Optimal values are 85–95% (v/v) for Mature Green and 90–95%
(v/v) for firm Ripe fruits (Suslow and Cantwell, 2009). Below these
ranges evapotranspiration increases which can lead to higher TSS
but quickly result in fruits that are visibly of poor appearance.
Carbon monoxide has been investigated as a postharvest treatment.
It accelerates ripening, so when used, it must be balanced
with low oxygen to delay senescence (Kader, 1983). Carbon monoxide
retards postharvest pathogen-infestation and simultaneously,
improves some quality parameters: tomato kept in 5 or 10% (v/v)
carbon monoxide with 4% (v/v) oxygen, had superior TSS and TA
profiles compared to those kept in air with less incidence of Botrytis
(Kader, 1983; Kader et al., 1978a). The use of carbon monoxide
is however complicated because it is hazardous to humans.