated storage stage of processing.
  
  
  CONCLUSIONS
  CEOs are natural compounds that have been designated as Generally Recognized as Safe (GRAS). They can be used to control Salmonella spp. and E. coli O157:H7 on beef carcasses at the chilling stage.
authors.affiliation: Dept. of Animal Sciences, Center for Meat Safety and Quality, Food Safety Cluster, Colorado State Univ., Fort Collins, CO 80523, USA.
authors.forename: Curtis I
authors.initials: CI
authors.lastname: Pittman
authors.forename: Sean
authors.initials: S
authors.lastname: Pendleton
authors.forename: Bledar
authors.initials: B
authors.lastname: Bisha
authors.forename: Corliss A
authors.initials: CA
authors.lastname: O'Bryan
authors.forename: Keith E
authors.initials: KE
authors.lastname: Belk
authors.forename: Lawrence
authors.initials: L
authors.lastname: Goodridge
authors.forename: Philip G
authors.initials: PG
authors.lastname: Crandall
authors.forename: Steven C
authors.initials: SC
authors.lastname: Ricke
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000191:economics / Q000494:pharmacology*; D002417:Cattle; D032084:Citrus sinensis / Q000737:chemistry*; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D005520:Food Preservatives / Q000191:economics / Q000494:pharmacology*; D005525:Food-Processing Industry / Q000193:education; D005517:Foodborne Diseases / Q000517:prevention & control; D005638:Fruit / Q000737:chemistry; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D007220:Industrial Waste / Q000032:analysis / Q000191:economics; D008460:Meat / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D009822:Oils, Volatile / Q000191:economics / Q000494:pharmacology*; D010938:Plant Oils / Q000191:economics / Q000494:pharmacology; D012034:Refrigeration; D012475:Salmonella / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D019779:Salmonella enterica / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D005520:Food Preservatives; D007220:Industrial Waste; D009822:Oils, Volatile; D010938:Plant Oils; C087245:orange oil