Agriculture Reference
In-Depth Information
higher levels of total phenolics, total antioxidant activity and significantly
lower electrolyte leakage than the untreated control fruits, thus attributed
to lower chilling injury symptoms. MeJA has also been implicated in de-
laying the onset of fruit ripening on the tree. Jasmonates have been found
to have close interaction with plant hormone ethylene in this regard. Ziosi
et al. (2009) reported jasmonate-induced ripening delay is associated with
up-regulation of polyamine levels in peach fruit. Kondo (2009) studied
the effect of MeJA on color development and aroma volatiles in apples.
The expression of UDP-glucose flavonoid 3-O-glucozyltransferase (UF-
GluT) anthocyanin biosynthetic gene was increased in the skin of fruits
treated with jasmonates and these fruits also had much higher anthocyanin
content than untreated controls. The impact of jasmonate application on
volatile compound production was dependent on fruit ripening stage; jas-
monates increased the volatiles in preclimacteric fruit, but decreased the
volatiles in climacteric fruit.
16.5 ETHANOL
Ethanol, also called as ethyl alcohol is a volatile, flammable and colorless
liquid. It is a small molecule produced either by chemical synthesis or
by microbial fermentation. The production of two anaerobic metabolites
acetaldehyde (AA) and ethanol in fruit, while still attached on the tree or
during postharvest storage, leads to dramatic changes in fruit ripening.
Ethanol is a volatile compound naturally produced by plant tissues under
anaerobic conditions. It is also accumulated in a short period in anaerobi-
cally stored fruits without adversely affecting fruit quality. Ethanol can
be applied by simply dipping fruit in an ethanol solution or as vapors. In
some fruits (grapes) spray method can also be used. Ethanol can be used
in controlling decay of fruits. Major target of ethanol is cell membrane.
Polar moiety of ethanol anchor to the phospholipid head group and non-
polar part bounds to phospholipid acyl-chains. Lipid acyl-chains from the
opposing monolayers are fully interpenetrated. This results to formation
of voids in bilayer interior and permeability of the membrane to lipophilic
compounds increases. Unbalanced cytoplasmic permeability and cytosol
leakage ultimately results in disintegration of cell. It has been reported to
effectively control postharvest table grape decay caused by
Botrytis ci-
nerea, Alternaria alternata
and
Aspergillus niger
when applied after or
