antioxidant activity in yellow and purple

ZESZYTY PROBLEMOWE POSTĘPÓW NAUK ROLNICZYCH 2008 z. 530: 241-247
ANTIOXIDANT ACTIVITY IN YELLOW
AND PURPLE-FLESHED POTATOES CULTIVATED
IN DIFFERENT CLIMATIC CONDITIONS 1
1
2
1
2
Karel Hamouz , Jaromír Lachman , Petr Dvořák , Kateřina Hejtmánková ,
3
Jaroslav Čepl
1
Department of Plant Production, Czech University of Life Sciences, Prague,
Czech Republic
2
Department of Chemistry, Czech University of Life Sciences, Prague, Czech Republic
3
Potato Research Institute, Havlíčkův Brod, Czech Republic
Introduction
Potato tubers represent in human nutrition a significant source of antioxidants,
which has a beneficial effect on cardiovascular diseases, inhibit certain types of cancer
and the degeneration of the retina [STINTZING, CARLE 2004]. Major potato antioxidants are
polyphenols and L-ascorbic acid. These compounds are principally soluble in water
alike to a lesser degree contained selenium. Among antioxidants soluble in lipids,
potatoes contained carotenoids, α-tocopherol and α-lipoic acid [LACHMAN, HAMOUZ
2005]. Potatoes with purple-coloured peels and flesh are new for consumers, and contain
natural anthocyanin pigments. The first such cultivar (Valfi) was registered in the Czech
Republic in 2005 [ŠULC et al. 2007]. Purple-fleshed cultivars have according to the
literature references, higher antioxidant tuber activity as compared to traditional yellowfleshed cultivars [REYES et al. 2005]; it is related to the content of anthocyanin pigments
[BROWN 2005; BROWN et al. 2005]. Main anthocyanin glycosides, which contribute to the
antioxidant properties of purple-fleshed potatoes are glycosides of peonidin, petunidin
and malvidin, whereas in purple-fleshed potatoes glycosides of pelargonidin prevail
[BROWN 2004].
The target of this work was to compare the antioxidant activity (AA) determined
in some purple or red-fleshed cultivars with its values in common yellow-fleshed
potatoes. The other aim was to determine the impact of climatic conditions in individual
localities with different levels above the sea on the antioxidant activity of tubers.
Material and methods
In precise field trials in the years 2006 and 2007 the total of five purple-fleshed,
one red-fleshed and two yellow-fleshed cultivars (Tab. 2) were cultivated according to
the unified method in the three localities with different levels above the sea (Tab. 1).
1
Supported by the National Agency for Agricultural Research of the Czech Republic, Grant No.
1G46058, and by the Ministry of Education, Youth and Sports of the Czech Republic, Research
Proposal No. 6046070901.
K. Hamouz et al.
242
After harvest the tuber samples of individual cultivars from all locations were analyzed
in the laboratory. Antioxidant activity was determined by the ABTS [2,2’-azinobis(3ethylbenzothiazolin)-6-sulfonate] method and total anthocyanin content (TAC) was
determined at the Department of Chemistry of CULS in Prague.
