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Comparison of different solvents and extraction methods for isolation of phenolic compounds from horseradish roots (Armoracia Rusticana)

Authors:
  • Latvia University of Life Sciences and Technologies (former Latvia University of Agriculture)
AbstractHorseradish (Armoracia rusticana) is a perennial herb
belonging to the Brassicaceae family and contains biologically active
substances. The aim of the current research was to determine best
method for extraction of phenolic compounds from horseradish roots
showing high antiradical activity. Three genotypes (No. 105; No. 106
and variety ‘Turku’) of horseradish roots were extracted with eight
different solvents: n-hexane, ethyl acetate, diethyl ether, 2-propanol,
acetone, ethanol (95%), ethanol / water / acetic acid (80/20/1 v/v/v)
and ethanol / water (80/20 by volume) using two extraction methods
(conventional and Soxhlet). As the best solvents ethanol and ethanol
/ water solutions can be chosen. Although in Soxhlet extracts TPC
was higher, scavenging activity of DPPH˙ radicals did not increase. It
can be concluded that using Soxhlet extraction method more
compounds that are not effective antioxidants.
KeywordsDPPH˙, extraction, solvent, Soxhlet, TPC
I. INTRODUCTION
LANTS provide abundant natural antioxidants, which are
vitally important for human health [1]. Phenolic
compounds commonly found in plants are biologically active
substances having antiseptic, vitamin activity etc. [2], [3]. It is
known that phenolic compounds are very effective
antioxidants [4], [5], [6]. Based on these statements, it can be
concluded that it is very important to develop the best method
for extraction of these compounds from plants.
Horseradish (Armoracia rusticana) is a perennial herb
belonging to the Brassicaceae family and cultivated in
temperate regions of the world mainly for the culinary value of
its roots. Since horseradish has long been used as a spice for
meat and fish products, the Food and Drug Administration
(FDA) approved it as seasoning, spice, and flavoring and
affirmed it as Generally Recognized As Safe (GRAS) [7].
Scientists are interested in horseradish because it is a rich
source of peroxidase, a heme-containing enzyme that utilizes
hydrogen peroxide to oxidize a wide variety of organic and
inorganic compounds [8]. Also horseradish is rich in other
valuable substances – vitamins, minerals, phenolic compounds
and also isothiocyanates [9].
Lolita Tomsone, Latvia University of Agriculture, Faculty of Food
Technology, Jelgava, LV-3001, Latvia (phone: 0037163005644; fax:
0037163022829; e-mail: lolita.tomsone@llu.lv).
Zanda Kruma Latvia University of Agriculture, Faculty of Food
Technology, Jelgava, LV-3001, Latvia (phone: 0037163005644; fax:
0037163022829; e-mail: zanda.kruma@llu.lv).
Ruta Galoburda Latvia University of Agriculture, Faculty of Food
Technology, Jelgava, LV-3001, Latvia (phone: 0037163005644; fax:
0037163022829; e-mail: ruta.galoburda@llu.lv).
.
Several authors reported that horseradish has a high
antioxidant activity compared to butylated hydroxyanisole
(BHA), butylated hydroxytoluene (BHT), and α-tocophero
[10], [11].
Many researchers reported influence of different extraction
solvents, techniques on the content of natural antioxidants in
extracts [12], [13]. Efficiency of solvents and methods are
strongly dependent on plant matrix used [14], [15], [13].
Solvents, such as methanol, ethanol, acetone, propanol and
ethyl acetate have been commonly used for the extraction of
phenolics from fresh product [16], [17]. The properties of
extracting solvents significantly affected the measured total
phenolics content (±25% variation) and antioxidant capacity
(up to 30% variation) in fruits and vegetables [13]. Very
important parameter is solvent polarity higher the polarity,
better the solubility of phenolic compounds [1]. The highest
extract yields (up to 22.8%) were obtained with polar alcohol
based solvents [12]. Addition of water to ethanol improves
extraction rate, but too high water content brought an
increased concomitant extraction of other compounds, and,
then to lower phenols concentrations in the extracts [15]. For
wheat, 50% acetone extracts contained the highest level of
total phenolics, whereas ethanol is the least effective solvent
for extracting phenolics from wheat bran samples [14].
Literature data shows that extraction efficiency of solvents is
strongly dependent on food matrix and the aim of current
research was to determine best method for extraction of
phenolic compounds from horseradish roots showing high
antiradical activity.
II. MATERIALS AND METHODS
A. Materials
Three genotypes (No. 105; No. 106 and variety ‘Turku’) of
horseradish roots (Armoracia rusticana) were collected in
Pure (latitude 57° 03’ N, longitude 22° 91’ E) during the
period from September to November, 2011. For analyses the
average sample of 300 grams was taken from 3 roots. Fresh
roots were washed, peeled and homogenized (for 5 minutes).
All samples of one type of horseradish were homogenized
together in order to obtain representative sample.
