Mineral components analysis of selected dried herbs

Abstract

This study includes the content of water, ash and volatiles in dried herbs like Oregano, Basil and de Provance. Moreover, amounts of H, N and C, and their calorific value were measured. The content of the following elements (Al,

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ECONTECHMOD. AN INTERNATIONAL QUARTERLY JOURNAL – 2016, Vol. 05, No. 1, 127--132
Mineral components analysis of selected dried herbs
G.Zaguła ,A. Fabisiak ,M. Bajcar ,M. Czernicka ,B. Saletnik,C.Puchalski
University of Rzeszow, Department of Bioenergy Technologies; e-mail: g_zagula@ur.edu.pl
Received April 12 2016: accepted June 07 2016
Abstract. This study includes the content of water,
ash and volatiles in dried herbs like Oregano, Basil and de
Provance. Moreover, amounts of H, N and C, and their
calorific value were measured. The content of the
following elements (Al, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn,
Na, Ni, P, S, Sr, Zn) in the tested herbs were established
using the ICP-OES method. Basil leaves had the highest
nitrogen and ash content at the level 4.5% and 15,9%.
These herbs were characterized by a darker color as
compared to oregano. Basil contained the richest source
of Ca, K, Mg and P, while the lowest was found in herbs
de Provence. The best source of Ca, K, Mg and P was
basil, while their lowest amount was found in herbs de
Provence (containing a mixture of different herbs), which
mostly likely was the reason for the low amount of
macro- and micro-components.
Key words: physical parameters, de Provence, Basil
and Oregano herbs, caloric value, color, minerals, ICP-
OES.
INTRODUCTION
From the earliest times medicinal plants were the
primary source of drugs, and the knowledge of their
operation and application has been passed on to future
generations [14]. In Western Europe, the art of plant
treatment originated from medieval herbalism. Herbs first
gave proper taste and aroma to dishes and an additional
function was also the preservation of food. They have
also been used as drugs for a number of medical
conditions. Many species of herbal plants have medicinal
properties that beneficially impact the process of
digestion and assimilation of nutrients. They became less
significant as drugs when their place was taken by
chemistry, in particular antibiotics.
According to Kaiser et al. [2] marjoram extract
contains 78% polyphenols. Most rosemary acid is
contained by thyme and rosemary herbs, respectively 157
mg/g d.w. and 84 mg / g d.w., while oregano is rich in
caffeic acid- 12.6 mg/g d.w. [18].
The primary source of minerals for humans is food,
and pharmaceutical preparations should complement the
deficiency of certain elements [11]. Plant materials can be
a valuable source of many micronutrients present in
herbs. An additional asset for herbs is their bioavailability
[18]. Heavy metals are a threat that affect processed and
unprocessed food. According to the RASFF - Rapid Alert
System for Food and Feed [12] they concern mainly lead,
cadmium and mercury (more than 50% of reported alerts).
The high-concentration of heavy metals in plants is a
well-known problem.
According to studies, it is difficult to clearly
determine the primary source of pollution, in particular
since (in the case of herbs) heavy metals accumulate both
in leaves and roots. The influence of heavy metals and
other elements should be controlled so as not to exceed
the recommended values given by WHO [19]. This is of
particular importance not only in the case of herbs used in
medicine, where the concentration of heavy metals is a
major criterion in the production of the drug, but also in
foods which partly consist of herbs. In the case of food,
the acceptable level of micronutrients does not harm
health.
