Preparation of Nanochitin from Crickets and Comparison with That from Crab Shells

Abstract

Crickets are gaining worldwide attention as a nutrient source with a low environmental impact. We considered crickets as a new source of chitin raw material. Chitin isolated from crickets was successfully converted to nanochitin by pulverization. First, chitin was obtained from cricket powder in a 2.6% yield through a series of chemical treatments. Chitin identification was confirmed by FT-IR and 13C NMR. The chitin had an α-type crystal structure and a deacetylation degree of 12%. Next, it was pulverized in a disk mill to obtain nanochitin. Cricket nanochitin was of a whisker shape, with an average fiber width of 10.1 nm. It was larger than that of crab shells, while the hydrodynamic diameter and crystal size were smaller. Such differences in shape affected the physical properties of the dispersion. The transmittance was higher than that of crab nanochitin due to the size effect, and the viscosity was smaller. Moreover, the dry non-woven cricket nanochitin sheets were more densely packed, and their modulus and breaking strength were greater.