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65
Czech J. Food Sci. Vol. 25, No. 2: 65–72
The relation between nutrition and health has
been unequivocally established. Wrong eating
habits and losses of nutritional factors during
technological processing, storage, and culinary
treatments can lead to the diet deficient in some
nutritional factors.
Supported by the Czech Science Foundation, Project No. 525/05/0781.
Evaluation of Barley Grass as a Potential Source
of Some Nutritional Substances
I PAULÍČKOVÁ
1
, J EHRENBERGEROVÁ
2
, V FIEDLEROVÁ
1
,
D GABROVSKÁ
1
, P HAVLOVÁ
3
, M HOLASOVÁ
1
, J KOPÁČEK
2
,
J OUHRABKOVÁ
1
, J PINKROVÁ
1
, J RYSOVÁ
1
, K VACULOVÁ
4
and R WINTEROVÁ
1
1
Food Research Institute Prague, Prague, Czech Republic;
2
Mendel University
of Agriculture and Forestry in Brno, Brno, Czech Republic;
3
Research Institute
of Brewing and Malting, Brno, Czech Republic;
4
Agricultural Research Institute
Kroměříž, Ltd. and Agrotest fyto, Ltd. Kroměříž, Kroměříž, Czech Republic
Abstract
P I., E J., F V., G D., H P., H M., K J.,
O J., P J., R J., V K., W R. (2007): Evaluation of barley grass as a po-
tential source of some nutritional substances. Czech J. Food Sci., 25: 65–72.
Barley green matter was analysed for the contents of vitamin C, total polyphenols, phenolic compounds, proteins, amino
acids, and saccharides; the activity of catalase was also determined. The contents of vitamin C, total polyphenols, and
ferulic acid decreased with the age of barley plants. The influence of the variety has not been proved unequivocally.
The contents of vitamin C between 0.107–6.357 g/kg DM, of total polyphenols between 17.167–35.559 g/kg DM, and
of ferulic acid between 0–5.916 g/kg DM were found. Catalase activity amounted to 4.5–29.7 TSU. The monosac-
charide profile showed high contents of glucose (15.40–88.40 g/kg DM) and fructose (37.60–81.40 g/kg DM) which
decreased with the plant growth. The contents of saccharose and galactose were low, ranging between 0–7.70 g/kg DM
and 3.70–5.30 g/kg DM, respectively. The relations between their contents and the growth phase were insignificant. The
total amino acid content decreased with the plant age. High contents of aspartic (15.232–28.682 g/kg DM) and glutamic
acids (16.694–35.526 g/kg DM), as well as minimal contents of sulphur amino acids, especially methionin (2.586–5.03 g
per kg DM), could be noted. The highest catalase activity was found in the early growth phase (18.5–35.1 TSU), being
higher in all samples grown at the location Kroměříž. The yield of juice pressed out from frozen green matter amounted
to 68%. The pressed out juice was preserved by fluid drying, freeze drying, and freezing. In respect to folates and total
polyphenols contents and the antioxidant activity, freezing appears the most suitable procedure for preserving.
Keywords: barley grass; nutrition; preservation; antioxidants; vitamins
66
Vol. 25, No. 2: 65–72 Czech J. Food Sci.
One of the possibilities how to improve the balance
of the nutrient intake in a natural way is the diet
enriched by the so-called “green foods”, i.e. fresh or
delicately preserved foods of plant origin.
Generally speaking, young plant parts are char-
acterised by increased contents of some vitamins,
provitamins, antioxidants, and other bioactive sub-
stances. Barley grass contains significant quantities
of calcium, copper, iron, magnesium, potassium,
zinc, β-carotene, folate, pantothenic acid, vitamins
B
1
, B
2
, B
6
, C, and E, superoxide dismutase, catalase,
and chlorophyll. However, the nutrient contents
of all barley varieties depend on where the plants
are grown, the soil quality, the average rainfall, and
the harvest technique (D 1984). It is
known that the highest concentrations of nutrients
are present for just a few critical days.
Barley grass is promoted as a source of anti-
oxidants, the most important being O-glycosyl
isovitexin, superoxide dismutase (SOD), catalase
(CAT), vitamin E, vitamin C, and carotenoids
(B 1983; A & H 1987;
K et al. 1992; O et al. 1992; N
et al. 1998; A et al. 2001; J et al. 2003;
L et al. 2003).
Food supplements based on green plant parts
have their tradition especially in East Asian coun-
tries. In the USA, the food supplement Green Barley
is on the market. This is basically pressed out and
dried juice from barley grass grown under strictly
controlled conditions. The researches conducted
in the USA and Japan proved that an extract from
young barley leaves helps to suppress a number
of health disorders including obesity, diabetes,
circulatory disorders, arthritis, anaemia, excessive
cholesterol levels, renal difficulties, and cancer
(N et al. 1994; S et al. 1994).
