Package headspace analysis for O2 and CO2 concentration was carried out by a check point O2/CO2 instrument (PBI Dansensor,Denmark) at pre specified time of storage (Tirkey et al., 2014).
As mall self adhesive silicon septum is glued to the package and a needle is pierced through this septum into the pack to draw the gas sample.
The sensor signals is converted to concentration values of O2 and CO2, which are directly read on the digital display panelof the instrument.
The accuracy of 0.1% for O2 and 2% for CO2 are in full range.
The calibration for the instrument has been done with O2 and CO2 air percentages.
Parameters were expressed as CO2 and O2 percentage referred to initial values.