Biomedical Engineering Reference
In-Depth Information
and
E. faecium
CTC492 (producer of enterocins A and B) prevented slime formation
in cooked pork by
Lb. sakei
but not by
Leuconostoc mesenteroides
(Aymerich et al.
1998
). In sliced, vacuum-packaged cooked ham, the same enterococcal strain par-
tially prevented ropiness by
L.sakei
(Aymerich et al.
2002
). Inoculation of strains
producing sakacin P or leucocin in cooked meat products was shown to inhibit
growth of listeria (Katla et al.
2002
; Jacobsen et al.
2003
), and protective
L. sakei
cultures were also shown to inhibit
L. monocytogenes
and
E. coli
O157:H7 in vac-
uum-packed cooked meat products (Bredholt et al.
1999
). The bacteriocinogenic
strain
L. curvatus
CWBI-B28 reduced
L. monocytogenes
levels below detection lim-
its in bacon meat within 1 or 2 weeks in absence or presence of nitrites, respectively
(Ghalfi et al.
2006
). Anti-listerial effect was also observed with a plantaricin produc-
ing
L. plantarum
strain in cooked chicken meat (Enan
2006
). There are already sev-
eral LAB cultures in the market introduced as starter or bioprotective culture with
the aim of contributing to microbiological safety of semi-processed and cooked
meats (Aymerich et al.
2008
).
4.2.3
Fermented Meats
Certain lactic acid bacteria play key roles in meat fermentations. Therefore,
bacteriocin-producing strains have been proposed as starter cultures to combat
pathogens such as
L. monocytogenes
(Työppönen et al.
2003
; Leroy et al.
2006
;
Aymerich et al.
2008
). Bacteriocin-producing lactobacilli (mainly
L. sakei
and
L.
curvatus
, but also
Lactobacillus rhamnosus
and
L. plantarum
) have demonstrated
anti-listerial effects in sausage or salami fermentations, depending to a great extent
on strain and type of meat (Erkkilä et al.
2001
; Leroy et al.
2005
; Dicks et al.
2004
;
Benkerroum et al.
2005
; Todorov et al.
2007
) (Table
4.2
).
L. sakei
CTC 494 (producing sakacin K) is a promising functional starter culture
with antilisterial activity, being capable to successfully suppress
L. monocytogenes
in Spanish-style and German-style fermented sausages (Aymerich et al.
2008
) or to
reduce listeria populations in Belgian-style sausages, Italian salami, and Cacciatore
salami (Ravyts et al.
2008
). The effi cacy of
L. sakei
is infl uenced by environmental
factors such as sausage ingredients, salt, fat and nitrite content, acidifi cation level,
and temperature (Leroy et al.
2006
). Since
L. sakei
and
L. curvatus
can hydrolyze
muscle sarcoplasmic proteins and, in a lesser extent, myofi brillar proteins, they can
contribute to the generation of small peptides and amino acids which contribute as
direct fl avour enhancers or as precursors of other fl avour compounds during the
ripening of dry-fermented sausages (Leroy et al.
2006
). Exploitation of these activi-
ties may lead to the use of a new generation starter cultures with industrial or nutri-
tional important functionalities (Leroy et al.
2006
). Another, yet unexplored possible
application of these functional properties would be the generation of bioactive pep-
tides from the meat proteins by selected LAB with adequare proteolytic activities.
Bacteriocin-producing pediococci can reduce
L. monocytogenes
populations in
fermented meats (Amezquita and Brashears
2002
; Rodríguez et al.
2002
; Aymerich
