Agriculture Reference
In-Depth Information
(Abdul-Raouf et al.
1993
). A number of surveys stated the presence of
Listeria
monocytogenes
on cucumber, peppers, potato, radish, leafy vegetables, bean sprouts,
broccoli, tomato, and cabbage at sailing points (Heaton and Jones
2008
).
1.2
Modifi ed Atmosphere Packaging (MAP)
MAP is a technique for extending the shelf life of fresh and minimally processed
food. During the atmosphere modifi cation procedure the air surrounding the
product is replaced with the desired composition. MAP is applied in a wide variety
of products and the mixture of gases used are selected and affected by many factors
such as storage temperature, type of the product and packaging materials (Sandhya
2010
).
In MAP/Controlled atmosphere (CA) oxygen, carbon dioxide and nitrogen are
the most common gases used. Nitrous and nitric oxides, sulfur dioxide, ethylene,
chlorine, as well as ozone and propylene oxide have been used in many experiments
to investigate their effect on the postharvest quality of vegetables. The afore-
mentioned gases did not fi nd commercial use due to high cost and safety and regu-
latory considerations. The compositions of gases used in MA are, inert blanketing
using N
2
, semi-reactive blanketing using CO
2
/N
2
or O
2
/CO
2
/N
2
, or fully reactive
blanketing using CO
2
or CO
2
/O
2
(FDA/CFSAN
2001
).
The use of MAP can result in reduction of respiratory activity, retardation of
softening and ripening and restraint of pathogens and reduced incidence of various
physiological disorders (Caleb et al.
2012
).
In all food preservation techniques there are critical parameters that play an
important role in shelf life prolongation, functionality and effectiveness of the
method. The effect of storage temperature, gas composition, the nature of the
products and the wrapping fi lm is important to be defi ned and evaluate any interac-
tions in order to achieve the optimal results of modifi ed atmosphere packaging
(Arvanitoyannis and Bouletis
2012
).
1.3
Temperature
Temperature is an extremely important factor during packaging design due to its
effect on the physiology of the product. One of the main responses to stress is pro-
tein dysfunction, disrupting cellular homeostasis, known as heat shock proteins.
The production of these proteins is triggered by conditions like oxidative stress,
low temperatures and fruit ripening. Exposure of sensitive products to low storage
temperatures may have benefi cial effect on shelf life and preserve quality but there
are some limitations. If these limits are exceeded may lead to chilling injury
(Aghdama et al.
2013
).
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