SENSITIZATION OF Listeria innocua TO INORGANIC AND ORGANIC ACIDS BY NATURAL ANTIMICROBIALS

G. LEHRKE, L. HERNAEZ, S. MUGLIAROLI, M. VON STASZEWSKI, R.J. JAGUS

LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2011 p. 984 - 989

0023-6438

Acid tolerance of two strains of Listeria innocua as single strain culture and co-culture, were evaluated in liquid cheese whey after exposure to nisin, MicrogardTM and green tea. Inorganic and organic acids were applied after natural antimicrobials treatments and microbial counts were made to analyze the bacterial response. The results have demonstrated that natural antimicrobials like nisin, MicrogardTM and green tea, present in the liquid cheese whey, did not produce any cross-protection effects. On the contrary, in most of the cases, the antimicrobial treatment increased the susceptibility of L. innocua to acid stress, particularly in the treatment with nisin or green tea extract and organic acids. These results were corroborated by different techniques, including transmission electron microscopy.