Mango - Crop Post-Harvest: Science and Technology - page 123

and disruption of cellular and subcellular structures,
leading to uneven ripening and poor fruit quality (Chaplin
et al . 1991; Chhatpar et al . 1971; Han et al . 2006; Lederman
et al . 1997; McCollum et al . 1993; Medlicott et al . 1990b;
Nair et al . 2003, 2004a, 2004b; Phakawatmongkol et al .
2004; Zauberman et al . 1988; Zhao et al . 2006). The cell
wall components and cuticle structure of mango are
adversely affected by chilling injury (Han et al . 2006;
Ketsa et al . 1999b). The texture of chill injured mango fruit
remained firm which was mainly due to the inhibitory
effect of chilling on the activities of polygalacturonase and
β-galactosidase (Ketsa et al . 1999b). The cell wall contents
of chilled fruit contained less water-soluble pectin, more
ammonium oxalate-soluble pectin and less alkali-soluble
pectin than nonchilled fruit (Ketsa et al . 1999b).
The treatment of mango with methyl salicylate (0.1mM)
prior to storage at 5°C for 35 days resulted in a decrease in
the incidence and severity of CI by positive modulation of
the cell wall components and ultrastructural changes in the
cuticular waxes (Han et al . 2006). CI adversely affected the
activities of ACC synthase and ACC oxidase leading
to reduced ethylene biosynthesis in fruit resulting in failure
to ripen (Nair et al . 2004b). Exogenous application of
ethrel prior to storage alleviated the chilling injury devel-
opment in 'Kensington' mangoes at 5°C for 28 days (Nair
& Singh 2003) which suggested that reduced ethylene
biosynthesis was associated with CI development.
Polyamines also play an important role in chilling stress
tolerance in mango (Malik & Singh 2005; Malik et al .
2003; Nair et al . 2004a). CI promoted the accumulation of
putrescine in mango peel and reduced the levels of
spermidine and spermine in skin and pulp of fruit (Nair
et al . 2004a). To replenish the depleted spermidine and
spermine contents in mango fruit during chilling, the pre-
storage exogenous application of spermine (0.50 mM) was
found to be the most effective method to impart chilling
tolerance in mango (Nair et al . 2004a). The role of methyl
jasmonate (MJ) in preventing CI in mango has also been
documented (Gonzalez-Aguilar et al . 2000, 2001; Kondo
et al . 2005). Exposure of 'Tommy Atkins' mangoes to
methyl jasmonate (MJ) vapours (10 −4 M) for 24 h at 25°C
reduced chilling injury during subsequent storage for 21
days at 7°C and after 5 days of shelf life at 20°C. The
chilling tolerance induced by MJ was positively correlated
with the reduction in electrolyte leakage of fruit tissue and
with improvement in fruit quality in terms of colour and
total soluble solids (Gonzalez-Aguilar et al . 2000, 2001).
The treatment of 'Choke Anan' mangoes with n-propyl
dihydrojasmonate (PDJ) solution at a concentration of
0.39 mM for 15 min reduced and delayed the CI

development during subsequent storage at 6°C (Kondo
et al . 2005). CA/MA has also been found helpful in
alleviation of CI in mango (O'Hare & Prasad 1993; Pesis
et al . 2000, 1997). CA at 5-10% CO 2 alleviated chilling
symptoms in 'Kensington' mangoes stored at <10°C, but
higher concentrations of CO 2 were injurious (O'Hare &
Prasad 1993). Short treatments of 'Tommy Atkins' fruit
with low O 2 induced higher CO 2 levels and were effective
in reduction of CI symptoms at 5°C (Pesis et al . 1997). A
modified atmosphere (~5% CO 2 and ~10% O 2 ) created by
microperforated polyethylene (PE) or Xtend ® film (XF) or
in CA chambers, alleviated CI in mango during storage at
12°C for three weeks plus 1 week at 20°C (Pesis et al .
2000). Coating of mangoes with carnauba natural wax
(0.1%) was found to be effective in preventing the develop-
ment of CI in 'Kensington' mangoes stored at 5°C for 28
days (Nair 2002). Individual shrink film wrapping of
'Banganpalli' and 'Alphonso' mangoes using Cryovac ®
films alleviated the CI symptoms during storage at 8°C for
one month followed by normal ripening under ambient
conditions (Sudhakar Rao & Shivashankara 2004). The use
of low temperature conditioning for alleviating chilling
injury has recently been studied as an alternative to other
approaches (Zhao et al . 2006). The low temperature condi-
tioning of 'Wacheng' mangoes at 0°C for 4 hours followed
by storage at 2°C for 12 days showed that CI index was
lower in fruit subjected to cold-shock than control. The
cold-shock treatment invigorated the antioxidant defence
mechanism of fruit as evidenced by the increased activities
of catalase, ascorbate peroxidase and higher contents of
glutathione and phenolic compounds during storage. The
reduced levels of malondialdehyde and ion leakage indi-
cated better membrane integrity in conditioned fruit (Zhao
et al . 2006). Therefore, CI in mango is possibly an oxida-
tive stress phenomenon and can be related to the failure of
antioxidant defence machinery. Pre-conditioning of
'Tommy Atkins' and 'Keitt' mangoes by decreasing the
temperature from 20°C to 17°C or 14°C for two days facil-
itated their safe storage at 9°C for three weeks (Pesis et al .
1997). Pre-storage heat treatment also inhibits the develop-
ment of CI symptoms during storage. Hot-water treatment
(HWT) at 55°C for 3 or 5 min induced chilling tolerance in
mangoes. At least 12 h of hot-air treatment (HAT) at 38°C
was needed to achieve similar results (Zhu et al . 2003).
'Keitt' mangoes kept at 38°C for 24 or 48 hours before
storage at 5°C for 11 days showed less CI symptoms upon
transfer to 21°C for 9 days (McCollum et al . 1993). Pre-
storage heating also reduced the respiration and ethylene
production rates without adverse effects on firmness. As
discussed above, there is a plethora of strategies that can be