Head-space gases CO2 and O2 were measured using a PBI
Dansensor CO2/O2 gas analyzer (Checkmate 9900, Ringsted,
Denmark) after removal from cold storage. Gas samples were
analyzed from three replicates of each non-destructive sample. The
respiration rates of O2 consumption and CO2 evolution were
obtained from a CO2 and O2 concentrate. A computer program was
developed using the MATLAB1 software (Mathworks Inc., USA) to
determine the respiration rates using the model proposed by Lee
et al. (1996), according to Eq. (1):
rO2
¼
d½O2
100dt
V
m
þ SPO2
ð0; 21
½O2=100Þp
mL
where rO2 is the respiratory rates for O2 consumption expressed as
mg kg1 s1; [O2] is the concentrations of O2 expressed as %; L is the
thickness of the
film in m; S is the area of the bag (m2); PO2 is the
permeability of the
film for O2, respectively (mL m2 s1 Pa1); t is
the time in h; Vm is the free volume in the bag (mL); and m is the
mass of product in the bag (kg).