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Mineral Properties and Dietary Value of Raw and Processed Stinging Nettle (Urtica dioica L.)


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Stinging nettle (Urtica dioica L.) has a long history of usage and is currently receiving attention as a source of fiber and alternative medicine. In many cultures, nettle is also eaten as a leafy vegetable. In this study, we focused on nettle yield (edible portion) and processing effects on nutritive and dietary properties. Actively growing shoots were harvested from field plots and leaves separated from stems. Leaf portions (200 g) were washed and processed by blanching (1 min at 96–98°C) or cooking (7 min at 98-99°C) with or without salt (5 g·). Samples were cooled immediately after cooking and kept in frozen storage before analysis. Proximate composition, mineral, amino acid, and vitamin contents were determined, and nutritive value was estimated based on 100 g serving portions in a 2000 calorie diet. Results show that processed nettle can supply 90%–100% of vitamin A (including vitamin A as β-carotene) and is a good source of dietary calcium, iron, and protein. We recommend fresh or processed nettle as a high-protein, low-calorie source of essential nutrients, minerals, and vitamins particularly in vegetarian, diabetic, or other specialized diets.
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International Journal of Food Science
Volume , Article ID , pages.//
Research Article
Mineral Properties and Dietary Value of Raw and Processed
Stinging Nettle (Urtica dioica L.)
Laban K. Rutto,1Yixiang Xu,2Elizabeth Ramirez,3and Michael Brandt1
1Alternative Crops Program, Agriculture Research Station, Virginia State University, Petersburg, VA 23806, USA
2Food Processing and Engineering Program, Agriculture Research Station, Virginia State University, Petersburg, VA 23806, USA
3College of Agriculture and Life Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
Correspondence should be addressed to Laban K. Rutto;
Received  February ; Accepted  April 
Academic Editor: Fernanda Fonseca
Copyright ©  Laban K. Rutto et al. is is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Stinging nettle (Urtica dioica L.) has a long history of usage and is currently receiving attention as a source of ber and alternative
medicine. In many cultures, nettle is also eaten as a leafy vegetable. In this study, we focused on nettle yield (edible portion) and
processing eects on nutritive and dietary properties. Actively growing shoots were harvested from eld plots and leaves separated
from stems. Leaf portions ( g) were washed and processed by blanching ( min at –C) or cooking ( min at -C)
with or without salt ( gL−1). Samples were cooled immediately aer cooking and kept in frozen storage before analysis. Proximate
composition, mineral, amino acid, and vitamin contents were determined, and nutritive value was estimated based on  g serving
portions in a  calorie diet. Results show that processed nettle can supply %–% of vitamin A (including vitamin A as 𝛽-
carotene) and is a good source of dietary calcium, iron, and protein. We recommend fresh or processed nettle as a high-protein,
low-calorie source of essential nutrients, minerals, and vitamins particularly in vegetarian, diabetic, or other specialized diets.
1. Introduction
Stinging nettle (Urtica dioica L.)hasalonghistoryasone
among plants foraged from the wild and eaten as a vegetable
[,]. Although not fully domesticated, the species remains
popular even in the current era for food and medicine as
reported, for example, in Nepal [] and Poland [].
Despite U. dioic a being recognized as an edible and highly
nutritious vegetable, research attention has focused more on
its value as a source of alternative medicine and ber. Clinical
trials have conrmed the eectiveness of nettle root and
saw palmetto (Serenoa repens (Bart.) Small) fruit extracts
in the treatment of benign prostatic hyperplasia []. Dried
nettle leaf preparations are also known to alleviate symptoms
associated with allergic rhinitis [], and a technology for
granulating lipophilic leaf extracts for medicine has been
developed []. A recent report from ongoing work in Italy
conrms the potential of U. dioica as a sustainable source of
textile ber [].
ere are a number of reports that address the role of U.
dioica in human nutrition. Fatty acid and carotenoid content
in leaf, stem, root, and seed samples have been measured
[], and the properties of phenolic compounds in leaves,
stalks, and bers have been reported []. Furthermore, the
quality and safety [] and microbiological properties []
of sucuk, a Turkish dry-fermented sausage, incorporating
dried U. di oic a leaf have been studied, and the capacity
of nettle extracts to improve oxidative stability in brined
anchovies has been reported []. In the Basque region of
Spain, young shoots are reportedly eaten raw or included in
omelets []. In terms of postharvest processing for long-term
method for preservation of leaf color, energy consumption,
and processing time []. Mineral content []andtracemetal
concentrations [] in nettle leaf tea made by infusion or
decoction have also been determined.
However, nettle is consumed primarily as a fresh veg-
etable whereby it is added to soups, cooked as a pot herb, or
International Journal of Food Science
used as a vegetable complement in dishes. In this sense, more
work needs to be done on nutritive value of fresh nettle, and
products. is information is essential because the capacity
of fresh nettle to irritate bare skin may discourage potential
consumers and postharvest processing methods that make it
safe to handle, while maintaining nutritive value will benet
the development of U. dioic a as a specialty vegetable.
In this study, we report dietary values, mineral properties,
and other quality attributes of raw, blanched, and cooked
stinging nettle.
2. Materials and Methods
2.1. Plant Materials. Plant samples were obtained from eld
plots planted as a part of an ongoing agronomic study on
U. dioica at Randolph Farm (.N; .W), Virginia State
University (VSU). Samples from fall and spring growth were
collected in October  and May , respectively, by
harvesting actively growing shoots (20 ± 2cm) before the
onset of owering. Individual shoots were clipped with a
transfer to a demonstration kitchen located at the VSU Farm
Pavilion for further processing.
2.2. Sample Processing. In the kitchen, the shoots were
washed, and twelve 200 ± 5g units were weighed before
separating leaves and tender shoot tips from the woody
stem. e edible portion (leaves and tender shoot tips) was
the weight of edible portion as a percentage of total unit
mass. Treatments, each replicated three times, were applied
as follows: raw samples were packaged and frozen without
further processing, blanched samples were immersed in
boiling water (-C)formin,andcookedsampleswere
boiled (–C) with or without salt ( gL−1 H2O) for
 min. Both blanched and cooked samples were cooled to C
with shaved ice immediately aer treatment. All samples were
kept in frozen storage (C) before analysis. Samples for
proximate composition analysis were submitted frozen, while
those for fatty and amino acid analysis were freeze-dried and
ground to a ne powder before analysis.
2.3. Proximate Analysis. All analysis was done according to
the Association of Analytical Chemists (AOAC) methods
(AOAC, ). Moisture content was determined by drying
samples to constant weight using a convection oven. Nitrogen
(N) content was measured using a CN analyzer (LECO ,
LECO Corp., St. Joseph, MI), and protein content was derived
by multiplying N values with .. Total fat was determined
by gas chromatography (Agilent , Agilent Technologies,
Santa Clara, CA, USA) aer extraction of saponiable and
unsaponiable fractions, and ash content was measured by
ignition at C to constant weight. Carbohydrate content
and calorie values were calculated by dierence. Total dietary
ber was determined following methods described by the
American Association of Cereal Chemists (AACCI method
2.4. Vitamin and Mineral Analysis. Total vitamin A and vita-
min A as 𝛽-carotene were determined by colorimetry aer
alkaline digestion followed by extraction with hexane. Vita-
min C was extracted in acid and sample content determined
by titration. For mineral analysis, samples were subjected to
wet digestion before calcium, iron, and sodium content was
determined using an ICP spectrometer (AOAC, ).
