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Researches were conducted in the years 2009-2011 on a brown soil, wheat faulty complex (Poland, Podkarpackie Voivodeship). The experiment was carried using the randomized blocks method in 3 replications. Three cultivars of sweet potato were studied: Carmen Rubin, Goldstar and White Triumph – with a different morphological and physiological type. Content of dry matter, carbohydrates, protein, vitamin C, ascorbic acid and macronutrients in tubers was determined using standard methods. The study discusses the content of nutrient in sweet potatoes’ tubers, which can help to reduce nutritional problems in the society. The biological value of sweet potato tubers was high. White Triumph cultivar with a white skin and flesh characterized by a significantly higher content of starch, sugar sum, protein, vitamin C, ascorbic acid and phosphorus, calcium and magnesium in comparison with skin colour and flesh cultivars (Goldstar and Carmen Rubin). The lowest variability was characterized by the starch and the largest – calcium.
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Marczak et al Page 169
Nutrition value of the sweet potato (
Ipomoea batatas
(L.) Lam)
cultivated in south eastern Polish conditions
Barbara Krochmal-Marczak1, Barbara Sawicka2, Jacek Supski3, Tomasz Cebulak4,
Katarzyna Paradowska5*
1Departament of Agriculture and Rural Development, State Higher Vocational School names
Stanislaw Pigonia in Krosno, Poland
2Department of Plant Production Technology and Commodity, University of Life Science Lublin,
3Department of Raw Materials and Processing of Fruit and Vegetables, Department of Food
Technology, University of Agriculture in Krakow, Poland
4Department of Technology and Quality Plant Products, Department of Biology and Agriculture,
University in Rzeszow, Poland
5 Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Poland
Article published on April 29, 2014
Key words: Chemical composition, macronutrients, sweet potato, variety.
Studies were conducted in the years 2009−2011 on a brown soil, wheat faulty complex (Poland, Podkarpackie
Voivodeship). The experiment was carried out using the randomized blocks method in 3 replications. Three
cultivars of sweet potato were studied: Carmen Rubin, Goldstar and White Triumph with a different
morphological and physiological type. Contents of dry matter, carbohydrates, protein, vitamin C, ascorbic acid
and macronutrients in tubers were determined using standard methods. White Triumph cultivar with white skin
and flesh is characterized by a significantly higher content of starch, sugars, proteins, vitamin C, ascorbic acid as
well as phosphorus, calcium and magnesium in comparison with cultivars (Goldstar and Carmen Rubin) with
coloured skin and flesh. The biological value of sweet potato tubers is high. The content of nutrients in sweet
potatoes’ tubers is discussed in terms of their nutritional utility. Sweet potatoes can help reducing nutritional
problems and can be especially recommended for diabetics.
* Corresponding Author: Katarzyna Paradowska
International Journal of Agronomy and Agricultural Research (IJAAR)
ISSN: 2223-7054 (Print) 2225-3610 (Online)
Vol. 4, No. 4, p. 169-178, 2014
Marczak et al Page 170
Sweet potato (Ipomoea batatas (L.) Lam.), known as
a patata, is well known long-term species in a warm
and hot climate zone and an annual plant (spring) in
temperate zone. This species has moist and delicate
tubers with a sweetish taste, pleasant and aromatic
smell. It has also a high nutritional value about 50%
higher than the potato. Therefore, it plays an
important role in the diet of the world’s population
(Ofori et al., (2005). Tubers are main usable part of
the sweet potato, although leaves can also be used.
Tubers are characterized by a high unit mass (1−3 and
even 5 kg); diverse shapes spherical, oval, spherical-
oval, fusiform; skin and flesh: white, cream, yellow,
orange, red, claret and even purple, depending on a
cultivar (Maloney et al. (2012). The main nutritional
material in sweet potato’s tubers are carbohydrates
(starches and simple sugars), protein, fat and fat-
soluble vitamins. Moreover, cultivars with a yellow
flesh also contain significant amounts of carotenes
(Allen et al. (2012). Maloney et al. (2012) pointed out
that potentially valuable proteins can be extracted
from the peel during the processing of sweet potatoes.
Sweet potato’s tubers have anti-diabetic, anti-oxidant
and anti-proliferative properties due to the presence
of valuable nutritional and mineral components
(Jaarsveld et al. 2005; Abubakar et al. (2010).
Furthermore, Ipomoea batatas tubers, which are
steady item in the Americans’ diet, appear to be very
beneficial in the diet of diabetics and consumers with
an insulin resistance, because they have a low
glycemic index (Ludvik et al. (2004), Allen et al.
(2012). Knowledge of the glycemic index (GI) diet for
diabetes may help to predict their daily diet in order
to control a blood glucose level. GI of a pure glucose,
which is used as the standard and a pattern for other
products, is 100, while the GI of sweet potato’s tubers,
depending on whether they are boiled, baked or
prepared in a microwave, is: 63 ± 3.6; 64 ± 4.3 or 66
± 5.7, respectively. It encourages using them in the
diet of diabetics (Allen et al. (2012); Maloney, 2012).
Recently, in Poland has been increasing interest in
the cultivation of these vegetables, as raw material
with excellent nutritional values, mainly for the food
and pharmaceutical industries. However, the
knowledge about these species is not sufficient,
especially on their nutritional values.
Hence, the aim of this study was to evaluate the
chemical composition and nutritional value of three
sweet potato’s cultivars, which are cultivated in
south−western Poland.
Materials and methods
Plant material and preparation plantation
Three cultivars of sweet potato were studied: Carmen
Rubin, Goldstar and White Triumph with a
different morphological and physiological type. The
research material was from a field experiment
conducted in 2009−2011 in Zyznow (Poland,
Podkarpackie Voivodeship), on a brown soil of the
faulty wheat complex. The field experiment was
realized using the randomized blocks method in 3
replications. Organic fertilization, at a dose of 25 ha-
1and mineral fertilization, phosphorus and potassium
(P 43.6 kg; K 124.5 kg ha-1) was applied in the
autumn, while a nitrogen fertilization in the amount
of 100 kg ha-1 in the spring before planting. Forecrop
of the sweet potato was the spring barley. Rooted
sweet potato cuttings (from in vitro reproduction)
were propagating material. Plants were planted into
the soil between 25−26 May in spacing: 75 × 40 cm.
Area of plots for harvest was 15 m2. Mechanical
cultivation involving the double ridging and hand
weeding was used in the experiment.
Chemical analysis
The harvest was realized during the technical
maturity, in early October. During the harvest,
samples were taken (30 tubers of various sizes in
proportion to their share in the crop) from every plot,
in order to determine a chemical composition of
tubers. Immediately after the harvest, in a fresh
weight of tubers following parameters were
evaluated: dry matter drier method, total protein
content Kjeldahl method, starch content
polarimetrically (according to Ewers−Grossfeld);
content of sugar sum and reducing sugars
Luff−Schoorl jodometric method in the Scales
modification; vitamins C spectrophotometrically via
Tillmans. In the dry weight of tubers were identified:
general content of phosphorus, potassium, calcium,
Marczak et al Page 171
magnesium and sodium in a stock solution, which
was obtained after the “dry” mineralization of tubers
in a muffle furnace at 450°C.
