Photocatalytic rice bran protein/carboxymethyl cellulose/ZrO2 fiber produced by microfluidics: Formation mechanism, bacteriostasis and strawberry preservation

Developing cost-effective and environmentally sustainable active packaging materials remains an important challenge. We have developed rice bran protein (RBP)-based fibers incorporating carboxymethyl cellulose (CMC) and ZrO₂ nanoparticles (ZrO₂ NPs, 0 %–7 %, m/m) using microfluidic spinning. The integration of RBP, CMC, and ZrO₂ NPs formed a robust hydrogen bond network that enhanced the fibers' thermal stability and crystallinity, reduced surface hydrophobicity, and aligned the molecular orientation. Under the catalysis of visible light (300 W, 12 h), ZrO₂ NPs in the fiber produced reactive oxygen species, which inhibited the oxidative stress resistance system of Bacillus subtilis and destroyed its biofilm and DNA, thus showing excellent antibacterial effect. Additionally, during storage, this fiber also showed the ability to scavenge ethylene, thereby reducing the rate of loss of luminance, hardness and weight of strawberries. This study offers a new idea for RBP fiber in food preservation, antibacterial, and value-added utilization of rice bran by-products.