2.5. Amino Acid Analysis. For amino acid analysis, a ground
subsample of nettle tissue was hydrolyzed with  M HCl at
C for  hr as previously described []. Acid hydrolyzed
amino acids were derivatized with phenyl isothiocyanate
(Acros Organics, Geel, Belgium) and separated using a 
Alliance HPLC equipped with a -cm Pico-Tag column, 
UV/Vis detector, and Empower soware (all from Waters
Corp., Milford, MA) using previously described conditions
[]. Amino acid concentrations are expressed in g/ g of
nettle leaf.
2.6. Fatty Acid Analysis. Fattyacidmethylesters(FAMEs)
were prepared by treating raw and processed samples with
ethyl chloride and absolute methanol as described []. Fatty
acid methyl esters were analyzed by gas chromatography
using an Agilent  N GC system (Agilent Technologies),
equipped with a HP-INNOWax column ( m ×. mm
I.D. ×. 𝜇m lm thickness) and ame ionization detector.
Peaks were identied against retention times for a known
included as an internal standard. e concentration of each
fatty acid is presented as a percentage of total saponiable oil
in sample.
2.7. Statistical Analysis. One-way analysis of variance
(ANOVA) using the Analyst function in SAS (version .
for Windows, SAS Institute, Cary, NC) was performed to
compare the eects of blanching and cooking on stinging
nettle quality and nutritive value. Treatments were treated as
independent variables, and data for fall  and spring 
were analyzed separately. Tukey’s HSD (𝑃 < 0.05)wasused
to separate treatment means within season.
3. Results and Discussion
3.1. Yield of Edible Portion in U. dioica. Actively growing
stinging nettle shoots are ideally harvested before owering
for consumption as a potherb or spinach alternative. Leaves
on stems were found to be tender enough for use as a
vegetable up to  cm from the growing point, but stems
become woody about cm away from the growing point
necessitating destemming aer harvest to separate the tender
tip (approx.  cm and leaves) from the woody stem. Our
% of total biomass with edible portion comprising of %
or more of harvested material (Tabl e  ). Yield (edible portion)
dierences in U. dioi ca growth characteristics. Consistent
with published observations [], U. dioica displays two
distinct phenological stages when grown in south-central
International Journal of Food Science
T : Edible portion (leaf) yield as a percentage of total biomass
in stinging nettle (Urtica dioica L.) harvested from eld plots in the
fall of  and spring of . Actively growing shoots ( ±cm)
were harvested and processed by de-stemming.
Season Shoot wt. (g) Stem wt. (g) Leaf wt. (g) Loss (%)
Fall   ±.a ±.  ±.  ±.
Spring   ±.  ±.     ±.  ±.
aMean (𝑛=3)±standard deviation.
Virginia: reproductive growth up to late spring, limited
development during summer, and mostly vegetative growth
in the fall.
3.2. Eect of Blanching and Boiling on Proximate Composition,
Vitamin, and Mineral Content in U. dioica. Aer draining,
there was not much dierence in moisture content between
raw and processed samples in the fall of , while there was
slightly more moisture in processed samples in the spring
of , likely due to dierences in draining time. ere
was a slight reduction in crude protein, ash, and fat aer
blanching or cooking in both fall and spring samples. In
both cases, the most signicant reductions were observed
with longer exposure to heat and also to salt. e same
applies to dietary ber, carbohydrate content, and calorie
value. Samples harvested in the spring contained signicantly
higher values for all parameters measured and showed higher
decline aer processing (Ta b l e ). Preparation and cooking
generally result in deterioration of vegetable quality. For
example, cooking signicantly reduces ash, carbohydrate
content, and caloric value in Cocoyam (Colocasia esculenta)
leaves [], while chopping amaranth (Amaranthus sp.) leaves
before cooking can result in increased loss of vitamins and
minerals []. Our results show that vitamin A, calcium,
and iron contents in U. dio ica leaf are similarly aected by
cooking. Sodium content was low and was not aected by
treatments signicantly (𝑃 < 0.05) increased sodium content
in drained samples (Ta b l e  ). Salt addition for seasoning or
preservation has been reported to aect vegetable quality
through dilution of minerals and other chemical changes
[]. Cooking led to changes in the fatty acid prole of U.
dioica with more saturated fat being converted into mono-
unsaturated and polyunsaturated forms (Tabl e  )orlostinto
solution. Saponiable oil content in raw and processed U.
dioica samples (.%–.% in the spring; .%–.% in the
spring) was comparable to that in wild asparagus (Asparagus
acutifolius)andblackbryony(Tamus communis), edible wild
greens common to Mediterranean diets [].
3.3. Eect of Cooking on Fatty and Amino Acid Composition
in U. dioica Tissue Samples. Data on individual amino and
fatty acid content in stinging nettle shows that the species
can supply signicant quantities of oleic (:), linoleic (:),
and 𝛼-linoleic (:) acids and is a good source of unsaturated
fatty acids. Considerable amounts of palmitic acid (:), a
saturated fatty acid, were found in the leaf (Tab l e  ;Figure ).
ere were no signicant dierences in fatty acid content
between samples collected from fall and spring growth.
Similarly blanching and cooking with or without salt did
not aect fatty acid content within season except for a
general trend showing an increase in unsaturated fatty acid
content and a corresponding decrease in the concentration of
saturated fatty acids (Table ). Similarly, high levels of linoleic
and 𝛼-linoleic acids in young and mature leaves and the
presence of relatively high concentrations of the same oils in
U. dioica seed, stem, and roots portions have been reported
[], with the seed containing up to % saponiable oil.
In terms of omega- fatty acid content, U. dio ica compares
favorably with frozen spinach (Spinacia oleracea L.) pre-
treated by steaming, blanching, or autoclaving []. Relative
to other commonly consumed wild plants, it contains a hig her
concentration of omega- fatty acids than borage (Borago
ocinalis), and about the same level as water-blinks (Montia
fontana)[], watercress (Rorippa nasturtium-aquaticum),
sheepsorrel(Rumex acetosella), and sorrel (Rumex induratus)
[]. However, carbohydrate content (including total sugars)
was signicantly lower in raw and processed U. dioica (.%–
.%) than in the four species above reported to constitute
.%–.% total carbohydrates []. ese results show
that processing by blanching and cooking has a minimal
impact on U. dioi ca fatty acid composition, implying that it
can be a good source of essential fatty acids when eaten as a
leafy vegetable.