Crude ash, which was obtained in a porcelain
crucible, was completely poured over by an aqueous
solution of hydrochloric acid HCI (1:1) in order to
dissolve carbonates and separate silica (SiO2) and
evaporated in a sand bath. 10 cm3 of 5% HCI helps to
obtain a solution containing chlorides of analyzed
elements and phosphoric acid (V). This solution was
transferred to a volumetric flask (100 cm3) and the
silica was separated on a hard filter. Furthermore, the
crucible was washed 3 times with deionised water,
and the solution was transferred via the filter in order
to remove chlorides and completed the volumetric
flask (AOAC, 2000). In such a prepared stock
solution, the concentration of examined
macronutrients was determined using ICP-AES
method on an emission spectrometer with the
inductively coupled plasma (argon) Optima 3200 RL,
produced by the Perkin Elmer Company. For this
purpose, the following wavelengths were used: for P
214.914 nm; K 766.490 nm; Ca 315.887 nm; Mg
285.213 nm; Na 330.237 nm. Operating parameters
of the camera were as follows: RF 1300 W, flow rate
of cooling argon 15 L min-1, auxiliary argon 0.5 L
min-1, nebulizated argon 0.8 L min-1 and the speed
of sample loading 1.5 L min-1.
Data analyses
The statistics was carried out using the analysis of
variance. The significance of variation sources was
checked by the Fisher-Snedecor “F” test. The
significance of object differences for researched traits
was evaluated using the Turkeys test. Furthermore
some features descriptive statistics, such as: standard
deviation, median, kurtosis and coefficients of
variation for the studied traits were also examined.
Rainfalls and air temperature during the growing
period of sweet potatoes
Distribution of temperature and precipitation in
analyzed years was diversified, as illustrated in Figure
1. In 2009 only May and July were wet and warm,
and the remainder of the growing season was
characterized by the deficiency of rainfall and average
air temperature. In 2010, May and July were wet and
cool total precipitation significantly exceeded the
amount of several years, while August was average,
both in terms of precipitation and air temperature,
September and October were dry. In 2011, May, June,
August, September and October were dry and cool,
and July was very wet and warm.
Fig. 1. Rainfalls and air temperature during the growing period of sweet potatoes according to the meteorological
station of IMGW in Dukla
Air temperature [°C]
Rainfall [mm]
Sum of rainfall 2009-2011
Sum of rainfall 1989-2004
Mean of air temperature 2009-2011
Mean of air temperature 1989-2004
Marczak et al Page 172
Results and discussion
Contents of chemical components
The content of tested nutrients in sweet potato’s
tubers appeared to be significantly dependent on
the specific characteristics (Table 2). The amount of
dry matter in tubers reaches 24.19 g 100 g-1 with
fluctuations from 19.69 g to 29.91 g, while the
coefficient of variation of this trait was V = 18.13%
it means its relatively high stability. A variation with
the highest content of dry matter in tubers was
White Triumph, while the lowest one Carmen
Rubin; however, Goldstar had higher content that
Carmen Rubin (Table 1).
Table 1. Content of dry matter and chemical components in fresh matter Ipomoea batatas tubers (mean for
g 100 g-1
g 100 g-1
g 100 g-1
g 100 g-1
g 100 g-1
g 100 g-1
g 100 g-1
Vitamin C
mg 100 g-1
mg 100 g-1
* − not significant at P<0.05
The coefficient of variation in this trait, which is a
measure of the dispersion in obtained results, was V
= 18.1% (Table 2) indicating that this characteristics
is quite stable. The content of dry matter in tubers,
which was presented by Sawicka et al. (2004), was
slightly higher and it averaged 27.15 g 100 g-1 with
fluctuations from 21.51 to 34.36 g. According to the
USDA National Nutrient Database for Standard
Reference (2007), the dry weight averages 22.72 g
100 g-1 of a fresh weight of sweet potato’s tubers.
Table 2. Statistical characteristics of chemical components of tubers of sweet potatoes
Mean ± standard
Dry matter g·100 g-1 fresh matter
Starch g·100 g-1 fresh matter
Total sugars g·100 g-1 fresh matter
Reducing sugars g.100 g-1 fresh matter
Protein g·100 g-1 fresh matter
Crude fibre g·100 g-1 fresh matter
Ash g·100 g-1 fresh matter
Vitamin C mg·100 g-1 fresh matter
Ascorbic acid mg·100 g-1 fresh matter
Potassium mg 100 g-1 dry matter
Phosphorus mg 100 g-1 dry matter
Calcium mg 100 g-1 dry matter
Magnesium mg 100 g-1 dry matter
Sodium mg 100 g-1 dry matter
24.47 ±4.43
14.83 ±0.68
2.97 ±0.64
1.21 ±0.29
1.35 ±0.32
1.32 ±0.45
22.89 ±9.62
19.50 ±8.19
2.12 ±0.19
0.26 ±0.03
0.51 ±0.26
0.13 ±0.05
The content of starch, in 100 g of fresh weight of
sweet potato’s tubers, averaged 14.83 g, with a
coefficient of variation V = 4.60%, which means a
very high stability of this trait (Tables 1 and 2). The
highest content of this component in tubers was
accumulated by the White Triumph variation, while
the lowest Carmen Rubin. Goldstar and White
Triumph variations were homogeneous in terms of
the amount of this component (Table 1). In tubers
of Cananua variation, which was cultivated in the
central-eastern part of Poland, Sawicka et al.
Marczak et al Page 173
(2004) obtained an average amount of starch: 21.98
g.100 g-1 with fluctuations from 15.96 to 26.24 g.100
g-1. In China’s conditions, the average value of
starch in the fresh weight of sweet potato’s tuber is
24.4 g 100 g-1 (Katayama et al., 2004). According to
the USDA National Nutrient Database for Standard
Reference (2007), carbohydrates are 20.12 g 100 g-1
of a fresh weight of tubers. Katayama et al. (2004)
showed that the content of starch in sweet potato’s
tubers, depending on the geographic area, may
range from 9.3 to 28.8 g.100 g-1.
The average content of sugars in tested cultivars of
sweet potato was 2.97 g.100 g-1 (fresh tubers) and
12.16 g.100 g-1 (dry weight), and reducing sugars
1.21g 100g-1 and 2.88g/100 g-1 in a fresh and dry
weight, respectively (Table 1). Coefficients of
variation for total sugars and reducing sugars were
21.55% and 23.97%, respectively (Table 2). Genetic
variation of researched variations decided about the
accumulation of both sugars sum and reducing
sugars. A variation with the highest concentration of
these components was White Triumph; so, due to
their high content, it can serve as a dietetic and
easily digestible food for children as well as for
diabetics. The lowest value of tested characteristics
was observed in Carmen Rubin tubers. The content
of soluble sugars in Goldstar tubers appeared to be
higher than in Carmen Rubin variation, but it was
significantly lower in comparison with the White
Triumph variation (Table 1).
