Partially degraded chitosan-based flocculation to achieve effective deodorization of oyster (Crassostrea gigas) hydrolysates.

Aquatic protein hydrolysates are usually associated with unpleasant odors and high fat content, which seriously restricts their industrial utilization. In this study, chitosans with different molecular weights produced by hydrogen peroxide degradation were applied to establish a flocculation method, using for the deodorization and defatting of oyster (Crassostrea gigas) hydrolysates. GC-MS analysis showed that the method markedly decreased the content of the fishy odor constituents. Up to 92 % fat and part of the heavy metals were effectively removed. Protein recovery percentage and solid recovery percentage were 83.43 ± 0.35 % and 76.36 ± 0.52 %, respectively, at the optimum dose (150 mg/L) of chitosan (83 % of deacetylation degree, 77 kDa). Thus, chitosan flocculation-coupled centrifugation (5000g, 1 min) can effectively solve the current drawbacks of engineering disc centrifuges and can be industrially used for defatting and deodorization during aquatic food processing.