Breaking force and penetration distance of gels without
setting increased gradually with NFB concentration (p < 0.05).
This may be due to the combined effects of ionic bonds and
TGase-mediated covalent bonds. Myofibrillar proteins carry an
overall net negative charge at the normal pH of surimi. Calcium
ions, having a divalent positive charge (Ca2þ), can thus form a
‘salt bridge’ between negatively charged sites on two adjacent
proteins (Lanier et al., 2005). However, breaking force of gels
without setting were relatively the same regardless of MFB
concentration (P > 0.05). Cooking surimi paste in 3-cm diameter
casing in a water bath (90 C) even without pre-incubation
(setting) is a slow heating process (Park, Yoon, & Kim, 2014).
As Alaska pollock surimi is in favor of slow heating
(Yongsawatdigul & Park, 1996), endogenous TGase was able to be
activated and contributed to gradual gel texture enhancement as
NFB concentration increased.