An extraordinary feature of the products derived
from young barley is their well-established ability
to degrade organophosphate pesticides (D
et al. 1999).
The aim of our work was to evaluate the contents
of the selected nutritional parameters in barley grass
grown under the soil and climatic conditions of the
Czech Republic. The retention of nutrients was
followed during three possible ways of processing
– freezing, freeze drying, and fluid drying.
MATERIAL AND METHODS
Material. In the course of the year 2005, the ex-
periments were started and conducted at Kroměříž
(KR) and Žabčice (ŽB) with two malting varieties
of hulled barley, i.e. Sebastian and Malz, and with
a hulless variety of spring food barley KM1910,
under restricted chemical inputs (basic fertilisa-
tion – autumn 2004), winter wheat having been
the previous crop. Analytical determinations of
the selected nutrients were carried out in three
samplings of barley green matter taken in defined
growth phases, as described by the decimal code
(DC) scale: sampling I at growth phase DC 29,
sampling II at phase DC 31, and sampling III at
phase DC 32 to 33 (
Z 1974).
According to the character of the individual
substances determined, the samples were ana-
lysed either as soon as possible after the harvest
(vitamin C), or after having been frozen (e.g. sac-
charides, phenolic compounds, total polyphenols,
amino acids).
Because of their specific structure, the samples
for the analytical determinations were homog-
enised in two steps, starting with Ultimate Chopper
(WS Teleshop International) followed with the
mixer A11 (IKA). To test various ways of preserving
juice from barley green matter, the variety Malz in
sampling III from the location Žabčice was chosen.
For practical reasons, all the products obtained
by three different ways of preservation were made
from previously frozen raw materials. Juice from
barley green matter was made using the extractor
Green Power (Woorideul Industrial Co. Ltd.) and
it was further processed by the laboratory freeze
dryer Lyovac GT2 (FINN-AQUA) and the labora-
tory fluid dryer TG1 (Retsch).
Methods. Dry matter was determined by a gravi-
metric method (D et al. 1981). The protein
content was determined by the Kjehldal method
(D et al. 1981). Ascorbic acid was deter-
mined by titration with 2,6-dichlorphenolindophe-
nol (ČSN ISO 6557/2 Method A). A potentiometric
indication of the equivalence point was used.
The enzyme activity of superoxid dismutase was
assessed using the kit Ransod. This kit, made by
the British company Randox, is intended for the
analysis of SOD activity in blood samples. The
necessary modifications of the respective phases of
the procedure, especially the sample preparation,
to suit the plant material were applied (B-
et al. 2006).
To assess the activity of catalase, a spectropho-
tometric method based on the measurement of the
drop of absorbance at 240 nm was used (B-
1970).
67
Czech J. Food Sci. Vol. 25, No. 2: 65–72
Total polyphenols were determined by a spec-
trophotometric method (L et al. 1997).
Phenolic compounds were quantified by a RP
HPLC method (O et al. 2000).
Total amino acids were determined after acid
hydrolysis. Cysteine was oxidised to cysteic acid
before hydrolysis. Ion exchange chromatography
with postcolumn derivatisation using ninhydrine
was applied for the sample separation and detection
(M & S 1954; S et al. 1958).
A HPLC method with a refractometric detector
was used for monosaccharide analysis. Fructose,
glucose, saccharose, and galactose were separated
on a HPLC system under the following conditions:
Hema-Bio 1000 Q (30 × 3 mm, 10 µm) and Hema-
Bio 1000 SB (30 × 3 mm, 10 µm) guard columns, an
Ostion LGKS 0800 Ca form (250 × 8 mm) column;
column temperature 80°C; mobile phase deminer-
alised water, flow rate of 0.3 ml/min.
Folates were assayed as 5-methyltetrahydrofolate
(main representative of natural folates in plant
materials). The determination of 5-methyltetrahy-
drofolate (5-MTHF) was performed by a RP HPLC
method after thermal and enzymatic hydrolysis and
purification of the samples using SPE (H
et al. 2004). The procedure cited was modified
in releasing folates from food matrix. α-Amylase
in addition to conjugase from hog kidney, and
incubation at 37°C for 3 h was used.
The total antioxidant status was determined
using the Randox kit (Randox Laboratories Ltd.,
Ardmore, Diamond Road, Crumlin, Co. Antrim,
United Kingdom) (M et al. 1993).
Three preservation procedures were chosen
for the treatment of the pressed out barley juice,
expected to keep the maximum of the original con-
tents of the nutritionally valuable substances. The
variety Malz in sampling III grown at the location
Žabčice was chosen for the juice production.