In conditions of the central-eastern Poland, Sawicka
et al. (2004) got an average of 2.16 g of soluble
sugars in 100 g of a fresh weight, with fluctuations
from 1.97 g to 2.43 g, while for reducing sugars
1.11g with fluctuations in the range between 1.06-
1.17g. Ofiori et al. (2005) state that the total sugar
content in the dry weight of tubers oscillates,
depending on the variety and growing conditions,
from 5.53 to 16.99 g.100g-1, and reducing sugar
0.53-1.62 g.100 g-1. According to the USDA (2007),
the content of soluble sugars in a fresh weight of
sweet potato is about 4.18 g.100g-1, including
reducing sugars (mostly fructose and glucose),
which represent about 1.66 g.100g-1. The rest (i.e.
about 2.52 g.100 g-1) of sugars is sucrose. The total
content of protein averaged 1.35g.100 g-1 of a fresh
weight, while the coefficient of variation of this trait
V = 23.70% (Table 1, 2). In conditions of the
central-eastern Poland, Sawicka et al. (2004) stated
double value of protein (2.82 g.100 g-1) in a fresh
weight of tubers in the Cananua variety, with a
coefficient of variation V = 6.9%. After recalculation
of the results, expressed as the dry weight, the
content of protein in the studied sweet potato’s
tubers was 4.7-6.3 g.100 g-1. These values were in a
range found for this vegetable, which was
determined by Ofori et al., (2005) and Katayama et
al., (2004) 3.74-8.63 g.100 g-1.
According to the USDA National Nutrient Database for
Standard Reference (2007), a daily energy
requirement for men is 2700 kcal and for women
2000 kcal, including 8.3% in a form of protein. Sweet
potato’s tubers have an energy value about 86 kcal,
including 6% in a form of protein. Therefore, food
products from the sweet potato provide sufficient
amount of protein for a suitable, calorific diet
(Katayama et al., 2004). According to Gopalakrishnan
et al. (2011) in Papua New Guinea, protein from
Ipomoea batatas represents about 50% of the total
protein intake in a diet. These authors found from 0.8g
to 1.4 g of protein in 100g fresh weight of this
vegetable. On the other hand, according to Katayama
et al. (2004), the total content of protein can fluctuate
in a slightly wider range from 0.49 g to 2.13 g.100 g-1
of a fresh weight, while according to the USDA
National Nutrient Database for Standard Reference
(2007), the content of this component was 1.57 g in
100g of fresh tubers.
The content of vitamin C in sweet potato’s tubers
was between 20.26-24.20 mg.100 g-1, and the
content of L−ascorbic acid represented 82-88% of
the total content of this vitamin. Results, which
were obtained in this study, were similar to
amounts given by Sawicka et al. (2004) and
Krochmal-Marczak and Sawicka (2007). According
to Otieno et al. (2008), the content of vitamin C in
the fresh weight of this vegetable is in the range of
16.13-23.42 mg.100 g-1. According to Ukom et al.
(2009), fresh sweet potato’s tubers contain slightly
higher amounts of this nutrient, what is mainly
Marczak et al Page 174
modified by genetic characteristics of cultivars. In
the Sawicka’s opinion (2000), observed differences
in the chemical composition of tubers are
conditioned by the phenotypic variability of tuber
cultivars. They reflect a combined effect of genetic
and environmental variation. It is worth mentioning
a high and stable content of crude protein and
vitamin C over the years, and also a crude ash and
fiber. In functional food, this last component is
mainly highlighted.
In view of the rich chemical composition of
Ipomoea batatas, and also due to the content of -
amylase, it is included to the plants with a much
higher nutritional value than tuberous species
known in our country, such as: potato or Jerusalem
artichoke (Sawicka et al., 2000, Krochmal-Marczak,
Sawicka, 2007). The content of fibre in a fresh
weight of Ipomoea batatas tubers averaged 0.99%
with a coefficient of variation V = 28,88% (Table
1,2). In Polish conditions, Sawicka et al. (2004)
obtained the content of fiber in a fresh weight of
tubers at the level of 0.93 g with fluctuations from
0.84 g to 1.07 g.100 g-1. Chandy et al. (Indian
researches) (2013) obtained a similar content of this
component (1.0 g.100 g-1 in a fresh weight).
Abubakar et al. (2010) stated that cooked sweet
potato’s tubers have about 0.84 g.100 g-1 of a crude
fibre. According to the USDA (2007), the content of
a total, digestible fibre is 3.0 g.100 g-1 of a fresh
weight. The content of this component significantly
depended on genetic characteristics in examined
cultivars. The highest content of this component
was observed in the Israeli variety Carmen Rubin,
and the lowest one in Goldstar (American variety).
White Triumph variety produced less fibre than
Carmen Rubin variety, but significantly more than
Goldstar variety. An influence of varietals
characteristics on the chemical composition trait of
tubers is confirmed by Sawicka et al. (2004), Ukom
et al. (2009), Abubakar et al. (2010), Maloney et al.
(2012) and Chandy (2013).
The ash content in sweet potato’s tubers averaged 1.32
g.100g-1 of their fresh weight; with a coefficient of
variation V = 34.09% (Tables 1 and 2). In Polish
conditions, Sawicka et al. (2004) noted 1.51 g.100 g-1 of
a fresh weight. Ukam et al. (2009) in Pakistan stated
1.02-1.70 g.100 g-1 of this component in a fresh weight,
depending on the variety. Abubakar et al. (2010)
detected in cooked sweet potato’s tubers 1.03-1.23
g.100 g-1 of ash. The variety, which accumulates the
most amount of element was the White Triumph,
while the least amount Carmen Rubin. Influence of
varietal characteristics on the content of mineral
compound in sweet potato’s tubers was confirmed by
Sawicka et al. (2004); Ukom et al. (2009), Abubakar
et al. (2010) and Chandy (2013).
Contents of macronutrient
The studied sweet potato’s tubers are rich in
phosphorus, potassium, calcium and sodium, while
low in magnesium. The content of macro-elements in
sweet potato’s tubers, due to the stability, can be
ranged as follows: potassium phosphorus sodium
magnesium calcium (Table 2,3), therefore, the
least stable trait of mineral composition proved to be
calcium. According to the USDA (2007), sweet potato’s
tubers have in 100 g of a fresh weight: 337 mg of
potassium, 55 mg of sodium, 47 mg of phosphorus, 30
mg of calcium and 25 mg of magnesium. Colato
Antonio et al. (2011) showed in a dry weight of the
tuber: 320 mg of potassium, 47 mg of phosphorus, 22
mg of calcium and 13 mg of magnesium.
