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Antioxidant properties of methanol extract and its solvent
fractions obtained from selected Indian red seaweeds
P. Ganesan, Chandini S. Kumar, N. Bhaskar
*
Department of Meat, Fish and Poultry Technology, Central Food Technological Research Institute (CFTRI), Mysore 570 020, Karnataka, India
Received 18 June 2007; received in revised form 3 July 2007; accepted 3 July 2007
Available online 13 August 2007
Abstract
In vitro antioxidant activities of three selected Indian red seaweeds – viz., Euchema kappaphycus,Gracilaria edulis and Acanthophora
spicifera were evaluated. Total phenolic content and reducing power of crude methanol extract were determined. The antioxidant activ-
ities of total methanol extract and five different solvent fractions (viz., petroleum ether (PE), ethyl acetate (EA), dichloromethane
(DCM), butanol (BuOH) and aqueous) were also evaluated. EA fraction of A. spicifera exhibited higher total antioxidant activity
(32.01 mg ascorbic acid equivalent/g extract) among all the fractions. Higher phenolic content (16.26 mg gallic acid equivalent/g extract)
was noticed in PE fraction of G. edulis. Reducing power of crude methanol extract increased with increasing concentration of the extract.
Reducing power and hydroxyl radical scavenging activity of E. kappaphycus were higher compared to standard antioxidant (a-tocoph-
erol). The total phenol content of all the seaweeds was significantly different (P< 0.05). In vitro antioxidant activities of methanol
extracts of all the three seaweeds exhibited dose dependency; and increased with increasing concentration of the extract.
2007 Elsevier Ltd. All rights reserved.
Keywords: Seaweeds; Antioxidant activity; Phenols; DPPH; Deoxyribose
1. Introduction
The total global seaweed production in the year 2004
was more than 15 million metric tones (FAO, 2006)of
which nearly 15–20% is contributed by Indian Ocean
region. Seaweed harvest across Indian coast is about
100,000 metric tones (wet weight) (Dhargalkar and Pereira,
2005). Seaweeds are the excellent source of bioactive com-
pounds such as carotenoids, dietary fibre, protein, essential
fatty acids, vitamins and minerals (Fleurence, 1999; Bhas-
kar and Miyashita, 2005). In Asian countries, Japanese
are the main consumers of seaweed with an average of
1.4 kg (dry weight) per capita (Burtin, 2003). But in India,
seaweeds are exploited mainly for the industrial production
of phycocolloids such as agar-agar, alginate and carra-
geenan, not for health aspects.
Reactive oxygen species such as hydroxyl, super oxide
and peroxyl radicals are formed in human tissue cells result
in extensive oxidative damage that leads to age related
degenerative conditions, cancer and wide range of other
human diseases (Reaven and Witzum, 1996; Aruoma,
1999). Carotenoids, the natural pigments from plant origin
react rapidly with these free radicals and retard or decrease
the extent of oxidative deterioration (Akoh and Min,
1997). Furthermore, antioxidants from natural sources
increase the shelf-life of foods (Schwarz et al., 2001). There-
fore, consumption of antioxidant and addition of antioxi-
dant in food materials protect the body as well as foods
against these events.
Many researchers have found different types of antioxi-
dants in various kinds of higher plants (Shon et al., 2003;
Kumaran and Karunakaran, 2007). More recently, reports
have revealed seaweeds to be rich source of antioxidant
compounds (Lim et al., 2002; Kuda et al., 2005; Duan
et al., 2006). Some active antioxidant compounds from
marine algae were identified as phylopheophylin in Eisenia
0960-8524/$ - see front matter 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.biortech.2007.07.005
*
Corresponding author. Tel./fax: +91 821 2517233.
E-mail address: bhasg3@yahoo.co.in (N. Bhaskar).
Available online at www.sciencedirect.com
Bioresource Technology 99 (2008) 2717–2723
bicyclis (Cahyana et al., 1992), phlorotannins in Sargassum
kjellamanianum (Yan et al., 1996) and fucoxanthin in
Hijikia fusiformis (Yan et al., 1999). Several researchers
have reported the antioxidant properties of both brown
and red seaweeds from across the globe (Nakayama
et al., 1999; Ismail and Hong, 2002; Lim et al., 2002;
Heo et al., 2005; Kuda et al., 2005; Yuan et al., 2005;
Duan et al., 2006). Further, the evidence available in the lit-
erature suggests the potential protective effects of seaweeds
against oxidative stress in target tissues and lipid oxidation
in foods (Yuan et al., 2005). However, there is paucity of
data on the antioxidant potential of seaweeds harvested
in India. Any studies evaluating the antioxidant potential
of these Indian seaweeds would enhance their utility value.