According to Łozak et al. [5] a good source of iron
can be found in infusions of mint and nettle (227 and 107
mg/kg). In contrast, fennel leaves are rich in compounds
of potassium (29%) [16]. Rosemary herbs contain a
significant amount of calcium, iron and potassium
[8].Basil is one of the most valued and most used spices
and the aromatic fresh or dried herb is used as an additive
to many dishes. In the Ocimum basilicum L. type, large
variations can be observed not only in the content and
composition of essential oil [6, 10]. Basil herb contains
0.5-2.5% essential oil with a variable chemical
composition [1]. Apart from the above, Basil contains
16% protein, 4.7% fat, 12% fiber, 5% of tannins, vitamin
C and E and carotenoids and
chlorophyll pigments and minerals. Oregano, aromatic
and rich in taste (Organum vulgare) contains antioxidants
(8%) and tannins (2%). This herb also contains vitamins
C, A, beta-carotene and minerals. Many authors have
reported that oregano is not harmful to health. One of the
most popular spice mixtures are Herbes de Provence. The
blend includes herbs such as basil, thyme, sage,
peppermint, summer savory,
marjoram and basil. The richness of the mixture sees it
used in salt-free diet. An objective of this paper was to

128 G.ZAGUŁA, A. FABISIAK , M. BAJCAR , M. CZERNICKA, B. SALETNIK....
define the active ingredients and the assessment of
cumulative elements in popular herbs.
Methods
The materials consisted of herbs of basil, oregano and
de Provence herbs purchased at the market. Each time 3
samples were taken to measure average values with
standard deviation. In the study, the content of ash,
moisture and volatile substances in the herbs was
determined by the LECO TGA 701 camera. The moisture
content was performed at 105°C, and the ash at 600°C
under nitrogen 0.01% comparator. The herbs' calorific
value was determined using an AC 500 camera.
For this purpose, the homogenized material was dried
in the oven at 105°C and then small tablets were made
using the Lormann press.
The calorific value was determined by the sample's
combustion in the oxygen atmosphere in a bomb
calorimeter placed in water. The content of sulfur, carbon,
hydrogen and nitrogen were determined using an S
module and CHN TrueSpecTM camera. The
measurements of Carbon, Hydrogen and Nitrogen were
carried out in an oven at 950°C and Sulphur at 1350°C.
The color of the samples was measured using the
UltraScan VIS spectrophotometer Hunter Lab. The white
plate standard was taken to establish the optical white
parametres values of L*=100.000, a*= 0.005, b*= -0.010.
The differences in energetics distance (between standard
and each herb sample) measured in the Lab color scale
were expressed as:






222 baLE  , (1)
where: ∆E is the difference in energetic distance,
∆ L, ∆ a, ∆ b - the difference in energetic distance in the
space for the parametres, respectively, L, a, b between the
optical plate parameter and sample.
The content of elements in the tested herbs was
determined by the ICP-OES method. The samples of the
studied herbs were mineralized in nitric acid 65% HNO3
(V) using the Milestone Spectro-Lab.
Standard solutions were prepared by diluting
polycyclic (Al, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P,
S, Sr, S, Zn) (Merck Millipore) standard solutions at the
concentrations of 1000ppm (mg/l). For the preparation of
standard solutions deionized water was used. In order to
determine the calibration curve, standard solutions at the
range of concentrations from (0.001-1 ppm) were used.
The study used the analytical lines of highest intensity.
Samples of the test material (5 g) containing 8 ml of
HNO3 were mineralized in accordance with the following
program: 5 minutes in temperature 150°C; 10 minutes in
temperature 150°C; 20 minutes in temperature 200°C; 30
minutes in temperature 50°C. An analysis of samples for
the presence of elements was carried out using an optical
emission spectrometer with the inductively coupled
plasma (ICP-OES). The operating conditions for ICP-
OES are shown in Table 1.
Table 1. ICP-OES operating conditions for the
determination of some elements in the herbs
Rf powers (W) 1150
Gas flow rate (ml/min) 5
Coolant gas 12
Auxiliary gas 0,7
Nebuliser gas 0,4
Sample uptake rate
(ml/min)
1
Pump rate (rpn) 70
Read time (s) 5
One-way analysis of variance (ANOVA) was
performed at the significance level of p = 0.05, n = 3 in
the test herbs for the mean values of water content, ash
content, volatile components, caloric value, C, H, N, and
measurement of color. The results were subjected to
statistical analysis in the Statgraphics Plus 4.1. program,
using the Student's t-test and Duncan's test at p = 0.05, n =
3. The principal component analysis of minerals and the
correlation matrix of macro-and microelements were
determined using the Statistica software package
(Statistica 6.0).
