FLEISCHWIRTSCHAFT international_04_2018

Fleischwirtschaft international 4_2018
31
Storage
vacuum packaging may inhibit the
obligate aerobic microorganisms
which causes spoilage of meat and
meat products, but a disadvantage
of this technology is, that it does not
maintain the color appearance and
stability during storage.
Meat and meat products are
highly perishable food items. Using
a suitable packaging method leads
to a number of benefits like the
delay of microbial spoilage, avoidance
of contamination during
handling and transport, maintenance
of a desirable color particularly
in red meat (fresh) preservation,
minimization of moisture loss
and simplification in transport and
distribution. Appearance especially
the color of meat and meat products
has a great influence on the consumer
acceptance and buying
decision. Fresh meat color, as an
indicator of wholesomeness, is
preferred and can be maintained by
using 60–80% oxygen (O2) which
retards the metmyoglobin formation
(a brown color pigment). The
bright-red color of fresh meat can
be stabilized by employing modified
atmosphere packaging (MAP)
and using a combination of gas
such as oxygen (O2), nitrogen (N2)
and carbon dioxide (CO2). Oxygen
(O2), nitrogen (N2) and carbon
dioxide (CO2) are the most frequently
used gases.
However, other gases used in
packaging system such as carbon
monoxide (CO), nitrous oxide (NO2)
and sulfur dioxide (SO2) have also
been used. CO2 and N2 gas combinations
are suitable for the preservation
of cured meat products, for a
numbers of reasons including
strong inhibition of the growth of
microorganisms (RONCALE , 1994).
Storage of meat is done in highoxygen
packaging conditions for
maintaining of the color, but packaging
conditions with less than
80% O2 had been found to decrease
meat quality (LUND et al., 2007)
(Tab. 1). Meat lipids form secondary
oxidative products upon oxidation
are leading to rancid off-flavor
development in meat and meat
products including poultry.
The rancid aromas produce a
detrimental effect on the product
quality and marketing possibilities.
An alternative antioxidant effect
may be found by packaging of meat
in combination with different
gasses like carbon dioxide, carbon
monoxide, sulfur dioxide etc.
(Fig. 2).
Various gasses and
their role in MAP
Following are some common
widely used gases in modified
atmospheric packaging:
r Carbon dioxide
r Oxygen
r Nitrogen
r Carbon monoxide.
At the moment for MAP packaging
three principal gas are used like
carbon dioxide (to inhibit aerobic
microbial growth), and oxygen (to
prevent anaerobic microbial
growth) and nitrogen used as inert
filler (prevents oxidation of fats and
pack collapse).
Carbon dioxide (CO2)
Carbon dioxide is an important gas
for the use in MAP because it has
unique properties of solubility in
the muscle as well as in lipid. One
liter CO2 can dissolve in one kilogram
of meat, i.e. in 1:1 ratio. The
solubility of CO2 in meat is inversely
related with temperature.
When using a CO2 rich gas combination
in packs, the ratio of the total
package volume (liter) to the meat
weight (kilogram) is dependent on
the gas mix composition and could
be up to 3:1 for mixtures in which
CO2 predominates.
Carbon dioxide enhances the
shelf-life of perishable meats by
retarding the microbial growth by
enhancing both lag phase and
generation time of microbes. The
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