One portion of barley juice was dried using the
laboratory fluid dryer Retsch. Another portion was
frozen at –24°C and subsequently freeze dried, and
the remaining portion was frozen in 0.5 litre PET
bottles at –18°C. In the case of fluid drying, guar
flour was used as a vehicle. Ten parts of juice were
mixed with one part of guar flour and the result-
ing gel was pressed through a sieve (5 mm mesh)
to obtain granules. The drying was conducted in a
laboratory fluid dryer under a very low temperature
regime (at 30°C for 8 h), when the juice granules
about 20 mm long were kept floating in an air stream.
Dried granules were then ground to obtain a light
green, partially water soluble powder.
RESULTS AND DISCUSSION
Young green parts of barley plants, as a poten-
tial source of nutritionally valuable substances,
were analysed for the contents of vitamin C, total
polyphenols, phenolic compounds, amino acids,
and saccharides, and for the activity of catalase.
Vitamin C is very unstable in the non-acid barley
plant environment. Due to the activity of enzymes,
vitamin C was rapidly oxidised by mere plant crum-
pling and wilting. The results obtained (Figure 1)
indicate that the content of vitamin C fluctuated
0
2000
4000
6000
8000
KM1910 KR KM1910 ŽB Malz KR Malz ŽB Sebastian KR Sebastian ŽB
Barley varieties and location
Vitamin C (mg/kg DM)
Sampling I
Sampling II
Sampling III
Figure 1. Total contents of
vitamin C in barley varieties
grown at the locations Kromě-
říž (KR) and Žabčice (ŽB)
68
Vol. 25, No. 2: 65–72 Czech J. Food Sci.
between 0.107 to 6.357 g/kg DM and decreased
with progressing growth. Higher contents of this
factor were found in the varieties Malz and Se-
bastian coming from both locations. No relation
was found between the vitamin C content and the
locality. Raw material crumpling or wilting can be
a possible explanation for the dramatic drop of the
vitamin C content during the growth period of
barley KM1910 from Kroměříž, and in sampling
III of the variety Sebastian from Kroměříž.
It is obvious from the evaluation of total
polyphenols in the barley grass samples from both
Kroměříž and Žabčice (Figure 2) that the total
polyphenols contents decreased with the plant
age. The influence of location was not proved
unequivocally.
Out of the phenolic compounds analysed (cat-
echine, epicatechine, caffeic, chlorogenic and
ferulic acids) only the presence of ferulic acid was
found (Figure 3). The results showed that it was
most abundant in sampling I of all varieties tested,
the highest values having been found in the variety
KM1910 from both locations (4.962–5.916 g/kg
DM). The content of ferulic acid decreased with
the plant age. The influence of location was not
established unequivocally. The presence of other
phenolic compounds followed was not analyti-
cally proved.
The assays of simple saccharides, namely sac-
charose, glucose, galactose and fructose, showed
low contents of saccharose and galactose (0 to
7.7 and 3.7 to 5.3 g/kg DM, respectively). In sam-
0
10000
20000
30000
40000
KM1910 KR KM1910 ŽB Malz KR Malz ŽB Sebastian KR Sebastian ŽB
Barley varieties and location
Total polyphenol (mg/kg DM)
Sampling I Sampling II Sampling III
Figure 2. Total polyphenol con-
tents in barley varieties grown
at the locations Kroměříž (KR)
and Žabčice (ŽB)
0
1000
2000
3000
4000
5000
6000
7000
KM1910 KR KM1910 ŽB Malz KR Malz ŽB Sebastian KR Sebastian ŽB
Barley varieties and location
Ferulic acid (mg/kg DM)
Sampling I
Sampling II
Sampling III
Figure 3. Ferulic acid contents
in barley varieties grown at the
locations Kroměříž (KR) and
Žabčice (ŽB)
69
Czech J. Food Sci. Vol. 25, No. 2: 65–72
pling I, all varieties grown at the location Žabčice
were found to have higher contents of glucose
and fructose than those grown at the location
Kroměříž (Figure 4). During the subsequent growth
phases, both saccharides decreased markedly in
the varieties from Žabčice. The varieties from the
location Kroměříž did not show such changes and
the contents of both saccharides fluctuated only
in the range of 1 to 2% (w/w). In sampling III, the
contents of glucose and fructose were higher in
the samples obtained from the location Kroměříž
than in those from the location Žabčice.
