Screening of special starches for use in temperature-tolerant fish protein gels

Five newly developed starches (tapioca acetylated, phosphated distarch; waxy maize acetylated distarch; waxy maize hydroxypropylated, phosphated starch; and two tapioca hydroxypropylated, phosphated starches) were compared, respectively, with native cornstarch. Starches were added to surimi at 2, 4, 6 and 8%. Textural properties of surimi were evaluated at various test temperatures (5, 25, 40, 55C), during frozen storage (0, 3, 6 freeze/thaw cycles) and refrigerated storage (0, 3, 6 days). The interaction between starch type and percent addition contributed to significant (P < 0.05) difference in starch-fish protein gel values for failure shear stress, puncture force, puncture deformation, L* (whiteness) and stickiness. For fracture shear strain, starch type had a significant (P < 0.05) effect on gel values, whereas percent addition did not have a significant (P > 0.05) effect. Lower concentration of starch addition (2-4%) generally contributed to improved gel textural properties compared with higher (8%) starch concentrations.. PRACTICAL APPLICATIONS: Tapioca acetylated, phosphated distarch (TAPDS) and waxy maize acetylated distarch (WADS) maintained higher (P < 0.05) fracture shear stress and shear strain values than native cornstarch (CS) at each test temperature (5, 25, 40, 55C). TAPDS and WADS also improved (P < 0.05) water retention ability (WRA) of starch-fish protein gels during 6 freeze/thaw cycles (FT) compared with CS. Puncture force values of TAPDS starch-fish protein gels were consistently maintained during 6 FT. Addition of TAPDS did not significantly (P < 0.05) increase gel stickiness values compared with native CS during 6 days refrigerated storage. Best performance (P < 0.05) of starch addition occurred at concentrations of 6% or less. Therefore, addition of modified starches, TAPDS and WADS, could be added to surimi seafood products at 2-6% concentration levels in order to minimize textural changes at either hot or cold serving temperatures and also to maintain gel properties (WRA and texture) during long-term frozen storage.