3. Results and discussion
3.1. Respiration rate and ethylene production
The effect of slicing resulted in an instantaneous
but not significant rise in CO2 production
of whole and fresh-cut tomato at 10°C (Fig. 1).
This increase was associated with the wound response
(Mencarelli et al., 1989). No others peaks
associated with the ripening process were observed.
Partially ripe fruit was used in this study,
whereas Mencarelli et al. (1989) used mature
green tomatoes, which could explain the climateric
stage reported. At 2°C, whole tomatoes had
similar respiratory patterns to those of fresh-cut
fruit. However, the respiration rate of fresh-cut
tomatoes increased significantly after 2 days at 10°C (Fig. 1). This suggested that the higher
temperature promoted deterioration and decay of
the tissues (Rhizopus spp. colonies were observed
after 6 days). The respiration rate of whole tomatoes
at 2°C was half that at 10°C and no chilling
injury disorders were observed after 7 days at
either temperature. This similarity of whole and
fresh-cut tomato respiration rates at low temperature
has also been observed by Watada et al.
(1996). The higher temperature increased respiration
rates of fresh-cut tomato compared to whole
fruit, probably in response to ethylene production
following the start of decay (Fig. 1). Hong and
Gross (1998) detected an increase in CO2 and C2H4 production due to microbial growth on
tomato slices from control fruit. However, slices
from tomatoes treated with NaOCl prior to slicing
showed no increase in CO2 and C2H4
production.
There was little detectable C2H4 production at
2°C in whole and fresh-cut tomato and few differences
were detected over the storage period (Fig.
2). On the other hand, storing tomato slices at
10°C caused the rate of C2H4 production to be
5-fold higher than that of whole fruit. This increase
started immediately after cutting, rising to
95–120 pmol kg−1 s−1 on day 1 and remaining
quite constant until 4 days after storage, de