Chitin nanofiber as a promising candidate for improved salty taste

- Widths of ultrasonicated chitin nanofibers for 30, 45, 60 min were 9.3, 5.6, 5.1 nm.
- Width, concentration and NaCl adding affected zeta potential of chitin nanofibers.
- Chitin nanofibers with 3.0 g/L NaCl were saltier than 3.0 g/L NaCl solution.
- Chitin nanofibers with 3.0 g/L NaCl were less astringent than without NaCl group.
- Saltiness raise of ultrasonicated chitin nanofiber for 60 min was better than others.

In this study, we prepared chitin nanofibers (CNFs) of varying diameter and added sodium chloride (NaCl) to CNF solutions. We performed ultrasonication on the CNFs for 30, 45, and 60 min, following which, the CNFs (i.e., CNF30, CNF45, CNF60) displayed a diameter of 9.3, 5.6, and 5.1 nm, respectively; the diameter decreased with the ultrasonication time. The zeta potential of CNFs with various concentrations and diameters ranged from 21.8 to 37.3 mV. The kinematic viscosities of the CNFs were affected with the CNF concentrations and addition of NaCl. When 0.15 and 0.30 g/L CNF solutions were added 3.0 g/L NaCl, they tasted saltier than the 3.0 g/L NaCl solution, but less astringent compared with the CNF solutions without NaCl. The saltiness enhancement of CNF60 was superior to that of the CNF30 and CNF45 due to CNF60 was smaller diameter and less intertwined. The NH3+ of CNF bound Cl− by electrostatic interactions that causing the ratio of free Na+ in the diffuse layer increased and then improving the saltiness and decreasing the astringency of the solutions. Therefore, application of CNFs in food is promising.