Storage temperatures (2007). Longan fruit
are nonclimacteric and harvested when fully
mature based on pericarp color and soluble
solids content. On the day of harvest, ‘Biew
Kiew’ fruit respiration rates were 92.8 mg
CO2/kg/h but decreased to 58.3 mg CO2/kg/h
after 1 d at 20 C (Fig. 1A). This indicates that
a modest temperature decrease can remove
significant field heat from the crop in the tropics.
No ethylene production was detected on
harvest day (Fig. 1B). Average respiration rates
for longans stored at 20 C (61.6mgCO2/kg/h)
were about twice the rate as those stored at
10 C (32.7 mg CO2/kg/h) and triple the rate
for those stored at 5 C (21.1 mg CO2/kg/h).
Ethylene rates remained below 0.4 mgkg–1h–1
at all temperatures except 20 C (Fig. 1B), at
which an increase in ethylene production was
associated with postharvest decay. This is the
first report of ‘Biew Kiew’ respiration and
ethylene production rates. Other longan cultivars
respired at lower rates, ranging from 20
to 60 mg CO2/kg/h at 10 C and 20 C, respectively
(Ketsa and Paull, 2004; Liao et al.,
1983).