Emulsifying properties of cellulose nanocrystals with different structures and morphologies from various solanaceous vegetable residues

The stems of solanaceous vegetables with attractive source of cellulose, have caused severe environmental problems as agricultural residues. For the reutilization of the residues, this study isolated cellulose nanocrystals (CNs) from the stems of tomato, eggplant, and pepper to explore their applications in Pickering emulsions. Detailed analyses of the crystalline structure and morphology revealed differences in their emulsifying properties. Tomato stem CNs had higher crystallinity of 82.1 % and a short, straight rod-like shape with a low aspect ratio of 8.0, while eggplant and pepper CNs were long, curved whisker-like fibers with lower crystallinities of 75.3 % and 75.4 %, respectively. Tomato stem CNs exhibited the best emulsifying properties, attributed to their relatively higher crystallinity and larger crystal brick size enhancing amphiphilicity, along with their lower aspect ratio improving interface coverage, which resulted in stable emulsions across different temperatures, pH levels, and ionic strengths. This study enhances our understanding of how the structure and morphology of CNs influence their emulsifying properties, thereby contributing to the promotion of agricultural waste reutilization.