title: Survival of Salmonella and Escherichia coli O157:H7 in chorizos.
abstract: Mexican-style raw meat sausages (chorizos) are not regulated in California when they are produced in small ethnic food markets. These sausages are sold uncooked, but their formulation imparts a color that may lead the consumer to assume that they are already cooked, and thus the chorizos may sometimes be eaten without proper cooking. If pathogens are present in such cases, illness may result. Survival of Salmonella and Escherichia coli O157:H7 in chorizos was evaluated under different storage conditions selected based on an initial survey of uninspected chorizos in California. Chorizos were formulated with five different initial water activity (aw) values (0.85, 0.90, 0.93, 0.95, and 0.97), stored under four conditions (refrigeration at 6 to 8 degrees C, room temperature at 24 to 26 degrees C, under a hood at 24 to 26 degrees C with forced air circulation, and incubation at 30 to 31 degrees C with convective air circulation), and sampled after 1, 2, 4, and 7 days. The initial pH was 4.8 and remained near 5.0 from day 1 of the sampling period. Two separate studies of packs inoculated with five-strain cocktails of Salmonella and of E. coli O157:H7 were performed twice for each initial aw. The three lowest aw values (0.85, 0.90, and 0.93) and the incubation and hood storage conditions were more effective (P < or = 0.05) at reducing the target pathogen levels in chorizos than were the two highest aw values (0.95 and 0.97) and the refrigeration storage condition, regardless of storage time. These results provide a scientific basis for guidelines given to producers of uninspected chorizo and should reduce the probability of foodborne illness associated with these products.
authors.affiliation: Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, California 95616, USA.
authors.forename: Carrie M
authors.initials: CM
authors.lastname: Hew
authors.forename: Maha N
authors.initials: MN
authors.lastname: Hajmeer
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Farver
authors.forename: James M
authors.initials: JM
authors.lastname: Glover
authors.forename: Dean O
authors.initials: DO
authors.lastname: Cliver
mesh_terms: D000818:Animals; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D019453:Escherichia coli O157 / Q000254:growth & development*; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D008461:Meat Products / Q000382:microbiology*; D012475:Salmonella / Q000254:growth & development*; D013552:Swine; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water