Gas concentrations inside CL or MP
packages remained at 21 kPa O2 and 0.04
kPa CO2, regardless of temperature regime
(data not shown), but were modified inside
PF bags. At constant 10 C, steady state CO2
levels averaged 12 kPa inside PF bags, but
under the SS treatment CO2 levels reached 21
to 23.5 kPa during the periods at 22 C (Fig.
5). For both temperature regimes, O2 concentrations
dropped below 1 kPa inside PF
packages during the first week of storage, and
then rose 1 to 3 kPa thereafter (Fig. 5). The
MA may account for the slightly lower taste
scores of longans packaged in PF and stored
under SS temperatures (Fig. 4). MA of 1–5
kPa O2 reportedly delays browning, aril
breakdown, and decay, but 1 kPa O2 results
in minor off-flavors (Cheng et al., 2009;
Ketsa and Paull, 2004). For lychee, a related
Sapindaceae crop, late-harvest fruit in MAP
produced greater acetaldehyde and ethanol,
and subsequently poorer flavor scores than
early-harvest fruit (Pesis et al., 2002). This
suggests that storage of fully or overripe fruit
in MAP can lead to accumulation of anaerobic
compounds and off-flavor development