Postharvest treatments to reduce chilling injury symptoms in stored ...

v) As the fruit ripens the flesh becomes softer. At the peak of ripening the fruit
firmness decreases and softening of the fruit is associated with an increased
solubility of cell wall pectins (Roe and Bruemmer, 1981).
vi) Certain monoterpene hydrocarbons and lactones are responsible for mango
flavor (Wilson et al., 1990).
vii) At the early stage of growth polyphenolic content are high and decrease with
the ripening and remain fairly steady (Lakshminarayana et al., 1970).
viii) During ripening lipid content increases along with increases in glyceride and
linolenic acid (Bandyopadhyay and Gholap, 1973)
2.6.1 Ripening of mangoes by using chemicals
Mango fruits ripen unevenly on the tree and natural ripening can be very slow and
unpredictable. Hence, to overcome these problems certain chemicals are used to ripen the
fruits artificially. Fruits were briefly exposed to ethylene or similar gases like acetylene to
initiate the ripening process. Ethylene is known to be a plant hormone that triggers fruit
ripening. It has been reported that if ethylene is applied exogenously it helps fruit
ripening (Medlicott et al., 1988). Ethylene -treatment is usually given at the packing house
or at the point of distribution.
Ethephon is known as one of the most common ethylene-generating chemical and
postharvest treatments. Ethephon accelerates ripening and improves the peel color of the
mangoes (Lakshminarayana et al., 1975). Use of chemicals promotes the ripening
process and improves color development of the fruits. Aside from this, ethylene is an
explosive gas and is very expensive. Certain developing countries use calcium carbide as
a fruit ripening agent. Acetylene gas is generated from calcium carbide, which initiates
the ripening process. This practice is commercially used in Brazil and Senegal (Medlicott,
1986a). Acetylene is also an explosive gas and calcium carbide is more commonly used
in welding applications. It is very toxic and has disadvantages compared to ethylene.
Calcium carbide is considered as extremely hazardous sometime it contains traces of
arsenic and phosphorus hydride, which is harmful for human consumption (Delpierre,
1974). MJ -treatment reduces the CI symptoms of mangoes cv. Kent and enhances the
skin color development of the fruit (González-Aguilar et al., 2001).
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