Agriculture Reference
In-Depth Information
Table 31.1.
Physical and chemical characteristics of selected Indian jujube cultivars.
'Mundia
Murhra'
Characteristics
'Katha'
'Bagwari'
'Umran'
'Chhuhara'
'Illaichi'
'Karaka'
'Narma'
Yellow to
reddish
brown
Yellow to
reddish
brown
Yellow to
reddish
brown
Golden
yellow
Golden
yellow
Greenish
yellow
Greenish
yellow
Light
green
Appearance
Average fruit weight (g)
18.50
16.00
21.00
12.50
3.60
23.00
22.00
17.50
Pulp:stone ratio
25.00
13.30
19.60
11.30
24.80
—
16.70
12.90
Moisture (%)
74.33
77.92
77.81
76.42
73.97
86.60
88.13
79.30
Total soluble solids (
◦
B)
21.40
18.00
22.70
17.20
24.70
11.80
13.00
16.80
Acidity (%)
0.10
0.11
0.29
0.35
0.22
0.31
0.22
0.25
Reducing sugars (%)
4.54
5.94
4.38
3.72
3.91
5.88
4.00
3.70
Total sugars (%)
19.65
16.17
14.84
16.23
16.98
9.97
11.10
14.90
Source: Pareek (2001); Pareek et al. (2009).
to 100.3 mg CO
2
/kg/hr as the fruit entered the ripening
phase. Later, the rate of CO
2
production declined rapidly
as the fruit became overripe (such pattern of respiration
rates is typical of climacteric fruits). Singh et al. (1981)
observed that on average, the rate of respiration was 52.4 mg
CO
2
/kg/hr at the green stage and reached up to 127.64 mg
CO
2
/kg/hr at the red-ripe stage. The rate of respiration
among various cultivars at the red-ripe stage was found
to be 119.72 mg, 131.54 mg, 137.32 mg, and 133.33 mg
CO
2
/kg/hr in 'Umran,' 'Rashmi,' 'Kaithli,' and 'Ponda,'
respectively.
Indian jujube produces high amounts of ethylene and
shows responses to exogenous ethylene treatments as mea-
sured by changes in skin color, juice color, and compo-
sition (Pareek et al., 2009). Ethylene production was not
detected until the 12th week after anthesis. Thereafter,
ethylene production increased rapidly, reaching a maxi-
mum of 13.0
μ
l/kg/hr as the fruit entered the maturity
phase 18 weeks after anthesis and then declined rapidly.
The ethylene production rate in ripe jujube fruits is con-
sidered “high” according to the classification of Paull and
Duarte (2011).
Jujube fruit is susceptible to a number of postharvest
diseases; as during packaging, storage, and transport, fruits
may be exposed to various decay-causing microflora (Pa-
reek et al., 2009). Kainsa et al. (1978) reported that some of
the predominant organisms observed on freshly harvested
fruits were
Aspergillus niger, A. sydowii, Rhizopus oryzae,
Penicilium chrysogenum, Alternaria tenisima, Phoma
spp.,
and
Cuvrularia
spp., of which
A. niger
and
R. oryzae
caused
the greatest fruit spoilage.
Postharvest storage, treatment, and shelf life
The storage life of jujube fruits is extremely short and the
rapid perishability of the fruits is the main postharvest prob-
lem. The typical shelf life at ambient temperatures (
25
◦
C)
is 2-4 days. Due to the surplus of fruits in the local markets
during peak season, a substantial quantity goes to waste,
resulting in heavy postharvest losses (Pareek et al., 2009).
It is possible that the high rate of respiration and ethylene
production during jujube fruit ripening are responsible for
the short storage life under room temperature conditions
(Abbas, 1997).
Gupta and Mehta (1987) suggested that postharvest dip-
ping of fruits in cold water can effectively reduce respira-
tion, ethylene production, and enzymatic activities, whereas
hot water treatment controls the growth of pathogens,
thereby prolonging the shelf life and overall quality of
fruits. After harvest, dip treatments of 'Gola' jujube fruits
in cold water for 2 hours or keeping them exposed to air
for 4 hours improved their shelf life. Dipping fruits in
500 ppm thiabendazole, Captan, and Dithane M-45 im-
proved the shelf life by reducing respiration rate. Siddiqui
and Gupta (1989) reported that hot water (40
◦
C) dipping of
fruits has been reported to reduce transpiration and physi-
ological weight loss of fruits during storage. The hot water
dipping treatment may prevent surface molds from devel-
oping, resulting in a lower fruit loss due to decay.
Zhong and Xia (2007) reported that 1-methyl
cyclopropene (1-MCP) treatment in combination with chi-
tosan coating significantly improved the storage life and
quality of Indian jujube fruit at room temperature storage.
Ozone and potassium sorbate treatment has been shown to
∼
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