Sweet cherry stalks to nanocrystalline cellulose: Synthesis, characterization, and stabilization of insect oil/water Pickering emulsions

Ultrasound-assisted acid-catalyzed hydrolysis produced moderately elongated, rod-like cellulose nanocrystals (CNCs) from bleached cellulosic fibrils of sweet cherry stalks (SCSs). Ultra-white SCS-derived CNCs, with desired hydrophilicity were 327.1 nm particles with a ζ-potential of -34.18 mV. Fourier transform infrared (FTIR) spectra revealed the purified cellulose content in SCS-derived CNCs by eliminating carbonyl, benzene skeleton, and acetyl-aryl ether peaks, coupled with enhanced cellulosic peaks. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) of the SCS-CNCs (crystallinity 69 %) showed enhanced thermal stability below 200 °C but degraded rapidly at higher temperatures owing to their ordered nanoscale structure. ¹H nuclear magnetic resonance (NMR) and ¹³C NMR spectra confirmed the synthesized CNCs' purity, with specific hydrogen and carbon peaks indicating a crystalline structure aligned with elementary cellulose crystallites. Insect oil/water Pickering emulsions with 6.0 % SCS-based CNCs maintained superior colloidal stability and improved viscosity and opacity with controlled droplet size over a 28-day storage.