Mango - Crop Post-Harvest: Science and Technology - page 128

in ripened mesocarp, internal cavities, and sometimes
fermented odours also (Jacobi & Wong 1992; Jacobi et al .
1995b; Miller et al . 1991; Mitcham & McDonald 1993;
Spalding et al . 1988). To reduce the heat damage to fruit,
hot air conditioning has been strongly recommended
(Jacobi et al . 1995a, 2000; Joyce & Shorter 1994).
Conditioning of 'Kensington' mangoes at 40°C for 8 hours
prior to a hot-water treatment of 47°C for 15 min was very
effective in alleviating heat-induced damage. Conditioning
temperatures of 40°C accelerated the process of ripening
and resulted in elevated sugar levels in tissue which helped
the fruit to withstand high heat stress during HWT (Jacobi
et al . 2000).
A hot-water treatment of 'Kensington' mangoes where
fruit core temperature was held for 15 min at 47°C
increased weight loss (50%), fruit softness (15%), disrupted
starch hydrolysis and reduced the skin yellowness
(40-51%) of early harvested fruit (Jacobi et al . 2001a).
Immature fruit were found to be more susceptible to
hot-water treatment-induced skin scalding, starch layer
and starch spot injuries. Thus, harvest maturity is a key
factor affecting the heat tolerance in mango. Despite appre-
ciable differences in fruit quality during heat treatments,
only minor differences in antioxidant phytochemicals were
observed in heated mangoes (Talcott et al . 2005). There is
a paucity of information on the effects of heat treatments
on nutritional and phytochemical contents in mangoes.

fruit fly ( A. serpentina ) and the Mediterranean fruit fly
( Ceratitis capitata ) in mangoes. Irradiating 'Kensington'
mangoes with a dose of 74-101 Gy resulted in disinfesta-
tion of eggs and larvae of Queensland fruit fly in Australia
(Heather et al . 1991). However, irradiation is not an
approved quarantine treatment in Australia (Heather et al .
1997). Moreover, the results of studies on efficacy of
irradiation in killing stone weevil are not consistent (Seo
et al . 1974; Shukla & Tandon 1985). According to Shukla
and Tandon (1985), 'Alphonso' mangoes could not be
disinfested of seed weevil with a dose of 500 Gy while Seo
et al . (1974) observed that irradiation doses less than
500 Gy (206 and 329 Gy) killed mango weevils in Hawaiian
mangoes. The irradiation of mangoes provides additional
benefits of extension of shelf life as discussed earlier in
this chapter.

Insecticidal controlled atmospheres (ICA)
Insecticidal controlled atmospheres (ICA) involve the
short-term exposure of a commodity to very low O 2 (<1%)
and/or very high CO 2 (50-80%) at low or high temperature
to achieve insect disinfestation (Yahia 2006). The possible
detrimental effects of ICA may include low-O 2 and/or high-
CO 2 injury along with off-flavour due to fermentation in
tissue. The application of ICA in mango for achieving
insect disinfestation against various tephritid fruit fly
species has proven successful (Ortega-Zaleta & Yahia
2000; Yahia 1993; Yahia & Hernandez 1993; Yahia et al .
1989; Yahia & Ortega-Zaleta 2000; Yahia & Vazquez-
Moreno 1993). Mango is the most suitable fruit for ICA
treatments as it is quite tolerant to high CO 2 (Yahia 2006).
'Keitt' mangoes could tolerate extreme atmospheres
containing ≤ 0.5 kPa O 2 (= 0.5%) and/or ≥ 50 kPa CO 2
(= 50%) for up to 5 days at 20°C (Yahia 1993; Yahia &
Hernandez 1993; Yahia & Vazquez-Moreno 1993). The
ICA treatments not only serve as a possible means of insect
disinfestation but also delay ripening as shown by
suppressed respiration, flesh firmness and colour develop-
ment (Yahia & Hernandez 1993; Yahia & Vazquez-Moreno
1993). On the basis of these studies, it is clear that 'Keitt'
mango is highly tolerant to ICA. Any quarantine treatment
should be completed in the shortest possible period to avoid
delay in the transportation and distribution of the fruit to
destination market. To promote the efficacy of ICA in
terms of insect mortality in a shorter period, treatment tem-
perature can be elevated to room or high temperatures
(44-45°C) (Ke & Kader 1992). Yahia & Ortega-Zaleta
(2000) reported that dry hot air at ≥ 44°C and 50% RH in
CA (0 kPa O 2 + 50 kPaCO 2 ), for 160 min or longer, is effective
in increasing in vitro mortality of eggs and third instar

Irradiation
Irradiation is an ideal technology for developing generic
quarantine treatments because it is effective against most
insect pests at dose levels that do not affect the fruit quality
(Follett 2004). Irradiation can provide quarantine security
for a broad range of pests. Hallman (1999) reported that
most of the tephritid fruit fly species which act as quaran-
tine barriers for international trade of mangoes can be
controlled by irradiation treatment with a dose ranging
between 150-250 Gy and emphasized that even lower dose
levels should be tried to avoid quality losses in fruits. The
use of irradiation of mango for quarantine purposes is
restricted to Hawaii and the US mainland. Hawaii has
become the first place in the world to use irradiation as a
quarantine treatment for fruits (Moy & Wong 2002).
Irradiation treatments have been found to be very effective
against most of the tephritid fruit fly species in mango
(Bustos et al . 1992, 2004; Heather et al . 1991; Von
Windeguth 1986). Bustos et al . (2004) recommended a
dose of 150 Gy as a generic quarantine treatment against
potential infestation of the Mexican fruit fly ( Anastrepha
ludens ), the West Indies fruit fly ( A. obliqua ), the sapote