Antioxidant Activity of Red Rice (Oryza Nivara. L) Through the

DPPH (2,2-Diphenyl-1pilkrilhidrazil) Method

Lia Puspitasari

, Made Asmarani Dira

and Ni Putu Desy Ratna Wulan Dari

Department of Clinical and Community Pharmacy, Faculty of Health, Institute of Technology and Health Bali, Indonesia

Keywords:

Red Rice, Oryza Nivara, Antioxidant Activity, DPPH.

Abstract:

Free radicals are one of the causes of various degenerative disease that can be overcome with the use of

antioxidant. One antioxidant source is a plant that contains high polyphenol and flavonoids. Red rice (Oryza

nivara L.) is known to be rich in anthocianin pigment, polyphenol, flavonoids, protein, and vitamins. Due to

these contents, red rice was developed to be tea, as a drink consumed for the treatment of some degenerative

diseases. Antioxidant activity tests were conducted on red rice tea harvested and processed from Apuan,

Baturiti, Tabanan, Bali. The antioxidant activity test utilized the DPPH method by observing colour changes

after DPPH incubation. If all DPPH electrons paired with electrons from red rice samples, the sample colour

changed from dark purple to bright yellow. The absorbed sample was then measured with a Uv-Vis-

spectrophotometer in 515.6 nm. Infused red rice tea had an IC level of 50 for 3,635.72 ppm with the regression

equation y = 13.328x – 1.5431 and r

= 0.9834. It can be concluded that infused red rice tea had weak

antioxidant activity.

1 INTRODUCTION

Degenerative diseases are the diseases with the

highest mortality in Southeast Asia. The increase in

deaths due to degenerative diseases is also predicted

to increase from year to year (World Health

Organization (WHO), 2020). One of the causes of

these diseases is free radicals.

Free radicals are molecules or compounds that can

stand alone containing one or more unpaired and

highly reactive electrons that tend to react with other

molecules to achieve stability (Yuslianti, 2018). The

high reactivity of these free radicals will then initiate

a chain reaction in one formation. The result of such

reactions will give rise to abnormal compounds and

initiate a chain reaction that can damage important

cells in the body. Free radicals can be overcome

through the use of anthoxydants (Yuslianti, 2018).

Antioxidants have a very important role for the

human body’s health because their function can

inhibit and neutralize oxidation reactions involving

free radicals. Based on the aforementioned source,

https://orcid.org/0000-0002-9286-4521

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https://orcid.org/0000-0003-2453-6427

antioxidants can be divided into synthetic

antioxidants and natural antioxidants. Synthetic

antioxidants are chemically synthesized compounds.

Meanwhile, natural antioxidants are antioxidant

compounds that are naturally present in the body as a

normal body defence mechanism or come from

external intake.

One of the antioxidant compound sources is a

plant with high polyphenol and flavonoid content.

Brown rice (Oryza nivara. L) is one of the

carbohydrate sources that have been frequently

consumed. Brown rice is rich in anthocyanin

pigments, phytochemicals, proteins and vitamins

(Pengkumsri et al., 2015). Another advantage of

brown rice is the presence of components that are

suspected to be antioxidants, and can play a role in

warding off free radicals in the body. The total

phenolic content in brown rice ranges from 200-700

mg EAG / 100g of ingredients, depending on the

variety used (Sompong et al., 2011). Polyphenols

present in brown rice are compounds from the

flavonoid group, such as flavones, flavones-3-ols,

flavonone, flavan-3-ols and anthocyanidin.

Puspitasari, L., Dira, M. and Dari, N.

Antioxidant Activity of Red Rice (Oryza Nivara. L) Through the DPPH (2,2-Diphenyl-1pilkrilhidrazil) Method.

DOI: 10.5220/0011937600003576

In Proceedings of the 2nd Bali Biennial International Conference on Health Sciences (Bali BICHS 2022), pages 5-7

ISBN: 978-989-758-625-5

 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)

Anthocyanin pigments themselves are known to act

as antioxidants, antimicrobials, antivirals, anti-

inflammatories, photoreceptors, as well as

antiallergenics (Pietta, 2000). In brown rice, there are

a number of carotenoid, tocopherol and tocotrienol

compounds that can also act as antioxidants (Shao et

al., 2013).

Various ingredients are contained in brown rice,

allowing for carbohydrate sources to be developed in

the form of brown rice tea. Brown rice tea itself is

made through a series of simple processes, and it has

been widely consumed for the treatment of various

degenerative diseases such as diabetes and

cholesterol. Until now, scientific testing of the

antioxidant content contained in brown rice tea has

never been done in Indonesia. Hence, it is necessary

to test brown rice tea’s antioxidants through DPPH

testing to allow further testing of brown rice tea as an

antidiabetic.

2 METHOD

This is an invitro study with an experimental type of

research. The research was carried out at the

Integrated Service Laboratory, Faculty of

Agricultural Technology, Udayana University in

December 2020-March 2021. The sample used was

brown rice harvested from the Apuan Baturiti

Village, Bali.

2.1 Red Rice Tea

Brown rice was processed into tea through a series of

processes that began with the washing process, and

continued with the roasting process until it was ready

to be brewed into brown rice tea. The tea was

manufactured by adding 1200 ml of aquadest to 100

grams of brown rice tea; it was then heated to a boil

and filtered.

2.2 Antioxidant Activity Test

DPPH compounds in quantities of 15.8 mg were

weighed and dissolved into up to 100 ml of methanol

p.a, and a concentration of DPPH solution of 0.4 mM

was obtained. The solution was covered with

aluminium foil. As much as 1 ml of the solution was

mixed with 4 ml of the test extract, fraction, and

quercetin (standard) for differences in concentration.