With regard to individual amino acids, tissue content
was similarly not aected by season. Our results show
that U. dioica can supply considerable amounts of essential
amino acids including threonine, valine, isoleucine, leucine,
phenylalanine, and lysine, along with lower concentrations
of histidine and methionine (Table ;Figure ). Amino acid
content was largely unchanged in the spring as compared
with fall growth though asparagine, glutamine, leucine, and
histidine levels were generally lower in samples from spring
growth. ere were slight to signicant increases in amino
acid content aer blanching or cooking in fall samples,
but no similar observation was made for samples collected
in the spring (Tab l e ). ere may be dierences between
and within species in response to postharvest handling and
processing conditions. In one study, a signicant increase in
amino acid content was recorded aer cooking relative to
raw spinach [], while the opposite was true for cooked and
frozen versus raw Brussels sprouts [].
Data from this experiment show that both raw and
cooked U. dioica can be important sources of dietary protein.
e species can supply higher concentrations of essential
amino acids than Brussels sprouts []andhasabetter
amino acid prole than most other leafy vegetables. Although
similar to S. oleracea in terms of total amino acid content,
U. dioica contains higher levels of all essential amino acids
incorporating U. dioica leaf our in bread, pasta, and noodle
dough suggest that it can be used as a protein-rich supplement
in starchy diets associated with poor and undernourished
populations. is is because on a dry weight basis, U. dioica
leaf is better than almond (dry) and is comparable to com-
mon bean (Phaseolus vulgaris)andchicken(Gallus gallus)
asasourceofessentialaminoacids[]. e agronomic
International Journal of Food Science
T : Proximate composition, vitamins, minerals, and fatty acid prole of rawand processed stinging nettle (Urtica dioica L.) shoots harvested from eld plots in the fall of  and spring
of .
Fall  Spring 
Raw Blanched Cooked Cooked + salt Raw Blanched Cooked Cooked + salt
Proximate analysis
Moisture (%) . ±.a. ±.a. ±.a. ±.a. ±.c. ±.b. ±.b. ±.a
Protein (%) . ±.a. ±.ab . ±.a. ±.b. ±.a. ±.b. ±.b. ±.c
Fat (%) . ±.a. ±.b. ±.b. ±.b. ±.a. ±.a. ±.a. ±.b
Ash (%) . ±.a. ±.ab . ±.b. ±.b. ±.a. ±.b. ±.c. ±.c
Fiber, total dietary (%) . ±.a. ±.b. ±.c. ±.bc . ±.a. ±.b. ±.b. ±.c
Carbohydrates, total (%) . ±.a. ±.ab . ±.b. ±.b. ±.a. ±.b. ±.b. ±.c
Other carbohydrates (%) . ±.ab . ±.a. ±.b. ±.a. ±.a. ±.b. ±.b. ±.c
Calories, total (kcal/ g) . ±.a. ±.a. ±.a. ±.b. ±.a. ±.b. ±.c. ±.d
Calories from fat (kcal/ g) . ±.a. ±.ab . ±.bc . ±.c. ±.a. ±.ab . ±.b. ±.c
Vitamins and minerals
Vitamin A, total (IU/ g)  ±a ±a ±b ±b ±a ±bc  ±c ±b
Vitamin A, as 𝛽-carotene (IU/ g)  ±a ±b ±b ±c ±a ±b ±b ±c
Vitamin C (mg/ g) . ±.a. ±.b. ±.b. ±.b. ±.a. ±.a. ±.a. ±.a
Calcium (mg/ g)  ±c ±a ±ab  ±bc  ±a ±b ±b±c
Iron (mg/ g) . ±.c. ±.b. ±.a. ±.a. ±.a. ±.b. ±.b. ±.c
Sodium (mg/ g) . ±.b. ±.b. ±.b. ±.a. ±.b. ±.b. ±.b. ±.a
Fatty acid prole
Saturated fat (%) . ±.a. ±.b23.6 ± 4.1c. ±.d. ±.a. ±.bc . ±.b. ±.c
Monounsaturated (%) . ±.c. ±.a. ±.a. ±.b.  ±.a. ±.b. ±.b. ±.c
Polyunsaturated (%) . ±.c. ±.b. ±.c. ±.a. ±.d. ±.b. ±.c. ±.a
Cholesterol (mg/ g) . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
aMean (𝑛=3)±standard deviation. Values within a year followed by dierent letters are signicantly dierent at 𝑃 < 0.05 (Tukey’s HSD).
International Journal of Food Science
ain raw and processed stinging nettle (Urtica dioica L.) shoots harvested from eld plots in the fall of  and spring of .
Total fat (%) Fatty acidb(% of total fat)
: : : : : : : : : : :
Fall 
Raw 3.15 ± 0.12c17.06 ± 0.05a2.54 ± 0.04b1.86 ± 0.01a2.18 ± 0.01c23.30 ± 0.20a49.55 ± 0.10d0.83 ± 0.01a0.03 ± 0.01a1.37 ± 0.02a0.06 ± 0.01b1.23 ± 0.03a
Blanched 4.72 ± 0.05ab 14.91 ± 0.12b2.54 ± 0.02b1.41 ± 0.02c2.23 ± 0.02b21.58 ± 0.20b54.42 ± 0.37c0.67 ± 0.01c0.06 ± 0.01a1.11 ± 0.01c0.09 ± 0.02ab 0.98 ± 0.01b
Cooked 4.65 ± 0.10b14.83 ± 0.09b2.45 ± 0.02c1.60 ± 0.01b1.91 ± 0.03d20.96 ± 0.10c55.48 ± 0.20b0.69 ± 0.01b0.03 ± 0.01a1.13 ± 0.01b0.05 ± 0.01b0.88 ± 0.01d
Cooked + salt 4.78 ± 0.14a14.22 ± 0.11c2.62 ± 0.01a1.35 ± 0.01d2.54 ± 0.01a19.67 ± 0.2d56.70 ± 0.34a0.67 ± 0.01bc 0.05± 0.01a1.13 ± 0.01b0.14 ± 0.01a0.91 ± 0.01c
Spring 
Raw . ±.d. ±.a. ±.b. ±.a. ±.a. ±.a. ±.d. ±.a. ±.a. ±.a. ±.a. ±.a
Blanched .±.b. ±.b. ±.d. ±.c. ±.a. ±.b. ±.c. ±.b. ±.c. ±.b. ±.b. ±.d
Cooked .±.a. ±.d. ±.a. ±.c. ±.c. ±.c. ±.a. ±.c. ±.b. ±.b. ±.b. ±.c
Cooked + salt 3.58 ± 0.06c14.29 ± 0.05c.±.c1.67 ± 0.03b. ±.b. ±.d. ±.b. ±.b. ±.d. ±.b. ±.c. ±.b
aMethylated samples were analyzed for total fatty acid content using gas chromatography.
bPalmitic acid (:); palmitoleic acid (:); stearic acid (:); oleic acid (:); linoleic acid (:); 𝛼-linoleic acid (:); gadoleic acid (:); behenic acid (:); erucic acid (:); lignoceric acid (:).
cMean (𝑛=3)±standard deviation. Column values followed by dierent letters within season are signicantly dierent at 𝑃 < 0.05 (Tukey’s HSD).