The average content of potassium was an average of
2.12 g.100 g-1 in a dry weight of sweet potato’s tubers
(Table 1). The coefficient of valuation of this trait was
low (V = 8. 96%) and it testifies a high stability of this
characteristic. In Polish conditions, the content of this
element in Ipomoea batatas tubers corresponds with
the amount of this element in potato and Jerusalem
artichoke tubers (Sawicka 2000, Sawicka and
Kalembasa 2008). According to the USDA (2007), its
average concentration in tubers is 337 mg.100g-1 of a
fresh weight, in Ukom et al. study (2009) 115-203
mg.100 g-1, depending on the variety.
The average content of phosphorus in tested tubers
was 0.26 g.100g-1 of a dry weight with the coefficient of
variation V=11,54% (Table 3,2) and it was in the
normal range (Bergman 1992). Genetic characteristics
of examined cultivars did not have a significant
Marczak et al Page 175
influence on the content of this element. These results
are confirmed in Krochmal-Marczak and Sawicka
studies (2007). A little higher content of this element
was noted by Sawicka et al. (2004). In the study of
Ukom et al. (2009), the content of phosphorus was
20.10-27.5 g.100g-1 in tubers, and according to the
USDA (2007) 47mg.100 g-1 of a fresh weight of
Table 3. Content macronutrients dry matter tubers Ipomoea batatas (g.100 g-1) (Mean for 2009-2011)
Carmen Rubin
White Triumph
* − not significant at P<0.05
Calcium is the basic mineral component of bones
and teeth. It takes part in blood coagulation
processes and it is essential for the proper
functioning of nerves and muscle contractions.
Therefore, it’s content in vegetables is very
important (Colato Antonio et at., 2011). In the
studied tubers, the content of this element averaged
0.51 g.100 g-1 with the coefficient of valuation
V=50.98%. This amount testifies its low stability
(Table 2,3). Among the tested cultivars, the richest
in calcium was White Triumph variety, while the
poorest Carmen Rubin. Goldstar variety
contained a significantly higher amount of this
element than the Carmen Rubin variety, but
considerably less than the White Triumph. In Ukom
et al. studies (2009), the content of calcium reached
the level of 40-91 mg.100 g-1, while according to the
USDA (2007) only 30 mg.100 g-1.
The average content of magnesium averaged 0.13
g.100 g-1 in a weight of sweet potato’s tubers.
Genetic characteristics of researched cultivars
proved to be a significantly modifying factor of the
potassium content in a dry weight of tubers. Tubers
of the White Triumph variety were the most
abundant in this element. Tubers in the Carmen
Rubin variety accumulated the least amount of
magnesium. On the other hand, the Goldstar variety
accumulated more of this element (in tubers) than
the Carmen Rubin variety, but significantly less
than the White Triumph variety (Table 3). This
macro-element showed an antagonist activity for K+
and NH4+ ions, and it reduces their accumulation
and binding with variety of enzymes. Magnesium
creates ionic bonds (bridge type), for example with
protein and ATP, and also participates in the pH
regulation in a cell. In opinion of Barłóg’s and
Frąckowiak Pawlak’s, (2008) and Touyz (2003),
food products of vegetable origin often contain too
small amounts of magnesium. This low level in
human and animal organisms (due to its role in the
activation of enzymatic processes) accelerates
processes of atherosclerosis and disorders of
nervous and muscle system.
The content of sodium in sweet potato’s tubers
formed at the level of 0.19 g.100 g-1 with a
coefficient of variation V = 21.05%. According to the
USDA (2007), the content of this element is 55
mg.100 g-1, while in Ukom et al. studies (2009)
28-33 mg.100 g-1 in tubers.
It was found, during the evaluation of relative
proportions of mineral components in plant
material, that the Ca:P proportion significantly
deviates from a recognized optimum (Table 4).
Relative proportions Ca:Mg and K:Mg were below,
and K:Ca above the optimum ration of these
components. Only K (Ca+Mg) proportion can be
considered as the optimal.
The standard deviation, as a measure of volatility a
classic, in addition to the arithmetic mean, it tells
you how widely the values of the treats are scattered
around the mean. The smaller the standard
deviation, the more observations are concentrated
Marczak et al Page 176
around its mean, and vice versa: it is the greater the
value characteristics are more varied. The low value
of the standard deviation for example, the dry
matter content of tubers say with a high
concentration of this trait. The median of the data
set is a value dividing the set, in this case, the
content of each component of the chemical
composition of tubers in two parts half of the data is
below a half - than the median.
Table 4. The proportion of mineral components in
Ipomoea batatas tubers (Mean weighed with years
K: (Ca
+ Mg)
K : Ca
K: Mg
Ca : P
Carmen Rubin
White Triumph
Kurtosis was in turn strongly varied and ranged
between -0.93 - for dry matter and 2.95 - for
vitamin C (Table 2). Skewness coefficient is set to
zero for a symmetric distribution, negative values
for distributions with left-sided asymmetry (left arm
extended distribution) and positive for distributions
with right-sided asymmetry (right arm extended
distribution). A negative value for the left-hand side
asymmetric distributions (left arm extended
decomposition) was observed for the starch,
protein, vitamin C, ascorbic acid, ash, calcium and
sodium. Negative kurtosis for the studied traits
indicates a flattening of its scope. The positive
coefficient of skewness level, for dry weight, total
sugars and reducing sugars, crude fibre, phosphorus
and potassium, is evidence of right-hand
distribution of features around the mean, or the
right-hand asymmetry. In contrast to the standard
deviation, which determines absolute differences
characteristics, the coefficient of variation is a
measure of the absolute, depending on the size of
the arithmetic average and the measure of the
spread of the results. The greatest variation among
the examined characteristics of the chemical
composition of tubers was characterized by calcium
(50.98%), while the lowest starch (4.59%), which
means that the value of the latter, in the conditions
of south-eastern Polish, is a treat very stable, while
the calcium content of the sweet potato tubers -
most characteristic variable.
1. The sweet potato’s tubers are rich in protein, total
sugars, reducing sugars, vitamin C, ascorbic acid
and macro-elements. The level of vitamin C and
starch in sweet potato’s tubers was similar to the
level in tuberous vegetables, which are cultivated
in Poland. On the other hand, the level of sugar
sum and reducing sugars in tubers was higher
than in tuberous vegetables in Poland.
2. Genetic characteristics of researched cultivars
significantly influenced the nutrient content in
sweet potato’s tubers. The most valuable variety
appeared to be White Triumph variation,
because it had the highest amount of dry weight,
total sugars and reducing sugars, protein,
vitamin C, ascorbic acid calcium and magnesium
in comparison with other cultivars.
3. The amounts of phosphorus, potassium, calcium
and sodium were proved to be high, while of
magnesium low. Goldstar variety was
characterized by the highest content of
potassium and sodium, while the lowest content
of magnesium and calcium was observed in the
Carmen Rubin variety.
