Figure 23. Changes in TSSTA of mangosteen fruit treated with CoSO
4
during storage. Table 5. Effects of CPPU and CoSO
4
interaction on TSSTA ratio of mangosteen fruit during storage at d18
CPPU ppm CoSO₄ ppm
500 1000
2000 26.89
ab
27.98
a
22.57
bc
20.47
c
10 21.62
c
22.49
bc
21.31
c
23.58
abc
20 22.96
bc
22.91
bc
23.63
abc
22.85
bc
30 19.78
c
23.92
abc
23.90
abc
22.80
bc
Note: Different letters indicate significant differences among treatment means P 0.05
by Duncan‟s multiple range test DMRT.
Experiment two: Physiological Changes and Colour Development of Mangosteen Fruit Treated with CPPU and CoSO
4
during Storage
4.3. Physiological Changes and its Relation to Color Development
4.3.1. Respiration Rate of Mangosteen Fruit
Respiration rate of mangosteen was very fluctuant during storage at hour 3 to hour 60 Figure 24. The fluctuation was because of the adaptation of
mangosteen fruit to microclimate during early storage. After adaptation, the respiration remained constant from h72. The respiration was highest at hour 3
5 10
15 20
25 30
4 8
10 12
14 16
18 24
30
T S
S T
A
Storage time days
0 ppm 500 ppm
1000 ppm 2000 ppm
when measured at the first three hours of storage after treatment. The peak may not represent climacteric peak, but indicated early adaptation of fruit from room
temperature, where treatments were applied, to cold storage at15
o
C. CPPU and CoSO
4
showed similar effect which could reduce respiration by 37, while the combination of two substances could reduce only 28 compared to control
Appendix table 17. As shown in Table 6, there were significant interactions between CPPU and CoSO
4
at hour 300, 372, 492, 516, 540, 564, and 588. CPPU 30 ppm had the same effect to inhibit respiration as CoSO
4
2000 ppm and significantly different from control and the combination of the two substances at
hour 300, 372 and 492. However, CPPU andor CoSO
4
were similarly effective and statistically significant from control at hour 516, 540, 564, and 588 Table 6.
Mangosteen fruit is a climacteric fruit which shows the characteristic changes after harvesting. Kader 2003 recommended that the fruit produced CO
2
at the rate of 6-10 mlkgh at 20
o
C could maintain postharvest quality. The amount of CO
2
recommended was similar to that found in our experiment. Although mangosteen fruit is generally grouped as climacteric fruit, many researches
including our research did not find a clear climacteric pattern when fruit were stored at 15
o
C.
Figure 24. Respiration rate of mangosteen fruit treated with CPPU and CoSO
4
during storage. Hour 0 was the measurement before treatment.
5 10
15 20
25 30
35
0 3 6 9 11 14 16 24
30 36 42 48 60 72 84 108 132 156 180 204 228 252 276 300 324 348 372 396 420 444 468 492 516 540 564 588 612 636 660
R es
pir at
ion rat
e C
O
2
ml kg
−1
h
−1
Storage time hours
0 ppm 0 ppm 30 ppm 0 ppm
0 ppm 2000 ppm 30 ppm 2000 ppm
Table 6. Effects of CPPU and CoSO
4
interaction on respiration rate of mangosteen fruit during storage
CPPUCoSO
4
Storage time hours 300
372 492
516 540
564 588
0,0 9.11a
9.45
a
10.65
a
12.53
a
14.09
a
15.86
a
14.89
a
0,2000 6.48
b
8.00
b
6.85
b
7.34
b
6.83
b
8.46
b
8.23
b
30,0 5.69
b
7.97
b
6.60
b
8.23
b
7.52
b
8.78
b
8.42
b
30,2000 8.64
a
9.31
a
9.49
a
8.62
b
7.30
b
8.18
b
7.34
b
Note: Different letters in the same column indicate significant differences among treatment means P 0.05
by Duncan‟s multiple range test DMRT. Day 0 means the measurement before treatment application.
4.3.2. Ethylene Production of Mangosteen Fruit
