Food Sci. Tec'hno!. Res., 10 (2), 152-156, 2004
DPPH Radical-Scavenging Activity and Poly phenol Content in Dried Fruits
I '2*
K. ISHIWATA,1 T. YAMAGUCHl,2 H. TAKAMURA2,3 andMATOBA
T.
IGraduate School of Human Culture, 2Department of Food Science and Nutrition, and 3KYOUSEI Science Cente/~for
Lrf~ and Nature, Nara
Women's Unive,'.,ity. Kitauoya-Nishimachi, Na,1a, 630-8506 .lapan
Received August 26, 2003; Accepted January 20, 2004
The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and polyphenol content of 25 dried
fruits were evaluated and compared with fresh fruits. The contribution of ascorbic acid to this activity was also
determined. All dried fruits contained DPPH radical-scavenging activity with hawthorn, apricot and blueberry
having the highest. Other dried fruits containing rind also had high activity. The DPPH radical-scavenging activity
and polyphenol content of dried fruits were highly correlated.
Keywords: dried fruits, fresh fruits, ascorbic acid, polyphenol, radical-scavenging activity
Recently it has become evident that free radicals and reactive
Reagents DPPH, L-ascorbic acid, tris(hydroxyrne-
oxygen species injure DNA and biological membrane, and con-
thyl)aminomethane (Tris), 2,4-dinitrophenylhydrazine, acetoni-
sequently induce cancers, aging and life-style related diseases.
Free radical-scavenging activities are detected in various kinds
trile (HPLC grade) and Folin-Ciocalteu reagent solution were
obtained from Nacalai Tesque Inc. (Kyoto). Ethanol and meth-
of foods (Arai et a/., 200 1 ; Wang and Lin, 2000; Hirota et a/.,
anol (HPLC grade) were obtained from Wako Pure Chemical
2000) and the results of clinical applications have been reported
Industries (Osaka). The water used in this experiment was puri-
(Hibatallah et al., 1 999). In addition, the changes of free radi-
fied with Milli-Q Labo equipment (Millipore Japan, Tokyo).
cal-scavenging ingredients during processing and cooking of
vegetables have also become evident (Crozier et a/., 1997;
P/'eparation of mate/'ials Dried fruits from the market
were cut into small pieces, smashed in liquid nitrogen and
Yamaguchi et a/., 200 1). Therefore, it is anticipated that intake
freeze-dried (Vinson et al., 1998). We used those freeze-dried
of these radical-scavenging ingredients in the daily diet can
fruit powders throughout this work.
prevent cancers, aging and lif~e-style related diseases.
Measurement of DPPH /'adica/-scavenging ac'tivities
Dried fruit powder was first extracted twice by ethanol, and
then the residue was extracted twice by water. Before determination, extracts were filtered through a Cosmonice filter-W
Processed foods, and alcoholic and non-alcoholic beverages
with added functional ingredients have been increasing on the
market, and the production and consumption of these functional foods and beverages are also increasing (Chandan,
(0.45 um, 25 mm i.d.). Measurement of DPPH radical-scav-
1999). There are many reports of the functional ingredients in
enging activities was carried out using the DPPH-HPLC
vegetables and fruits. We previously reported the functional
ingredients of alcoholic and non-alcoholic beverages (Ishiwata
method (Yamaguchi et a/., 1998). The HPLC analysis was car-
et a/., 2000, 200la, b).
Tosoh, Tokyo) equipped with a Hitachi L-7420 UV-VIS detector at room temperature. The mobile phase was methanol/water
Since fresh fruits are rich in radical-scavenging compounds,
ried out on a TSK gel Octyl-80Ts column (4.6Xl50 mm,
dried fruits are also expected to be good sources of these com-
(70 : 30, v/v) and the flow rate was I ml/min. Detection wave-
pounds. However, these compounds may be decomposed dur-
length was 5 17 nm.
Ing drying. Therefore, radical-scavenging compounds in dried
fruits have to be determined in order to determine the food
The radical-scavenging activities of ethanol and water
extracts were determined separately and summation of the
function of these fruits.
activities in the two extracts was used. A blank was run without
In this paper, we evaluated I , 1-diphenyl-2-picrylhydrazyl
(DPPH) radical-scavenging activity of various dried fruits as
well as ascorbic acid and polyphenol contents, and compared
them to those of fresh fruits.
