Effect of freezing and frozen storage on restructured FISH prototypes made with glucomannan and FISH mince

• Water binding properties are poorer after freezing the fish muscle-glucomannan gels.
• Partial dehydration during frozen storage hardened the fish muscle-glucomannan gels.
• The filler in lot O had a stabilizing effect during freezing and frozen storage.
• Networks in lots C and S were more sensitive to frozen storage.

This paper examines the physicochemical and rheological properties to determine the freezing and frozen stability of restructured fish prototypes made with glucomannan (GM) and fish mince lacking any protein functionality. The effect of adding salt and fish oil to the fish prototype formulae is also examined. Three prototype fish gels at 1.25% final GM concentration were made: control lot (C); oil lot (O): control gels with 5% added fish oil, and salt lot (S): control gels were made with 0.8% NaCl. The analyses were performed after 24 h refrigerated storage (5 °C) and 30, 90 and 150 days frozen storage at −20 °C.Freezing produced hardening of gels due to partial dehydration caused by ice crystal formation, particularly in Lot S where the gels were more rigid with less water binding capacity (WBC) and more cooking loss (CL) after 30 days storage. Conversely, lot C exhibited some synergy between GM and protein molecules, giving time-stable networks with higher WBC after freezing. Lot O showed less CL and a more regular trend in mechanical and viscoelastic parameters between 90 and 150 days frozen storage, demonstrating the stabilizing effect of the “oil–protein–water” complex in a GM matrix.

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