finding is in agreement with the results observed by Glowacz et al.
(2015b) who did not observe significant differences between red
bell peppers exposed to ozone at 0.1 and 0.3 lmol mol
1
and control samples. Tzortzakis et al. (2007) also reported that no signifi-
cant differences were observed between tomatoes exposed to
ozone at 1 lmol mol
1
and untreated control. The slight decline
in total phenolic content at the end of the storage period could
be associated with their oxidation by ozone.
3.5.4. Antioxidant activity
Regardless of ozone concentration, antioxidant activity was not
affected in red chilli peppers (Table 4). Tzortzakis et al. (2007) also
did not observe changes in antioxidant activity in tomatoes
exposed to ozone at 1 lmol mol
1
for 6 days. In contrast, antioxidant activity was found to be significantly reduced after 14 days
in green chilli peppers exposed to ozone at 2 lmol mol
1
when
compared with control samples while it was not affected at 0.45
and 0.9 lmol mol
1
(Table 5), suggesting that green peppers were
more sensitive to ozone treatment. Since total phenolic content
was not significantly reduced, the observed change in antioxidant
activity could be associated with a decline in ascorbic acid content
and/or changes in phenolic composition in those samples, presumably due to oxidative stress.