Materials and Methods
Mate/'ials Dried fruits were purchased from local markets in Nara and Yokohama, Japan. Water content of each dried
fruit was determined by drying method at 1 10'C.
sample, and Trolox was used as the positive control. Radicalscavenging activity was expressed as ascorbic acid equivalent.
Measu/~ement ofascol~bic acid Dried fruits were extract-
ed by 5% metaphosphoric acid with or without I % stannous
chloride to deteamine [dehydroascorbic acid+diketogulonic
acid] or Lascorbic acid+dehydroascorbic acid+diketogulonic
acidj, respectively. Ascorbic acid was measured by HPLC
according to Kishida et a/. ( 1992). HPLC analysis was carried
out on a Cosmosil C 1 8-AR-II column (4.6x250 nm. Nacalai
Tesque) with a Hitachi L-7420 UV-VIS detector at room temperature. The mobile phase was acetonitrile/water (50 : 50, v/v)
*TO whom correspondence should be addressed.
E-mail : matoba@ cc.nara-wu.ac.jp
adjusted at pH 3.5 with 0.1% triethylamine and phosphoric
153
Radical-Scavenging Activlty in Dried Fruits
Table 1. Radical scavengmg actrvlty of dned and fresh frurts
Fruit
Apple
Apricot
B anana
Cherry
D-rf
China
875 t 28' >
O. 1
F - r!)
Japan
4,754i69
O. l
China
3_ ,846lt96
Japan
29,4 1 3 It 1 72
0.0
O.O
0,0
0.0
0.0
D+rt'
F+rf)
Grape
Hawthom
Ju jube
Kiwlfruit
Mango
Melon
Papaya
Pe ac h
Pear
547t20
p+r
D+r
China
l ,OIOi3_ 3
O.7
3_O
USA
USA
6,_529 i 3_ _3
O. 1
78
3_ ,079 It 22
O. l
1,087lt I l
O. 1
31
21
D+r
D+r
D+r
F+r
Turkey
Japan
D+r
USA
Prune
Rakanka
Strawberry
2,869t49
l .8
l 6,724 t 80
77
32
87
79
2,524lt_37
l ,346 t25
O. l
O, l
14
F+r
Japan
2,883_ i27
O. l
79
D+r
D+r
D-r
China
China
China
5,439t68
31
2~57t7
0.2
0.0
0.3
NZ")
Japan
Thailand
2,049 t 3_ 4
3.-5
25
84
1 89t 16
0,0
22
456 It 24
l .6
_31
F-r
PH
6,84 1 It92
D-r
D-r
China
Japan
China
P-r
J apan
Dr
F-r
PH
PH
5.2
87
D=r
China
l ,442t 1 6
O, 1
39
F-r
Japan
l ,949 t 88
D-r
China
Japan
Taiwan
Taiwan
D+r
D-r
F-r
Pineapple
lO
295 It 1 8
F-r
Muscat
19
88
PH
USA
USA
F-r
Kumquat
34
84
PH,*)
D-r
F+r
Cranberry
Fig
AsA<'] contribution (o/c) Water content (olo)
Country
F-r
B Iueberry
Radical-scavenging activity
(mg ASA eq/1 OO g dry weight)
Status
D-r
Fr
F+r
USA
USA
D+r
D-r
China
China
D+r
2,649 t 1 9
_30
1 .2
84
0.9
20
2, 1 95 t 83
2,~3
87
l,106i6
O. 1
19
l ,374t 1 2
O, l
79
27
440~t 14
1 .3
32~5 t 6
950t4_3
0,7
91
1,3_ Ol t6
O. l
~34
l ,748 t 66
0.3
0.3
89
1.l
79
40
79
321 i3
798i38
3 ,213_ i 123
0.0
0.0
0.0
l ,997 i 62
O. l
3, 1 12t85
1 0,90 1 i 94
*33
9
26
")ASA contribution, ascorbic acid content/radical-scavenging activity>< 100% b)D-r, Dried fruits without rind. ' ) Data were meanstSD of three
determlnauons. '!) F-r, fresh fruits without rind. ") D+r, dried fruits with rind. f) F+r, fresh fruits with rind. ,~) pH, Philippines. h) NZ. New Zealand.
acid at the flow rate of I ml/min. Detection wavelength was at
ever, dried fruits generally contained higher activity than fresh
505 nm. Ascorbic acid content was calculated by subtraction
of [dehydroascorbic acid+diketogulonic acidl from [ascorbic
fruits. These results suggest that the dried fruits, especially
acid + dehydroascorbic acid + diketogulonic acidj .
ity.
