330 Chapter 18
pieces, covered with fresh immersion brine,
and held for up to 3 days. The cured pieces
are then removed, stacked, and matured just
long enough to dry the surface. They are then
ready for slicing.Bag Curing
This process differs in that it has no immer-
sion stage. Instead, the boneless pieces
are injected and, after a short drainage
period, placed in a moisture - and oxygen -
impermeable bag, vacuum sealed, and held
for a minimum of two days to allow time for
equilibration and the development of the
characteristic cured color. As there is no
immersion stage, all the necessary salt, pre-
servative, and other ingredients have to be
introduced into the injection brine. The fi nal
salt content is typically 3%.Dry Curing
Some bacon is dry cured, but the process is
quite different and much shorter than that
used in the dry curing of hams (e.g., Parma
or Iberian), which can take up to two years
to develop the characteristic aroma and fl avor
(Toldr á 2002 ). Often the process takes no
more than a couple of weeks, which does not
allow suffi cient time for the proteolytic and
lipolytic changes that occur in the production
of dry - cured hams. The major contributors to
fl avor and odor in dry - cured bacon, therefore,
are those derived from the curing ingredients
and generated during cooking.
Production involves rubbing the dry - cur-
ing ingredients manually into the surfaces of
exposed lean tissue. The treated pork is
vacuum packed and stored under chill condi-
tions for about 10 to 14 days (depending on
the thickness of the product), after which it
is ready to slice. A sweet cure can be obtained
by rubbing in sugar after 7 days before re -
packing and leaving the product for another
7 days.point of slaughter is important to reduce pre -
slaughter stress that might otherwise cause
a high incidence of PSE. The poor water -
holding capacity of the latter can adversely
affect brine uptake and retention (Kauffman
et al. 1978 ; Fisher et al. 2000 ).
The pigs are killed humanely and dressed
hygienically. Electrical stunning, followed
by prompt sticking, has been the usual
method, although this is being superseded by
carbon dioxide stunning throughout Europe.
Singeing the carcass improves the sliceability
of rind - on product.
Toughness is not a problem in bacon, so
interventions to improve tenderness (e.g., hip
suspension, electrical stimulation, and long
aging periods) are unnecessary. Butchery
normally commences immediately after
overnight chilling. The other parts of the
carcass are sold fresh or used for processing
(shoulders for sausages and the hindlimb for
ham). Most plants employ a traceability
system that can trace product back to the day
of slaughter.
Immersion Curing (Tank Curing)
The pieces to be cured, whether boneless
loins or bellies, are fi rst injected mechani-
cally with a brine containing salt and preser-
vative (sodium nitrite alone or in combination
with nitrate). Sodium polyphosphate, where
included, will improve the water - holding
capacity but its use is less common than for-
merly, due to consumer concerns. Sodium
ascorbate may be added to promote develop-
ment of the cured meat pigment and improve
the color shelf life (Ranken 1981 ). Sugar is
used in the production of sweet - cured bacon,
which helps to mask the salty fl avor. The
target weight gain, typically 10%, is based on
the total weight of the piece(s) to be injected,
although it will be appreciated that propor-
tionally more brine is taken up by muscle
rather than adipose tissue.
Following injection, the pieces are stacked
in small tanks, with a capacity for 30 to > 50