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 zeta-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 degrees 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.