Optimization of microwave-assisted extraction of rice bran protein and its hydrolysates properties

Suphat Phongthai, Seung Taik Lim, Saroat Rawdkuen

Research output: Contribution to journalArticlepeer-review

167 Citations (Scopus)


Microwave-assisted extraction (MAE) was applied for extracting rice bran protein with a response surface methodology (RSM). The optimal condition was 1000 W of microwave power, 90 s of extraction time, and a solid to liquid ratio of 0.89 g rice bran/10 mL of distilled water. The protein yield of MAE was higher than that of alkaline extraction (ALK) by about 1.54-fold (P < 0.05), while the protein digestibility was similar. The protein hydrolysates (PHs) with at different degrees of hydrolysis (DH) (5.04, 10.37 and 15.04%) were produced by alcalase. The molecular weight (MW) of the rice bran protein concentrates (RBPC) and the PHs ranged between <11 kDa and 100 kDa. The excessive enzymatic hydrolysis resulted in a negative effect on water and oil absorption capacities. The PHs with DH15.04% acted as the strongest DPPH radical scavenger, ferric reducing agent, and also metal ion chelator (P < 0.05). However, a DH of 5.04% was sufficient for improving the functional properties of RBPC, especially foam ability and the emulsion activity index. This study suggests that the desirable properties of rice bran protein can be controlled with enzymatic modification.

Original languageEnglish
Pages (from-to)146-154
Number of pages9
JournalJournal of Cereal Science
Publication statusPublished - 2016 Jul 1

Bibliographical note

Funding Information:
This study was financially supported by a grant from the Research and Researcher for Industry (RRI) under the Thailand Research Fund (TRF) to Mr. Suphat Phongthai (Grant no. PHD57I0018 ) and Mae Fah Luang University . The authors thank Urmatt Ltd (Chiang Rai, Thailand) for providing the Thai Jasmine organic rice bran. Thank you to Matthew Robert Ferguson of Mahidol University International College for language and editing support.

Publisher Copyright:
© 2016 Elsevier Ltd.

Copyright 2017 Elsevier B.V., All rights reserved.


  • Antioxidant
  • In vitro digestibility
  • Microwave-assisted extraction
  • Response surface methodology
  • Rice bran protein

ASJC Scopus subject areas

  • Food Science
  • Biochemistry


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