Mango - Crop Post-Harvest: Science and Technology - page 117

period of two weeks followed by a period in the wholesale
and retail markets at different temperatures (Mohammed &
Brecht 2002). However, in some cases, for example during
export from Australia to Europe, the transit period may be
as long as 4-6 weeks. Therefore, storage at low tempera-
ture becomes imperative to prolong its green life followed
by ripening to provide consumers with the best quality
fruit. Mango, being a fruit crop of tropical origin, is highly
sensitive to chilling temperatures (Medlicott et al . 1990b;
Nair 2002; Nair et al . 2003, 2004a, 2004b; O'Hare &
Prasad 1993; Pesis et al . 1997). A wide range of storage
temperatures has been described in various investigations
on the storage of mango, but the most common safe storage
temperature for mango is 12-13°C for 2-3 weeks storage
(Kader 1992; Kalra & Tandon 1983; Malik & Singh 2005;
Medlicott et al . 1990b; Mohammed & Brecht 2002;
Thomas & Oke 1983). The predominant factors affecting
storage of mango include genotype (Farooqui et al . 1985),
developmental stage, and season of harvest (Medlicott
et al . 1988, 1990b; Seymour et al . 1990). 'Tommy Atkins'
and 'Keitt' can be stored for three weeks at 13°C (Medlicott
et al . 1990b). Other varieties such as 'Alphonso'(Thomas
& Oke 1983), 'Kensington Pride' (O'Hare & Prasad 1993),
'Kent' (Veloz et al . 1977) and 'Samar Bahisht' (Farooqui
et al . 1985) can also be stored at 13°C up to about three
weeks. The ripe fruit can tolerate lower temperatures while
mature green unripe fruit are generally more sensitive to
chilling conditions (Cheema et al . 1950). Tree-ripe 'Keitt'
and 'Tommy Atkins' mangoes can be stored for two weeks
at 5°C without chilling injury development followed by
five days at 20°C (Bender 1996; Bender et al . 2000a).
According to Medlicott et al . (1990b), fruit from mid- and
late harvest stored better at 10°C than 12°C with no
apparent signs of chilling injury. Certain pre-storage
treatments such as ethrel dip (Nair & Singh 2003), low-
temperature preconditioning (Pesis et al . 1997; Thomas &
Oke 1983), hot air (McCollum et al . 1993; Pesis et al .
1997), hot-water treatment (Jacobi & Wong 1992), ethanol
vapours and low oxygen (Pesis et al . 1997) can positively
modulate the response of mango to chilling storage
temperatures. Pre-conditioning of 'Tommy Atkins' and
'Keitt' mangoes by decreasing the temperature from 20°C
to 17°C or 14°C for two days facilitated their safe storage
at 9°C for three weeks (Pesis et al . 1997). However, low-
temperature storage for 2-3 weeks is not sufficient to
achieve the supply chain goals in mango and, therefore,
needs further extension using other strategies.
Storage temperature and duration have great influence
on the sensory and nutritional quality of ripe mangoes. Aroma,
an integral component of flavour, influences the consumer

acceptability of mango. Storage at low temperature (5-15°C)
resulted in significant reduction of total aroma volatile
compounds in 'Kensington Pride' mango (Nair et al . 2003).
The storage of mature green or tree-ripe 'Irwin' mangoes at
5°C for 20 or 30 days, respectively, led to the development
of off-flavours in pulp due to presence of aldehydes
(Shivashankara et al . 2006). Development of typical aroma
and flavour of 'Alphonso' mangoes stored for 14 days at
<20°C was suppressed during ripening (Thomas 1975),
whilst, ripe chill-injured 'Alphonso' mangoes after 30 days
at 10°C had poor flavour and carotenoid development
(Thomas & Oke 1983). Thus, cold storage of mango at safe
temperature is indispensable to assure the acceptable fla-
vour and nutritional quality of fruit.

Controlled atmosphere (CA) storage
The international trade of fresh mangoes is limited due to
its highly perishable nature and susceptibility to chilling
injury when stored below 13°C. Low temperature storage
of mango at 12-13°C is successful only for 2-3 weeks
accompanied by substantial losses of fruit quality.
Controlled atmosphere (CA) in combination with an
optimum storage temperature has been reported to prolong
the shelf life and maintain fruit quality in mango. However,
the application of CA for mango is limited on a commer-
cial scale. There are several serious issues related to CA
induced physiological and biochemical changes which
adversely affect fruit quality. The research on CA storage
of mango began about seven decades ago when Singh et al .
(1937) reported that mango can be stored in CA containing
9.2% O 2 to prolong their ripening period. Various research-
ers have tried to optimise CA conditions for different
cultivars of the world (Table 6.5). The CA requirements of
mangoes vary among cultivars and also depend upon the
harvest maturity. A slight variation in CA from its optimum
may result into the development of poor flavour quality of
mango. A very low O 2 and/or high CO 2 shift the equilibrium
from aerobic to anaerobic metabolism. Respiratory
quotient (RQ) and ethanol concentration can serve as good
indicators of anaerobic metabolism. A linear relationship
exists between RQ and ethanol content (Beaudry et al .
1993). The tolerance of mango to a low O 2 and/or a high
CO 2 level has been evaluated (Bender et al . 1994, 2000b;
Lalel et al . 2005; Yahia and Hernandez 1993; Yahia et al .
1989). Mango is tolerant to high CO 2 concentrations for a
short period (Yahia & Hernandez 1993; Yahia et al . 1989)
which warrant the use of high CO 2 for insect disinfestation
purposes. Mature-green New World mango cultivars can
tolerate 25% CO 2 for 3 weeks at 12°C (Bender et al . 1994).
Atmospheres with CO 2 concentrations higher than 25%