RESULTS AND DISCUSSION
Biologically active ingredients present in herbs are
important for the quality of herbal raw materials and
products, which are an additional component of the herbs
[15, 20].
Physicochemical parameters of the tested herbs
Table 2 shows the water, volatility, and ash content
in the tested herbs. The water content changed from 7,80
to 9,59% depending on the type of herbs.
Table 2. Identified parameters for herbs
Type herbs
De
Provence Basil Oregano
Identified
parameters for
herbs
x
±SD
x
±SD
x
±SD
Humidity (%) 8,72 ± 0,7b 9,59 ±
3,5c 7,80 ± 4,9a
Ash (%) 9,83 ± 0,7e 15,9 ±
0,8f 7,81 ± 3,0d
Volatiles (%) 22,2 ± 0,9g 22,6 ±
0,8g 22,4 ± 1,5g
Nitrogen, N
(%) 2,8 ± 0,7B 4,5 ±
3,1C 1,5 ± 0,6A
Carbon, C (%) 48,6 ± 1,7F 43,4 ±
0,7D 47,3 ± 1,1E
Hydrogen, H
(%) 5,8 ± 0,4G 5,3 ±
0,6G 5,4 ± 0,5G
Calorics
(MJ/kg dry
weight)
21382 ±
105b 17846 ±
150a 24015 ±
104c

MINERAL COMPONENTS ANALYSIS OF SELECTED DRIED HERBS 129
Explanatory notes:
Values are means with standard deviation.
a-g; A-I; a-c- (the same letters denote no statistically
significant differences at p = 0.05)
Dried herbs of different species did not significantly
influence the amount of volatile compounds. On the other
hand, the difference in ash content was significant. The
amount of ash in basil was 2 times higher than in
oregano. According to Kaloustian et al. [3], the value of
ash is closely related to the species of dried herbs. The
ash content of the tested herbs ranged from 7.8-15.9%.
Similar results were obtained by Santos et al. [13].
The results of the analysis of nitrogen, carbon and
hydrogen were different (Table 3). The highest content of
nitrogen at the level of 4.5% was reported in basil herbs,
while oregano contained only 1.5% of this element. The
contents of carbon and hydrogen, according to the tested
herbs, ranged respectively from 43.4-48.6% and 5.3-
5.8%.
The highest energy content with value of 24015
MJ/kg d.w. was found in oregano, while the lowest one
was obtained for basil, in which it amounted to 17
846 MJ/kg d.w.
The parametres of the dried herbs colors are shown
in Table 3. Type of herb significantly affected the L*
parameter. Colors of the tested herbs were characterized
by lightness with ∆L value in the average of 50 (mid
gray), greenness with negative ∆a from -2.55 to -1.76 and
yellowness refereed by positive ∆b value from 10.9 to
14.1.
Table 3. Color assessment of herbs de Provence,
basil and oregano
Type of herbs
Herbs de
Provence Basil Oregano
Identified color
parameters
x
±SD
x
±SD
x
±SD
∆L 46,9 ± 0,01a 50,3 ±
0,04b
52,3 ±
0,02c
∆a -2,55 ±
0,02d
-2,52 ±
0,01d
-1,76 ±
0,01e
∆b 10,9 ± 0,32f 12,8 ±
0,35g
14,1 ±
0,13h
Δ E 6,56 ±
0,09B
3,88 ±
0,03A
3,75 ±
0,07A
Explanatory notes:
Values are means with standard deviation.
a-h; A-I (the same letters denote no statistically
significant differences at p = 0.05)
In his studies Alibas [1] proved that the loss of color
(L*, a*, b*) nettles was the result, among others, of
thermal degradation. Changes in the content of
parameters a* and b* influenced the saturation of color in
the tested herbs. The total color difference (ΔE) between
the standard and sample was 3.75 for oregano, similar for
basil (3.88) and amounted to 6.56 for de Provence herbs.
