-
Volume 52(1):7-15, 2008Acta Biologica Szegediensis
http://www.sci.u-szeged.hu/ABS
ARTICLE
Horticulture Department, Faculty of Agriculture, Kafrelsheikh
University, Kafr El-Sheikh, Egypt, and Department of Vegetable and
Mushroom Growing, Faculty of Horticulture, Corvinus University,
Budapest, Hungary
Improvement of postharvest keeping quality of white pepper
fruits (Capsicum annuum, L.) by hydrogen peroxide treatment under
storage conditionsYousry A. Bayoumi
ABSTRACT Sweet pepper is one of the most important vegetable
crops in the world, it has excellent nutritive value but it is
susceptible to relatively fast quality changes after harvest time.
The objective of the present research was to evaluate the effect of
dipping pepper fruits in hydrogen peroxide solutions on postharvest
keeping quality during storage time. Whole pep-per fruits were
soaked for 30 min in a solutions of hydrogen peroxide (0, 1, 5 and
15 mM) then, air dried and stored at room temperature (20ºC) for 2
weeks and in fridge (10ºC) for 4 weeks. Hydrogen peroxide
treatments significantly reduced weight loss, rot rate index and
nitrate content of fruits specially with 15 mM hydrogen peroxide as
compared with control treatement (0 mM hydrogen peroxide).
Moreover, hydrogen peroxide treatments significantly increased
general appearance, ascorbic acid content and the activity of the
antioxidant enzymes such as ascorbate peroxidase and
dehydroascorbate reductase. For dry matter and TSS%, there are no
significant differences among treatments. Therefore, the use of
hydrogen peroxide in posthar-vest treatments have a good potential
strategy to improve the postharvest quality, extend shelf life
period and maintained some nutritional quality as well as inhibited
decay development of white peppers which natural infected under
storage conditions.Acta Biol Szeged 52(1):7-15 (2008)
KEY WORDS
pepper fruitshydrogen peroxidepostharvest quality
-
Materials and Methods
Figure 1. General appearance in zero time (before storage) and
affter storage time (10 and 20 days) as influenced by hydrogen
peroxide treat-ments under both room temperature (20 oC) and fridge
(10 oC) conditions. Means designed by the same letter are not
significantly difference at the 5% level according to Duncan’s
test.
a a a a
b
a aa
c
b
aa
c
b
a
a
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Gen
eral
app
eara
nce
Zero time After 10 days After 10 days After 20 days
At room temp. At fridge
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
-
Treatments
A
D
B
C
Figure 2. Effect of hydrogen peroxide treatments on the general
appearance and delaying senescence of pepper fruits. A- Fruits
after 1 week stored at 20°C, B- Fruits after 2 weeks stored at
20°C, C- Fruits after 2 weeks stored at 10°C and D- Fruits after 4
weeks stored at 10°C.
-
Initial and stored quality measurements
Statistical analysis
Results and Discussion
Effect of hydrogen peroxide treatments
General appearance
At 20 oC
a
a
a
aa
a
a
b
bb
bb
a
a
cbb
bb
a
aa
a
bb
bb
c
0
5
10
15
20
25
30
35
40
45
2 4 6 8 10 12 14
Storage time (days)
wei
gh
t lo
ss %
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
At 10 oC
aa
a
a
a
a
a
aa
a
a c
b
b
aa
a
a
b b
c
a a
a
a
c cd
0
2
4
6
8
10
12
14
16
4 8 10 16 20 24 28
Storage time (days)
Wei
gh
t lo
ss %
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
Figure 3. Weight loss of pepper fruits as influenced by hydrogen
peroxide treatments during storage time at both room temperature
(20°C, every 2 days) and fridge (10°C, every 4 days). Means
designed by the same letter (at the same storage time) are not
significantly difference at the 5% level according to Duncan’s
test.