Table 1; Tabela 1
Characteristics of experimental locations
Charakterystyka miejsc uprawy
Locality;
Miejscowość
Altitude above the sea
level
Wysokość
nad poziomem morza
(m)
Average annual
temperature
Średnia roczna
temperatura
(°C)
Annual sum
of precipitations
Roczna suma opadów
(mm)
Přerov nad Labem 1)
178
8.8
622
Praha-Suchdol
286
8.2
510
Valečov 2)
460
6.9
649
1)
2)
Central Institute for Supervising and Testing in Agriculture; Centralny Ośrodek Badania Odmian
Roślin Uprawnych
Potato Research Institute Havlíčkův Brod; Instytut Ziemniaka
Table 2; Tabela 2
Impact of variously colour-fleshed cultivars on antioxidant activity (AA)
of tubers - average from 3 locations
Wpływ odmian o róŜnym zabarwieniu miąŜszu na aktywność przeciwutleniająca (AA)
bulw - średnia dla 3 miejscowości
Cultivars / flesh colour2)
Odmiany / zabarwienie
miąŜszu2)
Karin / y
Saturna / y
Highland Burgundy Red / r
Blue Congo / lp
Salad Blue / lp
Valfi / lp
Violette / dp
Vitelotte / dp
2006
2007
Average of 2006-2007
Średnia dla 2006-2007
AA1)
sign.; istot.3)
AA1)
sign.; istot.3)
AA1)
sign.; istot.3)
40.1
28.1
82.8
66.3
60.1
65.3
65.3
114.2
e
f
b
c
d
c
c
a
13.6
13.4
55.1
47.0
50.1
38.1
38.1
70.2
f
f
b
d
c
e
e
a
26.8
20.7
69.0
56.7
5.1
51.7
51.7
92.2
e
f
b
c
c
d
d
a
LSD0.05; NIR0,05 = 3.13 (2006)
LSD0.05; NIR0,05 = 2.16 (2007)
LSD0.05;NIR0,05 = 1.88 (average; średnia 2006-2007)
1)
ascorbic acid amount in mg, which is its AA equivalent to 100 g FM of tubers; ilość kwasu
askorbinowego w mg, która jest równowaŜna z punktu widzenia AA 100 g św.m. ziemniaków
2)
y - yellow; Ŝółte
r - red; czerwone
lp - light purple; jasnofioletowe
dp - dark purple; ciemnofioletowe
3)
homogenous groups; grupy jednorodne
ABTS assay
54.2 mg ABTS were dissolved in phosphate buffer (pH 7.0; 5 mM) and activated
to ABTS•+ radical by the addition of 1 g MnO2 with occasional stirring and 30 min time
of activation [PENNYCOOKE et al. 2005]. Then the solution was centrifuged (5 min, 7 000
g), filtered (25 µm) and diluted with phosphate buffer to absorbance (t0) 0.700 ± 0.01.
Sample addition was 5 µl, time of reaction 20 min. The absorbance of the solution was
measured at the wavelength of λ = 734 nm.
ANTIOXIDANT ACTIVITY IN YELLOW AND PURPLE-FLESHED ...
243
Total anthocyanin content (TAC) determination
The measurement of non hydrolysed TAC using the pH differential method
described by LAPORNIK et al. [2005] based on the total anthocyanin transformation to
flavylium cation at pH of extracts decreasing to values between 0.5 and 0.8 was carried
out. TAC was expressed as cyanidin (ε1%1 cm = 300; 523 nm).
Results and Discussion
Table 2 shows the apparent differences in AA of tubers between yellow, purple or
red-fleshed cultivars. Purple and red-fleshed cultivars showed a significantly higher AA
(in average 2.9 times) in comparison to yellow-fleshed cultivars. In addition, REYES et al.
[2005] obtained similar results. The highest AA value between purple-fleshed cultivars
was determined in the cv. Violette (95.4 mg ascorbic acid⋅100 g-1 FM = 100%), in the
other purple-fleshed cultivars the AA decreased Vitelotte 3.4%, Blue Congo 40.6%,
Salad Blue 42.2% and Valfi 46.0%. In the red-fleshed cv. Highland Burgundy Red AA
decreased as compared to the cv. Violette 27.7% and the highest decrease was shown by
yellow-fleshed cv. Karin 71.9% and Saturna 78.4%. Higher AA values of the cvs Violette and Vitelotte as compared to a other purple-fleshed cultivars are obviously related
to their darker colour of the flesh and to higher content of anthocyanins, as described by
BROWN [2004]. Other evidence of BROWN [2005] also confirms our results and according
to them anthocyanins could be taken together with chlorogenic acid and caffeic acid for
main potato contributors to AA. Between the yellow-fleshed cultivars, the cv. Karin
significantly exceeded the cv. Saturna in AA.
The total anthocyanin content (TAC) was determined in purple and red-fleshed
cultivars. The highest values were determined in the cultivars with the darkest flesh
colour Violette and Vitelotte and further in the red-fleshed cv. Highland Burgundy Red
(Fig. 1). These cultivars at the same time had demonstrated the highest AA values and
TAC well correlated with them. The range of TAC between the cultivars was relatively
tidy; var. Blue Congo with the lowest content reaching 29% of the value determined in
the var. Violette (64.1 mg per 100 g FM) with the highest TAC. In addition, BROWN
[2005] attained the similar results and showed TAC in purple and red-fleshed potatoes
within the range from 9 to 38 mg per 100 g FM. Our results are in agreement with
DELGADO et al. [2001], who determined highly positive correlations between the
antioxidant capacity and anthocyanin content and total polyhenol content and consider
the former compounds as the major source of antioxidant capacity.