4. During the assessment of relative proportions of
mineral components in Ipomoea batatas tubers,
it was found that the K:(Ca + Mg) ratio is the
most optimal.
5. Conducted studies indicate that nutrients, which
are contained in available for consumption sweet
potato’s tubers, can significantly improve the
nutritional status of consumers and reduce their
nutrition and health problems.
Abubakar HN, Olayiwola IO, Sanni SA,
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... Calcium is the basic mineral component of bones and teeth. It takes part in blood coagulation processes and is essential for the proper functioning of nerves and muscle contractions [31]. ...
... The difference in the values may be varietal. Sweet potato roots are fairly rich in calcium [31] and were found to contain 182.7 mg/kg in the present study. Calcium content in similar studies on amaranth varied between 15,120 mg/kg and 23,810 mg/kg in dried amaranth leaves [33]. ...
... Sweet potato roots are rich in vitamin C [14] and vitamin A [7]. The present study obtained 30.99 mg/100g of vitamin C. Slightly lower values (20.26 -24.20 mg/100g) were previously reported [31]; while 17.3-34.5 mg/100 g which confirm the present findings were also reported in similar studies [21]. ...
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No data exist on the nutrient composition of some important Rwandan staples. The aim of this study was to evaluate the nutrient content of red kidney beans, sweet potato roots, amaranth leaves and carrot roots. About 6 kg of each raw material were cleaned and conditioned prior to mechanical drying, ground and sieved [60-mesh] into flour and then subjected to quantitative analysis for proximate content,energy, calcium (Ca), iron (Fe), zinc (Zn), vitamin A and vitamin C. Proximate composition determination was done using Near Infrared Spectroscopy (NIRS), carbohydrates were determined by difference, energy was calculated, mineral analysis was done by Atomic Absorption Spectroscopy (AAS) and vitamin analysis was performed by High Performance Liquid Chromatography (HPLC) methods. The results showed that red kidney beans, sweet potato roots, amaranth leaves and carrots contain 21.48, 6.66, 29.46 and 13.8% of protein; 2.58, 1.68, 7.89 and 2.08% of fat; 60.86, 79.13, 19.29 and 57.38% of carbohydrate; 2.33, 2.68, 8.98 and 9.63% of fiber; 8.82, 8.74, 10.08 and 8.88% of moisture content; 3.94, 1.11, 24.30 and 5.16% of ash; 357.2, 363.7, 284.0, 322.9 kcal/100g of energy; and 146.4, 182.7, 26,290 and 1,247mg/kg of calcium,respectively. Red kidney beans, amaranth leaves and carrots contained8.54, 30.48, and 15.55 mg/kg of zinc; and 21.36, 219.1and 8.81 mg/kg of iron,respectively. Zinc and iron were,however,not detected in sweet potato samples analysed. Red kidney beans, sweet potato roots, amaranth leaves and carrot contained 768.0, 10,880, 399.4, and 6,413 IU/100g of vitamin A; and 2.67, 30.99, 330.3 and 6.76 mg/100g of vitamin C,respectively. In conclusion, the staples analysed contained appreciable amounts of nutrients and could be used to overcome malnutrition and allow dietary diversity. It could be recommended to prepare a Rwandanfood composition database in order to improve awareness on local grown crops’ quality.
... In recent years, numerous studies have focused on finding the antioxidants, including plant extracts as well as secondary metabolites of plants, that would scavenge FRs and support the defensive and regenerative mechanisms of the skin (Nichols and Katiyar, 2010;Wölfle et al., 2014;Jadoon et al., 2015;Pai et al., 2014). An example of such raw plant materials is the sweet potato (Ipomoea batatas (L.) Lam., Convolvulaceae family), whose tubers contain many beneficial phytochemicals, including carotenoids, minerals (zinc, potassium, sodium, manganese, calcium, magnesium, and iron), vitamins (vitamin A, B6, C, K), phenolic acids, flavonoids, anthocyanin, terpenoids, tannins, saponins, glycosides, alkaloids, and steroids (Sun et al., 2019;Krochmal-Marczak et al., 2014;Ayeleso et al., 2016). Although the sweet potato is not widely known as a medicinal plant, some studies have demonstrated its beneficial effects on the prevention or treatment of chronic diseases due to antioxidant, anti-inflammatory, antilipogenic, immunomodulatory, anticancer, antiulcer, and antimicrobial activities it exhibits (Tang et al., 2015;Ji et al., 2015;Li et al., 2013;Sugata et al., 2015;Mbaeyi-Nwaoha and Emejulu, 2013;Panda and Sonkamble, 2012). ...
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Objective New raw materials are still being sought that could nurture the skin and protect it against various harmful factors, including free radicals responsible for ageing processes, cell mutagenesis and formation of cancerous lesions. Although the sweet potato (Ipomoea batatas (L.) Lam.) is not widely known as a medicinal plant, the available study findings suggest its multidirectional, health relevant properties, including anti-inflammatory, immunomodulatory, antimutagenic, and antimicrobial activities, as well as anticancer potential. However, the data on its antitirosinase and protective effects on skin cells are rather limited. Methods Our study evaluated the phenolic content, antioxidant, and antityrosinase activities, as well as cytotoxic effects of the extracts obtained from three sweet potato cultivars ('Beauregard', 'Purple' and 'Carmen Rubin') on two human cell lines - keratinocytes (HaCaT) and fibroblasts (BJ). Results The results evidenced that the cultivar characterized by the strongest antioxidant properties as well as the positive effect on the vitality of skin cells is the ‘Beauregard’ cultivar. Our findings showed that all three types of sweet potato extracts were tyrosinase inhibitors, yet their inhibitory capacities differed significantly. Conclusions Sweet potatoes can be considered a reservoir of biologically active substances with beneficial health properties.
... Nabubya et al. (9) showed that curing and storing sweet potatoes at room temperature over time increased the amylolytic enzyme content. The moisture content of the raw sweet potato agreed with the 71% reported by Ukom et al. (17), although Marczak et al. (18) reported a mean value of 21.7%. The pre-malting characteristics of millet grain used in this study are shown in Table 1. ...
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The use of high enzyme sprouted sweet potato flour (SSPF) as a saccharification enhancer to improve the brewing properties of pearl millet (Pennisetum glaucum, L.) was investigated. The results show a linear relationship between hot water extract (HWE) and increased substitution levels of SSPF up to a maximum of 363oL/kg at 40% substitution (40SM). Similarly, diastatic power (DP) increased from 21oL in 100% millet malt to 24 and 33oL at 20% (20SM) and 40% substitution (40SM). This can be attributed to the high amylolytic potential of sprouted sweet potato flour. Saccharification time reduced from 40 to 10 minutes for 20SM and 40SM (SSPF/millet malt) mash samples compared to the barley malt control. With increasing levels of SSPF substitution, the free α‐amino nitrogen of SSPF/millet malt wort samples declined from 154 mg/L in all millet malt sample to 126 mg/L in 40SM sample. However, all samples had a high rate of apparent attenuation in fermentation. This substitution method offers opportunities to optimise the brewing potential of millet in countries where the cost of importation of barley malt is prohibitive. However, the levels of modification in the composite samples, suggest sweet potato flour could be used in the brewing and distilling industries alone or together with malted millet.