Measurement (if Po!yphenol c'ontent Dried fruits were
extracted by 80% methanol. Measurement of polyphenol con-
those with rind, are a good source of radical-scavenging activRadic'a/-scavenging activity in /~ind and pulp of .files/7
tent was carried out according to Singleton and Rossi ( 1965)
f,•uits
Since high radical-scavenging activ
dried fruits with rind, the activity in rind and pulp of fresh fruits
and Kahkonen et a/. ( 1999) using Folin-Ciocalteu reagent solu-
was determined (Table 2). In all fruits except apricot, the activ-
tion .
ity of rind was higher than that of pulp. However, fresh fruits
Results and Discussion
rind are suitable for efficient intake of radical-scavenging activ-
are usually eaten without the rind. Therefore, dried fruits with
Radica/-scavenging activities oj' d/'ied and fresh f7-uits
DPPH radical-scavenging activity of 22 kinds of dried fruits
ity.
Leong & Shui (2002) reported that the contribution of ascor-
and 1 6 kinds of fresh fruits corresponding to the dried fruits are
bic acid to radical-scavenging activity in fresh fruits was higher
shown in Table I . Among dried fruits, hawthorn contained the
than our results. This may be due to the difference in the meth-
highest radical-scavenging activity. Dried fruits with rind such
ods used, as previously reported by Murakami et a[, (2002).
They determined 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activity, while we used
as apricot, cranberry, prune, and rakanka also contained high
activity. However, the contribution of ascorbic acid was negligi-
ble in dried fruits, which suggests that the radical-scavenging
activity may originate from other active compounds such as
polyphenols. Table I also shows that the radical-scavenging
DPPH radical .
Polyphenol c'ontent o,f d/-ied and,fresh fr'uits Polyphenol
activity of dried fruits was lower than that of the corresponding
content of dried and fresh fruits is shown in Table 3. Among
dried fruits, hawthorn contained the largest amount of total
fresh fruits on a dry weight basis. On a fresh weight basis, how-
polyphenols, followed by blueberry, grape, and apricot. In addi-
K. IsHIWATA et a/.
l 54
Table 2. Radical scavengmg actrvrty of pulp and nnd of fresh frults
Radical-scavenging activity
AsA") contribution (olc)
Water content (olc)
Country
Part
J ap an
rind
O. 1
71
Japan
pulp
4,75~5 t 69
O, l
Apricot
J apan
rmd
9,006t68
O, 1
pulp
20,_5 1 6i I _35
B anana
Japan
PH'
84
87
88
O, l
70
PH
pulp
547 It 20
O, l
Japan
Japan
Japan
rind
3_ ,420t I OO
O. 1
77
75
2,524i37
O, 1
79
0,0
77
J apan
pulp
1,283 t57
O. 1
81
NZ'~
rind
16,459t 13_ 4
0,2
65
NZ
pulp
2,049 t 34
3,.5
0,0
0,6
84
75
Pruit
Apple
Fig
Grape
Kiwifruit
(mg ASA eq/lOO g dry weight)
l 7,0 1 O t 84"'
O,O
l ,099i I l
nnd
pulp
l I , 1 26t42
rind
Mango
PH
PH
nnd
24,802t78
pulp
6,84 1 i92
Muscat
Japan
Japan
rind
3,458i80
O, l
80
pulp
1 ,374 It 62
O, 1
81
PH
PH
rind
4,0_56i77
0,7
5,2
82
Peach
J ap an
rind
8 ,460 t 67
O, l
76
Japan
Japan
pulp
1 ,949 It 88
nnd
2,4 16lt 17
J ap an
pulp
l ,748 It 66
USA
USA
nnd
4,906 t 80
0.7
0,2
0.3
O,O
91
Pe ar
pulp
l ,375 i 6
Papaya
Prune
") ASA contribution, ascorbic acid
p]nes. '!' NZ, New Zealand.
950t42
pulp
content/radical-scavenging
actrvrty X I OO%, h) Data
87
74
79
70
84
O, l
were meanstSD of three determinations.
' ) PH,
Philip-
Table 3. Polyphenol content of dried and fresh fruits.