The objective of the present study was to investigate the
antioxidant properties of solvent extracts of three different
Indian red seaweeds and their different fractions by various
in vitro free radical scavenging procedures. In addition,
antioxidant activity, total phenolic content, total antioxi-
dant activity and reducing power were also determined in
this study.
2. Methods
2.1. Chemicals
2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2-deoxy-D-
ribose and a-tocopherol were purchased from Sigma–
Aldrich Chemie (Steinheim, Germany). Ethylenediamine-
tetraacetic acid (EDTA), Folin-Ciocalteu’s phenol reagent
and hydrogen peroxide were purchased from Merck
(Mumbai, India). Thiobarbituric acid (TBA) was pur-
chased from Hi-Media (Mumbai, India). All other solvents
and chemicals were of analytical grade.
2.2. Seaweed material
Red seaweeds used in this study were Euchema kappa-
phycus,Gracilaria edulis and Acanthophora spicifera. They
were collected freshly from East and West coast of India.
Samples collected were washed thoroughly with freshwater,
transported to the laboratory immediately in an iced condi-
tion and shade dried at 38 ± 2 C in a drier (Kilburns-024
E, Mumbai, India). The shade dried seaweeds were pow-
dered and used for further experiments.
2.3. Preparation of seaweed extracts and fractions
First extraction of each seaweed was prepared by pour-
ing methanol into the bottle containing 50 g of seaweed
powder at the ratio of 10:1 (v/w), the mixture was flushed
with nitrogen and kept under orbital shaking incubator
(Technico, Chennai, India) at room temperature (29 ±
2C) for 24 h under dark condition. Like wise, second
extraction with chloroform and methanol mixture (1:1
(v/v)) and third extraction with chloroform were prepared
from the same powder. Three extracts of each sample were
pooled together and evaporated under reduced pressure
using rotary flash evaporator (Rolex, ILTC, Chennai,
India). The crude extract of each sample was weighed
and then dissolved in 90% aqueous methanol for fraction-
ation. Methanol fraction was further fractionated into dif-
ferent solvent fractions as per Duan et al. (2006). Briefly,
first fractionation was carried out with (3·) 100 ml petro-
leum ether (PE). PE fraction was collected and aqueous
methanol phase was evaporated under reduced pressure
to give a semisolid. Then semisolid portion was dissolved
in 200 ml distilled water and further fractionated with ethyl
acetate (EA), dichloromethane (DCM) and n-butanol
(BuOH). Resulting fractions including aqueous were evap-
orated to dryness. Dried fractions were dissolved in meth-
anol and stored in colored vials for further analysis.
Extracts used for all experiments were at the concentration
of 1000 lg. Further, a-tocopherol was used as the positive
control in case of reducing power, DPPH radical scaveng-
ing and hydroxyl radical scavenging (by deoxyribose assay)
activity estimations.
2.4. Total phenolic content
Phenolic contents of crude methanol extract and frac-
tions were estimated by the method of Taga et al. (1984).
Briefly, 100 ll aliquot of sample was mixed with 2.0 ml of
2% Na
2
CO
3
and allowed to stand for 2 min at room tem-
perature. After incubation, 100 ll of 50% Folin-Ciocal-
teau’s phenol reagent was added, and the reaction
mixture was mixed thoroughly and allowed to stand for
30 min at room temperature in the dark. Absorbance of
all the sample solutions was measured at 720 nm using
spectrophotometer (Shimadzu, UV-160, Japan). Phenolic
contents are expressed as Gallic acid equivalent per gram
(GE/g).
2.5. Total antioxidant activity
Total antioxidant activities of crude methanol extract
and fractions were determined according to the method
of Prieto et al. (1999). Briefly, 0.3 ml of sample was mixed
with 3.0 ml reagent solution (0.6 M sulfuric acid, 28 mM
sodium phosphate and 4 mM ammonium molybdate).
Reaction mixture was incubated at 95 C for 90 min under
waterbath. Absorbance of all the sample mixtures was
measured at 695 nm. Total antioxidant activity is expressed
as the number of equivalents of ascorbic acid.