The solution was vortexed for 30 minutes and read

with UV-Visible spectrophotometry at a wavelength

of 515.6 nm.

3 RESULT

Based on the results of the antioxidant activity test,

the brown rice tea infusion’s antioxidant activity in a

spectrophotometric manner are shown in the

following table:

Table 1: Antioxidant activity of brown rice tea infusion.

Concentration

(mg/mL)

Equation

(y = bx + a)

(PPM)

0.00

y = 13.328x –

1.5431

= 0.9834

3,635.72

2.09

4.18

6.28

The brown rice tea infusion’s IC50 value was

obtained from the linear regression equation

calculations in Table 1 above, with the regression

equation being y = 13.328x – 1.5431 and r

= 0.9834.

The y coefficient in this equation is as IC50, while the

x coefficient in this equation is the concentration of

squeezed water, where the value of x is the

concentration needed to be able to reduce 50% of the

DPPH radical’s activity. The brown rice tea’s IC50

value based on the calculation results obtained was

3,635.72 ppm. The following is the curve of the

brown rice tea infusion concentration’s relationship

with the inhibition percent in Figure 1 below:

Figure 1: Linear Regression Curve of Brown Rice Tea

Infusion.

The DPPH method was used to measure

antioxidant activity. The antioxidant activity test

method with DPPH (2,2-diphenyl-1-picrilhydrazyl)

was chosen because this method is a simple, easy,

fast, and sensitive method, and requires only a small

sample for evaluation of natural ingredient

compounds’ antioxidant activity. Antioxidant activity

was tested using UV-Vis spectrophotometry. The

optimal wavelength of DPPH is between 515-517 nm

(Julizan et al., 2019). In this study, brown rice tea

100

02468

IC50

Consentration

Attenuation at Wavelenght 515,6 nm

Bali BICHS 2022 - The Bali Biennial International Conference on Health Sciences

infusion absorption was measured at a wavelength of

515.6 nm.

This antioxidant activity test method’s principle is

the quantitative measurement of antioxidant activity

by measuring the captured DPPH radicals with a

compound that has antioxidant activity using UV-Vis

spectrophotometry. Thus, the free radical suppression

activity can be identified, which is expressed by the

IC50 (Inhibitory Concentration) value. The IC50

value is defined as the magnitude of the test

compound’s concentration that can dampen free

radicals by as much as 50%. The smaller the IC50

value, the higher the free radical suppression activity

(Molyneux, 2004).

The brown rice tea’s IC50 value based on the

calculation results was 3,635.72 ppm. This indicated

that the brown rice tea infusion had weak antioxidant

activity. If the IC50 value ranges from 150-200 ppm,

the antioxidant properties possessed are considered

weak, but still have the potential to be antioxidant

substances (Molyneux, 2004). The relatively weak

antioxidant activity in brown rice tea infusions is

likely due to the use of water solvents that can only

dissolve polar compounds. Boiling brown rice tea at

high temperatures may also result in a decrease in its

antioxidant activity.

4 CONCLUSION

Based on the results of the research that has been

carried out, the following conclusion can be drawn:

brown rice tea (Oryza Nivara. L) has weak

antioxidant activity.

ACKNOWLEDGEMENTS

The authors would like to thank ITEKES BALI for

providing research grants to allow this study to run

well and smoothly. The authors also express their

gratitude to ITEKES Bali for the support and all

forms of facilities provided.

REFERENCES

Ghasemzadeh, A., Karbalaii, M. T., Jaafar, H. Z. E.,&

Rahmat, A. 2018. Phytochemical constituents,

antioxidant activity, and antiproliferative properties of

black, red, and brown rice bran. Chemistry Central

Journal, 12(1). https://doi.org/10.1186/s13065-018-

0382-9

Pengkumsri, N., Chaiyasut, C., Saenjum, C., Sirilun, S.,

Peerajan, S., Suwannalert, P., Sirisattha, S., &

Sivamaruthi, B. S. 2015. Physicochemical and

antioxidative properties of black, brown and red rice

varieties of northern Thailand. Food Science and

Technology (Brazil), 35(2), 331–338.

https://doi.org/10.1590/1678457X.6573

Shao, Y., Xu, F., Sun, X., Bao, J., Beta, T. 2013. Phenolic

Acid, Anthocyanins, and Antioxidant Capacity in Rice

(Oryza sativa L.) Grains at Four Stages of Development

After Flowering. Food Chemistry, 90(6), 143-149

Sompong, R., Ehn, S.S., Martin, G.L., Berghofer, E. 2011.

Physiochemical and Antioxidative Properties of Red

and Black Rice Varieties from Thailan China and Sri

Lanka. Food Chemistry

Walter, M., Marchesan, E., Massoni, P. F. S., da Silva, L.

P., Sartori, G. M. S., & Ferreira, R. B. 2013.

Antioxidant properties of rice grains with light brown,

red and black pericarp colors and the effect of

processing. Food Research International, 50(2), 698–

703. https://doi.org/10.1016/j.foodres.2011.09.002

WHO. 2020. The Top 10 Causes of Death. (cited 2020

August 6). Available from: URL:

https://www.who.int/news-room/fact-sheets/detail/the-

top-10-causes-of-death

Yuslianti, E.R. 2018. Pengantar Radikal Bebas dan

Antioksidan. (hal.2). Yogyakarta: Deepublish

Antioxidant Activity of Red Rice (Oryza Nivara. L) Through the DPPH (2,2-Diphenyl-1pilkrilhidrazil) Method