Fruit
Apple
Apricot
Banana
Blueberry
Cherry
Status
Hawthorn
Kiwifruit
Kumquat
Mango
F - rf)
J ap an
2,256i 1 3
3 ,062lt25
Dr
F-r
PH,*>
413t3
PH
804 t 5
D+r
F+r
USA
USA
D+r
China
828lt7
226i 14
27 , ~3
USA
USA
l ,O17t28
265 i 5 l
26. l
1,819t8
3 32t6
D+r
D+r
D+r
D+r
D+r
D-r
18.2
361 t3
21.3
USA
2,414+7
3_54lt5
14.7
Japan
China
3,202lt_50
3,563+ 1 1
939t I l
29.3
l,13_8t5
China
China
1,152+4
3 50t4
758+6
276+4
676+ I _5
NZ" '
930+ 1 1
Japan
Thailand
530+4
885+9
Japan
China
F-r
Japan
Papaya
D-r
F-r
PH
PH
Peach
D-r
China
Strawberry
6.-5
66.6
l ,699 t 24
D+r
D-r
F-r
J apan
D-r
China
F-r
Japan
D-r
Taiwan
Taiwan
F+r
USA
USA
D+r
D-r
China
China
D+r
185i2
2,390t 1 4
6. 1
30.3
l 1.0
F-r
F-r
244 t 3
76. l
136t 1 6
D-r
Rakanka
3_ ,590t3 l
25 It O
l ,234i4 1
F-r
Prune
2,83_ 2lt4
2,3 30t52
2 1 .7
Turkey
Japan
D-r
Pineapple
28, 1
2,168t38
China
China
Pear
63_ 4lt 1 2
Japan
D + r'
PH
Muscat
l I .3
China
F-r
Melon
(%)
103t 1
470 t 28
F-f !)
F+r
J u jube
Aglycons
(mg GAE/lOO g dry weight)
916lt7')
F+r
Grape
Total polyphenols
(mg GAE"yIOO g dry weight)
D-rl')
F+r
Cranberry
Pig
Country
") GAE, gallic acid equivalent. !'i D-r, dried fruits without rind.
fruits with rind. r,F+r, fresh fruits with rind. ,*) PH. Philippines
1 ,448 + 9 l
55_5+8
l ,042 t 1 7
l,161+43
l ,558 i24
389+2
510+8
l ,260 t 29
193+5
323 + 6
544 + 24
3 1 .9
30,4
36.4
72,7
36.5
36,-5
l +0
37,6
O.2
13_8+2
13,2
163 + 10
304 + 2
284 t 3
14.0
19,5
236i2
222 t 1 6
1,83_ 3 + 13
3_ 98lt2
l,196i21
316t7
73.0
46.3
17.6
21.7
26.4
321 i6
24, l
293 i 3
36,5
1 ,248 t 1 3
349+ I O
27.9
l ,O_32i6
183+3
17.7
509 + 5
37.7
2,007 + 20
697+ 1 3
~34.7
l ,162lt 17
382i6
l ,328t 1 4
802i5
1350i7
< ) Data were meanstSD of three determinations.
") NZ, New Zealand.
d)F-r, fresh fruits without rind.
3~ 2,8
<') D+r, Dried
l_55
Radical-Scavenging Activity in Dried Fruits
4000
Rs0.831
Hawthern
O
,::
o
~ 3000
o B~ueberry
~,
O
a)
o
o
-UJ
<
(:) 2000
e ra ~e
o
O Apricot
R~kanka
o)
O eranbefry
S
~0$:
Fig
~
~uscat~ pear e~eh O Str~wberrV OJujt~be o
a
_>0 1000
~ange
eapple o PPie
CL
_~~ xi~
o Kuttx
fru~t
Prwe
CP O Cherry
at o rx~~,F~ek)tl
enas
h
\v papaya
o
O 1000
4000 SOOO
3000
2000
Radicai~;cavenging Aetivity (mg Ascorbic Acid eq!100g Dry Weight)
Fig. l.
Correlation betwcen radical-scavenging actlvlty and total polyphenols in dried fruits. GAE, gallic acid equivalent.
