Nanocellulose-chitosan nanocomplex stabilized pickering emulsions with extremely low internal phase: Stabilization mechanism and application in yogurt

In this study, a series of cellulose nanocrystal-chitosan nanocomplex (CNC-CSp) stabilized Pickering emulsions with extremely variable low internal phase volume fraction (2%–30%) was successfully fabricated by one-step homogeneous emulsification method. CNC-CSp can be considered as safe through in vitro toxicity assessment. Due to the nanostructure and flocculation network of CNC-CSp, its stabilized low internal phase Pickering emulsions (LIPPE) displayed obvious differences in microstructure and increased droplet size (18.76–56.30 μm) with increasing oil phase ratio. At an extremely low oil phase volume fraction (2%–5%), the stabilization of LIPPE was attributed to the formation of flocculation network in the continuous phase, which can effectively capture the droplets by this dense network structure of flexible CNC-CSp. At 10% oil phase ratio, the interface adsorption of CNC-CSp increased. As oil phase ratio further increased (20%–30%), the enhancements in interface adsorption and bridging structure between adjacent droplets facilitated the stabilization of LIPPE. Regardless of low oil phase ratio, all the LIPPE displayed good storage and environmental stabilities, especially excellent thermal and centrifugal stability. The introduction of CNC-CSp can improve the uniformity and granularity as well as friction behavior of yogurts.