B. Chemicals
Gallic acid, Folin-Ciocalteu phenol reagent was purchased
from Sigma-Aldrich (Switzerland). All other chemicals used in
the research were obtained from Acros Organic (USA). Eight
different solvents were used: n-hexane (HE), ethyl acetate
Lolita Tomsone, Zanda Kruma, Ruta Galoburda
Comparison of Different Solvents and
Extraction Methods for Isolation of Phenolic
Compounds from Horseradish Roots
(Armoracia rusticana)
P
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(EA), diethyl ether (DI), 2-propanol (PR), acetone (AC),
ethanol (95%) (ET), ethanol / water / acetic acid (80/20/1
v/v/v) (EWA), and ethanol / water (80/20 v/v) (EW).
C. Extraction procedure
For extraction of phenolic compounds the conventional
extraction and Soxhlet extraction was used.
1. Conventional extraction (CONVE)
Five grams of homogenized sample were extracted with
50 ml of an appropriate solvent in a conical flask with
magnetic stirrer (magnet size 4.0 x 0.5 cm) at 700 rpm for 1 h
at room temperature (20±1 °C). The root extracts were then
filtered (paper No. 89). The extraction process was done in
triplicate.
2. Soxhlet extraction (SOXE)
Three grams of the sample were placed in the filter cartridge
(paper No. 89) in a classical Soxhlet apparatus and extracted
with 170 ml of an appropriate solvent for 2 h. Extracts were
cooled to room temperature. The extraction process was
performed in triplicate.
D. Analytical methods
For all extracts total phenolic content and DPPH˙ radical
scavenging activity were determined.
1. Determination of total phenolic content (TPC)
The TPC of the roots extract was determined according to
the Folin-Ciocalteu spectrophotometric method [18] with some
modifications. To 0.5 ml of extract 2.5 ml of Folin–Ciocalteu
reagent (diluted 10 times with water) was added and, after
3 minutes 2 ml of sodium carbonate (Na2CO3) (75 g/L) was
added. The sample was mixed. The control sample contained
all the reaction reagents except the extract. After 2 h of
incubation at room temperature, the absorbance was measured
at 765 nm using a spectrophotometer JENWAY 6300
(Baroworld Scientifid Ltd., UK). Total phenols were
expressed as gallic acid equivalents (GAE)/100 g dry weight
(DW) of the horseradish.
2. Determination of DPPH˙ radical scavenging activity
Antioxidant activity of the plant extracts was measured on
the basis of scavenging activities of the stable 2,2-diphenyl-1-
picrylhydraziyl (DPPH˙) radical as outlined by Yu et al. [19].
The antioxidant reaction was initiated by transferring 0.5 ml of
plant extract into a sample cavity containing 3.5 ml of freshly
prepared DPPH˙ methanol solution (0.004 g DPPH˙ to 100 ml
methanol). After 30 min of incubation in the dark at room
temperature, the absorbance was measured at 517 nm using a
spectrophotometer JENWAY 6300. Inhibition of DPPH˙ in
percent (I%) of each extract sample was calculated from the
decrease of absorbance according to the formula:
100
.
%×
=
blank
sampleblank
A
AA
I,
where
Ablank - absorbance of control (methanol-water with DPPH˙);
Asample - absorbance of the tested samples.
Lower absorbance of the reaction mixture indicates higher
free radical scavenging activity [20].
Additionally for all horseradish roots moisture content was
determined according to standard ISO 6496:1999 and all
results are expressed to dry basis.
E. Statistical methods
Experimental results were means of three parallel
measurements and were analyzed by Microsoft Excel 2010 and
SPSS 17.00 for Windows. Analysis of variance (ANOVA) and
differences among samples were tested by post hoc Dunnett
test, Independent samples t-test was used to compare any
significant differences between one genotype roots of the two
types of extraction. A linear correlation analysis was
performed in order to determine relationship between TPC and
antiradical activity. Differences were considered significant at
p < 0.05.
III. R
ESULTS AND DISCUSSION
A. Total phenolic content (TPC)
Phenolic composition of plants extracts is affected by
different factors – variety, climate, storage, processing etc.