2.6. Reducing power
Reducing power of crude methanol extract obtained red
seaweeds was determined by the method prescribed by
Oyaizu (1986). Briefly, 1.0 ml of methanol containing dif-
ferent concentration of sample was mixed with 2.5 ml of
phosphate buffer (0.2 M, pH 6.6) and 2.5 ml potassium fer-
ricyanide (1%). Reaction mixture was incubated at 50 C
2718 P. Ganesan et al. / Bioresource Technology 99 (2008) 2717–2723
for 20 min. After incubation, 2.5 ml of trichloroacetic acid
(10%) was added and centrifuged (650g) for 10 min. From
the upper layer, 2.5 ml solution was mixed with 2.5 ml dis-
tilled water and 0.5 ml FeCl
3
(0.1%). Absorbance of all the
sample solutions was measured at 700 nm. Increased absor-
bance is indicated increased reducing power.
2.7. DPPH radical scavenging activity
The scavenging effects of crude methanol extract and
fractions were determined by the method of Yen and Chen
(1995). Briefly, 2.0 ml of 0.16 mM DPPH solution (in
methanol) was added to the test tube containing 2.0 ml ali-
quot of sample. The mixture was vortexed for 1 min and
kept at room temperature for 30 min in the dark. The
absorbance of all the sample solutions was measured at
517 nm. The scavenging effect (%) was calculated by using
the formulae given by Duan et al. (2006).
2.8. Deoxyribose radical scavenging activity
Deoxyribose non-site specific hydroxyl radical scaveng-
ing activity of methanol extract and fractions were deter-
mined according to the method of Chung et al. (1997).
Briefly, 2.0 ml aliquots of sample were added to the test
tube containing reaction mixture of 2.0 ml FeSO
4
Æ7H
2
O
(10 mM), 0.2 ml EDTA (10 mM) and 0.2 ml deoxyribose
(10 mM). The volume was made up to 1.8 ml with phos-
phate buffer (0.1 M, pH 7.4) and to that 0.2 ml H
2
O
2
(10 mM) was added. The mixture was incubated at 37 C
under dark for 4 h. After incubation, 1 ml of TCA (2.8%)
and TBA (1%) were added to the mixture, and then left
to stand under boiling waterbath for 10 min. After treat-
ment absorbance was measured at 532 nm. If the mixture
was turbid, the absorbance was measured after filtration.
Scavenging activity (%) was calculated using the equation
given by Heo et al. (2005).
2.9. Statistical analysis
The experiments were carried out in four different
batches of seaweeds. The means of all the parameters
were examined for significance by analysis of variance
(ANOVA) and in case of significance, mean separation
was accomplished by Duncan’s multiple range test using
STATISTICA software (Statsoft, 1999).
3. Results and discussion
3.1. Extract and fractions yield
Among the methanol extract of three seaweeds, A. spi-
cifera had higher yield of 5.01% followed by G. edulis
(3.98%) and E. kappaphycus (2.85%) (Table 1). Among
the fractions, BuOH fraction had a higher yield in all the
seaweeds. However, as compared to results of the present
study, Duan et al. (2006) observed a higher yield of total
extract (12.1%) and aqueous fraction (36.36%) in the red
alga, Polysiphonia urceolata.
3.2. Total phenolic content
Phenolic compounds are commonly found in plants and
have been reported to have several biological activities
including antioxidant properties. Earlier reports revealed
that marine seaweed extracts, especially their polyphenols,
have antioxidant activity (Yan et al., 1999; Lim et al., 2002;
Kuda et al., 2005). The major active compounds in differ-
ent seaweed extracts have been reported to be phlorotan-
nins and fucoxanthin (Yan et al., 1996; Yan et al., 1999).
The phenolic contents in total methanolic extract (Table
2) were significantly different between species (P< 0.05).
PE fraction of G. edulis and A. spicifera showed higher phe-
nolic content of 16.26 and 9.69 mg GE/g of seaweed
extract, respectively (Table 2), when compared to other sol-
vent fractions and total methanol extract. But in the case of
E. kappaphycus, aqueous fraction showed higher content of
8.50 mg GE/g. Significant difference (P< 0.05) was
observed in the phenolic content of three seaweeds. Duan
et al. (2006) observed higher phenolic content (73.7 GE/
g) in ethyl acetate soluble fraction of red alga, P. urceolata.
