title: Influence of sodium chloride on growth of lactic acid bacteria and subsequent destruction of Escherichia coli O157:H7 during processing of Lebanon bologna.
abstract: Due to undesirable quality changes, Lebanon bologna is often processed at temperatures that do not exceed 48.8 degrees C (120 degrees F). Therefore, it is important to study parameters that influence the destruction of Escherichia coli O157:H7 in Lebanon bologna. The objective of the present study was to determine the influence of curing salts (NaCl and NaNO2) on the destruction of E. coli O157:H7 during Lebanon bologna processing. Fermentation to pH 4.7 at 37.7 degrees C reduced populations of E. coli O157:H7 by approximately 0.3 log10, either in the presence or absence of curing salts. Subsequent destruction of E. coli O157:H7 during heating of fermented product to 46.1 degrees C was significantly reduced by the presence of 3.5% NaCl and 156 ppm NaNO2, compared to product without curing salts (P < 0.01). The presence of a higher level of NaCl (5%) in Lebanon bologna inhibited the growth of lactic acid bacteria (LAB), which yielded product with higher pH (approximately 5.0) and significantly reduced the destruction of E. coli O157:H7 even further (P < 0.05). Lower concentrations of NaCl (0, 2.5%) yielded Lebanon bologna with higher LAB counts and lower pHs, compared to product with 5% NaCl. When lactic acid was used to adjust pH in product containing different levels of NaCl, it was determined that low pH was directly influencing destruction of E. coli O157:H7, not NaCl concentration.
authors.affiliation: Department of Food Science, The Pennsylvania State University, University Park 16802, USA.
authors.forename: N
authors.initials: N
authors.lastname: Chikthimmah
authors.forename: R C
authors.initials: RC
authors.lastname: Anantheswaran
authors.forename: R F
authors.initials: RF
authors.lastname: Roberts
authors.forename: E W
authors.initials: EW
authors.lastname: Mills
authors.forename: S J
authors.initials: SJ
authors.lastname: Knabel
mesh_terms: D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000187:drug effects / Q000254:growth & development*; D005285:Fermentation; D005511:Food Handling / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D008461:Meat Products / Q000382:microbiology*; D012965:Sodium Chloride / Q000494:pharmacology*; D013696:Temperature
chemical_list: D012965:Sodium Chloride