Document Type
Article
Publication Date
12-2025
Keywords
Rice bran protein, Ultrasound-assisted precipitation, Protein solubility, Functional properties, Nutritional profile
Abstract
While ultrasound-assisted protein extraction is well-studied, the application of ultrasound in both the extraction and precipitation stages has not been explored. This study explored the ultrasound (U)-assisted alkaline extraction (AE) at pH 9.5 and ultrasound-assisted isoelectric precipitation (UIP) at pH 3.5 on the rice bran protein yield, functionality, and nutritional quality. The UAE and conventional precipitation (UAE-IP) yielded the highest protein yield of 65.7 %, while conventional extraction yielded 38.9 %. FTIR showed that UAE-IP increased beta-sheets by 96.8 % while AE-UIP decreased the alpha-helices by 42.4 %. Although UAE-IP showed no significant change in surface hydrophobicity, UAE-UIP decreased it by 34.7 % to the control. Consequently, functional properties such as solubility, emulsifying, and foaming capacities were significantly improved by 5 %, 0.05, and 3 % respectively. AE-UIP exhibited the highest solubility at pH 7, while UAE-IP showed better solubility at acidic and alkaline pHs. UAE-UIP demonstrated superior emulsion and foaming properties. Ultrasound application enhanced protein digestibility, with AE-UIP showing the highest digestibility of 96.91 %. However, dual-stage ultrasound reduced protein digestibility and subsequently affected the amino acid score (AAS). The amino acid profile varied with extraction methods, with AE-IP showing the highest levels of essential amino acids. AE-IP and UAE-IP showed no significant difference in PDCAAS (protein digestibility-corrected amino acid score) and AAS, whereas AE-UIP and UAE-UIP reduced them to 0.9 and 0.6, respectively. In summary, while ultrasound-assisted extraction enhances protein yield and certain properties, ultrasound-assisted precipitation shows great promise in further enhancing mass yield and functionality, which underscores the importance of a dual-stage ultrasound.
Citation
Saydul Md Safwa, Nikitha Modupalli, Md Mahfuzur Rahman, Dual-stage ultrasound application for rice bran protein extraction: A novel method to improve yield, functional properties, and nutritional profile, Ultrasonics Sonochemistry, Volume 123, 2025,107681, ISSN 1350-4177, https://doi.org/10.1016/j.ultsonch.2025.107681.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Comments
Web of Science
Elsevier