However, Kuda et al. (2005) observed the phenolic content
of 0.18 mg catechin equivalents/g in ethanolic extract of
brown seaweed, Papenfussiella kuromo.
3.3. Total antioxidant activity
In phosphomolybdenum method, molybdenum VI
(Mo
6+
) is reduced to form a green phosphate/Mo
5+
com-
plex. Higher activity of 32.01 mg ascorbic acid/g extract
was observed in EA fraction of A. spicifera, whereas PE
fraction exhibited higher activity (P< 0.05) in both G. edulis
(18.04 mg ascorbic acid/g extract) and E. kappaphycus
Table 1
Yield of total extract (as % w/w of seaweed on dry weight basis) and fractions (as % of total methanol extract) of three red seaweeds (n=4)
Seaweeds Total ME extract Fractions
PE EA DCM BuOH Aqueous
Euchema kappaphycus 2.85 ± 0.21
a
14.15 ± 0.87 5.85 ± 0.19 22.71 ± 1.02 52.57 ± 1.69 5.03 ± 0.12
Gracilaria edulis 3.98 ± 0.09
b
5.88 ± 0.24 10.46 ± 0.89 28.27 ± 0.98 42.33 ± 1.57 13.05 ± 0.54
Acanthophora spicifera 5.01 ± 0.84
c
11.13 ± 0.58 8.90 ± 0.24 20.07 ± 1.35 55.82 ± 2.12 4.08 ± 0.75
All the values are mean ± SD; SD: standard deviation.
ME: methanol; PE: petroleum ether; EA: ethyl acetate; DCM: dichloromethane; BuOH: butanol.
a–c
Column wise values with same superscripts of this type indicate no significant difference (P> 0.05).
P. Ganesan et al. / Bioresource Technology 99 (2008) 2717–2723 2719
(8.04 mg ascorbic acid/g extract) as compared to different
solvent fractions of the same species (Table 3). Higher activ-
ity was observed in fractions when compared to total crude
methanol extract, in all the seaweeds. Published reports on
the total antioxidant activity of seaweed extracts are not
available. However, a total antioxidant activity of 245–
376 mg ascorbic acid/g extract has been reported in higher
plant extracts (Kumaran and Karunakaran, 2007). Higher
activity in fractions may be due to the interferences of other
compounds present in crude (methanol) extract; and, it has
also been reported that solvents used for extraction have
dramatic effect on the chemical species (Yuan et al., 2005).
3.4. DPPH radical scavenging activity
DPPH has been used extensively as a free radical to
evaluate reducing substances (Cotelle et al., 1996) and is
a useful reagent for investigating the free radical scaveng-
ing activities of compounds (Duan et al., 2006). Total
methanol extract from E. kappaphycus showed significantly
higher scavenging activity (P< 0.05) of 11.9% followed by
A. spicifera (6.91%) and G. edulis (5.20%) (Table 4). Among
the fractions of E. kappaphycus, PE fraction had higher
(8.86%) activity (P< 0.05) as compared to other fractions
of the same species. Similar observations were also made
in the case of PE fraction of both A. spicifera and G. edulis.
The observations of our study corroborates well with those
reported by Duan et al. (2006) in case of a red seaweed spe-
cies. The DPPH radical scavenging activity could not be
detected in the case of BuOH fraction of E. kappaphycus
and A. spicifera.
3.5. Hydroxyl radical scavenging activity
The effect of extracts and fraction in scavenging hydro-
xyl (OH) radicals, to prevent oxidative degradation of
Table 3
Total antioxidant activity (mg ascorbic acid equivalents/g extract) of total extract and fractions obtained from of three red seaweeds (concentration of
extracts used = 1000 lg) (n=4)
Seaweeds Total ME extract Fractions
PE EA DCM BuOH Aqueous
Euchema kappaphycus 2.88 ± 0.39
a
8.04 ± 0.43
p
1.61 ± 0.32
q
0.63 ± 0.11
r
0.26 ± 0.04
s
1.42 ± 0.23
q
Gracilaria edulis 0.31 ± 0.10
b
18.04 ± 0.57
p
7.17 ± 0.41
q
1.08 ± 0.21
r
0.34 ± 0.02
s
0.89 ± 0.07
r
Acanthophora spicifera 1.19 ± 0.07
c
23.98 ± 1.11
p
32.01 ± 2.35
q
3.05 ± 0.28
r
0.51 ± 0.06
s
1.87 ± 0.14
r,s
All the values are mean ± SD; SD: standard deviation.