-
Weight loss %
The rot rate index
At 20 oC a
a
a
a
b
bbb
b
bbbb bb b
0
10
20
30
40
50
4 8 12 14
Storage time (days)
Ro
t ra
te (
%)
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
At 10 oC a
a
a
a
bbba
bbb
a
bbb
a0
5
10
15
20
25
30
7 14 21 28
Storage time (days)
Ror
rate
(%
)
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
Figure 4. The role of hydrogen peroxide in reducing rot rate
index of pepper fruits during storage time under both 20°C (room
temperature) and 10°C (fridge) conditions. Means designed by the
same letter (at the same storage time) are not significantly
difference at the 5% level according to Duncan’s test.
-
Enzyme activities
Figure 5. Activities of both ascorbate peroxidase and
dehydroascorbate reductase in pepper fruits during postharvest
storage time (at the 10th day) as influenced by H2O2 treatments at
20 °C (room temperature) condition. Means designed by the same
letter are not significantly differ-ence at the 5% level according
to Duncan’s test.
Figure 6. Changes of ascorbic acid content in pepper fruits
during postharvest storage time at both room temperature (20°C) and
fridge (10°C) conditions as influenced by H2O2 treatments. Means
designed by the same letter (at the same storage time) are not
significantly difference at the 5% level according to Duncan’s
test.
c
a
ab
b
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
!M
asco
rbate
g-1
Fw
min
-1
control I mM H2O2 5 m M H2O2 15 mM H2O2
Ascorbate peroxidase activity
c
a
b
a
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
!M
DH
A g
-1 F
W m
in-1
control 1 mM H2O2 5 m M H2O2 15 mM H2O2
Dehydroascorbate reductase activity
b
aa a
b
a a a
0
20
40
60
80
100
120
140
160
180
200
Asc
orb
ic a
cid
co
nte
nt
(mg
/10
0g
fw
)
Initial time After 1week After 2 weeks
Storage time
At 20 oC
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
b
aa a
b
a a a
0
20
40
60
80
100
120
140
160
180
200
Asc
orb
ic a
cid
co
nte
nt
(mg
/10
0g
fw
)
Initial time After 1week After 2 weeks
Storage time
At 20 oC
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
-
Ascorbic acid content
Figure 7. Effect of H2O2 treatments on dry matter and TSS (%) of
pepper fruits during storage time under room temperature (20°C) and
fridge (10°C) conditions. Means designed by the same letter (at the
same storage time) are not significantly difference at the 5% level
according to Duncan’s test.
Figure 8. Effect of H2O2 treatments on nitrate content of pepper
fruits during storage time under room temperature (20°C) and fridge
(10°C) conditions. Means designed by the same letter (at the same
storage time) are not significantly difference at the 5% level
according to Duncan’s test.
a a a a
a a ab
0
1
2
3
4
5
6
7
8
Dry
mat
ter
%
Initial time After 1week After 2 weeks
Storage time
At 20 o
C
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
a a a
a
aaa
b
0
1
2
3
4
5
6
7
TS
S %
Initial time After 1week After 2 weeks
Storage time
At 20 oC
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
a
aa
a
a a aa
0
1
2
3
4
5
6
7
8
Dry
matt
er
%
Initial t ime After 2 weeks After 4 weeks
Storagetime
At 10 oC
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
a a a a
a a a a
0
1
2
3
4
5
6
7
TS
S %
Initial t ime After 2 weeks After 4 weeks
Storage time
At 10 oC
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
a
bb
c
a
ab abb
0
50
100
150
200
250
300
350
400
!it
ra
te c
on
ten
t (p
pm
)
Zero time 1 week 2 weeks
Storage time
At 20 oC
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
ab
cc
a
bb b
0
50
100
150
200
250
300
350
400
450
!it
ra
te c
on
ten
t (p
pm
)
Zero time 2 weeks 4 weeks
Storage time
At 10 oC
Cont. 1 mM H2O2 5 mM H2O2 15 mM H2O2
-
Dry matter and TSS (%)
Nitrate content (ppm)
Conclusion
Acknowledgements
References
!