Control of Listeria monocytogenes growth by bacteriocin-producing starter cultures in the manufacturing of dry fermented sausage

Abstract

The production of dry fermented sausages started as a home-made process, but large-scale industrial manufacture of these products has encountered some safety issues. Although these products present extended shelf-life and offer various hurdles against the growth of undesired organisms, pathogens such as Listeria monocytogenes were found to survive. Bacteriocins have been proposed to act as an extra barrier against the growth of Gram-positive bacteria, including L. monocytogenes. These antimicrobials are synthesized by some lactic acid bacteria (LAB), which are responsible for the fermentation of dry sausages. Many bacteriocins produced by LAB showed ability to inhibitL. monocytogenes growth (e.g. enterocin, pediocin and sakacin). However, the levels of bacteriocins needed to produce this effect in food systems are much higher than those necessary in vitro. Use of bacteriocinogenic starter cultures have shown promising anti-listerial activity in dry sausage, since the antimicrobials are produced in situ confering a better distribution and sustained synthesis throughout the fermentation period. This manuscript reviews the technological challenges of bacteriocin application in dry fermented sausage and the recent findings on using bacteriocinogenic autochtonous LAB to improve safety towards L. monocytogenes. Key words: Fermented sausages, Listeria monocytogenes, bacteriocins