Combined effects of organic acids and salt depending on type of acids and pathogens in laboratory media and acidified pickle

• DOI: 10.1111/jam.12845
• Publication Date: 2015-05-14T13:20:51Z
• Authors: Y.-M. Bae; S.-Y. Lee
• Keywords: 2. Zero hunger; 0404 agricultural biotechnology; Bacteria; Food Preservation; Vegetables; Food Microbiology; 04 agricultural and veterinary sciences; Sodium Chloride; 0405 other agricultural sciences; Acids; Culture Media; 3. Good health

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.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.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.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.