physicochemical and functional properties of crawfish chitosan as ...

At 0.1% concentration of chitosan, DMPCA showed the highest emulsion capacity of
166.4 ml/g, followed by DMCPA, DCMPA, and DPMCA with 156.9 ml/g, 155.7 ml/g, and
152.8 ml/g, respectively. At 0.5% concentration, DMCPA had EC of 265.5 ml/g, followed by
DMCPA (259.7 ml/g) and DPMCA (257.5 ml/g), but the latter two samples were not
significantly different. At 1.0% chitosan concentration, DPMCA demonstrated higher emulsion
capacity of 374.2 ml/g, compared with that of DMPCA (364.3 ml/g). DMPCA, DMCPA and
DCMPA and the control DPMCA demonstrated a better enhancer for emulsion capacity than the
commercial crab chitosans. Vanson75 had 146.8 ml/g in 0.1%, 254.9 ml/g in 0.5%, and 331.9
ml/g in 1.0% chitosan solution. Sigma91 had 147.8 ml/g in 0.1%, 209.8 ml/g in 0.5%, and 291.6
ml/g in 1.0% chitosan solution. The control containing no chitosan had 137 ml/g of emulsion
capacity compared with chitosan solutions that gave 166.3 ml/g in 0.1% of DMPCA, 265.5 ml/g
in 0.5% of DMCPA, and 374.2 ml/g in 1.0% of DPMCA (Figure 9).
4.15 Emulsion Viscosity (EV)
Emulsion viscosity (EV) of the soy protein containing modified crawfish chitosans was
evaluated and compared with Mayonnaise (pH=4.4) (Kraft Mayo, Kraft North America, Inc.
Glenview. IL) as the control sample (Figure 10).
Viscosity of mayonnaise (control) was 116,000 cP. This was relatively higher than the
viscosity of emulsions prepared from soy protein and modified chitosan samples. The modified
samples DMCPA showed high EV at pH 2.0 with 43,400 cP; at pH 4.0, DMPCA showed EV of
36,100 cP; at pH 6.0, DCMPA showed EV of 4,300 cP; at pH 8.0, DMCPA had EV of 26,300
cP; and DMPCA had EV of 33,100 cP at pH 10.0.
The results shown at different pHs with the different chitosan modified samples indicated
that almost all the modified processed chitosan exhibited high emulsion viscosity, except
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