Content uploaded by Charles Brown
Author content
All content in this area was uploaded by Charles Brown on May 09, 2016
Content may be subject to copyright.
ANTHOCYANIN AND CAROTENOID CONTENTS IN POTATO: BREEDING
FOR THE SPECIALTY MARKET
C. R. Brown
INTRODUCTION
The potato is an underground stem with specialized functions to vegetatively propagate
the plant. It should rightly be classified as a vegetable, and a recognition of its nutritional
contribution should be judged along side other vegetables. It is not commonly known,
for instance, that potatoes contain carotenoids, lutein and zexanthin, constituents of the
human retina. Carotenoids have been found to stimulate processes involved in the
immune system of animal models (Lee et al., 1999), and lutein has been found to inhibit
breast cancer development in mice (Park et al., 1998). Both carotenoids and
anthocyanins are antioxidants.
CAROTENOID CONTENT IN POTATO
White and yellow flesh potato have xanthophyllous carotenoids. Yellowness is a
determinant of xanthophyll up to a point. In Figure 1 we see the relationship of yellow
index to the concentration of carotenoids. Yellowness is correlated with content up to
about 1000 mcg per 100 g FW, but above these levels no further increase in yellowness is
measured.
y = 10.807Ln(x) - 7.706
R
2
= 0.723
20.0
30.0
40.0
50.0
60.0
70.0
0 1000 2000 3000
Total Carotenoid (micrograms per 100 g FW)
Yellow Index (YIE313)
Figure 1. Relationship of yellow index to total carotenoid content
Presented at Idaho Potato School, January 17, 2006, Pocatello, ID.
The total carotenoid content of white cultivars and breeding lines ranges from 50 to 100
mcg per 100 g FW. Yellow flesh cultivars may have carotenoid contents up to 270 mcg,
while more intensely yellow breeding clones will range up to 800 (Table 1).
Table 1. Total carotenoid content in yellow and white flesh named varieties and
experimental lines
Cultivar or Breeding Line
Skin/Flesh
Type\1
Total
Carotenoid
µg / 100 g FW
Significance\1
Light Yellow flesh cultivars and
breeding lines
Adora W/Y 227 cdefg
Divina W/Y 271 cdef
Fabula W/Y 179 cdefg
Ilona W/Y 176 cdefg
Morning Gold W/Y 101 defg
Provento W/Y 191 cdefg
Satina W/Y 248 cdefg
Yukon Gold W/Y 194 cdefg
POR00PG4-2 W/Y 250 cdefg
Dark Yellow flesh breeding lines
91E22 W/DY 795 a
PA99P11-2\w PR/DY 509 b
PA99P1-2\w PR/DY 525 b
PA99P2-1\w PR/DY 738 a
POR00PG4-1 W/DY 634 ab
Red and Yellow breeding lines
POR00PG9-1\w PR/R&Y 299 cd
POR00PG9-2\w PR/R&Y 307 cd
POR00PG9-3\w PR/R&Y 109 defg
POR00PG9-5\w PR/R&Y 273 cde
POR00PG9-6\w PR/R&Y 327 c
White flesh cultivars and
breeding lines
Norkotah RT/W 40 g
Ranger RT/W 71 efg
Burbank RT/W 58 fg
A8893-1 RT/W 56 g
A9014-2 RT/W 55 g
A90586-11 RT/W 99 defg
A9045-7 RT/W 64 efg
A90490-1 RT/W 101 defg
A91790-13 RT/W 75 efg
A92030-5 RT/W 54 g
A93157-6LS RT/W 66 efg
1RT/W = russet skin/white flesh, W/Y = white skin/light yellow flesh, W/DY = white
skin/dark yellow flesh, PR/R&Y = Partially red skin/red and yellow flesh, PR/DY =
partially red skin/dark yellow flesh. Means not sharing the same letter letter are
significantly different at the P < 0.05 level, using Duncan’s Multiple Range Test.
Although it is sometimes not directly observable, solidly red or purple flesh due to high
anthocyanin concentration may be accompanied by higher total carotenoids as noted in
the red-yellow flesh clones in Table 1.
There is a class of potato cultivars in South America called Papa Amarilla (PA) (yellow
potato), which have exceedingly high carotenoid values. We have found that certain
progeny of crosses made between PA parents produce progeny that exceed either of the
parents by more than two population standard deviations (Figure 2).
0
5
10
15
20
25
200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800
Carotenoid Intervals
Number of Progney
Yema de Huevo
91E22
Figure 2. Distribution of total carotenoids contents in progeny of a cross between two
Papa Amarilla types (91E22 and Yema de Huevo [Egg yolk]).
Three progeny exceeded 2, 400 mcg per 100 g FW despite the fact that the mid parent
value is 900 mcg. This is an indication of transgressive segregation. It also indicates that
it may be possible to breed intensely yellow cultivars with exceptionally high total
carotenoids.
ANTHOCYANIN CONTENT IN POTATO
Anthocyanins are red to purple pigments ubiquitous in the plant kingdom. Anthocyanins
are water soluble and are potent antioxidants. The general public is familiar with red skin
potato. The skin is red due to a high concentration of red anthocyanins in the epidermal
layer. However, much higher levels of anthocyanins are present in clones that have
pigmented flesh. The degree of pigmentation can vary from streaks or blotches of
pigment to solid dark pigment (Figure 3).