Mineral components
Content of mineral significantly depends on macro-
and microelements. The threshold of measurement for
ICP-OES methods was above 0.001mg/g. Table 4 shows
the mineral content of basil, de Provence and oregano
herbs. The content of macro-and microelements was
significantly different in the tested herbs, with the
exception of copper for all herbs and chromium for basil
and oregano. Herbs de Provence constitute a mixture of
herbs with a similar amount of mineral components
compared to oregano (Table 4). In the case of basil the
content of elements was two times higher. Basil herbs
contain 25.1 mg/g Ca, 33.2 K, 9.59 mg/g Mg and 4.38
mg/g P. Similar results were obtained by Pachkore and
Markandeya [9], with reference to potassium. In the study
conducted by Özcan et al. [7, 8] chromium and
manganese, for the same varieties of basil, amounted to
0.068 mg/g and 0.17 mg/g.
In the studied spices, there was a high content of Mg
(2.92-9.59 mg/g), for which the range was similar to
herbal medicinal products tested by Ulewicz-Magulską
and Wesolowski [17].
In the case of herbs, the degree of accumulation of
minerals in leaves which are eaten directly or subjected to
drying methods, is of significant meaning. The analyzed
herbal plants differ in macronutrient content due to
differences in species.
Table 4. Concentrations of elements in tested herbs
Type of herbs
Herbs de
Provence Basil Oregano
Minerals
[mg/g]
x
±SD
x
±SD
x
±SD
Al 0,32 ± 0,27a 0,44 ± 0,06c 0,35 ± 0,17b
Ba 0,019 ±
0,05d 0,023 ± 0,04e 0,026 ±
0,03f
Ca 15,3 ± 0,31g 25,1 ± 0,42i 16,3 ± 0,47h
Cr b.t.m. b.t.m. b.t.m.
Cu b.t.m. b.t.m. b.t.m.
Fe 0,43 ± 0,10 B 0,74 ± 0,18C 0,41 ± 0,70A
K 18,1 ± 0,07E 33,2 ± 0,12F 13,4 ± 0,39D
Mg 5,07 ± 0,02H 9,59 ± 1,39I 2,92 ± 0,02G
Mn 0,08 ± 0,08a 0,07 ± 0,02a 0,05 ± 0,03a
Na 0,21 ± 0,09c 0,66 ± 0,03d 0,07 ± 0,02b
Ni b.t.m. b.t.m. b.t.m.
P 2,94 ± 0,12B 4,38 ± 1,21C 2,07 ± 0,01A
Pb b.t.m. b.t.m. b.t.m.
S 3,32 ± 0,31E 4,19 ± 1,03F 2,22 ± 0,05D
Sr 0,080 ±
0,003H
0,180 ±
0,007I
0,020 ±
0,002G
Zn 0,026 ±
0,005K
0,033 ±
0,001L
0,017 ±
0,003J
Explanatory notes:
Values are means with standard deviation.
a-k; A-J; a-I; A-J; A-F (the same letters denote no
statistically significant differences at p = 0.05)
b.t.m. - below the threshold of measurability

130 G.ZAGUŁA, A. FABISIAK , M. BAJCAR , M. CZERNICKA, B. SALETNIK....
An analysis of the major components (Ca, Mg, K, P)
of the tested herbs showed the formation of two groups.
The dendrogram in Figure 2 shows the first focus, which
includes herbs de Provence and oregano, and the second
bond (basil, herbs de Provence, and oregano). The
distances of the first and second bond were 5.3 and 22.2,
respectively.
