PRODUCTION OF NANOCHITIN FROM WHITELEG SHRIMP SHELLS VIA ACID HYDROLYSIS COMBINED WITH ULTRASONICATION FOR SALT REDUCTION APPLICATIONS IN FOOD

Abstract

Chitin sourced from white-leg shrimp shell waste presents low water solubility, restricting its incorporation into applied systems. However, transforming chitin into a nanoscale form enhances its dispersion behavior and functional performance, expanding its potential applications. This study focused on establishing conditions for acid-assisted hydrolysis coupled with ultrasonication to produce nanochitin to support sodium reduction in food systems. In the optimised procedure, shrimp shell chitin was hydrolyzed using 3.5 N HCl at 90°C with an acid-to-chitin ratio of 25: 1 (mL/g) for 150 minutes. The hydrolysate was then neutralized and subjected to ultrasonication at 86% amplitude for 36 minutes, applying a solvent-to-substrate ratio of 68:1. The final product was collected by freeze-drying. Characterization showed an average particle size of 420 nm, solubility of 67.62%, and a zeta potential of 20.7 mV. When 0.03% NaCl was introduced, a notable decrease in zeta potential was recorded, suggesting an interaction between nanochitin and chloride ions. This ionic association is believed to enhance saltiness perception. Sensory testing indicated that nanochitin at 100 μg/mL significantly intensified the taste of salt in a 0.65% NaCl solution (p < 0.05). The findings underline nanochitin’s potential role in reducing sodium levels in food without compromising flavor, contributing to healthier dietary strategies, and supporting cardiovascular health.