... Az 'Ásotthalmi12' fajta tenyészidejér l nincs hivatalos információ, de kísérletünkben az említettnél jelent sen hosszabb, körülbelül 130 napos tenyészid szerinti ültetés és betakarítás is megfelel termést eredményezett, még kés i ültetés esetén is. Hasonlóan hosszú, 120 napnál hosszabb tenyészid vel történ termesztés (május végi ültetés, október eleji betakarítás) jellemz különböz fajtákkal végzett lengyelországi kísérletekben is (Krochmal-Marczak et al., 2014). ...
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Absztrakt: A hazai édesburgonya termésének és termésbiztonságának javításában nélkülözhetetlen szerepe van-a vírusmentes szaporítóanyag-ellátás megoldása mellett-a term hely-és genotípus-specifikus termesztéstechnológia kísérleteken alapú kidolgozásának. Kísérletünkben egy hazai, min sített batátafajta, az 'Ásotthalmi12' ültetési és vetési idejének optimalizálásával kapcsolatban gy jtöttünk információt. Az ültetés négy id szakban, 2018. május 17. és június 26. között történt, a betakarításra 2018. szeptember 27. és november 7. között került sor. A maximális átlagtermést növényenként (2355 g) a legkorábbi, május 17-i ültetés és szeptember 28-i betakarítás esetén kaptuk, ugyanakkor a legalacsonyabb termést (1100 g) a legkés bbi, június 22-26. közötti ültetés és november 5-i betakarítás eredményezte. A hektárra átszámított (50 ezer növény Ha-1) termést tekintve, a legmagasabb és legalacsonyabb termés között 63 tonna Ha-1 különbség is lehet. Abstract: In addition to solving the supply of virus-free propagating material, the development of site-and genotype-specific cultivation techniques on the basis of experiments plays an essential role in improving the yield stability and production of Hungarian sweet potatoes. In our experiment, we collected information on the optimization of the planting and harvesting time of a domestic certified sweet potato variety, 'Ásotthalmi12', on medium-hard soil. Planting took place in four periods, 1. Bevezetés Annak ellenére, hogy a fokozott fogyasztói igényekkel párhuzamosan a termel i kedv, egyúttal a term terület is megnövekedett, a hazai édesburgonya [Ipomoea batatas (L.) Lam.] termés napjainkban nem tudja kielégíteni a magyar fogyasztók igényeit. A kereskedelemben a hazai termelés batátát március-áprilisban felváltja az import. Az édesburgonya-kutatás évszázados múltra tekint vissza Magyarországon, azonban a termésmennyiség és a termésbiztonság javítása napjainkra nélkülözhetetlenné tette-a vírusmentes szaporítóanyag-ellátás kérdésének megoldása mellett-a term hely-és genotípus-specifikus termesztéstechnológia kísérleteken alapú kidolgozását. Az édesburgonya szabadföldi ültetése a fagyok elmúltával kezd dhet meg, amikor a talajh mérséklet 10 cm mélységben eléri a legalább 18 °C-ot 4 egymást követ napon keresztül. A túl korai kiültetésb l fejl d növényeket károsíthatja a fagy, a dugványok gyökerei nem növekednek megfelel en, az indák lilás szín ek lesznek, vigoruk csökken, a gumóhozam alacsony, továbbá a gyökerek hosszúkás
... Interestingly, the vitamin C content was not influenced by the conditions (C1, C2, C3) of sweet potato. This retention of vitamin C was might be influenced by the slice thickness of the sweet potato during the sample preparation [59]. The slice thickness effect could be attributed to the higher holding capacity of vitamin C. It is important to note that vitamin C is an essential vitamin for the proper functioning of the human body to prevent hemorrhagic disease scurvy, maintain redox balance, synthesize amino acids, develop connective tissues, and absorb iron in the gastrointestinal tract [57,58]. ...
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In this study, physical and chemical properties (dry matter, ash, moisture, protein, fat, fiber, carbohydrate, starch, amylose, and vitamin C) of sweet potato tuber and flour of Anggun 1 cultivar were evaluated at different conditions. During peeling, the tuber and flour were processed subjected to three different conditions, which were unpeeled tubers (C1), peeled tubers (C2), and skin of tuber only (C3). From the results, the highest (p < 0.05) dry matter was observed in C1 while higher contents of ash, moisture, and protein were found in C3. Regarding the fat and vitamin C content, no significant differences (p > 0.05) were found between each condition. The highest fiber, carbohydrate, and amylose content (p < 0.05) were found in C1. The C1 and C2 reflected significantly higher (p < 0.05) starch content. Overall, these results provide important information about the peeling effect on the physical and chemical properties of Anggun 1. The information could be used as adding value to healthy food in the Malaysian diet due to the nutritional value of sweet potato.
Aim: Conduct research on the collection of new genotypes of sweet potatoes introduced under growing conditions in the Kharkiv district of Ukraine. Results and discussion: In the conditions in the Kharkiv district of Ukraine, an assessment was made of 13 genotypes of sweet potato a domestic and foreign selection. The genotypes were very different in length of the growing season, biometric parameters of plants, and productivity. The studied genotypes were divided into three ripeness groups. Samples that characterized the three groups - early ripening: V-1, V-6, А-7, В-4; medium ripening: Оr-3, D-2, М-8; late-ripening: B-9, P-11, B-10, J-12, Е-5, Оk-14. A wide range of shapes was obtained along the length of the stem. All genotypes that entered the mid-ripening group formed long, climbing stems. So, plants of the genotype Or-3 formed long stems similar to vines, 214 cm long. The genotypes of the early ripening group were characterized by lengths from 144 cm (V-6) up to 153 cm (А-7). According to the “Quantity of additional shoots” attribute, the variability range was 4–8 cm, and the coefficient of variation was 17%. Significant variation was observed along the length of the internodes (V = 30%). The variability range was 4.39–9.97 cm. According to the “Quantity of leaves” characteristic, the variability range was 40–77 pcs. And the coefficient of variation was 20%. The genotypes of the middle ripening group that had the largest “Quantity of leaves” were 77 pcs./plant (Оr-3) and 71 pcs./plant (D-2). The smallest was 40 pcs./plant (B-10), 42 pcs./plant (B-9), 44 pcs./plant (P-11). The root tubers in genotype V-6 had an oval shape, smooth peel, and pink color. The flesh was a creamy solid color; it was a sample of sweet potato. The shoots were long, climbing, leaves of a dark green color without anthocyanin color, kidney-shaped. The genotype of sweet potato D-2 of Ukrainian selection was a dessert variety. The tubers of the genotype were elliptical, orange with a smooth peel; the flesh was firm and bright orange. The shoots of the plants were very long, very climbing, and light green. The shoots of the leaves were kidney-shaped, light green. The results showed that table genotypes are of greater value for dietary nutrition. Dessert genotypes are conducive to a variety of diets for people with diabetes. A list of genotypes that can be used by people who follow a diet has been provided. Conclusion: In the conditions in the Kharkiv district of Ukraine, 13 introduced genotypes of sweet potato domestic and foreign breeding were evaluated. They already discovered that the genotypes were different in the growing season by biometric parameters of plants and yields. By using clonal selection in vitro culture, two completely new promising genotypes of domestic selection of sweet potatoes V-6 and D-2 were obtained. Tubers of genotype V-6 were oval, skin smooth, and pink. The average weight of one was 351 g. The raw flesh was cream-colored. Long shoots were woven, their length was 144 cm; the leaves were dark green, and kidney-shaped. Another example of a domestic selection of sweet potato D-2 was a dessert type. The root tubers were elliptical and had an orange color with smooth skin. The average weight of the tubers was 410 g. The raw flesh was a solid bright orange color. Shoots were extremely long -198 cm, very creeping, and had a light green color. The leaves were kidney-shaped and light green.
