Surimi wash water treatment by chitosan-alginate complexes

Muraki and others (1993). In this method, acetic acid solutions, glucosamine
standards and the test sample are scanned in the UV region to obtain first
derivatives of each spectrum. Acetic acid solutions (0.01, 0.02, and 0.03 M) are
used to construct the zero crossing point (ZCP) which is the point where acetic acid
does not interfere with the sample spectra. The point in which the spectrum passes
through the ZCP is used to determine the base line. A series of standard solution of
N-acetyl-D-glucosamine (GlcNAc) in 0.01 M acetic acid is used to prepare a
standard calibration curve. The curve is a plot of GlcNAc concentration versus the
vertical distance of each peak of the first derivative spectra to the base line (ZCP).
First derivative UV-adsorption of unknown sample in 0.01 M acetic acid is then
prepared and the vertical distance is determined with DD values calculated as:
with:
A
(W-204A)
DD=100_[______ xlOO (1)
+A1
161 )
A = G1cNAc amount/204
W = mass of chitosan sample
2.2.2. Determination of molecular weight
The solubility of a polymer decreases when its MW increases and there are
several methods to determine it that can be applied for chitosan. They include
membrane osmometry, light scattering, gel permeation chromatography and steric