Table 4. Polyphenol content of pulp and nnd of fresh frurts
Fruit
Country
Part
Total polyphenols
(mg GAE">/10O g dry weight)
Aglycons
(mg GAE/1 OO g dry weight)
3,_555 t 35/"
2,_33_ 5 i 27
J apan
rind
Japan
pulp
2, 168lt3 8
Apricot
J ap an
rind
1 ,390t 38
97 1 i23
pulp
3 ,063 t 24
B anana
Japan
PH'
rmd
2,799 t 1 3
2,330lt35
l ,724i9
PH
pulp
804 i 5
Japan
Japan
rind
2,092 i 1 7
pulp
1 ,699 t 24
J ap an
rind
l ,450 jl 24
Japan
pulp
NZ'!'
nnd
l ,282 It 24
NZ
pulp
930lt I l
Apple
Fig
Grape
Kiwifruit
Mango
Muscat
Papaya
Peach
Pear
Prune
470t28
244 It 3
798lt6
361 It3
I ,280t 14
74 t 6
442t~3
l ,068~t 10
676t I _5
14, 157t 1 27
(clc)
65.7
21.7
69.9
76. 1
61.6
3O.3
3X.2
21.3
88.3
l 6.7
83.3
72.7
85.9
37.6
60.3
rind
l 6.47_5 It 1 89
pulp
l ,448 t 9 1
Japan
nnd
3 .418t52
J ap an
pulp
l ,5_58 It 24
PH
PH
nnd
744 t 9
12lt3
l .6
pulp
51Oi8
236t2
46.3
Japan
Japan
rind
2,2_58i30
pulp
l.833_ i 13
J ap an
rind
2.013_ jl24
Japan
pulp
1 ,328 t 1 4
3 21 i6
24. 1
USA
USA
rmd
4,6O8 It 55
3,730t20
8 1 .O
pulp
1 .800 i 38
l ,424 t 33
79. l
PH
PH
"} GAE, Gallic acid equivalent. !') Data were meansiSD of three determinations. ' ) PH.
tion, the total polyphenol content of dried fruits with rind was
544 It 24
2,061 i 12
304 i 2
l,013 t 15
398 It 2
I ,958 t 8
Philippines.
19.5
44 . 9
2 1 .7
97.3
</] NZ, New Zealand.
In this study, individual polyphenolic compounds could not
high. The fruits containing high DPPH radical-scavenging
be determined, however, polyphenols in some fresh fruits have
activity tended to contain a large amount of polyphenols; as
shown in Fig. I , these two factors are highly correlated in dried
been reported: cyanidin and peonldin-3-galactose in cranberry
(Kankdnen et a!., 2001); cyanidin and chlorogenic acid in blue-
fruits. These results suggest that the contribution of polyphe-
berry (Tsushida, 1 998) and prune (Donovan et a/., 1998); and
nols to radical-scavenging activity is large in these fruits.
catechin, epicatechin, gallic acid and malvidine-3_ -glucoside in
Table 3 also shows that the polyphenol content of dried fruits
was lower than that of the corresponding fresh fruits on dry
weight basis. The ratio of aglycons was also lower in dried
fruits. Aglycons probably became more decomposed than glycosides during preparation of the dried fruits, since aglycons
are less stable than glycosides (Rice-Evans & Miller, 1 996;
Chuda et a/., 1998).
grape (Iwashina, 1994). Further study on individual compounds in fresh and dried fruits is necessary.
Po!ypheno/ content oj' rind and pulp of ,
Polyphenol content of rind and pulp of fresh fruits was deter-
mined (Table 4). In all fruits except apricot, the polyphenol
content of rlnd was higher than that of pulp, as true of the radi-
cal-scavenging activity. Since fresh fruits are usually eaten
156
without rind, eating dried fruits with rind are a good means of
efh~cient intake of polyphenols as well as radical-scavenging
activity.
K. ISHTWATA et a!.
493.
Ishiwata, K., Murakami, M., Takamura, H, and Matoba, T. (200la).
Changes in the DPPH radical-scavenging activity and ascorbic acid
content of commercial beverages during preservation. J. Cook. Sci.
,lpn., 34, 68-72.
Conclusions
Among the dried fruits examined, hawthorn, apricot and
blueberry had the highest radical-scavenging activity. Though
ascorbic acid did not contribute to this activity, polyphenol con-
tent was highly correlated with it. Since dried fruits, especially
with rind, contain high radical-scavenging activity and
polyphenol content, they as well as fresh fruits are considered
healthy and suitable for preventing life-style related diseases.
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