International Journal of Food Science
T : Amino acid content in raw and processed stinging nettle (Urtica dioica L.) shoots harvested from eld plots in the fall of  and spring of .
Amino acid (g/ g) Fall  Spring 
Raw Blanched Cooked Cooked + salt Raw Blanched Cooked Cooked + salt
Isoleucine . ±.b. ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
Leucine . ±.b. ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
Lysine . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
Methionine . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
Tyrosine . ±.b. ±.ab . ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a
Phenylalanine . ±.b. ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
reonine . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
Valine . ±.b. ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
Histidine . ±.b. ±.ab . ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a
Total essential amino acids . ±.b. ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
Arginine . ±.b. ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
Aspartic acid + asparagine . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
Glutamic acid + glutamine . ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a. ±.a
Serine . ±.b. ±.ab . ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a
Proline . ±.b. ±.ab . ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a
Glycine . ±.b. ±.ab . ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a
Alanine . ±.b. ±.ab . ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a
Total amino acids . ±.b. ±.ab . ±.ab . ±.a. ±.a. ±.a. ±.a. ±.a
Dry matter (g/  g edible portion) . . . . . . . .
aMean (𝑛=3)±standard deviation. Row values followed by dierent letters within season are signicantly dierent at 𝑃 < 0.05 (Tukey’s HSD).
International Journal of Food Science
1.5 2 32.5 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5
Retention time (min)
Absorbance units (AU)
Glu +Gln −1.731
Asp +Asn − 1.568
Ser − 2.985 Gly − 3.147
His − 3.257
Arg −3.556
r − 3.722 Ala − 3.837
Pro −3.949
Tyr − 5.069
Val − 5.484
Met − 5.616
Cys2 − 2.785
Ile −6.539 Leu −6.665
Phe − 7.317
Lys − 8.136
Nleu − 6.917
0 2 4 6 8 1012141618
Retention time (min)
Peak area (pA)
16:1 − 6.282 17:0−6.917
18:0 − 8.134
18:1 − 8.444
18:3 − 10.062
20:0 − 10.868
20:1 − 11.179
22:0 − 13.571
20:1 − 14.254
24:0 − 16.449
F : Representative chromatograms showing peaks and retention times for dierent amino (a) and fatty (b) acids in raw and processed
stinging nettle (Urtica dioica L.) leaf samples.
F : Suggested food labeling information for raw and processed stinging nettle (Urtica dioica L.).
properties of U. dioi ca including perennial growth, quick
response to fertilization, and high biomass yield make it an
excellent candidate for low-cost mass production for such a
3.4. Labeling Information for Processed U. dioica. Results
from this study show that U. dioica retains a signicant
portion of minerals, vitamins, and essential nutrients aer
pre-treatment by blanching or cooking prior to frozen stor-
age. Processing may be the most eective approach to availing
the nutritional benets of U. dioi ca to consumers discouraged
by the stinging quality of live or fresh nettle. e nutritional
information in Figure , representing means of data from
raw and processed U. dioica leaf.However,lowervitaminA
and higher carbohydrate content and other data reported for
International Journal of Food Science
blanched U. di oica samples collected from the wild []show
that more work is required to evaluate the properties of U.
dioica products as aected by interactions between landrace,
environment, harvesting time, and processing conditions.
4. Conclusions
Although the usage of U. dioica as a leafy vegetable is
widespread, there is little information on processing poten-
tial, and the impact of dierent processing methods on nutri-
tive and functional value. e results presented in this report
show that U. dioi ca retains signicant amounts of minerals,
vitamins, and other functional values aer blanching or
cooking. We recommend processing and selling of U. dioi ca
leaf as a highly functional and nutritive food.
Conflict of Interests
e authors declare that they have no conict of interests.
e authors are grateful to Mr. Robert Kraemer and Mr. Lan-
don West, VSU Farm Manager and Assistant Farm Manager,
respectively, for eld support and to Dr. Ngowari Jaja for
assistance with sample preparation. is is a contribution of
Virginia State University Research Station Article No. .
[] A. di Tizio, J. Ł. Łuczaj, C. L. Quave, S. Redzic, and A. Pieroni,
South-Slavic diaspora of Mundimitar/Montemitro (Southern
Italy),Journal of Ethnobiology and Ethnomedicine,vol.,article
, .
[] Y. Uprety, R. C. Poudel, K. K. Shreshta et al., “Diversity of use
and local knowledge of wild edible plant resources in Nepal,
Journal of Ethnobiology and Ethnomedicine,vol.,article,
[] Ł. Łuczaj, A. Pieroni, J. Tard´
ıo et al., “Wild food plant use in
st century Europe: the disappearance of old traditions and the
search for new cuisines involving wild edibles,Acta Societatis
Botanicorum Poloniae,vol.,no.,pp.,.
[] N. Lopatkin, A. Sivkov, C. Walther et al., “Long-term ecacy
urinary tract symptoms—a placebo-controlled, double-blind,
multicenter trial,World Journal of Urology,vol.,no.,pp.
–, .
[] P. Mittmann, “Randomized, double-blind study of freeze-dried
Urtica dioica in the treatment of allergic rhinitis,Planta Medica,
[] S. A. Minina and M. G. Ozhigova, “Development of granulation
technology for lipophilic extracts,Pharmaceutical Chemistry
[] L. Bacci, S. Baronti, S. Predieri, and N. di Virgilio, “Fiber yield
and quality of ber nettle (Urtica dioica L.) cultivated in Italy,
Industrial Crops and Products,vol.,no.-,pp.,
[] J.L.Guil-Guerrero,M.M.Rebolloso-Fuentes,andM.E.Torija
Isasa, “Fatty acids and carotenoids from Stinging Nettle (Ur tica
dioica L.),JournalofFoodCompositionandAnalysis,vol.,no.
, pp. –, .
[] P. Pinelli, F. Ieri, P. Vignolini, L. Bacci, S. Baronti, and A.
Romani, “Extraction and HPLC analysis of phenolic com-
pounds in leaves, stalks, and textile bers of Urtica dioica L.,
Journal of Agricultural and Food Chemistry,vol.,no.,pp.
–, .
[] S. Karabacak and H. Bozkurt, “Eects of Urtica dioica and
Hibiscus sabdaria on the quality and safety of sucuk (Turkish
dry-fermented sausage),Meat Science,vol.,no.,pp.
, .
[] G. Kaban, M. I. Aksu, and M. Kaya, “Behavior of Staphylococcus
aureus in sucuk with nettle (Urtica dioica L.),Journal of Food
Safety, vol. , no. , pp. –, .
[] S. Turhan, I. Sagir, and H. Temiz, “Oxidative stability of
brined anchovies (Engraulis encrasicholus) with plant extracts,
International Journal of Food Science and Technology,vol.,no.
