Parenchyma cells from fruits and root vegetables represent promising feedstocks for cellulose nanofiber (CNF) production through ultrasonic treatment, as their cell walls require relatively mild fibrillation. This study investigated the feasibility of continuous ultrasonic fibrillation of parenchyma pulp derived from citrus fruit residues, with the objective of assessing its potential for scale-up toward industrial CNF production. The results demonstrated that the total energy input per unit mass of pulp is the key operational parameter determining the degree of nanofibrillation and, consequently, the efficiency of the process. Although the morphology and mechanical performance of CNFs obtained by ultrasonication did not match those produced by batch-type fibrillation by blender, optimization of sonication parameters could enable comparable results while offering a continuous, scalable, and potentially more energy-efficient production route.
Nakagaito et al. (Tue,) studied this question.