Chitin extraction from Allopetrolisthes punctatus crab using lactic fermentation

Abstract

Chitin extraction from Allopetrolisthes punctatus, a crab species proliferating in Chile and Peru seashores, was carried out applying preliminary lactic ensilation. For this purpose, Lactobacillus plantarum sp. 47 isolated from Coho salmon was inoculated in crab biomass. Previously, fermentation parameters (carbon source, inoculum concentration and incubation temperature) to obtain peak lactic acid production and bacterial growth were studied. The optimal fermentation conditions were 10% inoculum, 15% sucrose and 85% crab biomass, producing 17 mg lactic acid/ g silage. Extracted and purified chitin, after 60 h fermentation, showed 99.6 and 95.3% demineralization and deproteinization, respectively, using low concentrated acids and bases. As a means of comparison, chitin was also extracted by chemical hydrolysis using high concentrated acids and bases, giving a lower yield and lower quality product. Keywords: Silage, Lactic acid, Demineralization, Deproteinization, Molecular weight, Degree of deacetylation