Total amino acids declined with the plant devel-
opment; the highest content was observed in sam-
pling I, which corresponds to the protein content
in dry matter. An example of a typical amino acid
spectrum is shown in Figure 5. Sampling I of the
variety Malz contained 30.44 g, sampling II 23.19 g
0
20
40
60
80
100
glucose
fructose
glucose
fructose
glucose
fructose
glucose
fructose
glucose
fructose
glucose
fructose
KM1910 KR KM1910 ŽB Malz KR Malz ŽB Sebastian KR Sebastian ŽB
Monosaccharide/barley varieties and location
Saccharide content (g/kg DM)
Sampling I Sampling II Sampling III
Figure 4. Monosaccharide contents in the respective growth phases of barley varieties grown at the locations Kroměříž
(KR) and Žabčice (ŽB)
0
50
100
150
200
250
Asp Thr Ser Glu Pro Gly Ala Val Met Ile Leu Tyr Phe Lys His Arg Cys
Amino acid
Amino acid content (g/kg DM)
Sampling I Sampling II Sampling III
Figure 5. Total contents of amino acids in the respective growth phases of barley variety Malz grown at the location
Kroměříž
70
Vol. 25, No. 2: 65–72 Czech J. Food Sci.
and sampling III 18.81 g of protein/100 g DM,
respectively. In general, high contents of aspar-
tic and glutamic acids could be noted. Higher
contents of leucine, alanine, valine, arginine and
also phenylalanine were also demonstrated. The
content of sulphur amino acids, notably methio-
nine, was at a minimum. The content of histidine
was also low.
The contents of the respective amino acids did
not show any significant fluctuations depending
on the barley variety or growth site.
The highest barley catalase activity was measured
in sampling I. The location was a factor influencing
significantly the catalase activity; a higher activ-
ity was found in the samples from the location
Kroměříž. The samples from this location were
found to have a higher catalase activity in sampling
III than in sampling II, in contrast to the varieties
grown at Žabčice.
For the utilisation of barley grass as a raw mate-
rial for food supplements, the retention of health
beneficial factors during processing is substan-
tional. Among others, the fluid drying, freezing,
and freeze drying of pressed out juice might be
used. The yield of juice by pressing out was high,
repeatedly amounting to 68%. The juice obtained
was dark green, with a typical flavour, containing
8.2% of dry matter. Pressed out juice was preserved
by fluid drying, freezing, and freeze drying.
The preserved products were then analysed for
total polyphenols, ferulic acid, folates, and for
the antioxidant and enzyme activities (Table 1).
The lowest values of the analytes were found in
the fluid dried product. The losses were much
higher than related to dilution with guar flour.
They might be attributed to the sample exposi-
tion to elevated temperature and oxygen for a
relatively long period. Freezing appears to be the
most delicate preservation procedure from the
viewpoint of the antioxidant factors and the folate
content. Freeze drying caused a decrease in the
contents of polyphenols, folates, and antioxidant
activity by approximately 30% in comparison with
the freezing procedure.
0
5
10
15
20
25
30
35
40
KM1910 KR KM1910 ŽB Malz KR Malz ŽB Sebastian KR Sebastian ŽB
Barley varieties and location
Catalase activity (TSU)
Sampling I
Sampling II
Sampling III
Figure 6. Catalase activity in bar-
ley varieties grown at the locations
Kroměříž (KR) and Žabčice (ŽB)
Table 1. Contents of dry matter, total polyphenols, ferulic acid, and folates, and antioxidant and enzyme SOD activities
Way
of preservation
Dry matter
(g/100 g)
Total polyphenols
(mg/kg sample)
Ferulic acid
(mg/kg sample)
5-MTHF
(µg/kg sample)
Antioxidant activity
(mmol/kg sample)
SOD
activity (U/g)
Freezing (–18°C) 8.2 2804 163 134 344 60
Fluid drying (30°C) 90.9 15 793 481 272 1677 200
Freeze drying 91.4 22 567 1717 1082 2320 800
71
Czech J. Food Sci. Vol. 25, No. 2: 65–72
CONCLUSION
The results of this study provide information
that can help in the utilisation of barley grass as a
unique and fully natural source of valuable nutri-
tional substances. The assays of these substances
characterise young barley plants grown in 2005
at two locations and harvested in three growth
phases. The analysis of the contents of vitamin C,
total polyphenols, ferulic acid, monosaccharides,
amino acids, and the determination of the activ-
ity of catalase have yielded data indicating that
this is a valuable plant material which is worth
becoming an object of continued, more detailed
studies. The results also indicate that the contents
of nutritional substances are strongly dependent
on the growth phase; the barley variety and the
growth site appear to be less important.
The high yield of juice achieved by pressing
out suggests that juice utilisation should be pre-
ferred to processing whole barley plants in the
food supplement production. Out of the preser-
vation procedures tested, freezing appears the
most suitable for preserving selected antioxidant
factors and folates.
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Received for publication July 13, 2006
Accepted after corrections October 27, 2006
Corresponding author:
Ing. I P, Výzkumný ústav potravinářský Praha, Radiová 7, 102 31 Praha 10, Česká republika
tel.: + 420 296 792 368, fax: + 420 272 701 983, e-mail: i.paulickova@vupp.cz
