Comparative influence of cellulose nanofiber variants on the structural properties and digestion of traditional tofu

This study evaluated the effects of different cellulose nanofibers (CNF) on the structure and digestion of MgCl₂- and CaSO₄-coagulated tofu. CNF exhibited rod-like fibrous structures. The mean particle sizes for Polygonati rhizoma CNF (P-CNF), okara CNF (O-CNF), and TEMPO-oxidized okara CNF (TO-CNF) were 538-781 nm. O-CNF incorporation led to a 17%-32% increase in tofu yield. P-CNF addition resulted in no significant difference. This aligns with the increased semi-bound water within the gel network. Microstructure indicated that CNF reduced aggregation, with O-CNF producing a continuous microstructure with micropores. Alterations in the β-sheet suggest interactions between amino acid residues, contributing to a more ordered conformation. Molecular dynamics simulations further revealed a direct interaction between soy protein and O-CNF, stabilized by approximately 10 hydrogen bonds. The hydrolysis rates of tofu incorporating O-CNF or TO-CNF were lower than those observed for P-CNF tofu. These findings support the development of dietary fiber-reinforced tofu.