Bioscience Methods 2015, Vol.6, No.2, 1-7
6
Phenolic content can be calculated as
Where, O.D
sample
is Optical density of sample, DF is
Dilution Factor, and A
650
is Absorbance of standard at
650 nm,
4.3 Determination of anti-oxidant activity
Beta carotene bleaching method
For the determination of anti-oxidant activity, alcoholic
(80%) vegetable extracts were prepared. Vegetable
( 2 g ) were homogenized in the respective media and
centrifuged at 10,000 rpm for 15 min. Supernatants
were stored in capped tubes until further use.
Anti-oxidant activity was determined according to the
b-carotene bleaching method as described by (Anna et
al., 2008) with modifications. β- Carotene (2 mg) was
dissolved in 20 ml of chloroform. A 4 ml aliquot of
the solution was added to a conical flask with40 mg
linoleic acid and 400 mg Tween-40. Chloroform was
removed with a rotary evaporator at 50
℃
. Oxygenated
distilled water (100 ml) was added to the b-carotene
emulsion mixed well and aliquots (3 ml) of the
oxygenated b-carotene emulsion and 0.2 ml of
water/alcoholic extracts were placed in capped culture
tubes and mixed well. The tubes were immediately
placed in a water bath and incubated at 50
℃
.
Oxidation of the β-carotene emulsion was monitored
with spectrophotometer taking absorbance at 10-min
interval at 470 nm for 100 min. A control consisted of
0.2 ml distilled water instead of vegetable extract.
Anti-oxidant activity was expressed as per cent
inhibition relative to control using the equation
Where: Abs
sample 0min
is Absorbance of sample at 0
minute, Abs
sample100min
is Absorbance of sample at 100
minute, Abs
control 0min
is Absorbance of control at 0
minute and Abs
control 100min
is Absorbance of control at
100 minute,
4.4 Procedure for standard curve
Prepared a stock solution of 10mg of catechol in 100
ml of distilled water, 0.2ml, 0.4ml, 0.6ml, 0.8ml and
1ml of this solution were diluted to 3 ml with water
and 0.5 ml of Folin-Ciocalteu reagent was added.
After 3 min, 2 ml of 20% of sodium carbonate was
added and the contents were mixed thoroughly. The
color was developed and absorbance measured at 650
nm spectrophotometer after 60 min. Figure 1 shows
the standard curve by using catechol as a standard for
calculating the total phenolic content in vegetables
samples.
Acknowledgement
Authors are extremely grateful to the Chancellor, Dean and
entire Biotechnology department, Lovely Professional University
for the support.
References
Wong S. P., leong L. P. and William J. H., 2006, Antioxidant activities of
aqueous extracts of selected plants food science and technology
program me, Food Chemistry, 99: 775-783
Jose A. M. G., 2013, Oxidative Stress and Chronic Degenerative Diseases -
A Role for Antioxidants, Published by In Tech, DOI: 10.5772/45722
Ghasemzadeh A., Hawa, J. and Rahmat A., 2010, Antioxidant activities,
total phenolics and flavonoids content in two varieties of malaysia
young ginger (zingiber officinale roscoe), Journal of Medicinal Plants
Research, 4: 881-890
Kaur C. and Kapoor C. H., 2002, Anti-oxidant activity and total phenolic
content of some asian vegetables, International Journal of Food
Science & Technology, 37(2):153-161
Thamizhvanan K., Kumuda P. and Sateesh B., 2012, Evaluation of
antioxidant activity of whole plant of ipomoea eriocarpa extract,
International Journal of Innovative Drug Discovery, 2: 1-3
Kamonrat R., Lalida S. and Griangsak C., 2010, Phenolic content and
antioxidant properties of green chilli paste and its ingredients,
International Journal of Science and Technology, 4:193-200
Safaa Y. Q., Ahmed N. and Mona A. B. L., 2010, Screening of antioxidant
activity and phenolic content of selected food items cited in the Holy
Quran, Journal of Biological Science, 2:40-51
Patel V.R. and Patel P.R., 2010, Antioxidant Activity of Some Selected
Medicinal Plants in Western Region of India, Advances in Biological
Research, 4: 23-26
Yafang S., Liang J., Gan Z., Yan L., Yun S. and Jinsong B., 2010,
Association mapping of grain color, phenolic content, flavonoid
content and antioxidant capacity in dehulled rice, 122:1005-10016
Ljiljana S. , Mihajlo S., Vesna N., Ljubisa N., Dusica R J., Canadanovic B.
and Vesna T., 2009, Antioxidant Activity and Total Phenolic and
Flavonoid Contents of
Hieracium pilosella
L. Extracts, 9: 5702-5714
Oviasogie P. O., Okoro D. and Ndiokwere C., 2009, Determination of total
phenolic amount of some edible fruits and vegetables, African Journal
of Biotechnology, 8: 2819-2820
Mohamed A. A. and Aly A. A., 2008, Alterations of some secondary
metabolites and enzymes activity by using exogenous antioxidant
compound in
Allium cepa
plants grown under seawater salt stress,”
American-Eurasian Journal of Scientific Research, 3:139-146
Anna L. H., Lavanya R., Ndambe M. N., John B. B. and Miller J. C., 2008,
Interspecific Variability for Antioxidant Activity and Phenolic Content
among
Solanum
Species, American journal of potato research, 85:332-341
Bukhari S.B, Bhanger M. I and Memon S., 2008, Anti-oxidative activity of
extracts from fenugreek seeds (
trigonella foenum-graecum),
Pak. J.
Anal. Environ. Chem, 9: 78-83
Patricia M., Suhaila M., Noordin M., Mustapha, Kharidah M., and Cheng H.
M., 2008, Antioxidant activities and phenolics content of eight species
of seaweeds from north Borneo, 20: 367-373
