Surimi wash water treatment by chitosan-alginate complexes

Many studies have shown the relationship between the physicochemical
characteristics of chitosan and its functional properties. Intrinsic parameters such as
degree of deacetylation and molecular weight (Domard, 1998; No and others, 2000;
Chinadit and others, 1998; Lian and others, 1999; Chen, 1998) may affect the
adsorption process of suspended solids (e.g., proteins) contained in wash water.
This study will investigate the effect of these parameters on the protein adsorption
from surimi wash water by chitosan polyanion complexes. In previous studies, no
significant difference in protein adsorption was found among polyanions of
carrageenan, pectin and alginate (Savant, 2001), thus this study will focus on
chitosan-alginate complexes. Molecular weight and degree of deacetylation are
practical means to improve the efficacy of polymeric chitosan complexes and thus
studying the effect of these two factors may lead to recommendations lowering
chitosan production costs. Using chitosan with higher molecular weight may
improve the efficacy of Chi-Aig complexes on protein adsorption. Also, a high
degree of deacetylation does not appear necessary for Chi-Aig complexation with
proteins. Therefore, to optimize and possibly improve the efficacy of Chi-Aig on
protein adsorption and subsequent water recovery, a study on the effect molecular
weight and degree of deacetylation is a necessary next step in the continuing efforts
of our laboratory to optimize commercial chitosan applications.
The suspended solids contained in wash water generated by surimi
processing plans are composed mostly of protein and fat. Adequate technologies to
allow reuse of this wash water and the recovery of co-products such as protein
3