Isolation and characterization of nutrients and value-added products from snow crab (Chionecetes opilio) and shrimp (Pandalus borealis) processing discards
Shahidi, F.; Synowiecki, J.
Journal of Agricultural and Food Chemistry 39(8): 1527-1532
ISSN/ISBN: 0021-8561 DOI: 10.1021/jf00008a032
By products from shrimp and different parts of crab contained, on a dry basis, from 17.0 to 32.2% of chitin and from 3.4 to 14.7 mg/100 g of carotenoid pigments, mostely astaxanthin and its esters. Chitin was produced at a yield of about 86%, and carotenoids were extracted in cod liver oil at a yield of up to 74%. Optimal deproteinization involved treatment with 1% KOH solution for shrimp and 2% KOH for crab shells, at 90.degree. C for 2 h, with a shells to alkali solution ratio of 1:20 (w/v). Optimal conditions of demineralization were 2.5% HCL at 20.degree. C for 1 h with a solid to solvent ratio of 1:10 (w/v). The chitin preparations isolated from shell waste without or with the initial extraction of carotenoids were not different. They contained 6.29% nitrogen in shrimp and 6.42% nitrogen in crab chitins. The residual protein contents in chitin from shrimp and crab shells were 2.3 and 0.4%, respectively. The ash content in both cases did not exceed 0.11%.