ME: methanol; PE: petroleum ether; EA: ethyl acetate; DCM: dichloromethane; BuOH: butanol.
a–c
Column wise values with same superscripts of this type indicate no significant difference (P> 0.05).
p–s
Row wise values with different superscripts of this type indicate significant difference (P< 0.05).
Table 4
DPPH radical scavenging activity (%) of total extract and fractions obtained from of three red seaweeds (concentration of extracts used = 1000 lg) (n=4)
Seaweeds Total ME extract Fractions
PE EA DCM BuOH Aqueous
Euchema kappaphycus 11.90 ± 0.40
a
8.86 ± 0.54
p
2.33 ± 0.10
q
6.41 ± 0.26
r
ND
s
3.82 ± 0.17
t
Gracilaria edulis 5.20 ± 0.35
b
5.49 ± 0.17
p
4.73 ± 0.21
q
3.45 ± 0.24
r
2.82 ± 0.23
s
2.17 ± 0.09
s
Acanthophora spicifera 6.91 ± 0.42
c
12.00 ± 0.38
p
3.90 ± 0.25
q
2.79 ± 0.11
r
ND
s
4.28 ± 0.28
q
a-Tocopherol 95.56 ± 0.58
d
NA NA NA NA NA
All the values are mean ± SD; SD: standard deviation; NA: not analysed.
ME: methanol; PE: petroleum ether; EA: ethyl acetate; DCM: dichloromethane; BuOH: butanol.
a–d
Column wise values with same superscripts of this type indicate no significant difference (P> 0.05).
p–t
Row wise values with different superscripts of this type indicate significant difference (P< 0.05).
Table 2
Total phenolic content (mg gallic acid equivalents/g extract) of total extract and fractions obtained from three red seaweeds (n=4)
Seaweeds Total ME extract Fractions
PE EA DCM BuOH Aqueous
Euchema kappaphycus 1.5 ± 0.11
a
5.04 ± 0.21
p
0.55 ± 0.03
q
0.82 ± 0.03
r
0.24 ± 0.03
s
8.50 ± 0.23
t
Gracilaria edulis 4.1 ± 0.31
b
16.26 ± 1.40
p
7.81 ± 0.76
q
1.49 ± 0.10
r
0.15 ± 0.04
s
3.99 ± 0.20
t
Acanthophora spicifera 3.55 ± 0.22
c
9.69 ± 0.32
p
9.02 ± 0.02
q
4.84 ± 0.25
r
0.33 ± 0.07
s
5.89 ± 0.54
t
All the values are mean ± SD; SD: standard deviation.
ME: methanol; PE: petroleum ether; EA: ethyl acetate; DCM: dichloromethane; BuOH: butanol.
a–c
Column wise values with same superscripts of this type indicate no significant difference (P> 0.05).
p–t
Row wise values with different superscripts of this type indicate significant difference (P< 0.05).
2720 P. Ganesan et al. / Bioresource Technology 99 (2008) 2717–2723
deoxyribose substrate, was determined. The inhibition was
more than 90% in DCM, BuOH and aqueous fraction of
all the three seaweeds (Table 5). Lower inhibition rate of
65.81% was observed in PE fraction of E. kappaphycus.
Scavenging activity of total methanol extracts obtained
from the three different seaweeds were statistically signifi-
cant (P< 0.05). Heo et al. (2005) found 47% inhibition in
enzymatic extract of Sargassum fullvelum (a brown sea-
weed) and concluded that enzymatic extracts of seaweed
possessed little effect on scavenging the hydroxyl radical.
But, results of our study indicate a higher activity (>65%)
in all the extracts and solvent fractions. This could be
due to the fact that most of the enzymatic extraction is
aqueous based and may not be as effective in extracting
the active principles like in the case of solvent extraction.
3.6. Dose dependency of antioxidative activities
Concentration dependency of antioxidant activity was
investigated as a function of reducing power (Fig. 1) as this
gives a general view of reductones present in the sample.
Reducing power increased with increasing concentration
in all the samples. Same trend has also been reported by
Kumaran and Karunakaran (2007) in methanol extracts
of higher plants. All concentrations exhibited the OD value
<1.0. Similar findings were also reported by Kuda et al.
