Agriculture Reference
In-Depth Information
promotes internal browning, and the development of fungi.
Guelfat-Reich (1970) found that storage at 0
◦
C caused
the least weight loss, withering, and internal browning.
Ogata (1950) studied the effect of high or low temperature
(23
◦
-25
◦
Cor7
◦
-10
◦
C) on fully ripe and firm fruit quality.
The results showed 65% spoilage of the fully ripe fruit at the
high temperature and 30% spoilage at the low temperature
after 11 days of storage. Morton (1987) reported that after
removal from storage, the shelf life of loquat may be only
3-4 days. Treatment with the fungicide, benomyl, makes it
possible to maintain the fruit for one month at 15
◦
C, with
minimal decay.
The low-temperature storage commonly used for loquat
fruit to inhibit decay and extend postharvest life can also
increase the incidence of chilling injury (CI) in red-fleshed
fruit. The use of 1-methylcyclopropene (1-MCP) has been
suggested to reduce the development of CI in cold-stored
loquat (Cai et al., 2006a; Cao et al., 2009, 2011). Cai et al.
(2006a) investigated the effect of 1-MCP at 0.5, 5, and
50 μl/liter on loquat fruit quality during 8 day storage at
20
◦
C; the fruit firmness was shown to improve significantly
(Table 31.4). These researchers reported that that lipoxy-
genase (LOX) and phospholipase-C (PLC) were possibly
associated with the induction of CI in loquat fruit. The 1-
MCP might reduce CI by inhibiting activities of LOX and
PLC and alleviate oxidative damage.
Cai et al. (2006b) reported that low-temperature condi-
tioning (LTC) treatment of loquat (cv. 'Luoyangqing') for
6daysat5
◦
C and then storing it at 0
◦
C can effectively al-
leviate CI damage caused by direct 0
◦
C storage. The LTC
treatment was shown to be an effective commercial low-
temperature treatment maintaining acceptable external and
internal quality of loquat fruit. In addition to other qual-
ity benefits (e.g., firmer fruit and lower browning index),
water loss was also significantly lower in LTC-treated fruit
(Fig. 31.5).
At times, calcium is exogenously applied to loquat fruit.
The use of calcium treatment (
80
1
°
C
60
5
°
C
10
°
C
40
20
C
°
20
0
1.6
1
°
C
5
°
C
1.2
10
°
C
20
C
°
0.8
0.4
0
0
10
20 30
Storage period (days)
40
50
60
Figure 31.4.
Respiration and ethylene production
rates of loquat fruit stored at different temperatures
(source: Ding et al., 1998).
shown in Fig. 31.4. It produces relatively low amounts
of ethylene and is not particularly sensitive to ethylene
exposure after harvest (Ding et al., 1998; Ding, 2004).
Recommended conditions for commercial storage, as
suggested by Ding et al. (1998), are at 0
◦
-5
◦
C with over
90% relative humidity. Loquat fruit can be kept in good
condition for 3-4 weeks at 0
◦
C and for 2 weeks at 10
◦
C.
Ding et al. (1999) reported that loquat fruit can be eas-
ily bruised and scratched, thereby resulting in the damaged
areas usually turning brown or black; therefore careful han-
dling and packaging during and after harvest are important.
Internal browning and brown surface spotting occur during
long-term or high CO
2
storage.
Use of polyethylene bags is shown to retard weight loss
and minimize decreases in organic acids (Ding et al., 1997).
However, Morton (1987) reported that cold storage of lo-
quats in polyethylene bags alters the flavor of the fruit,
1%) is helpful in main-
taining the postharvest quality of fruit by increasing cohe-
sion between cell wall subunits (Kirkby and Pilbeam, 1984;
White and Broadley, 2003; Akhtar et al., 2009; Akhtar et al.,
2010). Table 31.5 shows the effect of 1-3% CaCl
2
appli-
cation on the fruit firmness and other selected physical and
chemical quality parameters of loquat fruit (cv. 'Surkh').
The CaCl
2
treatment, in addition to improving the firm-
ness, resulted in a lower fruit weight loss during 10 weeks
of storage at 4
◦
C.
The modified atmosphere packaging (MAP), coupled
with low-temperature storage, can be used to maintain
freshness, long shelf life, and safety of the loquat (Robert
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