[] G. Menendez-Baceta, L. Aceituno-Mata, J. Tard´
ıa, and M. Pardo-de-Santayana, “Wild edible plants tra-
ditionally gathered in Gorbeialdea (Biscay, Basque Country),
Genetic Resources and Crop Evolution,vol.,pp.,
[] I. Alibas, “Energy consumption and color characteristics of net-
tle leaves during microwave, vacuum and convective drying,
Biosystems Engineering,vol.,no.,pp.,.
[] M. M. ¨
Ozcan, A. ¨
Unver, T. Uc¸ar, and D. Arslan, “Mineral con-
tent of some herbs and herbal teas by infusion and decoction,
Food Chemistry,vol.,no.,pp.,.
[] D. Kara, “Evaluation of trace metal concentrations in some
herbs and herbal teas by principal component analysis,Food
[] D. M. Albin, J. E. Wubben, and V. M. Gabert, “Eect of
hydrolysis time on the determination of amino acids in samples
of soybean products with ion-exchange chromatography or
precolumn derivatization with phenyl isothiocyanate,Journal
of Agricultural and Food Chemistry,vol.,no.,pp.,
[] S. A. Cohen, M. Meys, and T. L. Tarvin, e Pico-Tag Method: A
Manual of Advanced Techniques for Amino Acid Analysis,Waters
Division of Millipore, Milford, Mass, USA, .
[] G. Lepage and C. C. Roy, “Improved recovery of fatty acid
through direct transesterication without prior extraction or
purication,Journal of Lipid Research, vol. , no. , pp. 
, .
[] M. ˇ
utek, “Growth responses of Urtica dioica to nutrient
supply,Canadian Journal of Botany,vol.,no.,pp.,
[] M.N.Lewu,P.O.Adebola,andA.J.Afolayan,“Eectofcooking
on the proximate composition of the leaves of some accessions
of Colocasia esculenta (L.) Schott in KwaZulu-Natal province of
South Africa,African Journal of Biotechnology,vol.,no.,pp.
–, .
[] O. M. Funke, “Evaluation of nutrient contents of amaranth
leaves prepared using dierent cooking methods,” Food and
Nutrition Sciences,vol.,pp.,.
[] J. C. Rickman, C. M. Bruhn, and D. M. Barrett, “Nutritional
comparison of fresh, frozen, and canned fruits and vegetables
II. Vitamin A and carotenoids, vitamin E, minerals and ber,
Journal of the Science of Food and Agriculture,vol.,no.,pp.
–, .
International Journal of Food Science
[] D.Martins,L.Barros,A.M.Carvalho,andI.C.F.R.Ferreira,
“Nutritional and in vitro antioxidant properties of edible wild
greens in Iberian Peninsula traditional diet,Food Chemistry,
vol. , no. , pp. –, .
[] E. Cho, J. Lee, K. Park, and S. Lee, “Eects of heat pretreatment
on lipid and pigments of freeze-dried spinach,Journal of Food
[] J. Tard´
ıo, M. Molina, L. Aceituno-Mata et al., “Montia fontana
L. (Portulacaceae), an interesting wild vegetable traditionally
consumed in the Iberian Peninsula,Genetic Resources and Crop
[] C.Pereira,L.Barros,A.M.Carvalho,andI.C.F.R.Ferreira,
“Nutritional composition and bioactive properties of com-
monly consumed wild greens: potential sources for new trends
in modern diets,Food Research International,vol.,no.,pp.
–, .
[] Z. Lisiewska, W. Kmiecik, P. Gebczynski, and L. Sobczynska,
(Spinacia oleracea L.),Food Chemistry, vol. , no. , pp. –
, .
[] Z. Lisiewska, J. Słupski, R. Skocze´
n-Słupska, and W. Kmiecik,
“Content of amino acids and the quality of protein in Brussels
sprouts, both raw and prepared for consumption,International
Journal of Refrigeration,vol.,no.,pp.,.
[] FAO, Amino-acid content of foods and biological data on
proteins,FAO Food and Nutrition Series no. , Rome, Italy,
[] U.S. Department of Agriculture, Agricultural Research Service,
“USDA Nutrient Database for Standard Reference,” Release ,
... All of these factors are substantial obstacles to the successful control of viruses, including CMV, notably the lack of resistance genes in plants that present naturally, the emergence of new virus strains, and the escalating resistance of viral vectors to pesticides [32]. The resistance provided by RNA interference against viruses is based on transgenes, expressing RNA homologous to the target virus, on the other hand, can be an efficient and dependable strategy for viral disease management [27,42]. ...
... The first pathogenderived resistance described was in transgenic tobacco against the tobacco mosaic virus (TMV) as coat protein-mediated resistance [41]. Utilizing RNA interference (RNAi) technology has proven to be the most reliable and effective method for inducing virus resistance in plants [16,42,44]. Utilizing transgenic techniques, RNAi was produced in plants to confer pathogen-derived resistance to invading plant viruses [48,58]. ...
... Agricultural products adhere to internationally recognized quality standards across the world. The primary purpose of food packaging must be to maintain food safety and quality during storage and transportation [41][42][43][44], i.e., ...
Weed control is one of the most challenging chores in agriculture which accounts for a significant portion of the cost of output. The use of mechanical devices for weed extraction reduces the cost of labor and saves time. However, a mechanical device is rarely used in the northeastern part of the country. The reason may include the undulated terrain condition, lack of awareness and technical knowledge, and poor economic conditions. To help farmers in rural areas overcome their challenges, a low-cost portable device for uprooting and eliminating weeds has been developed. A rolling wheel with spikes on the periphery at the front end and a fixed rake at the back end make up the developed tool's working mechanism. The fixed rake's function is to ensure that all weeds left behind by the rolling wheel are eliminated. As a result, there's a high probability that weeding efficiency could be improved when compared to currently available tools.KeywordsNortheasternLow costRuralPeripheryFixed rake
... There is a long list of herbs that improve digestive enzymes and, eventually, growth [45,46], which is not within the scope of this article. Nettle contains essential amino acids [47], and phenolic compounds, such as vanillic acid (which is used as a flavoring agent), could increase feed palatability [27]. The improved feed intake and digestibility in both cold-water and warm-water species can be explained by these reasons. ...
... Dügenci et al. [57] reported that vitamin C increased iron uptake in fish intestines. Since nettle is rich in vitamin C and iron [47], an increase in RBCs, Ht, and Hb can be attributed to these vitamins' synergistic effect via stimulation of the head kidney [22,33]. The results of the administration of nettle in the fish diet on hematological parameters are presented in Table 2. ...
