Integrated extraction optimization and nanoencapsulation of Ziziphus jujuba leaf: Comparative functional evaluation...

This study provides a comprehensive comparison of dried fruit and leaf of Ziziphus jujuba, integrating phytochemical profiling, antioxidant activity, and enzyme inhibition assays. Ultrasound-assisted extraction was optimized via Response Surface Methodology, revealing higher total phenolic, flavonoid, and triterpenoid contents in leaves, correlating with stronger DPPH, ABTS, and FRAP activities and enhanced α-amylase and α-glucosidase inhibition. Leaf extracts were successfully nanoencapsulated using chitosan-TPP nanoparticles (≈182 nm, 87.6% encapsulation efficiency), improving phenolic stability, in vitro bioaccessibility, and controlled release, predominantly governed by diffusion as indicated by Higuchi modeling. Nanoencapsulation further enhanced enzyme inhibitory activity compared to free extracts. These findings highlight the potential of Ziziphus jujubа leaf as a high-value functional ingredient and demonstrate that nanoencapsulation is an effective strategy to preserve and deliver plant-derived bioactives. The integrative approach provides novel insights into extraction, formulation, and functional evaluation of jujube leaf phytochemicals.