to postharvest senescence often causes serious commercial losses.
However very little is presently known about postharvest changes
in quality attributes of sweet basil leaves. Sweet basil is a chillingsusceptible
plant of tropical origin and exposure of leaves to
temperatures below 12 ◦C during storage results in development
of chilling injury, which is visually expressed by the appearance of
darkened pitted lesions on the leaves, followed by decay (Lang and
Cameron, 1994). Therefore, low temperature is not an option for
prolonging shelf-life.
Senescence of green leaves involves enhanced chlorophyll and
protein degradation, and accumulation of amino acids in detached
leaves. Artificial senescence is induced as a consequence of detachment,
together with the various stresses involved, including water
and nutrient supply stresses, exposure to darkness, leading to inhibition
of photosynthesis, and induction of stress-related hormones,
especially ethylene (Ella et al., 2003). A major aim in the storage
of fresh products, including herbaceous leaves, is to nullify the
senescence promoting effect of ethylene, through its removal or by
reducing the sensitivity of the plant tissue towards the hormone.