Wet ball-milling fabricated deacetylated chitin nanofibers for meat saltiness enhancement

The reduction of salt usage in meat products is of significant interest to the meat processing industry. In this context, chitin nanofibers (ChNFs) have emerged as a potential candidate for reducing salt usage in meat products. In this study, deacetylated chitin nanofibers (D-ChNFs) with varying degrees of deacetylation (DDs) were prepared by subjecting native chitin to a partial deacetylation process, followed by a wet ball-milling treatment. The fabricated D-ChNFs were characterized and used as saltiness enhancers for pork fillets. The enhanced saltiness mechanism was elucidated by exploring the interaction between ChNFs and Cl⁻. The results have shown that when DD is increased from 5.9 % to 28.6 %, D-ChNFs with a more dispersed nanostructure can be obtained, with a diameter range of 10–30 nm and a length of several microns. Furthermore, the pork fillets cured with D-ChNFs exhibited higher saltiness values compared to the control groups, and the optimal perceived saltiness was obtained when the ChNF-12 (DD = 28.6 %) was added. Quantum chemical calculation results demonstrated that the interaction intensity between Cl⁻ and the functional groups on the D-ChNFs is in the order of -NH₃⁺/−OH > -NH₃⁺>-NHCOCH₃. D-ChNFs can bind Cl⁻ to their surface through electrostatic attraction as the dominant force, and scale up the proportion of Na⁺ on the meat surface that can bind to taste receptor cells, thus enhancing the meat saltiness. The findings of this study provide a theoretical basis for the development of novel salt reduction methods in meat industry.