Use of Organic Acids to Inactivate Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on Organic Fresh Apples and Lettuce

• Published in: Journal of food science 2011-08, Vol.76 (6), p.M293-M298
• Main Authors: Park, Sang-Hyun, Choi, Mi-Ran, Park, Jeong-Woong, Park, Ki-Hwan, Chung, Myung-Sub, Ryu, Sangryeol, Kang, Dong-Hyun
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Apples; Biological and medical sciences; Carboxylic Acids - pharmacology; Colony Count, Microbial; E coli; Escherichia coli O157 - drug effects; Escherichia coli O157 - growth & development; Escherichia coli O157:H7; Food contamination & poisoning; Food industries; Food microbiology; Food Preservatives - pharmacology; Food, Organic - microbiology; Foodborne Diseases - prevention & control; foodborne pathogens; fresh produce; Fruit - drug effects; Fruit - microbiology; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Lactuca - drug effects; Lactuca - microbiology; Lettuce; Listeria monocytogenes; Listeria monocytogenes - drug effects; Listeria monocytogenes - growth & development; Malus - drug effects; Malus - microbiology; Microbial Viability - drug effects; organic acid; Osmolar Concentration; Phytochemicals; Pigmentation - drug effects; Plant Leaves - drug effects; Plant Leaves - microbiology; Republic of Korea; Salmonella typhimurium - drug effects; Salmonella typhimurium - growth & development; Salmonella Typhimurium; Time Factors
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/j.1750-3841.2011.02205.x

:  This study was undertaken to investigate the antimicrobial effect of organic acids against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on whole red organic apples and lettuce. Several studies have been conducted to evaluate organic acids as sanitizers. However, no studies have compared antimicrobial effects of various organic acids on organic fresh produce, including evaluation of color changes of produce. Apples and lettuce were inoculated with a cocktail of 3 strains each of 3 foodborne pathogens provided above and treated with 1% and 2% organic acids (propionic, acetic, lactic, malic, and citric acid) for 0, 0.5, 1, 5, and 10 min. With increasing treatment time and acid concentration, organic acid treatments showed significant reduction compared to the control treatment (distilled water), and differences in antimicrobial effects between organic acids were observed. After 10 min of treatment with 1% and 2% organic acids in apples, propionic (0.92 to 2.75 log reduction), acetic (0.52 to 2.78 log reduction), lactic (1.69 to >3.42 log reduction), malic (1.48 to >3.42 log reduction), and citric acid (1.52 to >3.42 log reduction) exhibited significant (P < 0.05) antibacterial effects against 3 foodborne pathogens compared to the control treatment. In lettuce, propionic (0.93 to 1.52 log reduction), acetic (1.13 to 1.74 log reduction), lactic (1.87 to 2.54 log reduction), malic (2.32 to 2.98 log reduction), and citric acid (1.85 to 2.86 log reduction) showed significant (P < 0.05) effects compared to the control treatment. Changes in sample color subjected to organic acids treatment were not significant during storage. Practical Application:  It is suggested that organic acids have a potential as sanitizers for organic fresh produce. These data may help the organic produce industry provide safe fresh produce for consumers.