3.3.2. Microstructure of gelatin gels
Microstructures of gels of swim bladder gelatins without
EECH (A) and those added with EECH at levels of 0.5 mg g
1
dry
gelatin (B) and 5 mg g
1
dry gelatin (C) are illustrated inFig. 5.
All gelatin gels were sponge or coral-like in structure. Generally,
the arrangement and association of protein molecules in the gel
matrix directly contributed to the gel strength of the gelatin
(Benjakul et al., 2009). The control gel showed the finest gel
network with very small voids. When EECH at 0.5 mg g
1
was
incorporated, the uniform structure with larger strands was
formed. This was coincidental with the increase in gel strength
(Fig. 2). However, non-uniform structure with disconnected large
strands and large voids was obtained as EECH at 5 mg g
1
was
present. Gelatin could undergo the coagulation more effectively
in the presence of EECH at an excessive amount. The coagulated
gelatin chains could not undergo the gelation with the ordered