Impact of cellulose nanofibrils in biopolymer based-oleogels designed for curcumin encapsulation and 3D-printed food applications.

This study investigated the effects of cellulose nanofibrils (CNF) and TEMPO-oxidized CNF (T-CNF) on improving the physicochemical properties, stability, and controlled release characteristics of biopolymer (BP)-based oleogels designed for curcumin encapsulation and 3D-printed food applications. Incorporation of CNF and T-CNF to BP-based oleogels (pectin, carboxymethyl cellulose (CMC), alginate, hydroxypropyl methylcellulose (HPMC400), and methylcellulose (MC400)) resulted in a structural change from a disordered network to a highly interconnected fibrous structure, thereby enhancing oil retention. As a result, CNF- and T-CNF-BP-based oleogels exhibited higher elasticity and solid-like properties compared to BP-based oleogels. Depending on the type of biopolymer, the incorporation of T-CNF improved the oil binding capacity from 75-95% to 94-98%, and increased curcumin release from 29-45% to 35-56%. Simulated gastrointestinal digestion, however, revealed that CNF had no significant effect on delayed free fatty acid (FFA) release, while HPMC400 and MC400 had a significant effect. Textural analysis of the 3D-printed oleogels revealed that CNF and T-CNF increased the hardness of BP-based oleogels, contributing to improved structural integrity during printing and subsequent post-processing. This study demonstrates the potential of CNF and T-CNF to enhance the functional performance, improve their structural properties, and expand the practical applications of BP-based oleogels in advanced 3D-printed food systems.