Extracts of horseradish roots were prepared using conventional
and Soxhlet extraction, and TPC was determined using Folin-
Ciocalteu reagent, that reacts nonspecifically with phenolic
compounds; it can also be reduced by a number of non-
phenolic compounds, e.g., vitamin C, Cu(II), etc. The TPC
determined in different solvent extracts of horseradish roots is
shown in Fig. 1.and Fig. 2. For horseradish root No. 106, TPC
determined in extracts made by conventional and Soxhlet
extraction depending on used solvent ranged from 20.73 to
307.52 mg GAE/100 g DW and from 169.77 to 985.87 mg
GAE/100 g DW, respectively. In the case of horseradish root
‘Turku’, TPC ranged from 23.02 to 334.29 mg GAE/100 g
DW using conventional extraction and from 68.68 to
743.49 mg GAE/100 g DW using Soxhlet extraction. While
TPC of horseradish root No. 105 TPC ranged from 19.21 to
327.49 mg GAE/100 g DW. Results of multivariate dispersion
analyses showed that both used solvent and extraction method
are significant factors affecting TPC (p < 0.05). Mainly, results
of TPC obtained using a Soxhlet extraction is higher compared
to a conventional extraction. TPC in plants grown over the
world differ significantly. Malaysian researchers reported that
in dates TPC ranged from 2.89 to 141.35 mg GAE/100 g DW
[21], and Italian researchers reported that in ginger flour TPC
ranged from 14.30 to 71.00 mg GAE/100 g DW [22]. It can be
concluded that in some plants content of phenolics is similar or
slightly lower compared to horseradish. But also many
investigations showed higher TPC in plants, compared to
horseradish. Škerget et al. [23] in their studies found that plant
material contains different amount of total phenols: laurel –
9970 mg GAE/100 g, oregano – 18600 mg GAE/100 g, olive
tree leaves– 14400 mg GAE/100 g. While other researchers
found that TPC leaves of Crithmum maritimum L., Eryngium
maritimum L. and Cakile maritima Scop. ranged from 1644 to
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3193 mg GAE/100 g DW [24], but TPC in the 13 dry spice
extracts analyzed ranged from 1970 mg GAE/100 g for
dahurian angelica root up to 7950 mg GAE/100 g DW for
clove [25]. Algerian researchers reported, that TPC varied in
some Algerian medicinal plants and ranged from 310 to
3230 mg GAE/100 g of dry material [26]. In fresh pistachios
TPC ranged from 801 mg GAE/100 g DW to 1620 mg
GAE/100 g DW [27].
0
50
100
150
200
250
300
350
HE EA DI PR AC ET EWA EW
TPC, mg GAE / 100g DW
106. 105. Turku
Fig. 1 TPC in horseradish depending on solvent using conventional
extraction
The recovery of polyphenols from plant materials is
influenced by the solubility of the phenolic compounds in the
solvent used for the extraction process [28]. In the current
research eight solvents with different polarity were used, and
they can be arranged as follows (starting from more unpolar
solvents): HE < EA < DI < PR < AC < ET < EWA < EW.
From selected solvents the lowest polarity is for hexane, but
the highest for EWA and EW.
0
200
400
600
800
1000
HE EA DI PR AC ET EWA EW
TPC, mg GAE / 100g DW
106. Turku
Fig. 2 TPC in horseradish depending on solvent using Soxhlet
extraction
Solvent polarity plays a key role in increasing phenolic
solubility [1]. Obtained results showed that TPC generally
increased by increasing a polarity of solvents, and a tendency
is more pronounced in the conventional extraction. Results of
Tukey’s test showed that using Soxhlet extraction all solvents
can be classified in two groups that differ significantly
(p < 0.05) – the first HE and EA (with lower TPC), and the
second with solvents DI, PR, AC, ET, EWA, EW. Polarity of
phenolic compounds differs therefore; it is hard to develop a
standard extraction procedure suitable for the extraction of all
plant phenols.
In a conventional extraction influence of solvent is more
significant, and there are no significant differences (p < 0.05)
only between EW, AC, EWA and AC, EWA and PR. The
results of analyses showed that the highest TPC of horseradish
was extracted using 95% ethanol by both extraction methods.
Ethanol and water mixtures are commonly used for the
extraction of phenols from plant materials [16], [17].
Nićiforović, [28] studied Soxhlet extraction, where the highest
TPC was found in H. sendtneri (Boiss.) extracted using 96%
ethanol, which agrees with horseradish results. This is due to
the wide range of phenols that the aqueous ethanol mixtures
can dissolve. Furthermore, ethanolic mixtures have
acceptability for human consumption models [17]. Contrary
results can be found in literature. Fresh leaves of C. siliqua
extracts presented the best TPC with solvents hexane and ethyl
acetate [29]. Literature data shows that acetone–water
mixtures are good solvent systems for the extraction of polar
antioxidants [30], [31], [32]. Results of the current research
show that acetone comparing to other solvents is good solvent
but it is not the best. Literature describes that acetone and
water extracts of fresh lychee (L. chinenesis Sonn.) flowers
presented the best total phenolic content [33]. Malaysia
researchers reported that the highest TPC was in 70% ethanol
honey pineapple extract, 90% acetone banana pisang mas
extract and 90% acetone guava extract, respectively [17].
Whereas for Spanish white onions 100% acetone showed the
lowest results [34].
B Radical scavenging activity (DPPH˙)
The scavenging activity of DPPH˙ radicals has been widely
used to determine the free radical-scavenging activity. DPPH˙
is a stable free radical that is dissolved in methanol and its
colour shows a characteristic absorption at 517 nm.
Antioxidant molecules scavenge the free radical by hydrogen
donation and the color from the DPPH˙ assay solution
becomes light yellow resulting in a decrease in absorbance.
Free radical-scavenging is one of the known mechanisms by
which antioxidants inhibit lipid oxidation [35].
