Optimization of ultrasonic-assisted extraction of anthocyanins, flavonoids and their antioxidant activity from Doi Saket purple rice (Oryza sativa L.)

Authors

  • Sureewan Rajchasom College of Integrated Science and Technology, Rajamangala University of Technology Lanna, Chiang Mai 50300, Thailand
  • Pornsawan Sombatnan College of Integrated Science and Technology, Rajamangala University of Technology Lanna, Chiang Mai 50300, Thailand
  • Yardfon Tanongkankit Department of Agriculture and Food Engineering, Faculty of Engineering and Agro-Industry, Maejo University, Chiang Mai 50290, Thailand
  • Nukrob Narkprasom Department of Agriculture and Food Engineering, Faculty of Engineering and Agro-Industry, Maejo University, Chiang Mai 50290, Thailand

Keywords:

Anthocyanin, Antioxidant, Product and process, Response surface methodology, Ultrasonic-assisted extraction

Abstract

Importance of the work: Doi Saket purple rice (Oryza sativa L.) is rich in anthocyanins, which are
found primarily in the rice grain. However, anthocyanins are sensitive to heat, pH, light, solvents,
enzymes and oxidative stress compounds. Systematic evaluation and optimization of the extraction
parameters and conditions is essential to maximize the yield of bioactive compounds through
ultrasonic-assisted extraction.
Objective: To investigate the optimization of various factors influencing ultrasonic-assisted
extraction (UAE) of the total anthocyanin content (TAC), total flavonoid content (TFC) and
hydrogen peroxide (H2O2) scavenging activity from Doi Saket purple rice using response surface
methodology (RSM).
Materials and Methods: The Doi Saket purple rice was extracted using UAE and the optimum
conditions were determined based on RSM. A Box-Behnken design was used to plan the
experimental runs, resulting in 15 experimental conditions. Three factors, each at three levels were
studied: solid-to-liquid ratio (1:1−1:3 weight per volume, w/v; X1), extraction time (20-60 min; X2)
and extraction temperature (60-80°C; X3).
Results: The optimal conditions for the UAE of TAC, TFC and H2O2 scavenging activity of
Doi Saket purple rice were a solid-to-liquid ratio of 1:2 w/v, an extraction time of 40 min and
an extraction temperature of 70°C. Under these conditions, the highest predicted values for TAC,
TFC and H2O2 scavenging activity were 131.83 mg/g, 38.62 mg of quercetin equivalent/g rice
(mg QE/g) and 83.75%, respectively. The experimental values mean (± SD) of the extracts obtained
under optimal conditions were as follows: TAC, 112.77 ± 2.34 mg/g; TFC, 39.26 ± 0.35 mg QE/g
and H2O2 scavenging activity, 75.06 ± 1.26%.
Main finding: The independent variables (solid-to-liquid ratio, extraction time and extraction
temperature) were systematically identified and optimized to maximize the extraction yields
of TAC, TFC and H2O2 scavenging activity from Doi Saket purple rice.

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Published

2026-03-10

How to Cite

Rajchasom, Sureewan, Pornsawan Sombatnan, Yardfon Tanongkankit, and Nukrob Narkprasom. 2026. “Optimization of ultrasonic-assisted extraction of anthocyanins, flavonoids and their antioxidant activity from Doi Saket purple rice (Oryza sativa L.)”. Agriculture and Natural Resources 59 (5). Bangkok, Thailand:590507. https://li01.tci-thaijo.org/index.php/anres/article/view/271114.

Issue

Vol. 59 No. 5 (2025): Agriculture and Natural Resources

Section

Research Article

License

Copyright (c) 2025 online 2452-316X print 2468-1458/Copyright © 2025. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/), production and hosting by Kasetsart University Research and Development Institute on behalf of Kasetsart University

online 2452-316X print 2468-1458/Copyright © 2022. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/),
production and hosting by Kasetsart University of Research and Development Institute on behalf of Kasetsart University.