Document Type
Article
Publication Date
11-21-2025
Keywords
rice bran film, rice bran protein film, plasma-activated water, surface modification
Abstract
While plasma has been used for decades for the surface modification of packaging films, in this study, rice bran (RB) and rice bran protein (RBP) films were developed using plasma-activated water (PAW), and the chemical composition, surface structure modifications, surface properties, and thermal properties of these films were characterized. Fourier-transform infrared spectroscopy (FTIR) of the bran and protein films showed that the reactive species in PAW improved hydrogen bonding, as evidenced by the increase in the O-H stretching band at 3300 cm-1 and reduced peak intensity at 2940-2925 cm-1 (C-H stretching), suggesting oxidation of the aliphatic side chains. For the RB films, the band at 1654 cm-1 for carboxyl anion stretching demonstrates intermolecular hydrogen bonding with cellulose chains; with PAW addition, the carbonyl peak intensity decreased, suggesting a decrease in hydrogen bonding between cellulose chains due to the reactive radicals present. Atomic force microscopy (AFM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) measurements for these films showed increased surface roughness, improved thermal stability, and crystallinity due to etching and molecular rearrangement induced by PAW generated reactive species. The RBP films showed a significant increase in hydrophilicity, as the water contact angle decreased from 84.42 +/- 9.4 degrees to 62.0 +/- 9.4, whereas the change in contact angle was insignificant for the RB films. The addition of PAW also yielded an increase in the WVTR (water vapor transmission rate) and moisture absorption (MA) of the RBP films by 12.90% and 13.75%, respectively. On the contrary, radical-induced cross-linking in the RB film resulted in a decreased WVTR and MA. Regarding antioxidant activity, the free radical scavenging activity increased for both RB (57 to 61%) and RBP (49 to 59%) films due to plasma-induced phenolic-protein complex breakdown. This study demonstrates that PAW shows great promise in modifying the physical and functional properties of the rice bran film.
Citation
Saydul Md Safwa, Muhammad Nazrul Islam, Nikitha Modupalli, Keisha B. Walters, Md Mahfuzur Rahman; Valorization of Rice Bran for Functional Bioplastic Fabrication Using Plasma-Activated Water. ACS Food Sci. Technol. 21 November 2025; 5 (11): 4267–4278. https://doi.org/10.1021/acsfoodscitech.5c00704
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This work is licensed under a Creative Commons Attribution 4.0 International License.
Comments
Web of Science
ACS Publications