Rice bran, wheat bran, and soybean residue-derived cellulose nanofibers for stabilizing pickering emulsions and protecting β-carotene

This study aimed to valorize underutilized agricultural by-products by converting them into functional cellulose nanofibers for stabilizing Pickering emulsions and protecting β-carotene. Cellulose nanofibers were prepared from rice bran, wheat bran, and soybean residue, and their performance was compared to bacterial cellulose nanofibers. The resulting emulsions exhibited excellent stability, with no significant phase separation over 30 days, and enhanced structural robustness. Higher concentrations of cellulose nanofibers accelerated the reduction of interfacial tension and increased viscosity. Notably, the retained lignin and hemicellulose in cellulose nanofibers contributed to their performance. Compared with bacterial cellulose nanofibers, the agricultural by-product cellulose nanofibers reduced interfacial tension more effectively and provided superior UV protection (>90 % β-carotene retention after 4 h) and antioxidant activity (approximately 90 % DPPH scavenging). This work highlights the value of partially purified cellulose nanofibers and presents a sustainable strategy for converting agricultural waste into effective emulsion stabilizers and bioactive protective agents.