Alkali- or acid-induced changes in structure, moisture absorption ability and deacetylating reaction of β-chitin extracted from jumbo squid (Dosidicus gigas) pens

Food Chem. 2014;152:355-62. doi: 10.1016/j.foodchem.2013.11.165. Epub 2013 Dec 4.

Abstract

Alkali- or acid-induced structural modifications in β-chitin from squid (Dosidicus gigas, d'Orbigny, 1835) pens and their moisture absorption ability (MAA) and deacetylating reaction were investigated and compared with α-chitin from shrimp shells. β-Chitin was converted into the α-form after 3h in 40% NaOH or 1-3 h in 40% HCl solution, and α-chitin obtained from NaOH treatment had higher MAA than had native α-chitin, due to polymorphic destructions. In contrast, induced α-chitin from acid treatment of β-chitin had few polymorphic modifications, showing no significant change (P>0.05) in MAA. β-Chitin was more susceptible to alkali deacetylation than was α-chitin, and required a lower concentration of NaOH and shorter reaction time. These results demonstrate that alkali- or acid-treated β-chitin retained high susceptibility toward solvents, which in turn resulted in good biological activity of β-chitosan for use as a natural antioxidant and antimicrobial substance or application as edible coatings and films for various food applications.

Keywords: Crystallinity; Deacetylating reaction; Jumbo squid pens; Moisture absorption ability; Structural modification; α-Chitin; β-Chitin.

MeSH terms

  • Absorption
  • Acetylation
  • Acids / chemistry
  • Alkalies / chemistry
  • Animal Structures / chemistry*
  • Animals
  • Carbohydrate Conformation
  • Chemical Fractionation
  • Chitin / chemistry*
  • Chitin / isolation & purification
  • Decapodiformes / chemistry*
  • Water / analysis

Substances

  • Acids
  • Alkalies
  • Water
  • Chitin