The objective of the paper was to compare the technologies, techniques of reproduction and their use in seed production of potatoes. The paper describes the use of the most important achievements of biotechnology, advanced breeding methods and emerging technologies for solving practical problems in potato cultivation and increasing their resistance to diseases and improving their quality. The most important, safe techniques for the propagation of potato propagating material is in vitro micro-propagation. Among alternatives to conventional propagated potatoes, the Micropropagation, through the aeroponic system (soilless cultivation in the air) is a prospective method of potato cultivation in terms of food safety and sustainability, as the cultivation of plants happens in the air, without any substrate. The nutrient solution is injected into the root zone at short intervals. The biggest advantages are higher yield with optimal quality, reduced consumption of water and nutrients, operation in a closed system and safety for the environment. Thus, an effective method of cooling the root zone and improving plant growth at higher temperatures under glass, signifies advantages making it widely be used in agricultural practice and in the micro-tubers production, offering a high reproductive rate as the tuber harvesting is possible for several times during the growing season and pathogen-free propagation material. The emerging technology enabled methods enable the production of seed potatoes in areas unsuitable for agriculture, unfavourable climatic conditions, or tropics, and allows for considerable water savings.
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Climate changes in the recent period, with a tendency to increase pedological and atmospheric droughts, determine Europe to choose new plant species that can more easily withstand thermal and hydrothermal stress, because the southern part of Hungary, Romania, Slovakia, and Poland is a natural background, who favouring of significant the impact of drought on crops. The importance of growing sweet potatoes is due both to the possibility of expanding the yield in areas where potatoes are degenerating and the need to diversify the vegetable assortment with less known species but with high nutritional value that will effectively use the mesoclimatic conditions, especially in sandy soil in of Romania, or Polish. New varieties of sweet potatoes to establish profitability of their cultivation in marginal soils in south-eastern and central-eastern Europe. The high nutritional, energy, pharmacological and fodder value of sweet potato is an important subject of scientific research, not only in America, Africa, and Asia, but also in Europe under the conditions of climate change. The content of basic substances, such as carbohydrates, proteins, lipids, carotenoids, anthocyanin’s, vitamins, minerals, and secondary metabolites, both in the root tubers and in sweet potato leaves, makes it a very nutritious herbaceous plant ensuring food safety for humans and animals. Sweet potato products can be effectively used as ingredients in food, medicine, cosmetics, but also as an energy base in European conditions and can compete with products imported from other continents.
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Lobjectif de cette etude est letude des caracteristiques mecaniques de varietes de tubercules dignames, de patates et de manioc consommes au Burkina Faso. Deux varietes ont ete etudiees par tubercules et les principaux paramètres mecaniques etudies sont la resistance à la penetration des tubercules et leurs forces maximales de decoupe. Un banc dessai traction compression muni dun capteur de compression dune force maximale de 2000 Newton (N) a ete utilise à cet effet.Un outil de decoupe ainsi quune tige ont ete utilises respectivement pour la decoupe des tubercules en tranche et pour leur penetration. Six (06) plages de vitesses (15, 30, 45, 60, 75, 90 mm/s) ont ete utilisees pour la decoupe des tubercules en tranches, et une vitesse de 20 mm/s pour la penetration. Les teneurs en eau moyennes des tubercules etudiees etaient comprises entre 58,8±1,8 % et 77,1 ± 1,8 %. Lanalyse des resultats des tests de durete et de decoupe des tubercules nous ont permis dobtenir leurs forces maximales de penetration qui sont de 145 N pour ligname bêtê bêtê, 216 N pour la patate douce fadanga blanche et 391 N pour le manioc kalagè.Les forces maximales de decoupe sont de 311 N pour ligname gogo, 347 N pour le manioc kalagè et 410 N pour la patate douce fadanga blanche. Cette etude nous permet de mieux comprendre les facteurs pouvant affecter lefficacite de decoupe des tubercules. Les donnees de cette etude peuvent être dintegrees dans le dimensionnement des motorisations des equipements de transformation post-recolte des tubercules en vue de leur optimisation energetique.
Many indigenous Nigerian plant species that served as foods several years ago are presently neglected and going extinct. The major challenge is that they are considered as food for low-income earners because there is little or no knowledge of the value additions made to these crops. Most of these species of crops are highly nutritious and can produce under marginal growing conditions therefore, they can be used to combat hidden hunger and food insecurity. This work is a compilation of research work performed over the years on some neglected Nigerian root and tuber crops: sweet potato (Ipomoea batatas); Polynesian arrowroot (Tacca leontopetaloides); water yam (Dioscorea alata); arieal yam (Dioscorea bulbifera); cocoyam (Colocasia esculanta) and Hausa potato (Solenostemon rotundifolius). The nutritional contents or food qualities of the above crops were highlighted and also the various ways of adding value to some of the crops were identified and discussed along their value chains. The purpose of this work is to bring out the need to refocus attention on these crops for increased food production, conservation of the crops and subsequent food security in Nigeria.
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The contents of copper, iron, manganese, molybdenum and zinc were estimated in tubers of Jerusalem artichoke Helianthus tuberosus L. coming from the field experiment conducted over 2003-2005. The experimental factors were cultivars of Jerusalem artichoke Albik and Rubik as well as their nitrogen fertilization levels, against phosphorus and potassium fertilization and the full dose of manure. The cultivar Rubik proved to be more abundant in mineral elements than Albik. The latter was characterized by a higher stability of characteristics. The largest mineral element concentrations of copper, manganese and zinc in the tubers were found in objects fertilized with 150 kg N ha-1, while the highest concentrations of molybdenum and iron were found in the control object without mineral fertilization.