... By contrast, after 8 weeks of feeding, total blood serum immunoglobulin levels and respiratory burst activity significantly increased in beluga (204 g) in the 12% nettle group [35]. Improvement of nonspecific immune parameters can be interpreted as the effect of the nettle supplement in the diet of fish due to its different essential amino acids [47] and phenolic compounds, including quercetin, kaempferol, myricetin, and rutin [67], especially quercetin [23], which is known as a phenolic compound, and stimulated immune parameters in fish [21,24,33,36,37]. Nettle can boost serum total protein level and immune response of fish, as previously mentioned. ...
Full-text available
Aquaculture will become an important food production sector for humans in the coming decades. However, disease outbreaks can be considered a significant obstacle to continually developing aquaculture. Plant powders and extracts are natural feed additives that, due to their bioactive compounds, including phenolic compounds, proteins, vitamins, and minerals, have antistress, antiviral, antibacterial, and antifungal effects on fish. One of these herbs is nettle (Urtica dioica), which has a long history of being used in traditional medicine. While it has been widely investigated in mammalian medicine, few studies have been done on aquaculture species. The positive effect of this herb on the growth performance, hematology, blood biochemistry, and immune system of fish species has been observed. When fish were exposed to pathogens, nettle-fed fish showed a higher survival rate and less stress than controls. Therefore, this literature review is aimed at reviewing the use of this herb in fish diets and its impacts on growth performance, hematology, blood biochemistry, liver enzymes, immune system stimulation, and challenges with pathogens.
... Nettle, as one of the most undervalued of economic plants, has a long history of use as food, dye, cosmetic, and drug in folk veterinary and human medicine. It is widely recognized and used as an edible and highly nutritious vegetable, from young leaves that are added to soups or salads to dried leaves for winter use [3][4][5]. Beside its usage in human nutrition, nettle has been used all over the world for centuries in traditional medicine. This plant was used for the treatment of arthritis, anemia, rheumatism of the joints and muscles, hypertension, gastrointestinal diseasas, eczema and used as diuretics, astrigents, cleansing tonic, component of antidiabetic teas and blood purifier [6][7][8][9][10]. ...
... In other study [46], a higher content of macroelements Ca and Na was extracted from dried nettle leaves using maceration, than by Soxhlet and ultrasound-assisted techniques. Still, all three extraction methods in present study showed a significantly higher calcium content compared to sodium, in both fresh and dried samples, which is consistent with other reports of nettle, where calcium dominates compared to other macrominerals [3,36,[47][48]. In addition to the highest content of macroelement calcium, the highest content among the analyzed microelements of the parent sample of nettle leaves had iron. In the comparison research of nutritional properties of Stinging nettle (Urtica dioica) powder with wheat and barley powders, calcium and iron levels in nettle powder were much higher than those from wheat and barley powders [49]. ...
The samples of stinging nettle were collected during June in the Tuzla region. Aqueous extracts were prepared from fresh and dried leaves in order to determinate and compare content of bioactive components and antioxidant potential. Conventional soxhlet, ultrasound assisted extraction and traditional maceration extraction were used as extraction methods. Quantitative determination of phenols and flavonoids was carried out using spectrophotometric methods. Antioxidant activity of nettle aqueous extracts was determined using ferric reducing antioxidant power and DPPH free radical scavenging activity. Extracts obtained by Soxhlet extraction showed the highest total phenolic and flavonoid content and expected the highest antioxidant capacity, while extracts obtained by maceration gave the lowest results. KEYWORDS:stinging nettle extract;bioactive components;extraction;antioxidant
... All respondents in the study agreed to have used U. dioica as vegetables. It has also been noted that high consumption of U. dioica, is primarily in form of fresh vegetables whereby it is added to soups, cooked as a potherb, or used as a vegetable complement in dishes [22].The study found the invasive nature of U. dioica as the main reason for the failure of farmers to cultivate the plant on their farms. It was also noted that farmers who had attempted to cultivate the plant for commercial and domestic consumption later found it difficult to control it due to its fast growth rate and its ability to suppress other food crops. ...
... Given this wide spectrum of compounds, the nettle leaf indicates various biological activities, such as antioxidant, antibacterial, antiinflammatory, anti-ulcer, anti-anemic, anti-asthmatic, and cardiovascular. The diuretic, hypoglycemic, immunostimulating, choleretic and metabolism-accelerating properties of the nettle leaf have been proved as well [3,12,[17][18][19][20][21][22]. Due to their high nutritional value, fresh leaves, young herb and seeds have been used traditionally as a healthy food and feed. ...
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The purpose of the work was to determine the intraspecific variability of the stinging nettle, in respect of the mass of leaves and their chemical composition, including the content of phenolic compounds and assimilative pigments. The objects of the study were 10 populations of nettle, originating from the eastern and southern part of Poland. The results obtained indicate a high level of variability between and within the populations investigated but not strictly related to their geographical locations. The mass of the leaves ranged from 0.19 to 0.28 kg dry weight (DW)/plant (Coefficient of variation (CV) = 16.33%). Using HPLC–DAD, four phenolic acids were detected, i.e., caffeoylmalic (570.97–1367.40 mg/100 g DW), chlorogenic (352.79–1070.83 mg/100 g DW), neochlorogenic (114.56–284.77 mg/100 g DW) and cichoric (58.31–189.52 mg/100 g DW) acids, with the last one differentiating populations to the highest degree (CV = 48.83%). All of the analyzed populations met the requirements of the European Pharmacopoeia (Ph Eur 10th) concerning the minimum content of caffeoylmalic and chlorogenic acids in nettle leaves (not less than 0.3%). Within the flavonoid fraction, two compounds were identified, namely rutoside (917.05–1937.43 mg/100 g DW, CV = 21.32%) and hyperoside (42.01–289.45 mg/100 g DW; CV = 55.26%). The level of chlorophyll a ranged from 3.82 to 4.49 mg/g DW, chlorophyll b from 1.59 to 2.19 mg/g DW, while the content of carotenoids varied from 2.34 to 2.60 mg/100 g DW. Given all the traits investigated, the level of a population’s polymorphism (CV) was visibly higher within a population than between populations. Population no. 4 was distinguished by the highest mass of leaves, and the highest content of rutoside, while population no. 2 was distinguished by the highest content of hyperoside, caffeoylmalic and chlorogenic acid.
... In our research the distribution of fatty acids was different and the ratio of PUFAs and MUFAs was 1.06 in leaves and 1.16 in roots. High saturated, polyunsaturated, and low monounsaturated fatty acids content was reported in the research of Rutto et al. [26], i.e., 35.5, 61.8, 2.7 and 32.7, 59.8, and 7.5%, respectively when investigating fall and spring nettle leaves. ...
