In poorly ventilated environments at optimum temperatures,
such as in
sealed
polyethylene packaging, we
observed
the phenomena similar
to
the green ripening at
high
temperatures.
Namely,
the fruit under such
conditions
stayed
green but
with normal softening
and sweetening in
the
pulp. The
environment inside
the sealed packaging
is
known
to be of higher concentration of CO
than regular
air due to the strong respiration of the fruits (Fonseca et al.
00.it is generally acknowledged that modified atmspheres
with elevated CO
inhibit fruit ripening, basically
by ethylene biosynthesis reduction (Saltveit 1999). However,
in
commercial situations, ripening in
poorly ventilated
environments
might
happen for
the fruits that had already
been
initiated
by ethylene.
Systematical investigation of
the
effect
of high CO
on various aspects of ripening may
uncover the mechanisms leading to abnormal ripening in
poorly ventilated environments. Many unripe fruits, such
as bananas, are covered by green peels that contain high
contents of Chls in the chloroplasts of green cells, while
the pulps are regarded as white tissue. In Brussels sprout,
green tissue was found to response differently to high CO
as the white tissue (Lipton and Mackey 1987). It is unclear
whether such potential difference in the responses to high
CO
between the peel and pulp may lead to abnormal ripening
of the banana fruit.