The nutrient and anti nutrient composition of some standardized sweet potato dishes in Kwara state was determined using official methods of analysis. The indigenous sweet potato dishes analysed included pounded sweet potato/yam; sweet potato leaf soup; boiled sweet potato; fried sweet potatoes and sweet potato/beans pottage. There were significant differences (p < 0.05) for moisture content which in the proximate, minerals and antinutrient contents of sweet potato dishes. The moisture contents varied between 35.15% in sweet potato and pounded yam to 70.54% in sweet potato leaf soup. The highest protein content of 12.21% was found in sweet potato leaf soup and least value of 1.42% in sweet potato and pounded yam. The fat content of the samples ranged from 0.30% in sweet potato boiled to 3.88% in sweet potato leaf soup. Sweet potato boiled sample had the highest carbohydrate content of 70.54% while sweet potato leaf soup sample had the least value of 25.74%. The ash contents varied from 1.13% in sweet potato boiled to 8.83% in sweet potato leaf soup. The sweet potato leaf sample had the highest content of iron 8.82 ± 0.05 mg/100g while boiled sweet potato sample was highest in zinc (0.26 ± 0.01mg/100g) among all the dishes. Phytate contents ranged from 0.57 to 1.07 mg/100g, oxalate contents ranged from 126.93 to 178.27mg/100g and tannin ranged from 0.22 to 0.86 mg/100g for sweet potato dishes. The contributions of these varied nutrient contents to reducing the nutritional problems in the society were discussed.
Human essential hypertension is a complex, multifactorial, quantitative trait under polygenic control. Although the exact etiology is unknown, the fundamental hemodynamic abnormality in hypertension is increased peripheral resistance, due primarily to changes in vascular structure and function. These changes include arterial wall thickening, abnormal vascular tone and endothelial dysfunction and are due to alterations in the biology of the cellular and non-cellular components of the arterial wall. Many of these processes are influenced by magnesium. Small changes in magnesium levels may have significant effects on cardiac excitability and on vascular tone, contractility and reactivity. Accordingly magnesium may be important in the physiological regulation of blood pressure whereas perturbations in cellular magnesium homeostasis could play a role in pathophysiological processes underlying blood pressure elevation. For the most part, epidemiological and experimental studies demonstrate an inverse association between magnesium and blood pressure and support a role for magnesium in the pathogenesis of hypertension. However data from clinical studies have been less convincing and the therapeutic value of magnesium in the prevention and management of essential hypertension remains unclear. In view of the still ill-defined role of magnesium in clinical hypertension, magnesium supplementation is advised in those hypertensive patients who are receiving diuretics, who have resistant or secondary hypertension or who have frank magnesium deficiency. A magnesium-rich diet should be encouraged in the prevention of hypertension, particularly in predisposed communities because of the other advantages of such a diet in prevention. The clinical aspect that has demonstrated the greatest therapeutic potential for magnesium in hypertension, is in the treatment of pre-eclampsia and eclampsia. The present review discusses the role of magnesium in the regulation of vascular function and blood pressure and the implications in mechanisms underlying hypertension. Alterations in magnesium regulation in experimental and clinical hypertension and the potential antihypertensive therapeutic actions of magnesium will also be addressed.
To investigate the tolerability, efficacy, and mode of action of Caiapo, an extract of white sweet potatoes, on metabolic control in type 2 diabetic patients. A total of 61 type 2 diabetic patients treated by diet were given 4 g Caiapo (n = 30; mean age 55.2 +/- 2.1 years; BMI 28.0 +/- 0.4 kg/m(2)) or placebo (n = 31; mean age 55.6 +/- 1.5 years; BMI 27.6 +/- 0.3 kg/m(2)) once daily for 12 weeks. Each subject underwent a 75-g oral glucose tolerance test (OGTT) at baseline and after 1, 2, and 3 months to assess 2-h glucose levels. Additionally, fasting blood glucose, HbA(1c), total cholesterol, and triglyceride levels were measured. After treatment with Caiapo, HbA(1c) decreased significantly (P < 0.001) from 7.21 +/- 0.15 to 6.68 +/- 0.14%, whereas it remained unchanged (P = 0.23) in subjects given placebo (7.04 +/- 0.17 vs. 7.10 +/- 0.19%). Fasting blood glucose levels decreased (P < 0.001) in the Caiapo group (143.7 +/- 1.9 vs. 128.5 +/- 1.7 mg/dl) and did not change in the placebo group (144.3 +/- 1.9 vs. 138.2 +/- 2.1 mg/dl; P = 0.052). A decrease in body weight was observed in both the placebo group (P = 0.0027) and in the Caiapo group (P < 0.0001), probably due to a better- controlled lifestyle. In the Caiapo group, body weight was related to the improvement in glucose control (r = 0.618; P < 0.0002). Two-hour glucose levels were significantly (P < 0.001) decreased in the Caiapo group (193.3 +/- 10.4 vs. 162.8 +/- 8.2 mg/dl) compared with the placebo group (191.7 +/- 9.2 vs. 181.0 +/- 7.1 mg/dl). Mean cholesterol at the end of the treatment was significantly lower in the Caiapo group (214.6 +/- 11.2 mg/dl) than in the placebo group (248.7 +/- 11.2 mg/dl; P < 0.05). No significant changes in triglyceride levels or blood pressure were observed, and Caiapo was well tolerated without significant adverse effects. This study confirms the beneficial effects of Caiapo on plasma glucose as well as cholesterol levels in patients with type 2 diabetes. For the first time, the long-term efficacy of Caiapo on glucose control was demonstrated by the observed decrease in HbA(1c). Thus, the neutraceutical Caiapo seems to be a useful agent in the treatment of type 2 diabetes.
Chemical composition of sweet potato (Ipomoea batatas Lam) dishes as consumed Fluctuation of Selected Microelements in Ipomoea batatas (L.) Lam. tubers
  • M A Idowu
Idowu M. A. 2010. Chemical composition of sweet potato (Ipomoea batatas Lam) dishes as consumed Fluctuation of Selected Microelements in Ipomoea batatas (L.) Lam. tubers. Polish Journal of Environmental Studies 16, 163−165.
Official Methods of Analysis Association of Official Analytical Chemist
  • Oac
  • G Eua Ofori
  • I Oduro
  • Elis
  • Dapaah
OAC. 2000. Official Methods of Analysis Association of Official Analytical Chemist. EUA Ofori G, Oduro I, Elis, HK Dapaah. 2005.
Nutrient composition of selected sweet potato (Ipomoea batatas (L.) Lam) cultivars as influenced by different levels of nitrogen fertilizer application
  • A N Ukom
  • P C Oijmelukwe
  • D A Pokara
Ukom AN, Oijmelukwe PC, Pokara DA. 2009. Nutrient composition of selected sweet potato (Ipomoea batatas (L.) Lam) cultivars as influenced by different levels of nitrogen fertilizer application.
USDA National Nutrient Database for Standard Reference
Pakistan Journal of Nutrition 8, 1791-1795 (in Polish) USDA National Nutrient Database for Standard Reference, Release 20, 2007