Full-text available
Stinging nettle (Urtica dioica L.) is an herbaceous plant that grows all over the world and is widely used as an edible and medicinal plant. Overall research results reveal that the chemical content and antioxidant activity of aerial parts and roots of stinging nettle depends on the growing region, soil, meteorological conditions (especially sunshine), collecting time, etc. The chemical composition of stinging nettle growing in Lithuania and the solid–liquid extraction efficiency of leaves and roots using different solvents were analysed. Additionally, we determined leaves phenols extraction efficiency using 96% methanol at different extraction conditions. Research results showed that a higher amount of crude fats, non-nitrogen extractives, and total carotenoids were in leaves, but the amount of crude proteins and ash did not differ significantly compared with roots. A higher amount of polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) were detected in roots instead of leaves while saturated fatty acids (SFAs) were in leaves. The extraction results showed that the most effective solvent for total phenols and flavonoids in leaves was 96% methanol, for total phenols in roots was 50% methanol and 50% ethanol for total flavonoids in roots. The most effective temperature for the Urtica dioica L. leaves phenols extraction was 70 °C, while time does not have a significant influence. The present study’s findings suggested that concentrated and binary solvents had different effects on the phenol’s extraction efficiency from different stinging nettle parts and extraction temperature performed a key role instead of extraction time.
... Nettle leaves are eaten fresh and can be used as a potherb, soup, and herbal infusion [5]. Stinging nettle leaves represent an inexpensive and excellent source of macroand micronutrients [6,7]. For a long time, beneficial effects of this plant have been confirmed in the treatment of many ailments including allergies, anemia, internal bleeding, wound healing, gastrointestinal tract, hemorrhage, skin, arthritis, gout, influenza, rheumatism, eczema, urinary system problems, cardiovascular system, and euglycemia [8,9]. ...
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Herbal treatment for diabetes mellitus is widely used. The pharmacological activity is thought to be due to the phenolic compounds found in the plant leaves. The present study aims to investigate the phytochemical composition of Urtica dioica (UD) hydroethanolic extract and to screen its antidiabetic activity by disaccharidase hindering and glucose transport in Caco-2 cells. The results have shown that a total of 13 phenolic compounds in this work, viz. caffeic and coumaric acid esters (1, 2, 4–7, 10), ferulic derivative (3), and flavonoid glycosides (8, 9, 11–13), were identified using HPLC-DAD-ESI/MS2. The most abundant phenolic compounds were 8 (rutin) followed by 6 (caffeoylquinic acid III). Less predominant compounds were 4 (caffeoylquinic acid II) and 11 (kaempferol-O-rutinoside). The UD hydroethanolic extract showed 56%, 45%, and 28% (1.0 mg/mL) inhibition level for maltase, sucrase, and lactase, respectively. On the other hand, glucose transport was 1.48 times less at 1.0 mg/mL UD extract compared with the control containing no UD extract. The results confirmed that U. dioica is a potential antidiabetic herb having both anti-disaccharidase and glucose transport inhibitory properties, which explained the use of UD in traditional medicine.
Four major lifestyle diseases (LD), viz. cardiovascular diseases, cancer, chronic lung diseases, and diabetes, are increasing rapidly and causing loss of human life and productivity worldwide, particularly in rural areas due to the lack of availability and accessibility to healthcare facilities in resource crunched areas. This increasing LD burden demands dietary strategies to prevent and treat such diseases. The present study has reviewed the secondary metabolites of several leafy vegetables, their role in human health, and how different species pose specific promise w.r.t the prevention/cure of diseases. It also makes a framework to establish how processing and cooking methods might affect the uptake and absorption of several biomolecules. Among 521 species of leafy vegetables, more than 100 leafy vegetables are documented with their compositional and functional details. In the model, to assess the bioavailability of the secondary metabolites in leafy vegetables, we considered two discrete classes based on their absorption properties, i.e. water soluble and lipid soluble. Also, cooking techniques like drying, boiling, steaming, and frying were simulated in the present work. However, the proposed framework gives a relative value to select better processing methods for leafy vegetables. Therefore, the current communication illustrates a strategy to harness the protective role of leafy vegetables, especially in rural areas.KeywordsLifestyle diseaseLeafy vegetablesProximate compositionConsumption pattern
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The purpose of the current research was to study the influence of dietary supplementation of nettle (Urtica dioica) on laying performance, egg quality and blood serum biochemical parameters of layers. A total of 60 laying hens (42 weeks old) from Lohman Klassik Brown breed were randomly allocated into three groups: a control and two experimental groups (n = 20 hens per group). All layers received compound feed with the following nutritional value: 2710 Kcal/kg metabolizable energy; 16.44% crude protein; 3.32% crude fats; 4.58% crude fibres; 3.73% Са; 0.49% Р. The hens from the experimental groups received 0.3% (experimental group 1) and 0.5% (experimental group 2) of dried nettle with the diet. Both experimental groups had significantly higher egg yolk pigmentation (p < 0.001) compared with the control group. A significantly lower egg yolk cholesterol content was found in hens from experimental group 1 (p < 0.05). Nettle addition reduced significantly blood serum glucose (p < 0.01 and p < 0.05 in experimental groups 1 and 2, respectively) as well as the total serum cholesterol content (p < 0.001).
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Purpose: The study aimed to document wild food plants usefulness in boosting immunity, fighting COVID-19 and other related viruses. The study also examined the diversity, distribution, parts used and season of availability of wild food plants that can be useful in boosting immunity to fight COVID-19. Subjects and Methods: The study was conducted in Himachal Pradesh (300 22' 40" to 330 12' 40" N Latitudes and 750 45' 55" to 790 04' 20" E Longitudes) northwest Himalaya from March 2020 to April 2021 by survey, sampling and interviewing knowledgeable persons through a questionnaire for the plants which are traditionally used as tonic and medicine to cure cough, cold and fever. Plants rich in antioxidant, Vitamin A,C and Zn were documented for their potential to boost immunity. Results: Ninety-five wild edible plants have been documented in this study belonging to forty families and seventy-seven genera. Family Asteraceae is found dominant, represented by 8 species followed by Lamiaceae (7 sp), Rutaceae and Brassicaceae (represented by 6 species each). Among genus, Ficus is found dominant represented by 4 species followed by Amaranthus, Oxalis, Rumex and Citrus (represented by 3 species each). These plants have been documented based on their medicinal and nutritive value like the richness in antioxidants, their ability to act as a body cleanser, cure common cold, cough and fever (Symptom similar to COVID-19) as revealed by a discussion with locals and literature reviews. These plants can be incorporated in our day-to-day life as a food, flavoring agent, or food supplement to boost immunity, fight COVID-19 or future challenges like COVID-19. Traditional knowledge of using these plants is on a sharp decline and their acceptability as a medicinal herb, food plants, or food supplement is the need of the hour to combat present and future challenges of pandemic COVID-19. Conclusion: Revitalization of our traditional health care and herbal healing with the use of nutritionally important medicinal wild food plants will be helpful to boost immunity and face ongoing and future challenges of pollution, stress, depression and pandemic like COVID-19. This can be done by the addition of documented plants as food and food supplements with some modern twist to our food plate.
