Value added fish by-products - Nordic Innovation

Table 3.6. Viscosity of the fish gelatin solutions measured with Brabender and Bohlin equipments (CP=collagen
peptide; HNWD=high molecular weight fish gelatin).
Viscosity
Viscosity
Sample
(BU) 16
54
(Pascal) 17
HMWD (6.67% w/v) Very strong gel Very strong gel
HMWD (3.0% w/v) 283 ± 4.24 0.041 ± 0.003
CP (6.67% w/v) NO viscosity NO viscosity
CP (10.0% w/v) NO viscosity NO viscosity
CP (15.0% w/v) NO viscosity NO viscosity
The CP had lower water content and higher protein (nitrogen) and salt content than HMWD.
The protein patterns of HMWD and CP were, as anticipated, very different. The molecular
weight of the HMWD covered the range from 212-61 kD while CP was from 66-2 kDa. The
CP is therefore more degraded (smaller protein units) which can be associated with the low
viscosity and low melting point.
Figure 3.17. Average FT-NIR spectra of the dried gelatin (Intensity (log(1/T)) vs. Wavelength (nm)). Red=HMWD
(high molecular weight fish gelatin); Blue=CP (collagen peptides).
The average FT-NIR spectra of the dried gelatins are shown in Figure 3.17. Similar spectra
were observed for the dried gelatins, but the bands for the HMWD showed higher intensity
compared to the CP. Assigning of peaks was done by referring to overtone reference tables
(Osborne et al. 1993). The peak at 1945 nm is very distinct between the gelatins but it
16 At +5°C (measured with Brabender®)
17 At +5°C to +7°C (measured with Bohlin)