There are variations of antioxidants contained in horseradish
roots. The results showed differences in DPPH˙ scavenging
activity between horseradish roots obtained using conventional
extraction (Fig. 3) and Soxhlet extraction
(Fig. 4).
Results of multivariate dispersion analyzes showed that
solvent significantly (p < 0.05) influence DPPH˙ scavenging
activity, but extraction methods does not have significant
(p > 0.05) influence.
For horseradish root No. 106, DPPH˙ determined by
conventional extraction and Soxhlet extraction ranged from
8.46 to 20.56% and from 3.16 to 14.72%, respectively. In the
case of horseradish root ‘Turku’, DPPH˙ scavenging activity
ranged from 1.98 to 6.99% and from 1.84 to 13.28%,
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respectively. While horseradish roots No. 105 DPPH˙
scavenging activity ranged from 1.16 to 12.07%.
Literature data showed that DPPH˙ scavenging activity
differs depending on used solvent and food matrix.
Researchers studied selected tropical fruits from Malaysia and
stated that DPPH˙ scavenging activity of pineapple ranged
from 12.7% to 93.7%, banana ranged from 32.8% to 79.1%,
but guava ranged from 67.5% to 94.6% [17].
0
5
10
15
20
25
HE EA DI PR AC ET EWA EW
I,%
106. 105. Turku
Fig. 3 Scavenging activity of DPPH˙ radicals of horseradish
depending on solvent using conventional extraction
Also antiradical activity of horseradish differed significantly
depending on solvents used and the highest activity was
determined in EWA (Fig. 3) and EW extracts of horseradish
root type No. 106 (Fig. 4).
0
2
4
6
8
10
12
14
16
HE EA DI PR AC ET EWA EW
I, %
106. Turku
Fig. 4 Scavenging activity of DPPH˙ radicals of horseradish
depending on solvent using Soxhlet extraction
Using both extraction methods it is possible to see increase
in DPPH˙ scavenging activity by an increased polarity of
solvent. López [36] reported that the highest activity was
observed in the aqueous algae extract. The selected tropical
fruits from Malaysia showed the highest DPPH˙ scavenging
activity for pineapple and guava 90% acetone extract [17].
Whereas Alothman [17] reported that the highest DPPH˙
antiradical activity for bananas showed 70% ethanol extract.
C Correlation between total phenolic content and radical
scavenging activity
Phenolic compounds have radical scavenging activity.
Regression and correlation analysis were performed to
determine relationship between these parameters (Fig. 5,
Fig. 6). Stronger correlation was found in TPC of extracts
obtained from roots No. 106 and ‘Turku’ using a conventional
extraction.
y = 24.529x - 153.09
R² = 0.6973
0
50
100
150
200
250
300
350
400
5 10 15 20 25
TPC, mg GAE / 100 g DW
I, %
Fig. 5 Correlation between TPC and DPPH˙ scavenging activity of
horseradish roots No. 106 extracted with conventional extraction
(n = 8)
There was no correlation between TPC and DPPH˙
antioxidant activity, since the estimated coefficient of
determination, R2 values were less than 0.5 at p < 0.05.
y = 67.653x - 133.55
R² = 0.6451
0
50
100
150
200
250
300
350
400
1.5 2.5 3.5 4.5 5.5 6.5 7.5
TPC, mg GAE / 100 g DW
I, %
Fig. 6 Correlation between TPC and DPPH˙ scavenging activity of
horseradish root ‘Turku’ extracted with conventional extraction (n =
8)
Results of our study showed that there was a medium and
weak correlation between TPC and antioxidant activity of the
tested extracts (Table 1). High correlation was observed in
extracts of ‘Turku’ and No. 106. horseradish root using
conventional extraction, allowing the determination of a single
indicator, quite accurately predict the other variable parameter
Moderate correlation was determined for horseradish root
No. 105. Generally conventional extraction has better positive
correlation between these parameters comparing to Soxhlet
extraction where weak positive and weak negative correlation
was observed depending on the used horseradish type. Totally
taking into account all samples no correlation was observed
between TPC and DPPH˙ scavening activity.
These results suggest that the antioxidant activity of some
tested extracts might be attributed to the presence of non-
phenolic compounds. Even more, simple phenols, although
they are not effective antioxidants, react with Folin–Ciocalteu
reagent [37]. Also, it should be taken into consideration that
different phenolic compounds may show different antioxidant
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activities, depending on their structure, as well as synergistic
or antagonistic effect of other compounds, which are present in
the crude extract [28]. Thus, the total phenolic content can be
used to predict their antioxidant activity with reasonable
accuracy [25].
Kubola [38] studied bitter gourd (Momordica charantia L.)
leaf, stem and fruit fraction and referred that correlation
between TPC and antioxidant activity was 0.711 (p < 0.01,
n = 12). Statistical correlations between TPC and antioxidant
activity of litchi seed extract were determined (R2 = 0.9773)
[39].
