Water migration, ice crystal formation, and freeze-thaw stability of silver carp surimi as affected by inulin under different additive amounts and polymerization degrees

This work investigated the effects of inulin on the water migration, ice crystal formation, and freeze-thaw stability of surimi under different additive amounts and polymerization degrees (DP). All the three types of inulin were shown to restrict water fluidity in surimi in a DP and amount dependent manner, and 10% long-chain inulin (L-INU) had the most conspicuous restriction on water migration. Short-chain inulin (S-INU) and nature inulin (N-INU) not only showed a more prominent effect than L-INU on decreasing freezing temperature and preventing ice crystal growth under an amount-effect relationship, but also were detected to interact with proteins to facilitate their stabilization. Freeze-thaw stability tests demonstrated all the three types of inulin could significantly inhibit the deterioration of surimi quality. After several freeze-thaw cycles, 8% L-INU showed the most significant inhibitory effect on thawing water loss, superior to commercial cryoprotectant (CC) (sucrose plus sorbitol), while 8% S-INU and N-INU were comparable to CC and showed better performance than L-INU in terms of chrominance of surimi, breaking force and deformation, water holding capacity, texture properties and whiteness of surimi gel. Overall, 8% S-INU can better maintain the surimi gel properties and 8% L-INU can better restrain the thawing water loss. These results suggest the potential of inulin as a promising cryoprotectant candidate in the frozen surimi industry. [Display omitted] •Inulin restricts water fluidity in DP and amount dependent manner.•Long-chain inulin (L-INU, 8%) restrains thawing water loss better than low DP inulin.•Low DP inulin (S-INU and N-INU) interact with fish proteins to stabilize their structure.•S-INU and N-INU can reduce freezing temperature and prevent ice crystal growth.•S-INU and N-INU (8%) can better maintain surimi gel properties than L-INU.