Figure 3. Different patterns and degrees of anthocyanin pigmentation in potato. The
degree of pigmentation is under polygenic control, while presence and absence of
pigment in the flesh are under single gene control.
The concentration of anthocyanins can have a large range. The concentration of
anthocyanin in skin tissue is quite high. However, the skin is such a small volume of the
whole tuber that generally a red-skinned white-fleshed potato has no more than 1.5 mg
per 100 g FW when skin and flesh are extracted together. However, potatoes with
anthocyanin in the flesh range from 15 to nearly 40 mg per 100 g FW (Table 2). We
have found that red-flesh potatoes contain predominantly acylated glucosides of
pelargonidin. Purple-flesh potatoes have a more complex content of acylated glucosides
of pelargonidin, petunidin, cyanidin, and malvidin (Brown et al., 2003).
It is very interesting that the antioxidant potential of potatoes is raised by the anthocyanin
concentration and a significant regression relationship is found (Figure 4).
Table 2. Total anthocyanin and associated antioxidant level hydrophilic Oxygen Radical
Absorbance Capacity (ORAC) for purple flesh and red flesh breeding lines.
Breeding lines Skin/Tuber
flesh Type\z Total
Anthocyanins
mg / 100 g FW
signifi-
cance Hydrophilic
ORAC
µmole / 100
g FW\y
signif-
cance
Purple skin / Purple flesh
PA97B29-2 P/P 17.0 de\w 800 c
PA97B29-4 P/P 20.1 cde 930 bc
PA97B29-6 P/P 17.3 de 840 bc
Red skin / red flesh
NDOP5847-1 R/R 37.8 a 1420 a
PA97B35-1 R/R 24.3 bcde 1100 abc
PA97B36-3 R/R 15.0 e 850 bc
PA97B37-7 R/R 31.5 abc 1410 abc
PA99P9-2 R/R 26.9 abcde 1210 abc
PA99P9-4 R/R 24.5 bcde 790 c
PA99P10-2 R/R 27.2 abcde 1150 abc
PA99P20-1 R/R 20.8 bcde 1040 abc
PA99P20-2 R/R 26.8 abcde 980 bc
PA99P32-5 R/R 23.8 bcde 850 bc
POR00PG1-4 R/R 35.1 ab 1020 bc
POR00PG2-1 R/R 22.2 bcde 950 bc
POR00PG2-7 R/R 28.1 abcde 1160 abc
POR00PG2-11 R/R 29.6 abcd 1100 abc
POR00PG2-16 R/R 24.3 bcde 1160 abc
POR00PG3-1 R/R 19.8 cde 1020 bc
\zKey to skin and tuber flesh types: R = red, P = purple.
\yHydrophilic ORAC = trolox equivalents,
\wMeans not sharing the same letter are significantly different
using the Duncan’s Multiple Range Test at P< 0.05
Atnhocyanin versus ORAC
y = 0.2234x + 4.8603
R
2
= 0.5337
0
5
10
15
0 10203040
Anthocyanin mg / 100 g FW
ORAC uMole / 100
g FW
Total Anthocyanin Content Versus
Antioxidant Value (ORAC)
Figure 4. Regression between anthocyanin content and antioxidant value (ORAC) is
significant.
BREEDING OBJECTIVES
Development of new potato cultivars with specific non-traditional traits designed to
appeal to a diet conscious populace is a relatively young endeavor. These potato have yet
to find a steady market. However, the genetic diversity and nutritional bonuses embodied
by the genetic diversity in pigment types and concentration have captured a faithful
audience. Home gardeners and small and large scale producers are watching this
phenomenon. Ultimately, the consumer will determine which direction the industry goes.
However, selection programs are looking for attractive skin that retains a bright color
even after extended storage. It appears that there is a market for less than four ounce size
tubers. At the same time, total yield is important, and it is likely that a high yield
somewhat evenly divided between small and medium size tubers might be the most
advantageous combination. It is likely that the crop destined for specialty markets will
need to be closely managed for size. In this regard, the overall yield is least likely to
suffer if a heavy set of small tubers is the innate yield characteristic of the variety.
Otherwise, the only way to limit size in more traditional plant types is to stop the growth
by killing the foliage quite early in the growing season, reducing yield by a considerable
amount.
REFERENCES
Brown, CR, R Wrolstad, R Durst, C-P Yang and BA Clevidence. 2003 Breeding studies
in potatoes containing high concentrations of anthocyanins. Am. Journal of Potato Res.
80:241-250.
Lee, CM, AC Boileau, TWM Boileau, AW Williams, KS Swanson, KA Heintz and JW
Erdman. 1999. Review of animal models in carotenoid research. Journal of Nutrition
129: 2271-2277
Park, JS, BP Chew and TS Wong. 1998. Dietary lutein from marigold extract inhibits
mammary tumor development in BALB/c mice. Journal of Nutrition 128: 1650-1656.