Head space O2 and CO2 analyses were carried out using an
O2/CO2 analyzer (Checkmate 9900, PBI Dansensor,
Denmark). Head space gas samples were drawn from the
packages through Teflon septa using an auto-injector. A minimum
gas volume of 5 ml was used to ensure representative
readings. The instrument was calibrated using 100 % O2 and
CO2 prior to analysis