Agriculture Reference
In-Depth Information
Calories
Fat
Protein
Carbohydrate
Magnesium
Manganese
Copper
Fiber
Potassium
Vitamin B6
Vitamin B5
Vitamin B3
Vitamin B1
Vitamin C
0
5
10
15
20
25
Percent of recommended daily value
Fig. 18.2.
Nutritional content of
100
g of baked potato. Note the amount of various nutrients relative to the
amount of calories provided.
in tubers are known to affect health positively
and are desirable in the diet (Katan and De Roos,
2004). A new study reports that potatoes and
beans provide the most nutrients per dollar out
of the
98
vegetables studied (Drewnowski and
Rehm, 2013).
Potassium (K)
Potatoes are a major source of potassium, an ele-
ment commonly deficient in the diet. The RDA for
K in adults is 4.7 g, but the median intake in the
USA is less than 3.3 g. Potassium reduces risk of
blood pressure and cardiovascular diseases,
along with hypokalemia (low K blood levels),
osteoporosis, strokes, inflammatory bowel dis-
ease (IBD), and kidney stones (Dyer
et al
., 1994;
Young
et al
., 1995). K is also important for tuber
starch synthesis. K levels in flesh among different
genotypes varied from
3
to
8
mg g
-
1
FW
(Sanchez-Castillo
et al
., 1998; Casanas
et al
.,
2002), and decreased from bud end to stem end
(Arteca
et al
., 1980). The flesh contains about
90% of tuber potassium and the skin 10%.
18.3 Minerals
Potatoes are a good source of minerals, with the
amounts varying by genotype and environ-
ment. Typically, a serving of potatoes provides
milligram amounts of phosphorus, magne-
sium, potassium, iron, and sodium, and micro-
gram amounts of copper, manganese, and zinc.
A survey of
74
Andean landraces found iron
ranged from 29.87 to 157.96 μg g
-
1
DW, zinc
from 12.6 to 28.83 μg g
-
1
DW, and calcium con-
tent 271.09 to 1092.93 μg g
-
1
DW (Andre
et al
.,
2007a). Location, stage of development, soil
type, soil pH, soil organic matter, fertilization,
and irrigation influence mineral content. Con-
centrations of
14
minerals varied markedly in
two cultivars grown with different fertilizer re-
gimes, and showed distinct gradients within the
tuber, with some higher in the center and others
showing stem- to bud-end gradients (LeRiche
et al
., 2009). Data suggest that potato mineral
content can be increased without compromising
yield, independent of any yield dilution effect
(White
et al
., 2009).
Iron (Fe)
Iron deficiency is one of the most widespread
health problems worldwide, especially for
women. Like all the minerals, recommended
amounts can vary by age, gender, and preg-
nancy, and is
8-18
mg day
-
1
for adults (IOM,
2011). Fe deficiency can lead to abnormally
small red blood cells with reduced hemoglobin,
resulting in decreased oxygen supply to tissues
and anemia (Alton, 2005). Fe deficiency in preg-
nant women causes fetal growth retardation or
low birth weight. In young children, it affects
