Control of ethylene biosynthesis and softening in `Cox's Orange Pippin' apples during low-ethylene, low-oxygen storage
J. R. Stow, C. J. Dover and P. M. Genge
Postharvest Biology and Technology Vol: 18 Issue: 3 Pages: 215-225
2000
บทคัดย่อ
The response of apples (Malus domestica Borkh.) cv. Cox's Orange
Pippin (`Cox') to low ethylene, controlled atmosphere (CA) storage was examined
in two seasons. The content of 1-aminocyclopropane-1-carboxylic acid (ACC) and
the activity of ACC oxidase (measured as the capacity for formation of ethylene
from exogenous ACC) in cortical tissue of apple fruits from low ethylene
containers, remained constant for about the first 20 weeks of storage, before
increasing. Removal of ethylene from the storage atmosphere was more effective
at reducing softening in <1% CO2+1.25% O2 after a
pretreatment with 5% CO2+16% O2 for 15 days, than storage
in <1% CO2+0.75% O2 without a pretreatment. Low
ethylene storage maintained fruit firmness by inhibiting initiation, rather
than reducing the rate of softening. Fruit was no softer after more than 28
weeks of storage when ethylene removal was discontinued after 12 weeks (1989¯90)
or 16 weeks (1990¯91) than when the removal had been continuous
throughout the storage period. It was concluded that, to obtain a benefit from
ethylene removal, internal ethylene concentrations must be maintained below
about 4 
mol
m-3 (0.1ppm). This could not be achieved with `Cox' apples in 1.25%
O2 by removal of ethylene without a 5% CO2 pretreatment.
The onset of autocatalytic ethylene production was not delayed appreciably by
the removal of ethylene and was initiated after 2¯5
weeks of storage, although the production rate of ethylene increased more
slowly in a low ethylene atmosphere.