A seasonal study of the chemical composition and chitin quality of shrimp shells obtained from northern shrimp (Pandalus borealis)

The chemical composition of shrimp shells from the deep-water shrimp (Pandalus borealis) obtained from a local factory in northern Norway that were harvested from January to December (2000) in the Barents Sea was investigated. The average dry matter content of the samples of shrimp shells was 22 ± 2%, with no significant seasonal variation. The protein content was found to vary between 33% and 40% of the dry weight, the chitin content varied between 17% and 20% and the ash content of dried shrimp shells was found to be relatively constant with an average value of 34 ± 2% of the dry weight and consisting mainly of calcium carbonate (CaCO3). No clear seasonal variations were found for the content of these three main components of shrimp shells (protein, chitin and ash). The shrimp shells had a very low lipid content, varying from 0.3% to 0.5% of the dry weight. The content of astaxanthin was found to vary from 14 to 39 mg kg−1 in the samples of wet shrimp shells. In relation to its use as a raw material for chitin production, no clear seasonal variation was found in the intrinsic viscosities/molecular weights of the chitin extracted from the shrimp shells using an optimized extraction procedure for chitin extraction, suggesting that chitin producers can rely on shrimp shell waste as a stable raw material for chitin production independent of season.