title: Combined effects of organic acids and salt depending on type of acids and pathogens in laboratory media and acidified pickle.
abstract: OBJECTIVE
  In this study, the effectiveness of combining each of seven types of acids with 3% salt as a treatment against pathogens was investigated in laboratory media and acidified food.
  
  
  RESULTS
  When 0.5% malic, 0.5% tartaric, 0.5% citric or 0.25% phosphoric acid was combined with 3% salt, there was a higher reduction in Gram-negative bacteria (Escherichia coli O157:H7 and Salmonella Typhimurium) compared to when using acid alone. However, when 0.5% acetic, 0.5% propionic or 0.25% lactic acid was combined with 3% salt, the salt provided protection against the acid treatment. However, the antagonistic effects of acetic, propionic and lactic acid seen with Gram-negative bacteria were not observed in Listeria monocytogenes. Antagonistic effects were similarly observed when E. coli O157:H7 was treated with acetic acid and salt in food.
  
  
  CONCLUSIONS
  These results show that the addition of salt increases the resistance of Gram-negative bacteria to acid treatments when using acetic, propionic and lactic acid.
  
  
  CONCLUSIONS
  This study shows that antagonistic effects were observed when Gram-negative bacteria were treated with organic acids of simple structure. It may provide useful information for understanding the acid resistance mechanism of Gram-negative bacteria and developing methods for preserving acidified food.
authors.affiliation: Department of Food Science and Technology, Chung-Ang University, Anseong-si, Gyeonggi-do, South Korea.
authors.forename: Y-M
authors.initials: YM
authors.lastname: Bae
authors.affiliation: Department of Food Science and Technology, Chung-Ang University, Anseong-si, Gyeonggi-do, South Korea.
authors.forename: S-Y
authors.initials: SY
authors.lastname: Lee
mesh_terms: D000143:Acids / Q000032:analysis / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D012965:Sodium Chloride / Q000032:analysis / Q000494:pharmacology*; D014675:Vegetables / Q000382:microbiology*
chemical_list: D000143:Acids; D003470:Culture Media; D012965:Sodium Chloride
keywords: antagonism; foodborne pathogens; hurdle effect; organic acids; salt