K. Hamouz et al.
mg cyjanidyny:100 g św.m.
-1
-1
mg cyanidin:100 g FM
244
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
e
e
Violette
Vitelotte
d
c
a
1)
Blue Congo
b
Valfi
Salad Blue
Highland
Burgundy
Red
cultivars; odmiany
1)
homogenous groups; grupy jednorodne
Fig. 1.
Effect of cultivar on total anthocyanin content (mg of cyanidin⋅100 g-1 FM); 2006,
average for 3 locations
Rys. 1.Wpływ odmiany na ogólną zawartość antocyjanów (mg cyjanidyny⋅100 g-1 św.m.), średnia
dla 3 miejscowości
ANTIOXIDANT ACTIVITY IN YELLOW AND PURPLE-FLESHED ...
245
120
b
110
b
mg ascorbic acid:100 g-1 FM;
mg kwasu askorbowego:100 g -1 św.m.
a
100
90
a
a
a
80
70
a
a
60
a
50
40
30
20
10
0
2006
Přerov n. L.
2007
Suchdol
2006-2007
Valečov
Effect of location on the AA of tubers (mg ascorbic acid⋅100 g-1 FM - average for all
purple-fleshed cultivars). Vertical lines represent standard differences
Rys. 2.Wpływ miejscowości na AA bulw (mg kwasu askorbinowego:100 g-1 św.m. - średnia
wszystkich odmian o fioletowym zabarwieniu miąŜszu). Linie pionowe wskazują
wartości błędu standardowego
Fig. 2.
The present two-year results did not confirm the impact of a location on AA of
tubers (Fig. 2); the effect of the year of cultivation prevailed. A trend was obsrved in
2006, when a significantly lesser AA was noted on the warmest location Přerov nad
Labem in the low ground alongside the Labe river however those observations were not
confirmed in 2007.
Conclusions
1.
2.
3.
4.
Potato AA is demonstrably affected by the varietal genotype.
Purple and red-fleshed potato cultivars showed on average 2.9 times higher AA
of tubers in comparison with yellow-fleshed potatoes .
Considerable differences of AA and TAC was found in the purple and red-fleshed
cultivars, where the highest AA were noted in the cultivars with high content of
total anthocyanins.
The obtained results did not prove the impact of location on AA of tubers.
References
246
K. Hamouz et al.
BROWN C.R. 2004. Nutrient status of potato: Assessment of future trends. Proceedings of
the Washington State Potato Conference: 11-17.
BROWN C.R. 2005. Antioxidants in potato. Am. J. Pot. Res. 82: 163-172.
BROWN C.R., CULLEY D., YANG C.P., DURST R., WROLSTAD R. 2005. Variation of anthocy-
anin and carotenoid contents and associated antioxidant values in potato breeding
lines. J. Am. Soc. Hort. Sci. 130: 174-180.
DELGADO E., SULAIMAN M.I., PAWELZIK E. 2001. Importance of chlorogenic acid on the
oxidative potential of potato tubers of two German cultivars. Pot. Res. 44(2): 207-218.
LACHMAN J., HAMOUZ K. 2005. Red and purple coloured potatoes as a significant anti-
oxidant source in human nutrition - a review. Plant Soil Environ. 51: 477-482.
LAPORNIK B., PROŠEK M., WONDRA A.G. 2005. Comparison of extracts prepared from
plant by-products using different solvents and extraction time. J. of Food Engineering
71: 214-222.
PENNYCOOKE J.C., COX S., STUSHNOFF C. 2005. Relationship of cold acclimation, total
phenolic content and antioxidant capacity with chilling tolerance in petunia (Petunia x
hybrida). Environmental and Experimental Botany 53: 225-232.
