Characterization of bamboo shoot cellulose nanofibers modified by TEMPO oxidation and ball milling method and its application in W/O emulsion

It has rarely been reported that the modification of bamboo shoot nanofibers by oxidation combined with physical and applied in food emulsions. In this study, the combination of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation and the ball milling technique was employed to prepare bamboo shoot cellulose nanofibers (TOCNF) for W/O emulsions. A comparative study of the properties and structures of CNF prepared only by ball milling and TOCNF prepared by oxidation-ball milling was carried out, and a preliminary structural and rheological study of their application to emulsions was carried out. The results showed that TOCNF had higher water holding, swelling, and oil holding properties, cholesterol and glucose adsorption capacity than CNF. The combination of oxidative pretreatment and ball milling resulted in a dense entangled network structure, uniform particle size distribution, and high zeta potential value of TOCNF. The higher crystallinity of the TOCNF (68%) resulted in improved thermal stability. In addition, compared with the CNF-stabilized emulsion, with TOCNF dispersion as the internal aqueous phase, the emulsion droplets had a more uniform particle size distribution (6.61 ± 3.59 μm), higher gel strength, and thixotropic resilience of up to 71.24%. Thus, TEMPO oxidation combined with the ball milling method can be an effective means to improve nanofibers and provide a theoretical basis for expanding the application of bamboo shoot cellulose resources in the food colloid field.