IV. C
ONCLUSION
Analysis of the TPC and free radical scavenging activity of
horseradish extracts showed differences depending on
extraction method and solvent used. As the best solvents
ethanol and ethanol / water solutions can be chosen. Although
in Soxhlet extracts TPC was higher, scavenging activity of
DPPH˙ radicals did not increase. It can be concluded that
using Soxhlet extraction method more compounds that are not
effective antioxidants, but react with Folin–Ciocalteu reagent,
are extracted.
A
CKNOWLEDGMENT
Authors acknowledge Pure Horticultural Research Centre
for supply of horseradish roots.
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TABLE
I
P
EARSON
S COEFFICIENTS BETWEEN
TPC
AND
DPPH
SCAVENING
ACTIVITY
Extracts
R2 A
R2 B
R2 C
106 0.83 -0.391 -0.43
105 0.56 - -
Turku
Conventional extraction
(106, 105,
Turku)
- - 0.42
Soxhlet extraction
(106, Turku) - - -0.14
Total - - 0.09
A
Correlation coefficient between GAE and DPPH˙ scavenging activity for
conventional extraction
B Correlation coefficient between GAE and DPPH˙ scavenging activity for
Soxhlet extraction
C Correlation coefficient between GAE and DPPH˙ scavenging activity
totally
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Lolita Tomsone, PhD student in Latvia University of Agriculture, Faculty
of Food Technology, was born in Latvia, Bauska in 1974. Main topics of
research: biologically active substances and natural antioxidants in
foodstuffs.
Zanda Kruma, Dr.sc.ing., leader researcher at the Latvia University of
Agriculture, Faculty of Food Technology, was born in Latvia, Aizpute in
1980. In 2008 she defended PhD thesis and obtained docoral degree in
engineering sciences (Food science). Main topics of research: biologically
active substances in foodstuffs, food aroma analysis. She has 22 scientific
publications and participated in 6 different projects.
Ruta Galoburda, Dr. sc. ing., professor at the Latvia University of
Agriculture, Faculty of Food Technology, was born in Latvia, Vainode in
1959. Scientific interests – effect of processing technologies on food quality,
development of new food products. She has 64 scientific publications and
participated in 10 different projects. At present R. Galoburda is a leader of the
project „Sustainable use of local agricultural resources for development of
high nutritive value food products (Food)” within the National Research
Programme “Sustainable use of local resources (earth, food, and transport) –
new products and technologies (NatRes)” (2010.-2013.)
World Academy of Science, Engineering and Technology
International Journal of Biological, Biomolecular, Agricultural, Food and Biotechnological Engineering Vol:6, No:4, 2012
241International Scholarly and Scientific Research & Innovation 6(4) 2012 scholar.waset.org/1999.1/8584
International Science Index, Agricultural and Biosystems Engineering Vol:6, No:4, 2012 waset.org/Publication/8584
... Accordingly, the extractability of the phenolic compounds generally increases with increasing polarity of the solvents. [16] In a study conducted on the effects of solvent polarity in the phenolics extraction, it has been shown that higher content of polyphenols is obtained with an increase in the polarity of the solvent. [17] The use of acetic acid for extraction of antioxidants of phenolic nature is justified by its relatively high polarity compared to other organic solvents. ...
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Introduction: Ipomoea batatas Lam. is grown in the Philippines for food. Its young leaves, reported to exhibit medicinal properties, are eaten fresh in salads with vinegar or shrimp paste. Objectives: However, the effect of varying acetic acid concentration on the extractability of its phenolics, flavonoid, and cytotoxic compounds using a safer and cheaper solvent such as acetic acid is not yet explored. Thus, the cytotoxicity and the total phenolics and flavonoid content of the aqueous acetic acid extracts of I. batatas leaves is evaluated. Materials and Methods: Cytotoxicity of the I. batatas leaves extracted with 5%, 3%, and 1% aqueous acetic acid were determined through Brine Shrimp Lethality Assay (BSLA) while the total phenolics and flavonoid content were analyzed using Folin-ciocalteu and aluminium chloride method, respectively. Results and Discussion: The 5% aqueous acetic acid extract contains significantly higher amount of phenolics and flavonoids as compared to the 3% and 1%. BSLA also showed that the 5% aqueous acetic acid extract (LC 50 = 520.61 mg/L) exhibited cytotoxic activity while the 3% (LC 50 >1000 mg/L) and 1% (LC 50 >1000 mg/L) extracts were non-cytotoxic. Conclusion: The concentration of the acetic acid affects the extractability of the phenolics, flavonoids and cytotoxic compounds in the I. batatas leaves. The 5% aqueous acetic acid is more efficient in the extraction than the 3% and 1%. The use of acetic acid for the extraction of phenolics, flavonoids, and cytotoxic compounds from I. batatas leaves can be a better option than other organic solvents.
