Physicochemical characterizations of tilapia fish protein isolate under two distinctively different comminution conditions

The effect of two distinctively different comminution conditions on biochemical, rheological, and microscopic characterization of fish protein isolate (FPI) and surimi prepared from tilapia was investigated. A significant increase in puncture gel texture was observed when FPI and surimi were chopped at 25°C for 18 min compared to samples chopped at 5°C for 6 min. Comparable results were observed as measured by storage modulus (G′) in oscillatory dynamic rheology. FPI chopped with 3% salt at 5°C for 6 min exhibited the lowest gel texture among all treatments. This treatment was represented well by larger protein aggregates and coarser gels in microscopic analyses and correlated well with puncture test results. This is the first study to report the gelling property of FPI as affected by comminution conditions and suggests that controlling chopping temperature and time is important to produce high quality gels from FPI, like from surimi. Practical applications: One of the various factors affecting gel-forming ability is comminution condition. The effect of chopping condition for surimi has been well documented. However, the application of fish protein isolate (FPI) has not been explored. The present study demonstrates that controlling chopping temperature and time can be significant factors to produce high quality gel from FPI.