Preparation of cellulose nanocrystals from the shells of Camellia oleifera Abel and their effect on the stability of camellia oil Pickering emulsions

ObjectiveTo prepare cellulose nanocrystals from the shells of Camellia oleifera Abel (SCOA-CNCs) for stabilizing camellia oil Pickering emulsions, and to investigate the storage stability and environmental stability of the resulting emulsions.MethodsCellulose is extracted from SCOA through bleaching and alkali treatment, and SCOA-CNCs are prepared by sulfuric acid hydrolysis and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The SCOA-CNCs are employed to stabilize camellia oil Pickering emulsions, the effects of the oil-to-water ratio and particle concentration on the emulsions are examined, and the stability of the emulsions under different environmental conditions is evaluated.ResultsRod-shaped SCOA-CNCs are successfully prepared, with an average length of (191.4±15.9) nm, an average diameter of (19.4±1.4) nm, and a crystallinity index of 73.46%. When the oil-to-water ratio is lower than 3∶7 (mL/mL) or the particle mass concentration exceeds 10 mg/mL, camellia oil Pickering emulsions with uniform droplet size and excellent stability are formed. The camellia oil Pickering emulsions stabilized by SCOA-CNCs exhibit no demulsification over a wide range of temperatures (20~100 ℃), pH(3~11), and ionic strengths (≤500 mmol/L).ConclusionCamellia oil Pickering emulsions stabilized by SCOA-CNCs demonstrate excellent storage stability and environmental stability.