... Bleakley et al. [29] reported that mainly products that require water extraction include hydrophobic compounds, metals, water-soluble amino acids, peptides, sugars, ions, nucleotides, etc. Furthermore, it was reported by Tomsone et al. [30] and Bouchard et al. [31] that products that require ethanol extraction consist of very polar, basic, acidic and neutral compounds. Many researchers reported that ethyl acetate extraction is needed for moderately hydrophobic products, low as well moderately polar, neutral etc. [32] Different traditional and novel extraction methods used to extract bioactive compounds from natural sources are shown in Figure 1. ...
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Consumers demand for functional foods and nutraceutical is increasing owing to their health endorsing properties. Natural bioactive compounds are getting attention due to their health promoting potential. In addition, the extraction of these bioactive compounds is a significant industrial and technological perspectives. These bioactive moieties can be extracted via various conventional and modern methods. For instance; solid-phase extraction, solid-phase micro-extraction, and liquid-liquid extraction are considered as traditional/conventional methods. In contrast, modern eco-innovative methods for extraction such as ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), pulsed electric field (PEF), supercritical fluid extraction (SFE), instant controlled pressure drop (DIC), etc. are more economical and environment friendly. Additionally, these are ever-increasing demands of energy-efficient methods for the recovery of valuable compounds. Moreover, these methods produced less wastewater and hazardous substances. Conclusively, this review highlighted the conventional and modern extraction technologies and the role of these eco-innovative technologies in achieving the goal of a sustainable food system. ARTICLE HISTORY
... The absorbance was recorded using the UV/Visible Spectrophotometer at 520 nm. [23] 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) Activity: ABTS assay was estimated conferring to the method outlined by Hossain et al., [24] Ferric Reducing Antioxidant Power (FRAP): The FRAP assay of the samples was carried out following the method Hameed et al., [25] Spectrophotometer was used to determine the FRAP content, and reading was recorded at 700 nm. ...
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... While most phenolic compounds can be soluble in water, some compounds present solubility only in organic solvents. In fact, ethanolic solvents may be more efficient in the extraction of total phenolic compounds than water (Vizzoto and Pereira, 2011;Tomsone et al., 2012;Menezes Filho and Castro, 2019). However, the processing degree, the size of particles, the extraction duration, the temperature, and the extracting solvent concentration can all also influence the phenolic compound yields (Shahidi and Wanasundara, 1998). ...
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... Additionally, studies have reported that the aerial parts of plants used for the extraction are of great importance because of different patterns of secondary metabolites [59]. For this purpose, water and methanol are considered the effective solvents for the extraction of the polyphenol constituents from plants [36,60]. The methanolic extract had high phenolic content of 24.49 mg GAE/g ex-tract. ...
... Additionally, studies have reported that the aerial parts of plants used for the extraction are of great importance because of different patterns of secondary metabolites [59]. For this purpose, water and methanol are considered the effective solvents for the extraction of the polyphenol constituents from plants [36,60]. The methanolic extract had high phenolic content of 24.49 mg GAE/g ex-tract. ...
... Additionally, studies have reported that the aerial parts of plants used for the extraction are of great importance because of different patterns of secondary metabolites [59]. For this purpose, water and methanol are considered the effective solvents for the extraction of the polyphenol constituents from plants [36,60]. The methanolic extract had high phenolic content of 24.49 mg GAE/g ex-tract. ...
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Our study evaluated the in vitro antioxidant properties, antibacterial and antifungal activities, anti-inflammatory properties, and chemical composition of the essential oils (EOs), total phenol, and total flavonoid of wild Mentha pulegium L. This study also determined the mineral (nutritional and toxic) elements in the plant. The EOs were extracted using three techniques—hydro distillation (HD), steam distillation (SD), and microwave-assisted distillation (MAD)—and were analyzed using chromatography coupled with flame ionization (GC-FID) and gas chromatography attached with mass spectrometry detector (GC-MS). The antioxidant effects of the EOs were tested with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), while the antibacterial and antifungal activities of the EO and methanolic extract were tested using Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. Twenty-six compounds were identified in the essential oil, representing 97.73% of the total oil, with 0.202% yield. The major components were pulegone (74.81%), menthone (13.01%) and piperitone (3.82%). Twenty-one elements, including macro- and micro-elements (Ba, Br, Ca, Cl, Co, Cr, Cs, Eu, Fe, K, Mg, Mn, Mo, Na, Rb, Sb, Sc, Sr, Th, U and Zn), were detected using neutron activation analysis (INAA) and inductively coupled plasma optical emission spectrometry (ICP-OES), with the concentration of mineral element close to the FAO recommendation. The results show that the EOs and extracts from Mentha pulegium L. had significant antimicrobial activities against the microorganisms, including five human pathogenic bacteria, one yeast (Candida albicans), and one phytopathogenic fungi. The in vivo anti-inflammatory activities of the leaf extracts were confirmed. The results indicate that the EOs and extracts from Mentha pulegium L. have promising applications in the pharmaceutical industries, clinical applications, and in medical research.
