Effect of Lactic Acid on Inactivation of Enterotoxigenic Escherichia Coli (ETEC) Isolated from Tuna Loins Produced in Côte D’Ivoire
Andree Emmanuelle Sika *
Laboratory of Biotechnology and Food Microbiology, Department of Food Science and Technology, Nangui Abrogoua University, 02 BP 801 Abidjan, Côte d’Ivoire.
Yolande Ake-Assi
Central Laboratory for Food Hygiene and Agribusiness, LANADA, 04 BP 612 Abidjan 04, Côte d’Ivoire.
Therese Anoman
Central Laboratory for Food Hygiene and Agribusiness, LANADA, 04 BP 612 Abidjan 04, Côte d’Ivoire.
Ollo Kambire
Department of Biochemistry and Food Sciences, Peleforo Gon Coulibaly University, BP 1328 Korhogo, Côte d’Ivoire.
Rose Koffi-Nevry
Laboratory of Biotechnology and Food Microbiology, Department of Food Science and Technology, Nangui Abrogoua University, 02 BP 801 Abidjan, Côte d’Ivoire.
Koffi Marcellin Dje
Laboratory of Biotechnology and Food Microbiology, Department of Food Science and Technology, Nangui Abrogoua University, 02 BP 801 Abidjan, Côte d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
Aims: The aim of this work was to study the effect of lactic acid on the growth of pathogenic strains of Escherichia coli (ETEC) isolated from tuna loins.
Study Design: Bacteriological study.
Place and Duration of Study: Laboratory of Microbiology of the Central Laboratory of Food hygiene and Agrobusiness (LCHAI), Abidjan, Côte d’Ivoire between September 2014 and December 2014.
Methodology: Enterotoxigenic Escherichia coli (ETEC) strains were isolated from tuna loins. Lactic acid (LA) 1%, 2% and 3% were tested in pathogenic strains in liquid medium (brain heart infusion broth, BHI) and in tuna loins.
Results: At lactic acid 1%, the bacterial loads decreased during the first two days and then stabilized. E. coli strains in tuna loins were higher (1.25 to 0.9 log CFU/g) than E. coli in liquid medium (0.69 to 0.3 log CFU/g). No bacterial growth was observed in the tuna loins and in BHI for concentrations of 2% and 3% of lactic acid.
Conclusion: Lactic acid has an inhibitory effect at 1% and bactericidal effect at 2% and 3% on the growth of E. coli. The use of lactic acid as a preservative could be a solution for the preservation of these products.
Keywords: Enterotoxigenic Escherichia coli (ETEC), lactic acid (LA), tuna loins, brain heart infusion broth (BHI).