0 5 10 15 20 25
Linkage Distance
Oregano
De provence herbs
Basil
Fig. 1. Dendrogram of cluster analysis
A correlation analysis is shown in Table 5. The
correlation coefficient, which is a measure of linear
dependence, can range from -1 to +1. The correlation
coefficients shown in Table 5 indicate a powerful
relationship between the elements in the tested herbs. This
may attest to the fact that to a large extent, the correlation
coefficient between the elements is higher than 0.5.
Similarly, high correlation coefficient elements were
obtained in the research of Karadaş i Kara [4] analyzing
selected herbs and spices.
This study showed significant correlations between Ca,
K, Mg, P. The elements which most often performed in
the correlation to other components were aluminum and
calcium. Generally herbs matrix was characterized by a
high propensity to the prevalence of high positive
correlation.
Table 5. Correlation matrix for the elements in dried herbs
Al Ba Ca Fe K Mg Mn Na P S Sr Zn
Al 1,00
Ba -0,18
1,00
Ca 0,98 0,02
1,00
Fe 0,94 0,16
0,99
1,00
K 0,87 0,33
0,95
0,98
1,00
Mg
0,82 0,42
0,92
0,96
1,00
1,00
Mn
-0,08
0,99
0,13
0,27
0,43
0,51
1,00
Na 0,87 0,34
0,95
0,98
1,00
1,00
0,43
1,00
P 0,78 0,47
0,89
0,95
0,99
1,00
0,56
0,99
1,00
S 0,64 0,64
0,78
0,86
0,94
0,96
0,72
0,94
0,98
1,00
Sr 0,79 0,45
0,90
0,95
0,99
1,00
0,55
0,99
1,00
0,97
1,00
Zn 0,65 0,63
0,79
0,87
0,94
0,97
0,71
0,94
0,98
1,00
0,98
1,00

MINERAL COMPONENTS ANALYSIS OF SELECTED DRIED HERBS 131
CONCLUSIONS
Dried herbs are still high in biologically active
compounds. The highest value of total color difference
(ΔE) between the sample and standard was found for
herbs de Provence. Physicochemical properties of herbs
depended on the type of the herb. Generally, high
contents of nitrogen and ash were found in dried leaves
of basil. Oregano herbs had the higher caloric value up
to 35% compared to basil.
Mineral content varied and was strictly correlated
with the grade of herbs. The best source of Ca, K, Mg
and P was basil, while their lowest amount was found
in herbs de Provence (containing a mixture of different
herbs), which mostly likely was the reason for the low
amount of macro- and micro-components.
REFERENCES
1. Alibas I., 2010: Determination of drying
parameters, ascorbic acid contents and color
characteristics of nettle leaves during microwave-,
air- and combined microwave-air –drying. Journal
of Food Process Engineering, 33, Pp. 213-233.
2. Kaiser A., Carle R., Kammerer D.K., 2013:
Effects of blanching on polyphenol stability of
innovative paste-like parsley (Petroselium crispum
(Mill.) Nym ex A.W.Hill) and marjoram (Origanum
majorana L.) products. Food Chemistry, 138, Pp.
1648-1656.
3. Kaloustian J., Portugal H., Pauli A.M., Pastor
J., 2002: Chemical, chromatographic and thermal
analysis of rosemary (Rosmarinus officinalis).
Journal of Applied Polymer Science, 83, Pp. 747-
756.
4. Karadaş C., Kara D., 2012: Chemometric
approach to evaluate trace metal concentrations in
some spices and herbs. Food Chemistry, 130,
Pp.196-202.
5. Łozak A., Sołtyk K., Ostapczuk P. Fijałek Z.,
2002: Determination of selected trace elements in
herbs and their infusions. Science of the Total
Environment, 289, Pp.33-40.
6. Miele M., Dondero R., Ciarallo G., Mazzei M.,
2001: Methyleugenol in Ocimum basilicum L. Cv.
Genovese Gigante. J. Agriculture and Food
Chemistry, 49, Pp.517–521.