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The sedentary lifestyle coupled with continuously changing food habits and search for nutrient-dense enriched protective foods has resulted in increased demand and consumption of natural foods. Among natural dietary ingredients, vegetables are the daily consumed dietary ingredients packed with vitamins, minerals, antioxidants, and an array of bioactive phytochemicals. Amongst vegetable crops, cruciferous vegetables like broccoli, cabbage, cauliflower, arugula, horseradish, mustard green, bok choy, brussels sprouts, etc. are the crops which are perceived far important than the mere table items for daily consumption owing to their rich functional bioactive profile. Presence of the sulfur-rich compounds (methyl cysteine sulfoxide and glucosinolates), coloring pigments (carotenoids, anthocyanins), minerals (Se, Fe, K, Ca), vitamins (B complex and C), dietary fiber, and other bioactive compounds (phytoalexins, terpenes, tocopherols, hydroxycinnamic acid, chlorogenic acid, ferulic acid, synapic acid and flavonols) give them the distinctive nutraceutical status with well documented therapeutic benefits. Most of the research effort in the last decade has been directed to effectively find out the exact mode of action of these bioactive compounds on health with their minimum effective concentration, means to ensure their effective delivery to the target organs, and increased bioavailability of these compounds. Though, there is substantial evidence based on in vivo and in vitro findings that scientifically demonstrate their benefits more research needs to be conducted with an exploration of the unknown beneficial activities as well as the unwanted effects. Future research should be directed towards the functional enrichment either through genetic modifications or through regulation of pathways for ensuring the national and health security to the general population and the health-conscious people.
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Book
Polyphenols are the second most abundant class of substances in nature, and include tannins and flavonoids, many of which have extremely important antioxidant properties which have now been shown to have a key role in the prevention of cancer in humans. This important book covers polyphenol chemistry, biosynthesis and genetic manipulation, ecology and plant physiology, food and nutritional aspects and the effects of polyphenols on health. Included within the contents are cutting edge chapters on biotic and abiotic stress in plants, safety and toxicity in foods, functionality and nutraceutical benefits in nutrition, and aspects of pharmaceutical and cosmetic discovery and development. Sponsored by Groupe Polyphenols, this landmark book has been edited by Professor Fouad Daayf and Professor Vincenzo Lattanzio, who have drawn together an impressive list of internationally respected contributing authors, each providing a comprehensive review of the current situation regarding each important subject covered. Recent Advances in Polyphenol Research is an important publication which will be of great use to chemists, biochemists, plant scientists, pharmacognosists and pharmacologists, food scientists and nutritionists. Libraries in all universities and research establishments where these subjects are studied and taught should have copies of this book on their shelves.
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The steam-volatile constituents of locally grown horseradish (Armoracia lapathifolia, Gilib.) have been studied by gas chromatography (G.C.) and combined gas chromatography — mass spectrometry (GC-MS). Of the ten components idendified overall, six were isothiocyanates, two were nitriles, one was allyl thiocyanate and one was carbon disulfide. The distribution and concentration of flavor components in crowns, primary and secondary roots and rootlets differed from those in tops. The primary and secondary roots and crowns accounted for the bulk of the weight of the root fraction as well as its essence content. Based on allyl isothiocyanate content, the quality of horseradish essence deteriorated as the distillation time was extended. Freeze drying and dehydration of sliced roots improved the recovery and quality of the essence. Some aspects of knowledge of the formation and decomposition of selected volatiles have been discussed as the basis of interpretation of the above findings.
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The effects of addition of ginger powder (0, 3, 4.5 and 6%) in formulation were examined in order to obtain an antioxidant-enriched bread with good physico chemical and sensorial properties. The rheological properties of doughs were evaluated using dynamic rheological measurements. Physical properties, total phenolics content (TPC- Folin-Ciocalteau method), radical scavenging activity (RSA- DPPH assay) and sensory analysis (hedonic test) of the supplemented bread were determined.The highest TPC (0.48 and 0.71 mg GAE/g DW on crumb and crust respectively) and RSA activity (0.15 and 0.24 μmol DPPH/mg DW ml−1 on crumb and crust respectively) were achieved in the bread having the highest percentage of ginger powder (6%). But this sample showed the worst results regarding the rheological properties indicating that the dough and the bread had a tough structure. Moreover, by sensory evaluation this bread sample was not acceptable.Among the studied samples, bread with 3% of ginger powder showed good rheological characteristics and doubled anti-oxidant content compared to the control bread and the highest sensorial acceptability.
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Significant levels of antioxidant activities and phenolic components have been detected in wheat and wheat-based food products, indicating that wheat may serve as an excellent dietary source of natural antioxidants for disease prevention and health promotion. Several solvent systems have been used to prepare antioxidant extracts from wheat and wheat-based food products. This makes it difficult to compare and understand the antioxidant activities of wheat reported from different research groups. The purpose of this study was to evaluate the effects of four selected solvent systems at ambient temperature for 15h and Soxhlet extraction with absolute ethanol on antioxidant activity measurements. The four solvent systems included 50% acetone (v/v), 70% methanol (v/v), 70% ethanol (v/v), and ethanol, and antioxidant activities were tested using ORAC, radical scavenging activities against stable DPPH• and cation ABTS•+, and total phenolic content. The results showed that the extracting solvent significantly altered the antioxidant property estimations of wheat bran, and 50% acetone is a recommended solvent for extracting phenolic antioxidants from wheat bran for analytical purpose.