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The effect of cooking on the proximate composition of the leaves of seven accessions (UFCe1 - UFCe7) of Colocasia esculenta (L.) Schott growing in KwaZulu-Natal Province of South Africa was investigated. Cooking significantly (P < 0.05) reduced the ash, carbohydrate and caloric contents of all the accessions tested in the study. In contrast, there was significant increase in the levels of moisture, crude protein, crude fibre and crude lipid in all the accessions except UFCe5 and UFCe6 where there was reduction in the crude lipid content. The results showed that cooking may improve the crude fibre contents as well as the levels of protein in the accessions. The accessions may be used in the management of obesity, diabetes, cancer and gastrointestinal disorders because of the high fibre content. The accessions can also serve as good candidates for proteins in cereal-based diets.
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Amaranth is a commonly consumed vegetable in households in Southwestern Nigeria. Raw amaranth is known to be rich in micronutrients particularly Iron and Vitamin C, which are lost during cooking due to the method of preparation. Hence, this study was conducted to determine the method of preparation that best retains nutrients. Three common me-thods of preparing amaranth were identified; method 1 in which no heat was applied but amaranth leaves were finely chopped (samples A), method 2 which was steaming before chopping the leaves (sample B) and method 3 involved chopping of leaves before blanching (sample C). These three samples were subjected to proximate analysis and micro-nutrient determinations. Results were mean of three determinations. Result of proximate analysis showed that sample B method of preparation has highest percentage of crude fat per gram of sample (2.31 ± 0.45), protein (4.35 ± 0.15) and fibre (1.09 ± 0.06). Sample A has highest percentage of moisture (90.35 ± 0.27) and ash content (1.36 ± 0.28) while sample C has highest percentage per gram of sample in carbohydrate (4.89 ± 1.21) only. Micronutrient determination results showed that sample A was highest in Vitamin C (1.57 mg ± 0.06) and Iron (535.84 ppm ± 123.42), followed by sample C (1.21 ± 0.07) and (501.88 ± 215.19) respectively while sample B had the least vitamin C (0.79 ± 0.06) and Iron (354.18 ± 121.84). The study showed that samples A best retained the nutrient contents of Amaranth leaves after preparation.
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Montia fontana L. is an aquatic plant traditionally consumed in the Centre and West of the Iberian Peninsula, where it is one of the most highly valued wild vegetables. The aim of this work wasto evaluate both the natural yield and nutritional value of this scarcely known plant. Two wild populations, from two different sites of Central Spain, were sampled during three consecutive years. Plant production was estimated by two parameters: production per unit of surface and plant percentage cover in the selected site. Nutritional analyses included proximate compositionand total energy, mineral macro and microelements, vitamin C, and organic acids.Mean yield at the growing areas was 2.64 kg/m2, though significant differences among sites and years were found. There is a positive correlation between production and accumulated rainfall from the beginning of the year till the collecting dates. The percentage cover of the species in the potential growing area was 8.25%, without significant differences among sites and years. Therefore, the wild populations of the species can reach a total mean production of 2138 kg/ha in this Spanish region.This is the first report of a global nutrient composition for Montia fontana. After moisture, the major constituent was fibre (4.44 %), much higher than many cultivated vegetables. Also appreciableamounts of vitamin C (34 mg/ 100g) and Mn (1.07 mg/100 g) have been found. Due to its high lipid content (1.94 %) this wild vegetable could be regarded as one of the richest source of omega-3 fatty acids among the leafy vegetables. This species can be considered an interesting wild resource for being included in the diet. More research is needed about its potential for being cultivated, different culture systems and selection of accessions with lower oxalate content.
Nettle leaves (Urtica dioica L.) were dried from an initial moisture content of 4·41 to 0·1 (dry basis) by involving microwave, convective and vacuum drying, respectively. Energy consumption and colour parameters for the nettle leaves were compared at these different drying conditions. In particular, the experiments were carried out at four different microwave power levels (500, 650, 750 and 850 W) and air temperatures (50, 75, 100 and 125 °C) to investigate the effect of these factors on the microwave and convective drying, respectively. Instead, under vacuum drying conditions both the influence of vacuum (20 and 50 mm [Hg]) and drying temperature (50 and 75 °C) were considered. Drying periods ranged from 4 to 6, 30 to 120 and 35 to 65 min for microwave, convective and vacuum drying, respectively. The semi-empirical Page's equation was able to reproduce the experimental drying curves at all operating conditions under microwave, convective and vacuum drying. The optimum method with respect to the drying period, colour and energy consumption was the microwave drying at 850 W.
The aim of the work was to evaluate the amino acid composition of fresh spinach and spinach products prepared for consumption. The investigation included fresh and cooked spinach and two kinds of frozen product: one obtained using the traditional method (blanching-freezing-refrigerated storage) and then cooked; and the other, of the ready-to-eat type, obtained using the modified method (cooking-freezing-refrigerated storage) and then prepared for consumption in a microwave oven. In 100g of edible parts of the as-eaten products, the content of amino acids exceeded that in the raw material from which they were obtained, except for sulphur amino acids and tyrosine. In the as-eaten products, the content of amino acids in protein calculated in 16g N was similar to that in the raw material, except for lower tyrosine and higher arginine content in the traditional frozen product prepared for consumption. Cystine with methionine was the amino acid limiting the quality of protein in the investigated samples, except for the traditional frozen product prepared for consumption, where the Chemical Score (CS) index was 100.
Sixteen trace metallic analytes (Ba, Ca, Ce, Co, Cr, Cu, Fe, K, La, Mg, Mn, Na, Ni, P, Sr and Zn) in acid digests of herbal teas were determined and the data subjected to chemometric evaluation in an attempt to classify the herbal tea samples. Nettle, Senna, Camomile, Peppermint, Lemon Balm, Sage, Hollyhock, Linden, Lavender, Blackberry, Ginger, Galangal, Cinnamon, Green tea, Black tea, Rosehip, Thyme and Rose were used as plant materials in this study. Trace metals in these plants were determined by using inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry. Principal component analysis (PCA), linear discriminant analysis (LDA) and cluster analysis (CA) were used as classification techniques. About 18 plants were classified into 5 groups by PCA and all group members determined by PCA are in the predicted group that 100.0% of original grouped cases correctly classified by LDA. Very similar grouping was obtained using CA.
This study examines the effects of nutrient supply (three N–P–K treatments: 75, 225, and 375 kg∙ha−1; 12.5% N, 8.5% P, 16% K) on growth, allometry, and architecture of Urtica dioica L., an expansive clonal plant found throughout Central Europe. Biomass allocation was significantly affected by nutrient supply: higher nutrient doses resulted in less biomass allocation to belowground organs, whereas the period of intensive production of aboveground biomass was prolonged. Shoot height increases with nutrient supply. The height ratios were constant over time. Within each treatment and each harvest, inflorescence biomass was positively correlated with shoot height. Branching of the main shoots (number of lateral branches) was positively correlated with plant height and changed with time. The number of new rhizomes was affected by both treatment and harvest, especially in older plants. The results suggest that high nutrient supply increased the allocation of biomass both to reproductive organs and to vegetative organs. Key words: allometry, biomass allocation, clonal plant, nutrients, plant architecture, Urtica dioica.