LACTIC ACID BACTERIA: AN APPROACH FOR NEW BIOPRESERVATION TECHNOLOGY

MARÍA R. MOREIRA; SARA I. ROURA; STELLA ECHARTE ; ALEJANDRA G. PONCE

Lactic Acid: Production, Properties and Health Effects

Nova Science Publishers, Inc.

Año: 2012; p. 105 - 117

The industry of minimally processed vegetables is constantly searching for new technologies for maintaining quality and inhibiting undesired microbial growth in all steps of production and distribution. New biopreservation technologies are recently considered as a promising perspective in order to reduce the chemical preservatives. The aim of this study was to determine the influence of added bacteriocin-producing lactic acid bacteria (LAB) on native microbial population associated to lettuce. We also determined the ?in vivo? protective effect of LAB against E.coli O157:H7. Lettuces were inoculated with single LAB strains (Enterococcus faecium, Lactococcus lactis, Enterococcus hirae and Enterococcus canis) or in combination with a pathogenic strain of E.coli O157:H7. The evolution of microorganisms in lettuce was followed during storage at 8 °C. Although the treatments did not completely eliminate the pathogen from lettuces, the results showed that LAB had a good colonization in both substrates. Biopreservation effect exerted by LAB on the E.coli O157:H7 population was bacteriostatic for the case of E.faecium and E.hirae. Microbial competition strategies require time, which in a products such as lettuce could produce the rapid quality deterioration. Therefore, it would be of great interest the study of these strains in products having a longer shelf life.