Synthesis of Ocimum extract encapsulated cellulose nanofiber/chitosan composite for improved antioxidant and antibacterial activities
Disha Mishra, Puja Khare, D. K. Singh, Vineet Yadav, Suaib Luqman, P.V. Ajaya Kumar, Karuna Shanker
Abstract
In this work, the Ocimum basilicum L. extract (OCE) was encapsulated in a cellulose nanofiber/chitosan composite system (CNF/CH) and examined for phenolic release, antioxidant, and antibacterial activities. The prepared OCE loaded composite had a smooth and porous surface with a high swelling index (60 mL g−1). The zeta potential of the CNF/CH was 18.7±0.8 mV. The fabricated CNF/CH exhibited excellent total antioxidant activity (598 µgAAeq mg−1), total phenolic content (62.4 µgGAeq mg−1) and DPPH (1, 1-diphenyl-2 picrylhydrazyl) (83%) scavenging activity. In vitro release experiment demonstrated the prolonged-release (up to 50% after 6 hours) of phenolic from CNF/CH due to a concentration gradient between CNF/CH and the solution. The release of phenolic occurs through both fickian and non-fickian diffusion. The CNF/CH exhibited excellent antibacterial activity against Gram-positive (Streptococcus mutans) and Gram-negative (Salmonella typhimurium) bacterial strains with the inhibition percentage 97% and 99%, respectively. Results suggest that CNF/CH is a promising biomaterial for the development of the phenolic rich material and maintain the antioxidant activities of OCE.