Preparation and characterization of high purity β-chitin from squid pens (Loligo chenisis)

• β-Chitin was successfully prepared from Squid pens Loligo Chenesis.
• Products had a high molecular weight with a negligible protein and minerals content.
• β-Chitin with long chains and high purity is suitable for producing high quantity β-chitosan.

Squid pens were extracted by a NaOH solution at 80 °C for 10 h to remove protein and minerals. The as-prepared β-chitin had a high molecular weight (8.5 ± 0.1 × 103 kDa), a low protein content (0.63 ± 0.02 wt.%), and a negligible amount of minerals. This method avoids the conventional method for the removal of minerals from shrimp and crab shells by HCl. The purity of resulting products was measured by NMR and FTIR. Moreover, the morphology and crystallinity of β-chitin was characterized by SEM and XRD. The β-chitin with long chains and high purity is suitable for producing high quantity β-chitosan for various potential applications.