REYES L.F., MILLER J.C., CISNEROS-ZEVALLOS L. 2005. Antioxidant capacity, anthocyanins
and total phenolics in purple- and red-fleshed potato (Solanum tuberosum L.)
genotypes. Am. J. Pot. Res. 82: 271-277.
STINTZING F.C., CARLE R. 2004. Functional properties of anthocyanins and betalains in
plants, food, and human nutrition. Trends in Food Science & Technology 15: 19-38.
ŠULC M., LACHMAN J., HAMOUZ K., ORSÁK M., DVOŘÁK P., HORÁČKOVÁ V. 2007. Výběr a
zhodnocení vhodných metod pro stanovení antioxidační aktivity fialových a červených
odrůd brambor. Chemické listy 101: 584-591.
Key words:
potatoes, purple and red-fleshed cultivars, antioxidant activity,
anthocyanins
Summary
In precise field trials on three locations in the Czech Republic the impact of
yellow, red and purple-fleshed potato cultivars in the years 2006 and 2007 was
investigated as well as the effect of location conditions on antioxidant activity (AA) of
tubers (expressed by ABTS assay in mg ascorbic acid 100 g-1 FM). The highest AA was
determined in the darkly purple-fleshed cv. Violette (95.4 mg ascorbic acid⋅100 g-1 FM).
In the purple and red-fleshed cultivars, AA was on the average 2.9 times higher as
compared to yellow-fleshed cultivars. Significant AA differences between purple and
red-fleshed cultivars were found; the cultivars of the highest total anthocyanin content
(TAC ranged from 18.6 to 64.1 mg⋅100 g-1 FM) were reaching the highest AA values.
The obtained results did not prove the impact of location on AA of tubers.
AKTYWNOŚĆ PRZECIWUTLENIAJĄCA ZIEMNIAKÓW
O śÓŁTYM I FIOLETOWYM ZABARWIENIU
MIĄśSZU UPRAWIANYCH
W RÓśNYCH WARUNKACH KLIMATYCZNYCH
ANTIOXIDANT ACTIVITY IN YELLOW AND PURPLE-FLESHED ...
247
Karel Hamouz 1, Jaromír Lachman 2, Petr Dvořák 1,
Kateřina Hejtmánková 2, Jaroslav Čepl 3
1
Katedra Produkcji Roślinnej,
Czeski Uniwersytet Rolniczy w Pradze, Republika Czeska
2
Katedra Chemii, Czeski Uniwersytet Rolniczy w Pradze, Republika Czeska
3
Instytut Ziemniaka, Havlíčkův Brod, Republika Czeska
Słowa kluczowe:
ziemniaki, odmiany z Ŝółtym i fioletowym miąŜszem, aktywność
przeciwutleniająca, antocyjany
Streszczenie
W ścisłych doświadczeniach polowych przeprowadzonych w trzech miejscowościach w Republice Czeskiej, w latach 2006 i 2007, stwierdzono wpływ odmian
ziemniaków o Ŝółtym, czerwonym i fioletowym zabarwieniu miąŜszu oraz wpływ
warunków badań na aktywność przeciwutleniającą - AA - bulw (ABTS metoda w mg
kwasu askorbinowego w 100 g św.m.). NajwyŜszą AA stwierdzono u odmiany Violette
o ciemnofioletowym zabarwieniu miąŜszu - 95,4 mg kwasu askorbinowego⋅100 g-1
św.m. U odmian o fioletowym i czerwonym zabarwieniu miąŜszu stwierdzono AA
średnio 2,9 raza wyŜszą niŜ u odmian o zabarwieniu Ŝółtym. Istotne róŜnice AA
występowały teŜ między odmianami o fioletowym lub czerwonym zabarwieniu
miąŜszu. NajwyŜsze wartości AA miały odmiany o największej zawartości antocyjanów
(wahała się w granicach od 18,6 do 64,1 mg⋅100 g-1 św.m.). Wyniki nie wykazały
wpływu środowiska na AA bulw.
Prof. Ing. Karel Hamouz, CSc.
Department of Plant Production
Czech University of Life Sciences in Prague
Kamýcká 129
165 21 PRAGUE 6 - SUCHDOL
e-mail: [email protected]