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This study was aimed to optimize the extraction of phenolic compounds from grape marc investigating extraction kinetics (from 1 to 24h) at 45 and 60°C, and the effect of solvent (ethanol with different water content) on phenols yield and quality of extracts (phenols concentration and antioxidant power). Extraction was a slow process, with higher yields at 60°C than at 45°C, and with apparent thermal degradation of constituents beyond 20h. Phenols yield increased for water content of ethanol from 10% to 30% and remained constant for water content from 30% to 60%, while phenols concentration of extracts decreased for water content above 50%. Antioxidant power (ABTS test) highly correlated to total phenols concentration, and was not influenced by water content of ethanol, suggesting that this variable influenced only the amount but not the nature of the extracted compounds. Freeze-drying did not alter composition and antioxidant property of extracts.
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Edible parts of date palm (Phoenix dactylifera) fruits (DPF) from Iran were analyzed for their antioxidant activities (AA) using Trolox equivalent antioxidant capacity (TEAC) method, 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS+) assays and the ferric reducing/antioxidant power method (FRAP assay). The total phenolic content (TPC) and total flavonoid content (TFC) of the DPF were measured using Folin–Ciocalteau and aluminum chloride colorimetric methods, respectively. The samples used included four types of soft dates (SD) namely Honey date, Bam date, Jiroft date and Kabkab date; three types of semi-dry dates (SDD) namely Sahroon date, Piarom date and Zahedi date and one type of dry date (DD) which was Kharak date. The AA (ABTS assay) of the DPF were 22.83–41.17, 47.6–54.61 and 500.33μmol Trolox equivalents/100g dry weights (dw) for SD, SDD and DD, respectively. The AA (FRAP assay) per 100gdw sample were 11.65–20, 19.12–29.34 and 387.34μmol FRAP for SD, SDD and DD, respectively. The TPC ranged from 2.89 to 4.82, 4.37 to 6.64 and 141.35mg gallic acid equivalents (GAE)/100gdw, while TFC ranged from 1.62 to 3.07, 1.65 to 4.71 and 81.79mg catechin equivalents (CEQ)/100gdw sample for SD, SDD and DD, respectively. Correlation analyses indicated that there was a linear relationship between AA and the TPC or TFC of DPF. This work demonstrates the potential of Iranian dates as antioxidant functional food ingredients.
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A nanometer-scale thin film of ruthenium supported on glassy carbon (nm-Ru/GC) was prepared by electrochemical deposition under cyclic voltammetric conditions. Scanning tunneling microscopy (STM) was used to investigate the structure and to measure the thickness of the thin film. It has been found that the Ru thin film is composed of layered Ru crystallites that appear in a hexagonal form with dimensions of about 250 nm and thickness around 30 nm. In situ FTIR spectroscopic studies demonstrated that such a nanostructured Ru thin film exhibits abnormal infrared effects (AIREs) for CO adsorption (G.Q. Lu et al., Langmuir 16 (2000) 778). In comparison with CO adsorbed on a massive Pt electrode, the IR absorption of COad on nm-Ru/GC was significantly enhanced. Moreover, the direction of COad bands is inverted and the full width at half maximum of COad bands is increased. It has been revealed that the enhancement factor of IR absorption of CO adsorbed on nm-Ru/GC electrodes depends strongly on the thickness of the Ru film. An asymmetrical volcano relationship between the enhancement factor and the thickness of the Ru film has been obtained. The maximum value of the enhancement factor was measured as 25.5 on a nm-Ru/GC electrode of Ru film thickness around 86 nm. The present study has contributed to exploration of the particular properties of nanostructured Ru film material and to the origin of the abnormal infrared effects.
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Antioxidant and antitryrosinase compounds from Litchi sinensis Sonn. seeds were extracted with five different types of polar solvents. The five extracts, namely ethanol extract (EE), 50% ethanol extract (50% EE), methanol extract (ME), 50% methanol extract (50% ME), and water extract (WE), were used for the evaluations of total phenolic content, antioxidant capabilities and antityrosinase activity. The 50% EE showed the highest total antioxidant capacity, scavenging the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical and inhibitory activity against lipid peroxidation, and it was comparable to the activity of the synthetic antioxidant, butylated hydroxyl toluene. Fifty percent EE showed a better antityrosinase activity compared to the other extracts. After application of reverse phase high performance liquid chromatography, coupled to a diode array detector and electrospray ionisation mass spectra, five phenolic compounds, namely, gallic acid, procyanidin B2, (−)-gallocatechin, (−)-epicatechin and (−)-epicatechin-3-gallate were identified from 50% EE. This study suggests that litchi seed can potentially be used as a readily accessible source of natural antioxidants.