7. Özcan M., Arslan D., Űnver A., 2005: Effect of
drying methods on the mineral content of basil
(Ocimum basillcum L.). J Food Enginering., 69,
Pp.375-379.
8. Őzcan M., 2004: Mineral contents of some plants
used as condiments in Turkey. Food Chemistry,
84, Pp.437-440.
9. Pachkore G.L., Markandeya S.K., 2010: Effect
of drying on the essentials oil and the mineral
contents of basil (Ocimum basilicum L.). The IUP
Journal of Life Sciences, 4,Pp. 39-43.
10. Purkayastha J., Nath S.C., 2006: Composition of
the camphor-rich essential oil of Ocimum
basilicum L. native to Northeast India. Journal
Essential Oil Research, 18, Pp. 332–334.
11. Pytlakowska K., Kita A., Janowska P.,
Połowniak M., Kozik V., 2012: Multi-element
analysis of mineral and trace elements in medical
herbs. Food Chemistry, 135,Pp. 494-501.
12. RASFF Raport, Rapid Alert System for Food and
Feed, 2008.
13. Santos J., Herro M., Mendiola J.A., Oliva-Teles
M.T., Ibáńez E., Delerue-Matos C., Oliveira
M.B.P.P., 2014: Fresh –cut aromatic herbs:
nutritional quality stability during shelf-life. LTW-
Food Science and Technology, (In Press).
14. Seidler-Łożykowska K., Koziak A., Golcz A.,
Mieloszyk E., 2006: Macroelements and
Essentials oil content in the raw material of the
selected medicinal plant species from organic
cultivation. Journal of Research and Applications
in Agricultural Engineering, 51,Pp. 1160-163.
15. Sharma, G. P., Prasad, S., 2004: Effective
moisture diffusivity of garlic cloves undergoing
microwave-convective drying. Journal of Food
Engineering, 65, Pp. 609–617.
16. Słupski J., Lisiewska Z., Kmiecik., 2005:
Contents of macro and microelements in fresk and
frozen dill (Anethum graveolens L.) Food
Chemistry, 91,Pp. 737-743.
17. Ulewicz-Magulska B., Wesołowski M., 2012:
Analiza porównawcza zawartości wybranych
biopierwiastków w ziołach o właściwościach
leczniczych i przyprawowych. Bromatologia i
Chemia Toksykologiczna, 1, Pp. 5-11.
18. Vallverdu-Queralt A., Regueiro J., Martinez-
Huelamo M., Alvarenga J.F., Leal L.N.,
Lamuela-Raventos R.M., 2014: A comprehensive
study on the phenolic profile of widely used
culinary herbs and spices: Rosemary, thyme,
oregano, cinnamon, cumin and bay. Food
Chemistry, 154,Pp. 299-307.
19. WHO, 2002: Traditional medicine strategy 2002-
2005. Geneva.

132 G.ZAGUŁA, A. FABISIAK , M. BAJCAR , M. CZERNICKA, B. SALETNIK....
20. Yongsawatdigul, J., Gunasekaran, S., 1996:
Microwave-vacuum drying of cranberries: Part II,
Quality evaluation. Journal of Food Processing and
Preservation, 20, Pp.145–156.
21. Piotrowski K., Wiltowski T., Mondal K., 2004:
Biomasa – kłopotliwe pozostałości czy
strategiczne rezerwy czystej energii? Cz. 1,
CzystaEnergia [Biomass – problematic remains or
strategic reserves of pure energy? P. 1, Pure
Energy], no. 10, Pp. 16-19.

MINERAL COMPONENTS ANALYSIS OF SELECTED DRIED HERBS 133
22. Saletnik B., Bajcar M., Zaguła G., Czernicka
M., PuchalskiCz., 2015: Optimization of
Physicochemical Properties of Torrefied Products
Obtained by Thermal Processing of Oat Straw.
TEKA.Commission of Motorization and Power
Industry in Agriculture, 15, 4, Pp.155-160.