Agriculture Reference
In-Depth Information
in water temperature. The addition of hypochlorite or
chlorine dioxide to the water might serve to reduce the
levels of contamination in the chiller, but because these
compounds would quickly be deactivated on contact
with skin, there would be little direct effect on carcase
bacterial burdens. The main value of chlorinating chiller
water is to minimise cross-contamination. Although
hyperchlorination is banned in the EU, it is allowed in
the United States (Fig. 10.14).
EC regulations state that the carcases must pass through
one or more tanks of water or of ice and water, the con-
tents of which are continuously renewed. Only a system
whereby the carcases are constantly propelled by mechan-
ical means through a counterflow of water is acceptable.
The temperature of the water in the tank measured at
the points of entry and exit of the carcases must not be
more than +16°C and +4°C, respectively.
Chilling must be carried out so that the required tem-
peratures of fresh chilled poultry meat of not more than
4°C and for frozen poultry meat of not more than −12°C
are reached in the shortest possible time.
The minimum flow of water throughout the whole
chilling process must be:
2.5 L per carcase weighing 2.5 kg or less
4 L/ per carcase weighing between 2.5 and 5 kg
6 L per carcase weighing 5 kg or more
others, not longer than necessary), equipment to be
thoroughly cleaned and disinfected when necessary and
at the end of the day, calibrated control equipment and
the need for microbiological monitoring.
In addition, when chlorine is used, it should be moni-
tored to ensure correct levels.
Static water chillers involve the use of static slush ice
tanks after immersion chilling and are required for larger
birds, especially for turkeys which must also be 'aged' to
ensure a tender product prior to freezing. The larger
carcases need to be chilled for longer periods. The disad-
vantages of this equipment are greater than those arising
from the use of immersion chillers. Water chillers are also
restricted in quality products on the ground of water pickup.
Spray chillers avoid the problems associated with the
build-up of contamination in the chill tanks but can give
rise to the spread of bacteria through aerosols. They are
not suitable for large carcases, for example, turkeys, and
are costly to operate as they use high volumes of water.
Air chillers are generally used where carcases are for
sale fresh. Chilling is effected either by batch in a chill
room or by continuous air blast. It requires the use of
low-scald temperatures to ensure a high-quality appear-
ance (Fig. 10.13 and Fig. 10.15). The differences in
microbial counts between air- and water-cooled carcases
are not constant.
After initial chilling birds may be processed as whole
birds or as parts (Figs. 10.17, 10.18, 10.19, 10.20, 10.21,
10.22 and 10.23).
Other requirements are the length of time the carcases
spend in the tanks (first tank not more than half an hour;
Figure 10.14
Immersion chilling (Reproduced with permission from Stork Poulty Processing, Boxmeer, The Netherlands).
