Agriculture Reference
In-Depth Information
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Alphonso
Banganapalli
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Storage period (days)
Figure 14.2. Respiration rate of 'Alphonso' and 'Banganapalli' mangoes during 25 days storage at 13 C
('Alphonso' recorded climacteric peak on 18th day compared to 'Banganapalli' on 21st) (source: Rao and Rao,
2008).
POSTHARVEST PHYSIOLOGY
Harvesting fruit at stages beyond mature green (MG) will
reduce their shelf stability and shorten their fresh market
life. Kalra et al. (1995) reported that mature ripe man-
goes perished within 6 days under ambient conditions. The
rate of respiration and ripening, development of pigments,
flavor compounds, polyphenolics, sugars, fruit quality, and
postharvest diseases are all affected by handling procedures
following harvest (Roy and Joshi, 1989; Narayana, 1989;
Medlicott et al., 1990; Lizada, 1991; Baldwin et al., 1999).
During ripening, starch is hydrolyzed by amylase and
converted to sugars. Meanwhile, cell wall carbohydrates
(pectin and hemicellulose) are enzymatically hydrolyzed
causing textural softening of mango pulp. Polygalactur-
onase (PG) and β -D-galacturonase are commonly regarded
as being responsible for tissue softening, as enzyme lev-
els increase simultaneously with pectin depolymerization
(Muda et al., 1995).
Organic acids are crucial to the ripening of mango as they
are primary respiratory substrates over glucose. Though
several organic acids have been identified in mango, only
citrate, malate, and succinate serve as respiration substrates.
The highest respiration rate in ripening mango fruit occurs
at the climacteric stage, paralleling the sigmoidal ethylene
production pattern. Once the fruits have fully ripened, they
begin the senescence process with respiration rates reaching
their lowest levels while ethylene production drop to unde-
tectable levels (McCollum et al., 1993; Ketsa et al., 1999).
Carotenoids are responsible for the attractive skin and
flesh color of ripe mangoes and may be used as a vi-
sual indicator of fruit maturity and ripeness as pigments
shift from green to yellows and oranges. As a result, total
carotenoids in mango flesh have been reported to increase
from 12.3 to 38.0 μ g/g in 'Keitt' and 17.0 to 51.2 μ g/g in
'Tommy Atkins.' Development of carotenoids provide ripe
Mango ripening
Mango is a climacteric fruit that is harvested at a physio-
logically MG stage and allowed to ripen for fresh market.
The ripening of mango fruit involves many chemical and
physiological changes as the climacteric peak of respira-
tion is reached. Unripe fruits are characterized by their hard
texture, high starch content, low carotenoids, high organic
acid concentrations and subsequent low pH. The mango
cultivar 'Alphonso' had higher respiration rate than 'Ban-
ganapalli' throughout storage at 13 C. 'Alphonso' recorded
higher climacteric peak at 712.7 nmol/kg/sec on the 18th
day compared to 'Banganapalli' cultivar, which had a sig-
nificantly lower respiratory peak at 312.9 nmol/kg/sec on
the 21st day (Figs. 14.2 and 14.3).
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