(2005). This property is associated with the presence of
reductones that are reported to be terminators of free rad-
ical chain reaction (Duh, 1998). Also, it was observed that
at any given concentration (between 100 and 1000 lg)
methanol extracts of E. kappaphycus and A. spicifera had
higher reducing power than G. edulis. The total methanol
extract of E. kappaphycus showed higher reducing power
(from 100 to 1000 lg concentrations) as compared to a-
tocopherol (Fig. 1). Similarly, A. spicifera exhibited higher
reducing activity up to a concentration of 500 lg and G.
edulis up to 200 lg as compared to the positive control.
The results (Fig. 2) indicate that the scavenging activity
of seaweed extracts were concentration dependent. How-
ever, the positive control (a-tocopherol) did not show dose
dependency and had a DPPH and hydroxyl radical scav-
enging activities about 95% and 78%, respectively. The
scavenging activity was found to increase with increasing
concentration of extract in both the DPPH and deoxyri-
bose assay and corroborated well with earlier reports
(Ismail and Hong, 2002; Kuda et al., 2005). However, the
Table 5
Hydroxyl radical scavenging activity (%) of total extract and fractions obtained from of three red seaweeds (concentration of extracts used = 1000 lg)
(n=4)
Seaweeds Total ME extract Fractions
PE EA DCM BuOH Aqueous
Euchema kappaphycus 57.87 ± 0.91
a
65.81 ± 1.44
p
84.06 ± 1.98
q
96.22 ± 0.90
r
97.84 ± 1.11
r
96.45 ± 1.53
r
Gracilaria edulis 88.26 ± 1.69
b
77.47 ± 1.46
p
84.84 ± 1.20
q
98.36 ± 1.33
r
97.87 ± 0.37
r
96.96 ± 0.34
r
Acanthophora spicifera 98.67 ± 0.85
c
83.28 ± 2.49
p
81.17 ± 0.74
p
92.84 ± 0.91
q
93.53 ± 0.66
q
98.33 ± 0.80
r
a-Tocopherol 75.41 ± 1.58
d
NA NA NA NA NA
All the values are mean ± SD; SD: standard deviation; NA: not analysed.
ME: methanol; PE: petroleum ether; EA: ethyl acetate; DCM: dichloromethane; BuOH: butanol.
a–d
Column wise values with same superscripts of this type indicate no significant difference (P> 0.05).
p–r
Row wise values with different superscripts of this type indicate significant difference (P< 0.05).
0
0.06
0.12
0.18
0.24
0 200 400 600 800 1000 1200
Concentration of extract,
μ
g
Absorbance at 700 nm
E. kappaphycus
G. edulis
A. spicifera
Tocopherol
Fig. 1. Reducing power of methanol extract from three Indian red seaweeds (n= 4).
P. Ganesan et al. / Bioresource Technology 99 (2008) 2717–2723 2721
methanol extracts showed a relatively low DPPH scaveng-
ing activity (Fig. 2) as compared to standard antioxidant
(a-tocopherol). This present finding corroborates well with
earlier reports in other higher plants including brown/red
seaweeds (Kuda et al., 2005; Kumaran and Karunakaran,
2007). Further, methanol extracts of all the three brown
seaweeds showed higher hydroxyl radical scavenging activ-
ity compared to standard antioxidant (Fig. 2).
4. Conclusion
It can be concluded that seaweeds or marine macroalgae
can be utilized as a source of natural antioxidant com-
pounds as their crude extracts and fractions exhibit antiox-
idant activity. The results indicate that different solvent
fractions obtained from total (methanol) extract exhibit
higher antioxidant activities as compared to the total
extract. This could be due to the fact that crude (methanol)
extract tend to have more interfering substances as com-
pared to fractions. The findings of this work are useful to
further research to identify, isolate and characterize the
specific compound which is responsible for higher antioxi-
dant activity. Bioactive compounds found in seaweeds
await a major breakthrough for a variety of food/medical
applications as they have the potential for application of
such compounds as natural antioxidants in different
food/pharamaceutical products.
Acknowledgements
The authors thank Department of Biotechnology
(DBT), India, for the partial funding of the project and
Director, CMFRI, Kochi (India), for support in collection
of seaweeds. Thanks to Director, CFTRI, for the encour-
agement and permission to publish this work.
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