Figure 4. Weight loss of mangosteen fruit treated with CPPU during storage.
Figure 5. Weight loss of mangosteen fruit treated with CoSO
4
during storage.
4.1.4. Fruit Color
4.1.4.1. Lightness
Fruit color is one of the most important appearance quality always employed by consumers when purchasing products. The darkening of mangosteen
fruit drastically increased from day 0 to day 4, and was constant from day 4 to day 16. The darkening was reaccelerated from day 18 in either fruit treated with CPPU
2 4
6 8
10 12
2 4
8 10
12 14
16 22
26 30
W eigh
t loss
Storage time days
0 ppm 10 ppm
20 ppm 30 ppm
2 4
6 8
10 12
2 4
8 10
12 14
16 22
26 30
W eigh
t loss
Storage time days
0 ppm 500 ppm
1000 ppm 2000 pmm
and CoSO
4
Figure 6, 7. Lightness of mangosteen fruit reduced darkening increased from 42 to 33 around 9 during storage time from day 0 to day 30.
CPPU 20 ppm could most effectively delay darkening of the fruit and significantly varied from other concentrations as shown in day 4 and day 6
Appendix table 4.
Figure 6. Changes in skin lightness of mangosteen fruit treated with CPPU during storage.
Figure 7. Changes in skin lightness of mangosteen fruit treated with CoSO
4
during storage.
5 10
15 20
25 30
35 40
45 50
4 8
10 12
14 16
18 24
30
S k
in c
olor L
Storage time days
0 ppm 10 ppm
20 ppm 30 ppm
5 10
15 20
25 30
35 40
45 50
4 8
10 12
14 16
18 24
30
S k
in c
olor L
Storage time days
0 ppm 500 ppm
1000 ppm 2000 ppm
4.1.4.2. ab Ratio
a b ratio in mangosteen fruit was increased from day 0 to day 4 and decreased considerably up to d30 in either fruit treated with CPPU and CoSO
4
Figure 8, 9. The increased ab was due to accumulation of red pigments in mangosteen during storage and was strongly associated with stage of fruit
ripening. Research on colour development of mangosteen fruit conducted by Palapol et al. 2009 illustrated that ab ratio of mangosteen fruit increased sharply
from stage one to stage six when stored at 25
o
C. The Increase was positively correlated with anthocyanin production in mangosteen fruit. As shown in the
appendix table 7 neither CPPU nor CoSO
4
had significant effect on ab ratio of mangosteen fruit over the storage time.
Figure 8. Changes in skin color ab of mangosteen fruit treated with CPPU during storage.
Figure 9. Changes in skin color ab of mangosteen fruit treated with CoSO
4
during storage. 0,0
0,1 0,2
0,3 0,4
0,5 0,6
0,7 0,8
0,9 1,0
4 8
10 12
14 16
18 24
30
S k
in c
olor ab
Storage time days
0 ppm 500 ppm
1000 ppm 2000 ppm
0,0 0,2
0,4 0,6
0,8 1,0
4 8
10 12
14 16
18 24
30
S k
in c
olor ab
Storage time days
0 ppm 10 ppm
20 ppm 30 ppm
4.1.4.3.Hue angle h
o
Hue value of fruit skin decreased from day 0 to day 4 and started increasing up to day 30. The trend of hue angle indicated that fruit underwent its
color development to be redder or more purplish during early days of storage, and began to gradually turn yellow due to anthocyanin degradation over prolonged
storage Figure 10, 11. Application of CPPU and CoSO
4
did not show any effect on ab ratio and hue angle of mangosteen fruit during storage period.
Figure 10. Changes in skin color h
o
of mangosteen fruit treated with CPPU during storage.
Figure 11. Changes in skin color h
o
of mangosteen fruit treated with CoSO
4
during storage. 10
20 30
40 50
60 70
80
4 8
10 12
14 16
18 24
30
S k
in c
olor h°
Storage time days
0 ppm 10 ppm
20 ppm 30 ppm
10 20
30 40
50 60
70 80
4 8
10 12
14 16
18 24
30
S k
in c
olor h
o
Storage time days
0 ppm 500 ppm
1000 ppm 2000 ppm
4.1.5. Sepal color
