199Chapter 10
Starter Cultures for Meat Fermentation
Pier Sandro Cocconcelli and Cecilia Fontana
Introduction
Dry sausages are made from a mixture of
frozen pork, beef, and pork fat. In addition,
these fermented products contain sugars, salt,
nitrite and/or nitrate, and spices. Fermentation
is a crucial phase of sausage production,
since the major physical, biochemical, and
microbiological transformations take place at
this stage (Lizaso et al. 1999 ; Villani et al.
2007 ). All these transformations, which are
infl uenced by the microbiota, the ripening
conditions, and the ingredients, have a con-
siderable effect on the sensorial quality of
fermented meat products. These changes can
be summarized as follows: decreases in pH;
changes in the microbial populations; reduc-
tion of nitrates to nitrites a; formation of
nitrosomyoglobin; solubilization and gelifi -
cation of myofi brillar and sarcoplasmic pro-
teins; proteolytic, lipolytic, and oxidative
phenomena; and dehydration (Casaburi et al.
2007 ).
Knowledge and control of the bacteria
present in the batter and involved in the fer-
mentation are essential in terms of the
microbiological quality, sensory characteris-
tics, and food safety. In the last decade,
numerous studies on the ecology of tradi-
tional fermented sausages confi rmed and
extended the knowledge, especially in terms
of technological lactic acid bacteria (LAB)
and Gram - positive catalase positive cocci
(GCC+), (Aymerich et al. 2003 ; Corbi è re
Morot - Bizot et al. 2004 ; Giammarinaro et al.
2005 ; Rantsiou and Cocolin 2006 ; Urso et al.
2006 ). The LAB species most commonly
identifi ed in traditional fermented sausages
are Lactobacillus sakei , Lactobacillus curva-
tus , and Lactobacillus plantarum (Fontana
et al. 2005 ; Aymerich et al. 2006 ; Urso
et al. 2006 ). Among GCC+ isolates,
Staphylococcus xylosus, Staphylococcus
equorum , Staphylococcus succinus , and
Staphylococcus saprophyticus are men-
tioned, often with S. xylosus predominant
(Mauriello et al. 2004 ; Fontana et al 2005 ;
Corbi è re Morot - Bizot et al. 2006 ; Drosinos
et al. 2007 ).
Improvement of quality and safety of
sausage and other fermented meat products
can be achieved by the introduction of selec-
tive decontaminating procedures targeted
toward spoilage and pathogenic bacteria but
preserving technological microbiota (Ammor
et al. 2004 ), and by the addition of microbial
starter cultures selected from meat - process-
ing environment in order to drive the fermen-
tation process.
Meat starter cultures are “ preparations
which contain living or resting microorgan-
isms that develop the desired metabolic
activity in the meat ” (Hammes 1996 ).
Inoculation of the sausage batter with a
starter culture composed of selected LAB
(i.e., homofermentative lactobacilli and/or
pediococci) and GCC+ (i.e., nonpathogenic,
coagulase - negative staphylococci and/or
kocuriae) improves the quality and safety
of the fi nal product and standardizes the pro-
duction process (Campbell - Platt and Cook
1995 ; Hugas and Monfort 1997 ; L ü cke 1998,
2000 ; H ü fner and Hertel 2008 ; Talon et al.
2008 ).