How to Choose Appropriate MAP Material

Modified Atmosphere Packaging (MAP) is a kind ofrespectively. Permeation of other gases should
preservative packaging developed on the basis ofnot be calculated simply by converting oxygen
vacuum and nitrogen-filled packaging and it istransmission rate (O2TR) according to experience.
mainly used for food preservation.It can be imagined that index testing mistakes or
The packaging principle of MAP is to replace air ininappropriate MAP material selection caused by
packaging bags and boxes with modifiedincomplete gas permeation testing would not only
preservative gas (mixture of 2?4 gases accordingcause great loss to enterprises but also waste
to food property), so as to change the internalthe resource as well.
environment of packed food,  restrain bacilliAt present, the commonly used methods for gas
growth as well as slow down the metabolic ratepermeation test are different pressure method
and extend the freshness or shelf life of the food.and equal pressure method. Equal pressure
Take fruit and vegetable preservative as anmethod instrument has limited testing objects. It
example, fresh fruit and vegetable still respirecan only test oxygen   permeation (Labthink
after pick. They consume oxygen and produceTOY-C1 Oxygen Permeation Tester) and carbon
carbon dioxide, which would result in increase ofdioxide  permeation. Nitrogen permeation testing
carbon dioxide content and decline of oxygeninstrument has not been developed by any
concentration. With high permeation film, oxygenenterprises. However, different pressure method
could be supplied and carbon dioxide be ventedinstrument could test common gases such as
through exchanging packaging gas withoxygen, nitrogen, carbon dioxide and it has low
atmosphere. When the gas permeation ratecost and can provide self-control testing
equals to respiratory rate of fruit and vegetable,temperature (Labthink VAC-V1 Gas Permeation
certain gas equilibrium concentration in theTester). With the support of film theory, vacuum
package is achieved. Then, fruit and vegetableinstrument of different pressure method can test
could maintain weak respiratory rate withoutcommon gas permeation as well as specimen
anaerobic respiration. Thereby, the maturation ofdiffusion coefficient and solubility coefficient.
fruit and vegetable is delayed and freshness isCompared with equal pressure method
preserved. MAP could ensure food taste,instrument, permeation testing instrument of
nutritional ingredient and freshness period withoutdifferent pressure method is more suitable for
applying preservative and additive.research institution and enterprises to have a
MAP material should be selected appropriatelycomprehensive testing and analysis of MAP
according to its gas permeation. The commonlymaterial.
used gas for MAP is a mixture of oxygen, carbonLabthink Instruments Co., Ltd.      
dioxide, nitrogen or mixture of oxygen and carbonNo. 144 Wuyingshan Road, Jinan 250031, China
dioxide.  Therefore, gas permeation of oxygenTracy Bao  info@labthink.
and nitrogen should be tested accurately and